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  • Saturday, October 27, 2018

    Maternal arsenic exposure and nonsyndromic orofacial clefts

    Author(s):
    Jonathan Suhl
    Stephanie Leonard
    Peter Weyer
    Anthony Roads
    Anna Maria Siega-Riz
    T. Renee Anthony
    Trudy L. Burns
    Kristin M. Conway
    Peter H. Langlois
    Paul A. Romitti

    Journal Title:
    Birth Defects Research

    Abstract:

    Background

    Arsenic is widely distributed in the environment in both inorganic and organic forms. Evidence from animal studies suggests that maternal inorganic arsenic may lead to the development of orofacial clefts (OFC)s in offspring. This evidence, together with the limited epidemiologic data available, supports the need for a comprehensive examination of major sources of arsenic exposure and OFCs in humans.

    Methods

    Using interview data collected in the National Birth Defects Prevention Study, public and well water arsenic sampling data, and dietary arsenic estimates, we compared expert‐rater assessed occupational arsenic exposure, individual‐level exposure to arsenic through drinking water, and dietary arsenic exposure between mothers of OFC cases (N = 435) and unaffected controls (N = 1267). Associations for each source of exposure were estimated for cleft lip ± palate (CL/P) and cleft palate (CP) using unconditional logistic regression analyses.

    Results

    Associations for maternal drinking water arsenic exposure and CL/P were near or below unity, whereas those for dietary arsenic exposure tended to be positive. For CP, positive associations were observed for maternal occupational arsenic and inorganic arsenic exposures, with confidence intervals that excluded the null value, whereas those for drinking water or dietary arsenic exposures tended to be near or below unity.

    Conclusions

    Positive associations were observed for maternal occupational arsenic exposure and CP and for maternal dietary arsenic exposure and CL/P; the remainder of associations estimated tended to be near or below unity. Given the exploratory nature of our study, the results should be interpreted cautiously, and continued research using improved exposure assessment methodologies is recommended.


    Citation:

    Suhl, Jonathan, Stephanie Leonard, Peter Weyer, Anthony Rhoads, Anna Maria Siega‐Riz, T. Renée Anthony, Trudy L. Burns, Kristin M. Conway, Peter H. Langlois, and Paul A. Romitti. "Maternal arsenic exposure and nonsyndromic orofacial clefts." Birth defects research (2018). DOI: doi.org/10.1002/bdr2.1386

  • Monday, December 15, 1997

    Characteristics of Persons Who Self-Reported a High Pesticide Exposure Event in the Agricultural Health Study

    Author(s):
    Michael C.R. Alavanja
    Dale P. Sandler
    Cheryl J. McDonnell
    David T. mage
    Burton C. Kross
    Andrew S. Rowland
    Aaron Blair

    Journal Title:
    Environmental Research

    Abstract:

    Characteristics of persons who report high pesticide exposure events (HPEE) were studied in a large cohort of licensed pesticide applicators from Iowa and North Carolina who enrolled in the Agricultural Health Study between December 1993 and December 1995. Fourteen percent reported having “an incident or experience while usinganypesticide which caused anunusuallyhigh personal exposure.” After taking into account total number of applications made and education, females (OR=0.76), applicators from NC (OR=0.65), and privately licensed applicators (OR=0.65) were less likely to have reported an HPEE. Work practices more common among both private and commercial applicators with an HPEE included delay in changing clothing or washing after pesticide application, mixing pesticide application clothing with the family wash, washing up inside the house after application, applying pesticides within 50 yards of their well, and storing pesticides in the home. Job characteristics more common among those with an HPEE included self-repair of application equipment and first pesticide use more than 10 years in the past. These job characteristics explained much of the difference in reported HPEE between males and females, but not between IA and NC subjects or between commercial or private applicators.


    Citation:

    Alavanja MC, Sandler DP, McDonnell CJ, Mage DT, Kross BC, Rowland AS, Blair A. Characteristics of persons who self-reported a high pesticide exposure event in the Agricultural Health Study. Environmental research. 1999 Feb 1;80(2):180-6. DOI: 10.1006/enrs.1998.3887

  • Tuesday, September 28, 2010

    Muscular Dystrophy Surveillance Tracking and Research Network (MD STARnet): Case Definition in Surveillance for Childhood-Onset Duchenne/Becker Muscular Dystrophy

    Author(s):
    Katherine D. Mathews
    Chris Cunniff
    Jiji R. Kantamneni
    Emma Ciafaloni
    Timothy Miller
    Dennis Matthews
    Valerie Cwik
    Charlotte Druschel
    Lisa Miller
    F. John Meaney
    John Sladky
    Paul A. Romitti

    Journal Title:
    Journal of Child Neurology

    Abstract:

    The Muscular Dystrophy Surveillance Tracking and Research Network (MD STARnet) is a multisite collaboration to determine the prevalence of childhood-onset Duchenne/Becker muscular dystrophy and to characterize health care and health outcomes in this population. MD STARnet uses medical record abstraction to identify patients with Duchenne/Becker muscular dystrophy born January 1, 1982 or later who resided in 1 of the participating sites. Critical diagnostic elements of each abstracted record are reviewed independently by >4 clinicians and assigned to 1 of 6 case definition categories (definite, probable, possible, asymptomatic, female, not Duchenne/Becker muscular dystrophy) by consensus. As of November 2009, 815 potential cases were reviewed. Of the cases included in analysis, 674 (82%) were either ‘‘definite’’ or ‘‘probable’’ Duchenne/Becker muscular dystrophy. These data reflect a change in diagnostic testing, as case assignment based on genetic testing increased from 67% in the oldest cohort (born 1982-1987) to 94% in the cohort born 2004 to 2009.


    CHEEC Project:

    Citation:

    Mathews, Katherine D., Chris Cunniff, Jiji R. Kantamneni, Emma Ciafaloni, Timothy Miller, Dennis Matthews, Valerie Cwik et al. "Muscular Dystrophy Surveillance Tracking and Research Network (MD STARnet): case definition in surveillance for childhood-onset Duchenne/Becker muscular dystrophy." Journal of child neurology 25, no. 9 (2010): 1098-1102.

  • Tuesday, May 14, 2019

    CrossRef citations to date 0 Altmetric  Listen  Original Articles Identification of Iowa Live Births in the Agricultural Health Study

    Author(s):
    Paul A. Romitti
    Shinobu Watanabe-Galloway
    William T. Budelier
    Charles F. Lynch
    Soman Puzhankara
    Donna Wong-Gibbons
    Jane A. Hoppin
    Michael C. R. Alavanja

    Journal Title:
    Archives of Environmental & Occupational Health

    Abstract:

    In the Agricultural Health Study, information on participant live births was largely provided by female partners of male private applicators. At the Iowa site, such information was available for 13,599 (42.9%) of 31,707 applicators. To improve identification of live births among Iowa participants, we used a probabilistic and deterministic approach to link available demographic data from 31,707 households and information on live births from 13,599 households with 1,014,916 Iowa birth certificates. Record linkage identified 16,611 (93.7%) of 17,719 reported live births and 17,883 additional live births, most (14,411 or 80.6%) not reported due to nonresponse by female partners. This record linkage produced an expanded cohort of live-born children among Iowa participants, which will facilitate improved study of the effects of agricultural exposures, including pesticides, on selected birth outcomes and childhood disease.


    Citation:

    Romitti, Paul A., Shinobu Watanabe-Galloway, William T. Budelier, Charles F. Lynch, Soman Puzhankara, Donna Wong-Gibbons, Jane A. Hoppin, and Michael CR Alavanja. "Identification of Iowa live births in the Agricultural Health Study." Archives of environmental & occupational health 65, no. 3 (2010): 154-162.

  • Friday, September 6, 2013

    Semen parameters in fertile US men: the Study for Future Families

    Author(s):
    JB Redmon
    W Thomas
    W Ma
    EZ Drobnis
    A Sparks
    C Wang
    C Brazil
    JW Overstreet
    F Liu
    SH Swan
    The Study for Future Families Research Group

    Journal Title:
    Andrology

    Abstract:

    Establishing reference norms for semen parameters in fertile men is important for accurate assessment, counselling and treatment of men with male factor infertility. Identifying temporal or geographic variability in semen quality also requires accurate measurement of semen parameters in well‐characterized, defined populations of men. The Study for Future Families (SFF) recruited men who were partners of pregnant women attending prenatal clinics in Los Angeles CA, Minneapolis MN, Columbia MO, New York City NY and Iowa City IA. Semen samples were collected on site from 763 men (73% White, 15% Hispanic/Latino, 7% Black and 5% Asian or other ethnic group) using strict quality control and well‐defined protocols. Semen volume (by weight), sperm concentration (hemacytometer) and sperm motility were measured at each centre. Sperm morphology (both WHO, 1999 strict and WHO, 1987) was determined at a central laboratory. Mean abstinence was 3.2 days. Mean (median; 5th–95th percentile) values were: semen volume, 3.9 (3.7; 1.5–6.8) mL; sperm concentration, 60 (67; 12–192) × 106/mL; total sperm count 209 (240; 32–763) × 106; % motile, 51 (52; 28–67) %; and total motile sperm count, 104 (128; 14–395) × 106 respectively. Values for sperm morphology were 11 (10; 3–20) % and 57 (59; 38–72) % normal forms for WHO (1999) (strict) and WHO (1987) criteria respectively. Black men had significantly lower semen volume, sperm concentration and total motile sperm counts than White and Hispanic/Latino men. Semen parameters were marginally higher in men who achieved pregnancy more quickly but differences were small and not statistically significant. The SFF provides robust estimates of semen parameters in fertile men living in five different geographic locations in the US. Fertile men display wide variation in all of the semen parameters traditionally used to assess fertility potential.


    Citation:

    Redmon, J. Bruce, William Thomas, Wenjun Ma, Erma Z. Drobnis, Amy Sparks, Christina Wang, Charlene Brazil et al. "Semen parameters in fertile US men: the Study for Future Families." Andrology 1, no. 6 (2013): 806-814. DOI: 10.1111/j.2047-2927.2013.00125.x

  • Wednesday, September 15, 1999

    Drinking Water Source and Chlorination Byproducts in Iowa, III. Risk of Brain Cancer

    Author(s):
    Kenneth P. Cantor
    Charles F. Lynch
    Mariana E. Hildesheim
    Mustafa Dosemeci
    Jay Lubin
    Michael Alavanja
    Gunther Craun

    Journal Title:
    American Journal of Epidemiology

    Abstract:

    The authors conducted a population-based case-control study in Iowa of 375 brain cancer patients and 2, 434 controls. A postal questionnaire was used to gather information on lifetime residential history, sources of drinking water, beverage intake, and other potential risk factors. Exposure to chlorination byproducts in drinking water was estimated by combining questionnaire data with historical information from water utilities and trihalomethane levels in recent samples. The analysis included 291 cases (77.6%) and 1, 983 controls (81.5%), for whom water quality information was available for at least 70% of lifetime years. Proxies represented 74.4% of cases. The mean number and mean duration of places of residence were comparable between direct and proxy respondents, suggesting little contribution to bias. After multivariate adjustment, odds ratios for brain cancer were 1.0, 1.1, 1.6, and 1.3 for exposure to chlorinated surface water of 0, 1-19, 20-39, and ≥40 years (p trend = 0.1). Among men, odds ratios were 1.0, 1.3, 1.7, and 2.5 (p trend = 0.04), and among women, 1.0, 1.0, 1.6, and 0.7 (p trend = 0.7)). Similar findings were found with estimates of average lifetime level of trihalomethanes. The association was stronger among men with above-median tap water consumption. These observations deserve further attention, especially in view of increasing glioma rates. Am J Epidemiol 1999: 150: 552-60.


    Citation:

    Cantor, Kenneth P., Charles R. Lynch, Mariana E. Hildesheim, Mustafa Dosemeci, Jay Lubin, Michael Alavanja, and Gunther Craun. "Drinking water source and chlorination byproducts in iowa, iii. Risk of brain cancer." American journal of epidemiology 150, no. 6 (1999): 552-560. DOI: 10.1093/oxfordjournals.aje.a010052

  • Thursday, January 1, 1998

    Drinking Water Source and Chlorination Byproducts II. Risk of Colon and Rectal Cancers

    Author(s):
    Mariana E. Hildesheim
    Kenneth P. Cantor
    Charles F. Lynch
    Mustafa Dosemeci
    Jay Lubin
    Michael Alavanja
    Gunther Craun

    Journal Title:
    Epidemiology

    Abstract:

     We evaluated the association between chlorination byproducts and colon and rectal cancer risk in a population-based case-control study conducted in Iowa in 1986-1989. Data were gathered from 685 colon cancer cases, 655 rectal cancer cases, and 2,434 controls. We calculated odds ratios for the 560 colon cancer cases, 537 rectal cancer cases, and 1,983 controls for whom water exposure information was available for at least 70% of their lifetime. We estimated exposure to chlorination byproducts with two types of measures: duration of lifetime at residences served by chlorinated water and estimated lifetime trihalomethane exposure. For rectal cancer, we observed an association with duration of chlorinated surface water use, with adjusted odds ratios of 1.1, 1.6, 1.6, and 2.6 for 1-19, 20-39, 40-59, and > or =60 years of exposure, compared with no exposure. Rectal cancer risk was also associated with several different measures of estimated lifetime trihalomethane exposure. For colon cancer and subsites, we detected no important increase in risk associated with duration of chlorinated surface water, nor with trihalomethane estimates. When we evaluated chlorination byproducts jointly with other factors, we found larger relative risk estimates for rectal cancer among subjects with low dietary fiber intake. The risk related to > or =40 years of exposure to a chlorinated surface water source was 2.4 (95% confidence interval = 1.5-4.0) for persons with low fiber intake and 0.9 (95% confidence interval = 0.4-1.8) for persons with high fiber intake, relative to the risk of persons with high-fiber diets and no exposure to chlorinated surface water. We observed a similar risk differential for low and high levels of physical activity.


    Citation:

    Hildesheim, Mariana E., Kenneth P. Cantor, Charles F. Lynch, Mustafa Dosemeci, Jay Lubin, Michael Alavanja, and Gunther Craun. "Drinking water source and chlorination byproducts II. Risk of colon and rectal cancers." Epidemiology (1998): 29-35.

  • Monday, September 1, 1997

    A study of the temporal variability of atrazine in private well water. part ii: analysis of data

    Author(s):
    Paul Pinsky
    Matthew Lorber
    Kent Johnson
    Burton Kross
    Leon Burmeister
    Amina Wilkins
    George Hallberg

    Journal Title:
    Environmental Monitoring and Assessment

    Abstract:

    In 1988, the Iowa Department of Natural Resources, along withthe University of Iowa, conducted the Statewide Rural WellWater Survey, commonly known as SWRL. A total of 686private rural drinking water wells was selected by use of aprobability sample and tested for pesticides and nitrate. A subsetof these wells, the 10% repeat wells, were additionally sampledin October, 1990 and June, 1991. Starting in November, 1991,the University of Iowa, with sponsorship from the United StatesEnvironmental Protection Agency, revisited the 10% repeat wellsto begin a study of the temporal variability of atrazine and nitratein wells. Other wells, which had originally tested positive foratrazine in SWRL but were not in the 10% population, wereadded to the study population. Temporal sampling for a year-long period began in February of 1992 and concluded in Januaryof 1993. All wells were sampled monthly, a subset was sampledweekly, and a second subset was sampled for 14 day consecutiveperiods. Of the 67 wells in the 10% population tested monthly,7 (10.4%) tested positive for atrazine at least once during theyear, and 3 (4%) were positive each of the 12 months. Theaverage concentration in the 7 wells was 0.10 µg/L. Fornitrate, 15 (22%) wells in the 10% repeat population monthlysampling were above the Maximum Contaminant Level of 10 mg/L at least once. This paper, the second of two papers on thisstudy, describes the analysis of data from the survey. The firstpaper (Lorber et al., 1997) reviews the study design, theanalytical methodologies, and development of the data base.


    Citation:

    Pinsky, Paul, Matthew Lorber, Kent Johnson, Burton Kross, Leon Burmeister, Amina Wilkins, and George Hallberg. "a study of the temporal variability of atrazine in private well water. part ii: analysis of data." Environmental monitoring and assessment 47, no. 2 (1997): 197-221. DOI: 10.1023/A:1005704920640

  • Monday, October 1, 1990

    The Iowa state-wide rural well-water survey: October 1990’, Repeat Sampling of the 10% Subset

    Author(s):
    KD Rex
    RD Libra
    GR Hallberg
    BC Kross
    RW Field
    LA Etre
    LS Seigley
    MA Culp
    BK Nations
    DJ Quade
    JK Johnson
    HF Nicholson
    KL Cherryholmes
    NH Hall

    Journal Title:
    Iowa Department of Natural Resources, Technical Information Series 25

    Abstract:

    The Iowa Department of Natural Resources, in conjunction with the University of lowa, Center for Health Effects of Environmental Contaminants, conducted the State-Wide Rural Well Water Survey (SWRL) between April 1988 and June 1989. The SWRL survey systematically selected and sampled 686 sites and provided a statistically valid assessment of the proportion ofprivate rural wells and rural Iowa residents affected by various environmental contaminants. The SWRL design framework also systematically selected a subset of 10% (68) of all sites for a one-time repeat sampling, to assess temporal changes in water quality during the original survey. The 10% repeat sites yielded a very consistent representation of the state-wide data, including proportionately representative detections of pesticides down to about a 1% occurrence interval. These sites provide a representative subset of SWRL for monitoring water quality over time as an indicator of temporal change. The first two samplings of this 10% subsct of wells are termed SWRL 10-1 and SWRL 10-2, respectively (abbreviated herein as 10-1 and 10-2). The SWRL 10-1 was part of the full SWRL sampling, and therefore is used as the basis for comparison with subsequent samples.

    The SWRL survey was conducted during the driest consecutive two year period in Iowa's recorded history. The objective of this study, the third sampling of the SWRL 10% subset (referred to here as SWRL 10-3 or 10-3), was to resample the subset during more "normal" climatic conditions, and to assess changes in water-quality that may have occurred. The 103 sampling was done in October 1990, after weather patterns in Iowa had changed from the drought conditions of 1988-1989, to more normal, to wetter-than-normal conditions. Longterm monitoring has shown that this mid-fall period is typically "calm," hydrologically, and often represents conditions near the annual average for such parameters as discharge (general water-flux) and nitrate concentrations, though typically fewer pesticide detections occur than in late-spring or summer. For cost and technical reasons there were some differences in the analytes included in SWRL 10-3.

    In October, 1990, during SWRL 10-3, about 20% of the sites showed nitrate-N > 10 mg/L, almost 50% were positive for total coliform bacteria, 19% positive for fecal col iform bacteria, and 13.5% contained detectable atrazine (the parent active ingredient, no metabolites included). Only 6 other common herbicides were included in the analytes for 10-3; compared to the 17 herbicide active ingredients and 2 metabolites that were included in the full SWRL. None of these other compounds were detected in 10-3, but with the significant increase in atrazine there was no real change in the proportion of wells where any pesticide was detected. The pattern of statistically significant differences in nitrate concentrations, bacteria occurrences, and atrazine detections between wells < 100 and > 100 feet deep continue to be apparent in the 10-3 sampling.

    The only statistically significant changes between the full SWRL (and 10-1) in 1988-1989 and the 10-3 sampling in October 1990, were: 1. the decline in the detection of dissolved organicnitrogen; 2. the increase in fecal coliform positives; and 3. the increase in atrazine detections. Results for nitrate and total coliform bacteria from SWRL 10-3 are statistically similar to prior samples.

    Based on the SWRL 10-3 sampling, and a relatively small subset sample of comparative well and kitchen tap samples (60 wells and 31 kitchen taps), no problems with lead in Iowa's rural drinking water-supplies were discerned. Lead concentrations in rural well-and tap-water are generally below lug/L. No samples analyzed contained lead at a concentration greater than the 15 ugfL USEPA drinking water standard. Also, the 10-3 resampling supported the full SWRL survey's findings on fluoride in well-water supplies. A small portion of wells (2-3%), primarily deep wells, may exceed the recommended concentrationsof fluoride, related to dental and skeletal fluorosis (2 and 4 mg/L). Rural well-water supplies should be tested for naturally occurring fluoride before supplements are prescribed for protection of dental cavities in young children.

    Within SWRL 10-3, a pilot study was conducted to assess the use of tritium in watcr-quality assessment studies. Tritium is a naturally occurring isotope that can be used as a groundwater age-dating tool. From a limited number of tritium analyses, wells >50 feet deep were several times as likely to produce groundwater with <6+/-4 T.U., which averages years old, than wells feet deep. Groundwaters containing detectable tritium showed much higher rates ofnitrate, and total- and fecal-col iform contamination, as would be expected. The data indicate a relationship between shallow wells, relatively recently recharged groundwaters, and higher rates of contaminant occurrence. This tool needs further application and testing.

    The change from drought to wetter than normal conditions did not appear to affect the SWRL 10-3 water-quality results to the same degree noted in other long-term monitoring projects in state. While atrazine detections did significantly increase in sample 10-3, the detection ofother herbicides fell. Nitrate concentrations, the proportion of wells with nitrate-N >10 mg/L, and total coliform detections were largely unchanged. Fecal coliform detections did increase, but this increase was unrelated to trends in othercontaminants. The state-wide nature ofthe SWRL 10% subset wells may be less responsive to climatic change, relative to the wells used in the longer-term monitoring projects. The long-term monitoring studies also have more frequent sampling which allows more defined trend analysis. Also, pesticides in water resources tend to show a seasonal distribution and it is not uncommon for fall or winter samples to only show detections of atrazine, typically one of the most persistent of pesticide contaminants in the environment in Iowa.
     


    Citation:

    Rex, K. D. "The Iowa state-wide rural well-water survey: October 1990, repeat sampling of the 10% subset." Iowa Department of Natural Resources, Technical Information Series 25 (1993).

  • Thursday, February 1, 1990

    The Iowa state-wide rural well-water survey design report: a systematic sample of domestic drinking water quality.

    Author(s):
    GR Hallberg
    BC Kross
    RD Libra
    LF Burmeiseter
    LMB Weih
    CF Lynch
    DR Bruner
    MQ Lewis
    KL Cherryholmes
    JK Johnson
    MA Culp

    Journal Title:
    Technical Information Series 17

    Abstract:

    The Iowa Department of Natural Resources and the University of Iowa (UI) Center for Health Effects of Environmental Contamination conducted a survey (a one-time sampling) of the quality of private drinking-water supplies used by rural Iowans. The State-Wide Rural Well-Water Survey (SWRL) was carried out between April 1988 and June 1989. The two primary objectives were to address: 1. What proportion of private rural wells in Iowa are affected by various environmental contaminants? and 2. What proportion of rural Iowa residents are utilizing well water containing these environmental contaminants?

    To provide a statistically valid framework, a systematic sample, stratified by rural population density, was designed. A target of 698 sites was defined, based on statistical considerations, available funds and logistical constraints. The systematic framework was defined using every 5-minute intersection of latitude and longitude in the state; the intersections chosen for sampling sites were distributed proportionally through the population, based on county-level rural-population density. The drinking-water well closest to each chosen intersection was selected for sampling. Iowa Cooperative Extension Service county staff identified eligible participants, based on design criteria.

    The effect of temporal variability in groundwater quality during the survey was addressed in two ways: 1. 10% of all sites were sampled a second time, but during a different season; 2. all sites within a county (or counties), typifying six general hydrogeologic regions in Iowa, were sampled quarterly. In addition, routine sampling was seasonally dispersed throughout the state.

    Standardized procedures for field activities were employed during SWRL. An appointment was arranged for each site, so that a resident was available to interview. Information was compiled on items such as well construction, agricultural practices, water treatment, past water-quality problems, waste disposal practices, and the general health status of rural residents. The drinking water wells' construction and placement characteristics and proximity to point-sources of contamination were inventoried by field staff. Sampling points were chosen as close to the well as possible; the water-system was purged until tracking measurements stabilized. Samples for laboratory analysis were collected in pre-treated containers supplied by the laboratories. Field quality assurance and quality control (QA/QC) included blank, spiked, and duplicate samples. Custody forms tracked the movement of all sample containers.

    All primary samples were analyzed for total coliform bacteria; nitrate (+ nitrite)-N, ammonia-N, and organic-N; major inorganic ions; 27 commonly-used pesticides; and selected pesticide metabolites. The participating laboratories had U.S. EPA QA/QC plans in place, and the SWRL plan utilized and verified their implementation. The method detection limits (MDL) for pesticide analyses were set as the minimum practical concentration quantitation limit for each analyte in a groundwater matrix, established through QA/QC procedures. Groundwater-matrix effects necessitated an increase in some SWRL MDLs, relative to a reagent water matrix. This may cause an increase in false negative detections, but should minimize false positive detections.

    Overall completion criteria were established for the and were met successfully. For 1. site-inventory, sample collection and analysis, and 2. return of voluntary health questionnaires, criteria of 95% and 60%, respectively, were set. These criteria were met, at 98% and 85%. The final SWRL well-water sample was 686 sites. Sample and analysis completeness were also set for each county. County criteria were met with one exception, for inorganic ions: 92 counties (of 99) were sampled at 100% of the design; 94% of the 10% repeat sites were resampled; and 93% of the quarterly sites were sampled 4 times. In total, 1 ,048 well water samples were collected and analyzed. Of the 686 sites, 47% were the primary rural-residence selected (i.e., closest to the 5-minute intersection), and 79% were among the first three choices. The most common reason a selected residence was not sampled was the inability to contact a current resident (70%); < 8% of persons contacted were unwilling to participate.


    Citation:

    Hallberg, G. R., Kross, B. C., Libra, R. D., Burmeister, L. F., Weih, L. M. B., Lynch, C. F., & Bruner, D. R. (1990). The Iowa state-wide rural well-water survey design report: a systematic sample of domestic drinking water quality.

  • Monday, September 1, 1997

    A Study of the Temporal Variability of Atrazine in Private Well Water. Part I: Study Design, Implementation, and Database Development

    Author(s):
    Matthew Lorber
    Kent Johnson
    Burton Kross
    Paul Pinsky
    Leon Burmeister
    Michael Thurman
    Amina Wilkins
    George Hallberg

    Journal Title:
    Environmental Monitoring and Assessment

    Abstract:

    In 1988, the Iowa Department of Natural Resources, along with the University of Iowa conducted the Statewide RuralWellWater Survey, commonly known as SWRL.A total of 686 private rural drinking water wells was selected by use of a probability sample and tested for pesticides and nitrates. Sixty-eight of these wells, the ‘10% repeat’ wells, were additionally sampled in October, 1990 and June, 1991. Starting in November, 1991, the University of Iowa, with sponsorship from the United States Environmental Protection Agency, revisited these wells to begin a study of the temporal variability of atrazine and nitrates in wells. Other wells, which had originally tested positive for atrazine in SWRL but were not in the 10% repeat population, were added to the study population. Temporal sampling for a year-long period began in February of 1992 and concluded in January of 1993. All wells were sampled monthly, one subset was sampled weekly, and a second subset was sampled for 14-day consecutive periods. Two unique aspects of this study were the use of an immunoassay technique to screen for triazines before gas chromatography/mass spectrometry (GC/MS) analysis and quantification of atrazine, and the use of well owners to sample the wells. A total of 1771 samples from 83 wells are in the final data base for this study. This paper reviews the study design, the analytical methodologies, and development of the data base. A companion paper (Pinsky et al., 1997) discusses the analysis of the data from this survey.


    Citation:

    Lorber M, Johnson K, Kross B, Pinsky P, Burmeister L, Thurman M, Wilkins A, Hallberg G. a study of the temporal variability of atrazine in private well water. part i: study design, implementation, and database development. Environmental monitoring and assessment. 1997 Sep 1;47(2):175-95.

  • Thursday, January 1, 2015

    2013 Survey of Iowa groundwater and evaluation of public well vulnerability classifications for contaminants of emerging concern

    Author(s):
    Claire E. Hruby
    Robert D. Libra
    Chad L. Fields
    Dana W. Kolpin
    Laura E. Hubbard
    Mark R. Borchardt
    Susan K. Spencer
    Michael D. Wichman
    Nancy Hall
    Michael D. Schueller
    Edward T. Furlong
    Peter J. Weyer

    Journal Title:
    Iowa Geological and Water Survey Technical Information Series 57

    Abstract:

    Studies in Iowa have long documented the vulnerability of wells with less than 50 feet (15 meters) of confining materials above the source aquifer to contamination from nitrate and various pesticides. Recent studies in Wisconsin have documented the occurrence of viruses in untreated groundwater, even in wells considered to have little vulnerability to contamination from near-surface activities. In addition, sensitive methods have become available for analyses of pharmaceuticals and pesticides. This study represents the first comprehensive examination of contaminants of emerging concern in Iowa’s groundwater conducted to date, and one of the first conducted in the United States.

    Raw groundwater samples were collected from 66 public supply wells during the spring of 2013, when the state was recovering from drought conditions. Samples were analyzed for 206 chemical and biological parameters; including 20 general water-quality parameters and major ions, 19 metals, 5 nutrients, 10 virus groups, 3 species of pathogenic bacteria, 5 microbial indicators, 108 pharmaceuticals, 35 pesticides and pesticide degradates, and tritium. The wells chosen for this study represent a diverse range of ages, depths, confining material thicknesses, pumping rates, and land use settings.

    The most commonly detected contaminant group was pesticide compounds, which were present in 41% of the samples. As many as 6 pesticide compounds were found together in a sample, most of which were chloroacetanilide degradates. While none of the measured concentrations of pesticide compounds exceeded current benchmark levels, several of these compounds are listed on the U.S. Environmental Protection Agency’s Contaminant Candidate List and could be subject to drinking water standards in the future. Despite heavy use in the past decade, glyphosate was not detected, and its metabolite, aminomethylphosphonic acid, was only detected in two of 60 wells tested (3%) at the detection limit of 0.02 μg/L.

    Pharmaceutical compounds were detected in 35% of 63 samples. Of the 14 pharmaceuticals detected, six had reported concentrations above the method reporting limit, with the maximum reported concentration of 826 ng/L for acetaminophen. Diphenhydramine was the only pharmaceutical to have two detections above the reporting limit, at 24.5 and 145 ng/L. Eight pharmaceuticals had confirmed detections at concentrations below the method reporting limit. Caffeine was the most frequently detected pharmaceutical compound (25%), followed by the caffeine metabolite, 1,7- dimethylxanthine (16%).

     Microorganisms were detected in 21% of the wells using quantitative polymerase chain reaction methodologies. The most frequently detected microorganism was the pepper mild mottle virus (PMMV), a plant pathogen found in human waste. PMMV was detected in 17% of samples at concentrations ranging from 0.4 to 6.38 gene copies per liter. GII norovirus, human polyomavirus, bovine polyomavirus, and Campylobacter were also detected, while adenovirus, enterovirus, GI norovirus, swine hepatitis E, Salmonella, and enterohemmorhagic E. coli were not detected. No correlations were found between viruses or pathogenic bacteria and microbial indicators.

    Wells with less than 50 feet (15 meters) of confining material were shown to have greater incidence of surface-related contaminants; however, significant relationships (p<0.05) between confining layer thickness and contaminants were only found for nitrate and herbicides.


    Citation:

    Hruby CE, Libra RD, Fields CL, Kolpin DW, Hubbard LE, Borchardt MR, Spencer SK, Wichman MD, Hall N, Schueller MD, Furlong ET. 2013 Survey of Iowa groundwater and evaluation of public well vulnerability classifications for contaminants of emerging concern.

  • Monday, February 1, 1993

    The nitrate contamination of private well water in Iowa.

    Author(s):
    BC Kross
    GR Hallberg
    DR Bruner
    K Cherryholmes
    JK Johnson

    Journal Title:
    American Journal of Public Health

    Abstract:

    The State-Wide Rural Well-Water Survey was conducted between April 1988 and June 1989. About 18% of Iowa's private, rural drinking-water wells contain nitrate above the recommended health advisory level (levels of NO3-N greater than 10 mg/L); 37% of the wells have levels greater than 3 mg/L, typically considered indicative of anthropogenic pollution. Thirty-five percent of wells less than 15 m deep exceed the health advisory level, and the mean concentration of nitrate-nitrogen for these wells exceeds 10 mg/L. Depth of well is the best predictor of well-water contamination. Individually, NO3-N levels of more than 10 mg/L occurred alone in about 4% of the private wells statewide; pesticides were present alone in about 5%. Total coliform positives occurred alone at 27% of the sites. In a cumulative sense, these three contaminants were detected in nearly 55% of rural private water supplies.


    Citation:

    Kross BC, Hallberg GR, Bruner DR, Cherryholmes K, Johnson JK. The nitrate contamination of private well water in Iowa. American Journal of Public Health. 1993 Feb;83(2):270-2.

  • Monday, March 1, 1993

    The Iowa State-Wide Rural Well-Water Survey: June 1991, Repeat Sampling of the 10% Subset

    Author(s):
    R.D. Libra
    G.R. Hallberg
    K.D. Rex
    B.C. Kross
    L.S. Seigley
    M.A. Culp
    R.W. Field
    D.J. Quade
    M. Selim
    B.K. Nations
    N.H. Hall
    L.A. Etre
    J.K. Johnson
    H.F. Nicholson
    S.L. Berberich
    K.L. Cherryholmes

    Journal Title:
    Technical Information Series 26

    Abstract:

    The Iowa Department of Natural Resources, in conjunction with the University of lowa, Center for Health Effects of Environmental Contamination, conducted the State-Wide Rural Well Water Survey (SWRL) between April 1988 and June 1989. The SWRL survey systematically selected and sampled 686 sites and provided a statistically valid assessment of the proportion of private rural wells and rural Iowa residents affected by various environmental contaminants. The SWRL design framework also systematically selected a subset of 10% (68) of all sites for repeat sampling, to assess temporal changes in water quality during the original survey. The 10% repeat sites yielded a very consistent representation of the statewide data, including proportionately representative detections of pesticides down to about a 1% occurrence interval. These sites provided a representative subset of SWRL for monitoring water quality over time as an indicator of temporal change. The first two samplings of this 10% subset of wells are termed SWRL 10-1 and 10-2, respectively (abbreviated as 10-1 and 10-2). The SWRL 10-1 was part of the full SWRL sampling, and therefore is used as the basis for comparison with subsequent samples.
    The SWRL survey was conducted during the driest consecutive two-year period in Iowa's recorded history. The objective of the resampling studies was to resample the subset during more "normal" climatic conditions, and to assess changes in water-quality that may have occurred. The 10% subset was resampled in October 1990 (10-3) and June 1991 (10-4), after weather patterns in Iowa had changed from the drought conditions of 1988-1989, to more normal and wetter-than-normal conditions. Long-term monitoring has shown that a mid-fall period, such as October, often represents conditions near the annual average for many parameters, though typically fewer pesticide detections occur than in late-spring or summer, such as the 10-4 (June 1991) resampling. For cost and technical reasons fewer analytes were included in SWRL 10-3 and 10-4 than the full SWRL survey.
    In June 1991, during 10-4, about 19% of the sites showed N03-N >10 mg/L; 57% were positive for total coliform bacteria and 24% positive for fecal coliform bacteria; 20% of wells had a detection of some herbicide compound, about 6% contained detectable atrazine (parent compound only), and about 11% showed detections of atrazine or one of two common metabolites. The pattern of greater nitrate and bacteria occurrences in samples from wells <IOO feet deep and lower contaminant levels in wells > 100 feet deep, continued to be statistically significant in the 10-3 and 10-4 sampling.
    Using tritium (3H) analysis as a groundwater dating tool, wells > 100 feet deep were more likely to produce groundwater with <6+/-4 Tritium Units, which averages >20 years old, than wells <IOO feet deep. Groundwater containing detectable tritium showed much higher rates of nitrate, and total- and fecal-coliform contamination, as would be expected. The data indicate a relationship among shallow wells, relatively recently recharged groundwaters, and higher rates of contaminant occurrence. All of the wells > 100 feet deep that exhibited >10 T.U. (i.e., modem recharge water) are from east-central or northeastern Iowa, where the hydrogeologic conditions promote much greater depth of groundwater circulation, and, hence, the depth to which contaminants occur is much greater than elsewhere in the state. This tool provides further insights on the mechanisms of groundwater contamination and may be useful for evaluating pollution potential of well waters.
    Relative to prior sampling, the proportion of sites positive for total coliform bacteria and those with any detection of total atrazine or other pesticide increased slightly. The percentage of wells with N03-N > 10 mg/L did not change, but the mean and median concentration did increase somewhat. The only water-quality changes and from the full SWRL and the 10-1 (1988-1989), the 10-3 (October 1990), and 10-4 (June 1991) samplings that were statistically significant as estimates for all rural well waters, statewide were: 1) the decline in the detection of dissolved organic-nitrogen in 10-3 and its increase again in 10-4; 2) the increase in fecal coliform positives in 10-3 and again in 10-4; 3) the decrease in NH4-N in 104; and 4) the increase in detections in 10-3, which subsequently declined in 10-4.

    The change from drought to wetter than normal conditions did not affect the 10-3 and 10-4 sample results as noticeably or consistently as it did in long-term monitoring projects in the state. Atrazine (parent) detections increased significantly in 10-3, but declined again in 104. Detections of other herbicides and total atrazine (metabolites included) increased somewhat in the June 10-4 sampling, as might be expected from the seasonal patterns discerned in other Iowa studies. While mean nitrate concentrations increased slightly, the proportion of wells with N03-N > 10mgL, and total coliform detections were largely unchanged. Fecal coliform detections increased, but this increase was unrelated to trends in other contaminants. As a sample of wells state-wide, this less pronounced response might be expected because the 10% subset integrates a variety of well-depths, well types and hydrogeologic settings. The SWRL 10% sample may react more slowly to climatic change; one indication of this is the low tritium content and therefore, relatively old (>20 years) average age of almost half the well water sampled during SWRL 10-3 and 10-4. The change to wetter conditions may explain the increases in total coliform and fecal coliform bacteria positives. Other studies have noted that bacteria, similar to chemicals, may be rapidly transmitted to the water table by preferential flow through the soil. Also, as water tables rise during wet periods, they are closer to the land surface and into contact with soil horizons where coliform bacteria are more abundant and more likely to survive.

    One sample was collected from a site using a rural water-supply (RWS) system for its home and farmwater. The RWS system uses surface water. Four herbicides were detected: alachlor (0.7 pg/L), atrazine (1.7 AWL), cyanazine (1.5 pg/L), and metolachlor (1.2 gg/L).

    Immunoassay (IMA) methods for scans provided promising results. With further refinements, these methods may provide a tool for inexpensive screening of water supplies for triazine occurrence.

     


    Citation:

    Libra RD, Hallberg GR, Rex KD, Kross BC, Seigley LS, Culp MA, Field RW, Quade DJ, Selim M, Nations BK, Hall NH. The Iowa state-wide rural well-water survey: June 1991. Repeat Sampling of the 10% Subset: Iowa Department of Natural Resources Technical Information Series. 1993;26:30.

  • Monday, December 30, 1991

    Pesticide Contamination of Private Well Water, A Growing Rural Health Concern

    Author(s):
    Burton C. Kross
    Mustafa I. Selim
    George R. Hallberg
    D. Roger Bruner
    Keith Cherryholmes

    Journal Title:
    Environment International

    Abstract:

    The Iowa Statewide Rural Well Water Survey (SWRL) was conducted between April 1988 and June 1989. SWRL was designed to provide a statistically valid assessment of the proportion of private rural wells and rural Iowa residents affected by various environmental contaminants. The survey was a systematic sample, stratified by rural population density. Approximately 14% of wells had detections of pesticides: 16 pesticide compounds (mostly herbicides) were detected, including 11 parent compounds and 5 environmental metabolites; 16 pesticides (mostly insecticides) were not detected. Atrazine and its metabolites were found in 8% of wells. Multiple residues were detected in all regions of the state. The mean concentrations were generally <1 μg/L. Lifetime Health Advisory Levels (HALs) were exceeded in 1.2% of private, rural wells in Iowa. Detailed evaluations of these sites indicate 25% are caused by point source contamination (spill and back-siphoning), while the majority, 62.5%, appear to be nonpoint sources related to normal agricultural practices. Statistical analyses show significant associations between many water quality parameters tested during SWRL, but the associations are not strong predictors based on state-wide data. By far the most significant factor explaining water quality variations is well depth.


    Citation:

    Kross BC, Selim MI, Hallberg GR, Bruner DR, Cherryholmes K. Pesticide contamination of private well water, a growing rural health concern. Environment international. 1992 Jan 1;18(3):231-41. DOI: 10.1016/0160-4120(92)90106-E

  • Wednesday, September 14, 2016

    Electrospun Hematite Nanofiber/Mesoporous Silica Core/Shell Nanomaterials as an Efficient Adsorbent for Heavy Metals

    Author(s):
    Shani Egodawatte
    Katherine E. Greenstein
    Ivy Vance
    Edris Rivera
    Nozang V. Myung
    Gene F. Parkin
    David M. Cwiertny
    Sarah C. Larsen

    Journal Title:
    RSC Advances

    Abstract:

    Functionalized nanomaterials hold tremendous promise for water treatment because their high surface area makes them ideal sorbents for pollutants like heavy metal ions that are pervasive in global water supplies. Here, a novel core/shell nanomaterial consisting of an electrospun hematite nanofiber core and a mesoporous silica shell of tunable thickness (from 20–60 nm) was prepared for the first time. The synthesis involved careful control of pH and sequential addition of the silica source to control the growth and ultimately, thickness of the mesoporous silica shell on the electrospun hematite nanofiber. The core/shell structure was subsequently tailored for heavy metal adsorption by grafting an aminopropyl functional group on the mesoporous silica surface. The resulting electrospun hematite/mesoporous silica core/shell nanomaterials were extensively characterized by energy dispersive spectroscopy (EDS) with high resolution transmission electron microscopy (HRTEM), and ζ potential measurements both before and after adsorption of the Cr(III), from aqueous solution. Notably, sorption capacities for Cr(III) exceeded those previously reported for other nanostructured sorbents for this metal. The advantages of these core/shell materials include controllable surface area through introduction of porosity and the option for facile surface modification to optimize physicochemical interactions for pollutant uptake. These nanocomposites also exhibit improved chemical resistance in harsh environments. At acidic pH values, for example, the core/shell nanomaterials were more chemically resistant to iron dissolution than the parent electrospun hematite nanofibers, which broadens the range of waste streams to which these sorbents can be applied.


    CHEEC Project:

    Citation:

    Egodawatte S, Greenstein KE, Vance I, Rivera E, Myung NV, Parkin GF, Cwiertny DM, Larsen SC. Electrospun hematite nanofiber/mesoporous silica core/shell nanomaterials as an efficient adsorbent for heavy metals. RSC Advances. 2016;6(93):90516-25. DOI: 10.1039/C6RA19876G

  • Saturday, March 31, 2018

    Endotoxin predictors and associated respiratory outcomes differ with climate regions in the US.

    Author(s):
    Angelico Mendy
    Jesse Wilkerson
    Paivi M. Salo
    Richard D. Cohn
    Darryl C. Zeldin
    Peter S. Thorne

    Journal Title:
    Environment International

    Abstract:

    Rationale
    Although endotoxin is a recognized cause of environmental lung disease, how its relationship with respiratory outcomes varies with climate is unknown.

    Objective
    To examine the endotoxin predictors as well as endotoxin association with asthma, wheeze, and sensitization to inhalant allergens in various US climate regions.

    Methods
    We analyzed data on 6963 participants in the National Health and Nutrition Examination Survey. Endotoxin measurements of house dust from bedroom floor and bedding were performed at the University of Iowa. Linear and logistic regression analyses were used to identify endotoxin predictors and assess endotoxin association with health outcomes.

    Results
    The overall median house dust endotoxin was 16.2 EU/mg; it was higher in mixed-dry/hot-dry regions (19.7 EU/mg) and lower in mixed-humid/marine areas (14.8 EU/mg). Endotoxin predictors and endotoxin association with health outcomes significantly differed across climate regions. In subarctic/very cold/cold regions, log10-endotoxin was significantly associated with higher prevalence of wheeze outcomes (OR:1.48, 95% CI:1.19–1.85 for any wheeze, OR:1.48, 95% CI:1.22–1.80 for exercise-induced wheeze, OR:1.50, 95% CI:1.13–1.98 for prescription medication for wheeze, and OR:1.95, 95% CI:1.50–2.54 for doctor/ER visit for wheeze). In hot-humid regions, log10-endotoxin was positively associated with any wheeze (OR:1.66, 95% CI:1.04–2.65) and current asthma (OR:1.56, 95% CI:1.11–2.18), but negatively with sensitization to any inhalant allergens (OR:0.83, 95% CI:0.74–0.92).

    Conclusion
    Endotoxin predictors and endotoxin association with asthma and wheeze differ across U.S. climate regions. Endotoxin is associated positively with wheeze or asthma in cold and hot-humid regions, but negatively with sensitization to inhalant allergens in hot-humid climates.


    CHEEC Project:

    Citation:

    Mendy A, Wilkerson J, Salo PM, Cohn RD, Zeldin DC, Thorne PS. Endotoxin predictors and associated respiratory outcomes differ with climate regions in the US. Environment international. 2018 Mar 31;112:218-26. DOI: 10.1016/j.envint.2017.12.003.

     

  • Saturday, April 21, 2018

    Exposure and Sensitization to Pets Modify Endotoxin Association with Asthma and Wheeze

    Author(s):
    Angelico Mendy
    Jesse Wilkerson
    Paivi M. Salo
    Richard D. Cohn
    Darryl C. Zeldin
    Peter S. Thorne

    Journal Title:
    The Journal of Allergy and Clinical Immunology: In Practice

    Abstract:

    Background
    Pets are major contributors of endotoxin in homes, but whether they influence endotoxin association with respiratory outcomes is unclear.

    Objective
    To examine whether exposure and sensitization to dog and cat modify the relationship between endotoxin exposure and asthma and wheeze.

    Methods
    We analyzed data from 6051 participants in the 2005-2006 cycle of the National Health and Nutrition Examination Survey (NHANES). House dust from bedroom floor and bedding was evaluated for endotoxin and for dog (Canis familiaris 1) and cat (Feline domesticus 1) allergens. The NHANES also collected data on respiratory outcomes and measured IgE specific to allergens. Associations of log-endotoxin and pet exposure with respiratory outcomes were examined, adjusting for covariates including pet avoidance.

    Results
    Dog and cat ownership among participants was 48.3% and 37.5%, respectively. Endotoxin geometric mean (SE) was 15.49 (0.50) EU/mg. Endotoxin and pet allergen levels were significantly higher in households with a dog or cat. Overall, endotoxin was positively associated with wheeze (odds ratio [OR], 1.30; 95% CI, 1.04-1.62), but not with asthma. However, in participants nonsensitized to dog, the odds of endotoxin association with wheeze were higher with exposure to dog allergen (OR, 1.80; 95% CI, 1.27-2.53; Pinteraction = .048). In participants sensitized to cat and exposed to cat allergen, endotoxin became positively associated with asthma (OR, 1.92; 95% CI, 1.21-3.0; Pinteraction = .040). With coexposure to dog and cat allergens, endotoxin association with asthma and wheeze was exacerbated (OR, 2.00; 95% CI, 1.04-3.83; Pinteraction = .012 and OR, 1.88; 95% CI, 1.32-2.66; Pinteraction = .016, respectively).

    Conclusions
    Exposure to dog and cat allergens enhances the association of endotoxin with asthma and wheeze.


    CHEEC Project:

    Citation:

    Mendy A, Wilkerson J, Salo PM, Cohn RD, Zeldin DC, Thorne PS. Exposure and Sensitization to Pets Modify Endotoxin Association with Asthma and Wheeze. The Journal of Allergy and Clinical Immunology: In Practice. 2018 Apr 21. DOI: 10.1016/j.jaip.2018.04.009

     

  • Thursday, March 1, 2018

    House Dust Endotoxin Association with Chronic Bronchitis and Emphysema

    Author(s):
    Angelico Mendy
    Paivi M. Salo
    Richard D. Cohn
    Jesse Wilkerson
    Darryl C. Zeldin
    Peter S. Thorne

    Journal Title:
    Environmental Health Perspectives

    Abstract:

    Background
    Endotoxin has been reported to be associated with chronic bronchitis or emphysema (CBE) at high occupational exposures. However, whether levels found in domestic environments have similar effects is unknown.

    Objectives
    We aimed to study the association between house dust endotoxin and CBE in a sample representative of the U.S. population.

    Methods
    We analyzed data from 3,393 participants ≥20 y old from the National Health and Nutrition Examination Survey (NHANES) 2005-2006. House dust from bedding and from bedroom floors was analyzed for endotoxin content. NHANES participants received questionnaires and underwent examination as well as extensive laboratory testing. Logistic regression was used to examine the association of endotoxin levels with CBE diagnosis and symptoms, adjusting for covariates. The survey design and weights were applied so that estimates were nationally representative and so that statistical inferences were made appropriately.

    Results
    The median endotoxin concentration in house dust was 14.61 EU/mg dust, and CBE was reported by 8.2% of participants. In the adjusted analysis, one unit (EU/mg) increase in log10-transformed endotoxin concentrations was associated with a 27% increase in the odds of CBE diagnosis [OR=1.27 (95% CI: 1.00, 1.61)] and a 78% increase in the odds of chronic bronchitis symptoms (defined as cough and phlegm for ≥3 mo in a year for ≥2 y) [OR=1.78 (95% CI: 1.01, 3.12)]. Sensitization to inhalant allergens (p=0.001) modified the relationship between endotoxin and CBE diagnosis, with stronger associations observed in sensitized participants [OR=2.46 (95% CI: 1.72, 3.50) for a unit increase in log10-endotoxin].

    Conclusions
    In a population-based sample of U.S. adults, endotoxin levels in homes were associated with a self-reported history of CBE diagnosis and chronic bronchitis symptoms, with stronger associations among people sensitized to inhalant allergens.


    CHEEC Project:

    Citation:

    Mendy A, Salo PM, Cohn RD, Wilkerson J, Zeldin DC, Thorne PS. House Dust Endotoxin Association with Chronic Bronchitis and Emphysema. Environmental Health Perspectives (Online). 2018 Mar 1;126(3). DOI: 10.1289/EHP2452.

  • Tuesday, July 17, 2018

    Drinking water disinfection byproducts and risk of orofacial clefts in the National Birth Defects Prevention Study

    Author(s):
    Peter Weyer
    Anthony Rhoads
    Jonathan Suhl
    Thomas J. Luben
    Kristin M. Conway
    Peter H. Langlois
    Dereck Shen
    Dong Liang
    Soman Puzhankara
    Marlene Anderka
    Erin Bell
    Marcia L. Feldkamp
    Adrienne T. Hoyt
    Bridget Mosley
    Jennita Reefhuis
    Paul A. Romitti
    The National Birth Defects Prevention Study

    Journal Title:
    Birth Defects Research

    Abstract:

    Background
    Maternal exposure to drinking water disinfection byproducts (DBP)s may contribute to orofacial cleft (OFC) development, but studies are sparse and beset with limitations.

    Methods
    Population-based, maternal interview reports of drinking water filtration and consumption for 680 OFC cases (535 isolated) and 1826 controls were linked with DBP concentration data using maternal residential addresses and public water system monitoring data. Maternal individual-level exposures to trihalomethanes (THM)s and haloacetic acids (HAA)s (µg/L of water consumed) were estimated from reported consumption at home, work, and school. Compared to no exposure, associations with multisource maternal exposure <1/2 or ≥1/2 the Maximum Contaminant Levels (MCL)s for total THMs (TTHM)s and HAAs (HAA5) or Maximum Contaminant Level Goals (MCLG)s for individual THMs and HAAs (if non-zero) were estimated for all OFCs and isolated OFCs, cleft palate (CP), and cleft lip ± cleft palate (CL/P) using logistic regression analyses.

    Results
    Compared to controls, associations were near or below unity for maternal TTHM, HAA5, and individual THM exposures with all OFCs and isolated OFCs, CP, and CL/P. Associations also were near or below unity for individual HAAs with statistically significant, inverse associations observed with each OFC outcome group except CL/P.

    Conclusions
    This study examined associations for maternal reports of drinking water filtration and consumption and maternal DBP exposure from drinking water with OFCs in offspring. Associations observed were near or below unity and mostly nonsignificant. Continued, improved research using maternal individual-level exposure data will be useful in better characterizing these associations


    CHEEC Project:

    Citation:

    Weyer P, Rhoads A, Suhl J, et al. Drinking water disinfection byproducts and risk of orofacial clefts in the National Birth Defects Prevention Study. Birth Defects Research. 2018;110:1027–1042. https://doi.org/10.1002/bdr2.1348

  • Tuesday, August 1, 2000

    Dissolution of 226 Radium from pipe-scale deposits in a public water supply

    Author(s):
    Eileen L. Fisher
    Laurence J. Fourtes
    Richard L. Valentine
    Marinea Mehrhoff
    R. William Field

    Journal Title:
    Environment International

    Abstract:

    This study was undertaken to determine if dissolution of 226Radium from pipe-scale deposits contributes to enhanced waterborne 226Radium concentrations at the point of use. Water samples were collected from residential water customers of a small rural Iowa town. Sites were evenly divided between new and old water main connections. Daily samples were collected from the point-of-entry water. Point-of-use 226Radium concentrations ranged from 0.4 to 12.9 pCi L−1 (0.01 to 0.5 Bq L−1). The mean 226Radium concentration for homes connected to old water mains was significantly higher than the mean 226Radium concentration of homes connected to new water mains, mean(standard deviation) equal 8.3(1.1) and 5.3(0.8) pCi L−1 [0.3(1.1) and 0.2(0.8) Bq L−1], respectively. 226Radium concentrations of the point-of-entry water ranged from 5.0 pCi L−1 to 10.3 pCi L−1 (0.2 Bq L−1 to 0.4 Bq L−1). This study indicates considerable variability of 226Radium exposure from drinking water among residents of the same water supply and has implications for regulatory compliance and exposure assessment in epidemiologic studies


    CHEEC Project:

    Citation:

    Fisher, Eileen L., Laurence J. Fuortes, Richard L. Valentine, Marinea Mehrhoff, and R. William Field. "Dissolution of 226Radium from pipe-scale deposits in a public water supply." Environment international 26, no. 1-2 (2000): 69-73.

  • Tuesday, May 23, 2000

    A comparison of continuous flow hydride generation laser-induced fluorescence and laser-enhanced ionization spectrometry approaches for parts per trillion level measurements of arsenic, selenium and antimony

    Author(s):
    H. L. Pacquette
    S. A. Elwood
    M. Ezer
    J. B. Simeonsson

    Journal Title:
    Journal of Analytical Atomic Spectrometry

    Abstract:

    Hydride generation (HG) is a sample introduction technique that provides enhanced sensitivity for metalloids and allows chemical speciation between selected arsenic (As) and selenium (Se) anion species. The present studies have demonstrated high sensitivity for As, Se, and antimony (Sb) using continuous flow HG-laser induced fluorescence (LIF) and HG-laser enhanced ionization (LEI) spectrometric techniques. The limits of detection (LODs) are 200, 90 and 300 fg ml−1 for As, Se and Sb, respectively, using HG-LIF and 50 and 2 pg ml−1 for As and Se, respectively, using HG-LEI approaches. Measurements performed using HG combined with LIF detection in an electrothermal atomizer resulted in LODs of 3 pg ml−1 (6 pg absolute mass) and 20 pg ml−1 (40 pg) for As and Se, respectively. All of the techniques are linear in their responses to at least 10 ng ml−1 for the corresponding elements. Reliable chemical speciation of As(III/V) and Se(IV/VI) species has been obtained using the flame HG-LIF approaches. Selective determinations of Se(IV) and Se(VI) have been carried out using an on-line pre-reduction procedure, where selective HG of Se(IV) is performed in 31% HBr at room temperature, while HG of [Se(IV) + Se(VI)] is performed following pre-reduction in 31% HBr at 100[thin space (1/6-em)]°C. Selective HG of As species is accomplished by control of the solution pH, where selective HG of As(III) is performed at pH 6 and HG of [As(III) + As(V)] is performed at pH 0. The results obtained demonstrate that the HG approaches are selective and provide quantitative recoveries of the individual Se and As species at sub-ppb levels.


    CHEEC Project:

    Citation:

    Pacquette, H. L., S. A. Elwood, M. Ezer, and J. B. Simeonsson. "A comparison of continuous flow hydride generation laser-induced fluorescence and laser-enhanced ionization spectrometry approaches for parts per trillion level measurements of arsenic, selenium and antimony." Journal of Analytical Atomic Spectrometry 16, no. 2 (2001): 152-158.

  • Monday, April 3, 2000

    Chapter 15: Pesticides in Ambient Air and Precipitation in Rural, Urban, and Isolated Areas of Eastern Iowa

    Author(s):
    M. E. Hochstedler
    D. Larabee-Zierath
    G. R. Hallberg

    Journal Title:
    ACS Symposium Series, Vol 751

    Abstract:

    Atmospheric transport and deposition of pesticides are significant issues in better understanding human and environmental exposure. Pesticide concentrations in air and precipitation were measured over a one-year-period at four sites in Iowa chosen to characterize rural, urban and regional effects. Twenty-eight pesticides including twenty-one herbicides and seven insecticides were detected in precipitation during the sampling period, October 1996 through September 1997. Pesticide concentrations were greatest during the planting-growing season, April through August. Peak concentrations reached 0.96 ug/L for acetochlor, 1.1 ug/L for 2,4-D, and 3.5 ug/L for atrazine, all commonly used herbicides in Iowa. Concentrations were generally higher at the farm site but were present at all sites indicating distant transport. Measurable air concentrations were occasionally seen, but most were below detection limit for the volume of air sampled.


    CHEEC Project:

    Citation:

    Hochstedler, M. E., D. Larabee-Zierath, and G. R. Hallberg. "Pesticides in Ambient Air and Precipitation in Rural, Urban, and Isolated Areas of Eastern Iowa." 2000.

  • Saturday, January 1, 2000

    Hydride generation laser-induced fluorescence of arsenic and selenium in the inductively coupled plasma and electrothermal atomizer

    Author(s):
    H. L. Pacquette
    S. A. Elwood
    M. Ezer
    D. J. Swart
    J. B. Simeonsson

    Journal Title:
    Applied Spectroscopy

    Abstract:

    The application of hydride generation (HG) sample introduction combined with laser-induced fluorescence (LIF) detection in the inductively coupled plasma (ICP) and electrothermal atomizer (ETA) is reported. Far-ultraviolet excitation of As at 193.696 nm and Se at 196.026 nm is accomplished by using a tunable dye laser system with frequency doubling and stimulated Raman scattering. HG-ICP-LIF and HG-ETA-LIF techniques have been developed and demonstrate good sensitivity and good linearity at the ng/mL to sub-ng/mL level for both elements. The relative standard deviation of replicate measurements is on the order of 3-10% at the 5 ng/mL level for the HG-ICP-LIF technique and 5-35% at the 0.6 ng/mL level for the HG-ETA-LIF technique. Detection limits of 1 ng/mL (5 ng absolute mass) for As and 0.06 ng/mL (0.3 ng) for Se are reported for the HG-ICP-LIF technique and 0.04 ng/mL (0.2 ng) for As and 0.16 ng/mL (0.8 ng) for Se are reported for the HG-ETA-LIF technique. Lower than expected sensitivity and precision are observed in the ETA, which may be due to inefficient trapping of the hydrides in the procedure. Selective HG procedures have been demonstrated for the speciation and recovery of selected oxidation states of As and Se. The analytical capabilities of the HG-LIF techniques are compared to those of other HG techniques, and recommendations are made for improved performance of future HG-LIF approaches.


    CHEEC Project:

    Citation:

    Pacquette, H. L., S. A. Elwood, M. Ezer, D. J. Swart, and J. B. Simeonsson. "Hydride generation laser-induced fluorescence of arsenic and selenium in the inductively coupled plasma and electrothermal atomizer." Applied Spectroscopy 54, no. 1 (2000): 89-93.

  • Friday, August 16, 2002

    Development of ultratrace laser spectrometry techniques for measurements of arsenic

    Author(s):
    J.B. Simeonsson
    S.A. Elwood
    M Ezer
    H.L. Pacquette
    D.J. Swart
    H.D. Beach
    D.J. Thomas

    Journal Title:
    Talanta

    Abstract:

    Several techniques based on laser induced fluorescence (LIF) spectrometry and laser enhanced ionization (LEI) spectrometry have been investigated for ultratrace measurements of arsenic. Studies by our group in this area that have been published previously are reviewed here, and are presented along with the results of recent studies that have not yet been published. The techniques presented include LIF detection in the inductively coupled plasma atomizer, the electrothermal atomizer, the tungsten coil atomizer, the flame atomizer and LEI detection in the flame atomizer, and include approaches that utilize hydride generation or laser ablation sample introduction. Recent efforts have been directed towards developing speciation approaches for arsenic that utilize LIF spectrometric detection. The capabilities of each technique are summarized including the sensitivity and limits of detection, which range from sub-pg ml−1 to ng ml−1 levels. Selected applications of the techniques are presented to demonstrate their utility for environmental and biological samples, and areas for future investigation and further development are discussed.


    CHEEC Project:

    Citation:

    Simeonsson, J. B., S. A. Elwood, M. Ezer, H. L. Pacquette, D. J. Swart, H. D. Beach, and D. J. Thomas. "Development of ultratrace laser spectrometry techniques for measurements of arsenic." Talanta 58, no. 1 (2002): 189-199. https://doi.org/10.1016/S0039-9140(02)00267-9

  • Tuesday, November 3, 2009

    Reduction of estrogenic activity of municipal wastewater by aerated lagoon treatment facilities

    Author(s):
    Robert B. Bringolf
    Robert C. Summerfelt

    Journal Title:
    Environmental Toxicology and Chemistry

    Abstract:

    The estrogenic activity of municipal wastewater in aerated lagoon treatment facilities was evaluated using plasma concentrations of vitellogenin (Vtg) in male fathead minnows (Pimephales promelas). Caged fathead minnows were exposed for 10 to 12 d in three lagoons that are connected in series at each of 10 municipal wastewater treatment facilities in central Iowa. USA, during October and November 2000. Fathead minnows held in the laboratory served as unexposed controls. Pooled (n = 4–10 fish) plasma Vtg, quantified by enzyme‐linked immunosorbent assay (ELISA), was 1,702 ± 670 (mean ± standard error [SE]) μg/ml in the first lagoons (n = 9), 0.94 ± 0.36 μg/ml in the second lagoons (n = 10), and 0.04 ± 0.02 μg/ml in the third lagoons (n = 8). Differences in mean fish plasma Vtg concentration among lagoons were highly significant (p < 0.001). The mean concentration of plasma Vtg in fish in the third lagoons was not significantly different (p = 0.990) from that of the control fish (0.04 ± 0.02 μg/ml). Plasma Vtg concentrations of fish in the first lagoons were inversely correlated with wastewater retention time in the lagoons (p = 0.002, r = −0.877). Water temperatures of the final effluents during the study ranged from 9 to 12°C General treatment efficiency of lagoons has been shown to be dependent on temperature, so the potential exists for decreased removal of estrogenic activity when water temperatures are lower (e.g., winter months) than the present study. In conclusion, wastewater entering aerated lagoon systems was estrogenic to fish, but with serial passage through the lagoons, the estrogenic activity decreased to a level that was not sufficient to induce vitellogenesis in male fathead minnows in a 10‐ to 12‐d exposure.


    CHEEC Project:

    Citation:

    Bringolf, Robert B., and Robert C. Summerfelt. "Reduction of estrogenic activity of municipal wastewater by aerated lagoon treatment facilities." Environmental Toxicology and Chemistry: An International Journal 22, no. 1 (2003): 77-83.  https://doi.org/10.1002/etc.5620220110

  • Tuesday, July 1, 2003

    Exposure to Particulates, Microorganisms, β(1–3)-Glucans, and Endotoxins During Soybean Harvesting

    Author(s):
    Chad J. Roy
    Peter S. Thorne

    Journal Title:
    AIHA Journal

    Abstract:

    Sclerotinia sclerotiorum is an emerging fungal pathogen affecting soybeans in the United States. In response to its emergence, exposures to particulates, bioaerosols, endotoxins, S. sclerotiorum, and b(1-3)-glucans were characterized during soybean harvesting. Air sampling was performed on soybean harvesters (combines) and on the farmers in closed cabs as personal samples during harvesting at 17 farms in 1997 and repeated at 15 in 1998. S. sclerotiorum infestation was evident in the fields at 8 of the sites (44%). The geometric mean concentrations (and geometric standard deviations) measured on the combines in 1998 were as follows: total dust, 11.9 (2.8) mg/m3; inhalable dust 11.7 (6.4) mg/m3; and b(1-3)-glucans, 5027 (7) ng/m3. Values for the personal samples in 1998 were as follows: total dust, 1.2 (6.7) mg/m3; inhalable dust, 1.1 (5.3); and b(1-3)-glucans, 674 (9) ng/m3. These concentrations were two- to threefold higher than in the previous year. Ambient endotoxin concentrations were 4438 EU/m3 in Year I and 459 EU/m3 in Year II. Particle size distribution measurements on the combines yielded mass median aerodynamic diameters of 6.6 mm on the combine and 4.0 mm inside the combine cab. Closed combine cabs provided an average workplace protection factor of 11.7 for total dust. Nevertheless, personal exposures to organisms inside combine cabins ranged from 3.63104 to 4.03108 organisms/m3. These data indicate the potential exists for high exposures to organic dust and bioaerosols during soybean harvesting.


    CHEEC Project:

    Citation:

    Chad J. Roy & Peter S. Thorne (2003) Exposure to Particulates, Microorganisms, β(1–3)-Glucans, and Endotoxins During Soybean Harvesting, AIHA Journal,64:4, 487-495, DOI: 10.1080/15428110308984844

  • Thursday, May 1, 2003

    Occurrence of Ovotestes and Plasma Vitellogenin in Feral Male Fathead Minnows from Lagoons of Municipal Wastewater Treatment Facilities in Central Iowa

    Author(s):
    Robert B. Bringolf
    Robert C. Summerfelt

    Journal Title:
    The Journal of the Iowa Academy of Science

    Abstract:

    Since the early 1990s, endocrine disrupting compounds have been recognized as an important environmental threat. Male fish exposed ro effluent from large, metropolitan municipal wastewater treatment facilities (WWTFs) have developed reproductive abnormalities including ovotestes and elevated levels of plasma vitellogenin (Vtg), a plasma protein typically produced by egg-laying females. In the summer of 2000, gonads and plasma Vtg concentrations were examined in feral male fathead minnows (Pimephales promelas) collected from lagoons of 11 small, rural municipal WWTFs and a reference site (a national wildlife refuge) in Iowa. Fathead minnows were captured in traps from five of the 33 lagoons (three per WWTF) sampled. No other fish species were captured. The five lagoons with fathead minnows were found at three WWTFs. Gonad histology indicated only one of 65 (1.5%) male fish living in the lagoons had ovotestes, which was similar to the incidence at a reference site (1 of 29, 3.4%). Plasma Vtg, however, was substantially higher in fish from four of the five lagoons than in fish from the reference site, indicating that fish in lagoons were exposed to estrogenic substances.


    CHEEC Project:

    Citation:

    Bringolf, Robert B., and Robert C. Summerfelt. "Occurrence of ovotestes and plasma vitellogenin in feral male fathead minnows from lagoons of municipal wastewater treatment facilities in central Iowa." Journal of the Iowa Academy of Science: JIAS 110, no. 1-2 (2003): 17-21.

  • Thursday, May 30, 2002

    Effects of environmental estrogens on reproductive biology of the fathead minnow

    Author(s):
    Robert Bruce Bringolf

    Journal Title:
    PhD Thesis

    Abstract:

    Since the early 1990s, environmental estrogens have been recognized as an important environmental threat. Wastewater of 10 aerated lagoon treatment facilities in Iowa was evaluated for estrogenic activity using a short-term caged fathead minnow exposure and a plasma vitellogenin (Vtg) assay. Plasma Vtg results indicated that wastewater entering the three-lagoon systems was estrogenic to male fish, but with serial passage through the lagoons, the estrogenic activity decreased to a level that was not sufficient to induce vitellogenesis. Wastewater retention time in the lagoons may have been a key treatment factor.

    Feral fathead minnows captured at aerated lagoon wastewater treatment facilities ( WWTFs) exhibited plasma Vtg trends similar to those of the caged fish. Incidence of ovotestes in feral fish was low (1 of 65; 1.5%) and similar to that of fathead minnows captured at a reference site (national wildlife refuge). The results of both the caged and feral fish studies indicate that effluents from aerated lagoon WWTFs are low in estrogenic activity, but that raw wastewater was estrogenic to fish. Thus, the potential exists for release of estrogenic effluents from these systems if the treatment is not complete.

    The plasma Vtg response of male fish exposed to estradiol for 10 days was dosedependent and predictable (/?" = 0.988) through the range of estradiol exposure concentrations tested. The lowest observed effects concentration (LOEC) for induction of plasma Vtg was 50 ng/L. The dose-response curve from this study may be used in conjunction with exposure of male fish to surface water or wastewater to estimate the magnitude of the estrogenic potency of the water in terms of "estradiol equivalents."

    Atrazine did not cause overt reproductive toxicity to adult fathead minnows in a shortterm reproduction assay. However, decreasing trends in relative testis weight, testis maturity, and percent embryo fertilization suggest that further investigation is warranted. Nearly all endpoints concerning fish exposed to estradiol (positive control) were significantly different from atrazine-exposed fish and control fish. The results suggest that atrazine did not have strong estrogenic effects and did not cause endocrine system disruption in fathead minnows at environmentally relevant concentrations.


    CHEEC Project:

    Citation:

    Bringolf, Robert Bruce, "Effects of environmental estrogens on reproductive biology of the fathead minnow " (2002). Retrospective Theses and Dissertations. 500. https://lib.dr.iastate.edu/rtd/500 

  • Thursday, July 4, 2019

    Quantifying the Interdependence of Metal-Ligand Covalency and Bond Distance using Ligand K-edge XAS

    Author(s):
    Kyounghoon Lee
    Anastasia V. Blake
    Courtney M. Donahue
    Kyle D. Spielvogel
    Brian J. Bellott
    Scott R. Daly

    Journal Title:
    Angewandte Chemie International Edition

    Abstract:

    Bond distance is a common structural metric used to assess changes in metal‐ligand bonds, but it is not clear how sensitive changes in bond distances are with respect to changes in metal‐ligand covalency. Here we report ligand K‐edge XAS studies on Ni and Pd complexes containing different phosphorus(III) ligands. Despite the large number of electronic and structural permutations, P K‐edge pre‐edge peak intensities reveal a remarkable correlation that spectroscopically quantifies the linear interdependence of covalent M‐P σ bonding and bond distance. Cl K‐edge studies conducted on many of the same Ni and Pd compounds revealed a poor correlation between M‐Cl bond distance and covalency, but a strong correlation was established by analyzing Cl K‐edge data for Ti complexes with a wider range of Ti‐Cl bond distances. Together these results establish a quantitative framework to begin making more accurate assessments of metal‐ligand covalency using bond distances from readily‐available crystallographic data.


    CHEEC Project:

    Citation:

    Lee, Kyounghoon, Anastasia V. Blake, Courtney M. Donahue, Kyle D. Spielvogel, Brian J. Bellott, and Scott R. Daly. "Quantifying the Interdependence of Metal‐Ligand Covalency and Bond Distance using Ligand K‐edge XAS." Angewandte Chemie International Edition (2019).

  • Tuesday, August 3, 2004

    Mixing of perfluorinated carboxylic acids with dipalmitoylphosphatidylcholine

    Author(s):
    Hans-Joachim Lehmler
    P.M. Bummer

    Journal Title:
    Biochimica et Biophysica Acta (BBA) - Biomembranes

    Abstract:

    Perfluorinated acids are emerging as an important class of persistent environmental pollutant, thus raising human health concerns. To understand the behavior of these compounds in biological systems, the mixing behavior of two perfluorinated acids, perfluorododecanoic and perfluorotetradecanoic acid, with dipalmitoylphosphatidylcholine (DPPC) was studied in monolayers at the air–water interface and in fully hydrated DPPC bilayers. The mixing behavior of both acids was indicative of an attractive interaction and partial miscibility with DPPC at the air–water interface. In the bilayer studies, the fluorinated acids cause peak broadening and elimination of the pretransition of DPPC. The onset temperature of the main phase transition remains constant in the presence of the fluorinated acids suggesting immiscibilities in the gel phase. Below X(DPPC)=0.97 significant peak broadening of the main phase transition can be observed. These results suggest strong interaction between the respective acid and DPPC, and that both acids are able to partition into the lipid bilayer. However, their mixing behavior is far from ideal, thus suggesting the presence of domains or lipid aggregates with high acid concentrations which may (adversely) impact the function of biological mono- and bilayers.


    CHEEC Project:

    Citation:

    Lehmler, H-J., and P. M. Bummer. "Mixing of perfluorinated carboxylic acids with dipalmitoylphosphatidylcholine." Biochimica et Biophysica Acta (BBA)-Biomembranes 1664, no. 2 (2004): 141-149.

  • Saturday, November 22, 2003

    Synthetic Musk Fragrances in Lake Michigan

    Author(s):
    Aaron M. Peck
    Keri C. Hornbuckle

    Journal Title:
    Environmental Science and Technology

    Abstract:

    Synthetic musk fragrances are added to a wide variety of personal care and household products and are present in treated wastewater effluent. Here we report for the first time ambient air and water measurements of six polycyclic musks (AHTN, HHCB, ATII, ADBI, AHMI, and DPMI) and two nitro musks (musk xylene and musk ketone) in North America. The compounds were measured in the air and water of Lake Michigan and in the air of urban Milwaukee, WI. All of the compounds except DPMI were detected. HHCB and AHTN were found in the highest concentrations in all samples. Airborne concentrations of HHCB and AHTN average 4.6 and 2.9 ng/m3, respectively, in Milwaukee and 1.1 and 0.49 ng/m3 over the lake. The average water concentration of HHCB and AHTN in Lake Michigan was 4.7 and 1.0 ng/L, respectively. A lake-wide annual mass budget shows that wastewater treatment plant discharge is the major source (3470 kg/yr) of the synthetic musks while atmospheric deposition contributes less than 1%. Volatilization and outflow through the Straits of Mackinac are major loss mechanisms (2085 and 516 kg/yr for volatilization and outflow, respectively). Concentrations of HHCB are about one-half the predicted steady-state water concentrations in Lake Michigan.


    CHEEC Project:

    Citation:

    Peck, Aaron M., and Keri C. Hornbuckle. "Synthetic musk fragrances in Lake Michigan." Environmental science & technology 38, no. 2 (2004): 367-372.

  • Thursday, July 1, 2004

    Enzymatic Transformations of Chloroacetanilide Herbicides and Explosive Chemicals by Plants: In Vivo and In Vitro Studies

    Author(s):
    Melissa P. Mezzari

    Journal Title:
    PhD Thesis

    Abstract:

    Understanding metabolic routes and catabolic enzymes involved in the transformation of xenobiotics in plants are of great importance to phytoremediation purpose. Studies were conducted to explore transformation reactions of acetochlor (AOC), metolachlor (MOC), 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine (HMX) in hybrid poplars and Arabidopsis. Here, we report the use of (1) spectrophotometric techniques for enzyme activities; (2) immuno-localization studies using an antibody developed against MOC; (3) confocal microscopy to study the in vivo conjugation reactions with reduced glutathione in root cells of poplar and Arabidopsis; (4) molecular techniques for gene isolation and quantification of three GST isoforms and 12-oxophytodienoate reductase (OPR) in Arabidopsis; (5) modeling of radiolabeled RDX and HMX in poplar cells based on the “green liver” concept. Results from MOC immunolocalization indicate that this compound is found in vascular tissues, which correspond to the localization of the parent compound without further transformations in the cytoplasm of the plant cell. Spectrophotometer assay results support variable induced activities from all enzymes tested in all chemicals. It was also observed that GRs are induced by TNT and RDX, which are enzymes that are thought to be involved in reduction reactions of these explosive compounds. Molecular analysis confirmed the induction of GST and OPR genes in Arabidopsis when exposed to TNT, AOC and MOC. RDX did not show significant increase in gene expression, and therefore GSTs and OPRs are enzymes that may not be involved in the transformation of this compound. In vivo conjugation reactions using multiphoton and confocal microscopy also confirm that glutathione conjugation reactions do not occur in plants exposed to RDX and TNT. Conjugation reactions with glutathione were observed only in plants exposed to AOC and MOC, which is a common detoxification pathway for these chemicals. Studies with three mathematical models imply high correlation between the collected and simulated data from plant culture exposed to RDX and HMX. Results show that the final fate of these compounds is binding to cell wall. The simplest model developed (model I) is the best model description of these particular results.


    CHEEC Project:

    Citation:

    Mezzari, Melissa Paola. Enzymatic transformations of chloroacetanilide herbicides and explosive chemicals by plants: In vivo and in vitro studies. The University of Iowa, 2004.

  • Wednesday, June 1, 2005

    Gene Expression and Microscopic Analysis of Arabidopsis Exposed to Chloroacetanilide Herbicides and Explosive Compounds. A Phytoremediation Approach

    Author(s):
    Melissa P. Mezzari
    Katherine Walters
    Marcela Jelınkova
    Ming-Che Shih
    Craig L. Just
    Jerald L. Schnoor

    Journal Title:
    Plant Physiology

    Abstract:

    Understanding the function of detoxifying enzymes in plants toward xenobiotics is of major importance for phytoremediation applications. In this work, Arabidopsis (Arabidopsis thaliana; ecotype Columbia) seedlings were exposed to 0.6 mm acetochlor (AOC), 2 mm metolachlor (MOC), 0.6 mm 2,4,6-trinitrotoluene (TNT), and 0.3 mm hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). In vivo glutathione (GSH) conjugation reactions of AOC, MOC, RDX, and TNT were studied in root cells using a multiphoton microscope. In situ labeling with monochlorobimane, used as a competitive compound for conjugation reactions with GSH, confirmed that AOC and MOC are conjugated in Arabidopsis cells. Reverse transcription-PCR established the expression profile of glutathione S-transferases (GSTs) and nitroreductases enzymes. Genes selected for this study were AtGSTF2, AtGSTU1, AtGSTU24, and two isoforms of 12-oxophytodienoate reductase (OPR1 and OPR2). The five transcripts tested were induced by all treatments, but RDX resulted in low induction. The mRNA level of AtGSTU24 showed substantial increase for all chemicals (23-fold induction for AOC, 18-fold for MOC, 5-fold for RDX, and 40-fold for TNT). It appears that GSTs are also involved in the conjugation reactions with metabolites of TNT, and to a lesser extent with RDX. Results indicate that OPR2 is involved in plant metabolism of TNT (11-fold induction), and in oxidative stress when exposed to AOC (7-fold), MOC (9-fold), and RDX (2-fold). This study comprises gene expression analysis of Arabidopsis exposed to RDX and AOC, which are considered significant environmental contaminants, and demonstrates the importance of microscopy methods for phytoremediation investigations.


    CHEEC Project:

    Citation:

    Mezzari, Melissa P., Katherine Walters, Marcela Jelínkova, Ming-Che Shih, Craig L. Just, and Jerald L. Schnoor. "Gene expression and microscopic analysis of Arabidopsis exposed to chloroacetanilide herbicides and explosive compounds. A phytoremediation approach." Plant Physiology 138, no. 2 (2005): 858-869.

  • Tuesday, July 20, 2004

    Atmospheric concentrations and deposition of synthetic musk fragrances, current-use pesticides and polycyclic aromatic hydrocarbons in Iowa and the Great Lakes

    Author(s):
    Aaron M. Peck

    Journal Title:
    PhD Thesis

    Abstract:

    Human activities are responsible for the global distribution of synthetic chemicals in the environment. In this study the role and relative importance of atmospheric transport of three groups of anthropogenic organic chemicals in Iowa and the Great Lakes was examined. The chemical groups were synthetic musk fragrances, polycyclic aromatic hydrocarbons (PAHs), and current-use pesticides.

    The partitioning of gas-phase anthracene with Ficus benjamina was investigated in a climate-controlled chamber. The effect of light, relative humidity, and temperature were investigated and evaluated with a chemical fate model developed for the chamber system.

    Synthetic musk fragrances were measured in the ambient environment in the United States for the first time. A lake-wide annual mass budget on Lake Michigan showed that wastewater treatment plant discharge is the major source (3470 kg/yr) of synthetic musks while atmospheric deposition contributes less than 1%. Volatilization (2085 kg/yr) and flow out of the lake (516 kg/yr) are both important loss processes.

    A method for the identification and quantification of current-use pesticides, synthetic musk fragrances, and PAHs was developed and used to measure these compounds over Lakes Erie and Ontario in August 2002 and at three sites in eastern Iowa during 2000–2002. HHCB and AHTN were the most frequently detected synthetic musks. The average gas-phase concentrations of the detected values for HHCB and AHTN were 0.35 ng/m3 and 0.26 ng/m 3, respectively. Average detected PAH concentrations ranged from 0.12 ng/m3 for 3,6-dimethylphenanthrene to 17 ng/m3 for 2-methylnapthalene. The average detected concentrations of three heavily used herbicides were 4.6 ng/m3 for acetochlor, 2.3 ng/m 3 for metolachlor, and 1.1 ng/m3 for alachlor. The most frequently detected insecticides were phorate and chlorpyrifos, which were found in 20% and 19% of the samples, respectively. The average detected phorate and chlorpyrifos concentrations were 25 ng/m3 and 1.0 ng/m3, respectively. The most frequently detected current-use fungicide was etridiazole, which was found in 10% of the samples. Gaseous deposition fluxes to a model plant were predicted using the measured gas-phase concentrations. Predicted yearly deposition rates were 5.1 μg/m 2 for metolachlor, 0.51 μg/m2 for alachlor, 4.0 μg/m 2 for atrazine.


    CHEEC Project:

    Citation:

    Peck, Aaron Michael. "Atmospheric concentrations and deposition of synthetic musk fragrances, current-use pesticides and polycyclic aromatic hydrocarbons in Iowa and the Great Lakes." PhD diss., The University of Iowa, 2004.

  • Wednesday, March 21, 2007

    Fate of Atrazine in a Grassed Phytoremediation System

    Author(s):
    Keri L. Henderson
    Jason B. Belden
    Joel R. Coats

    Journal Title:
    Environmental Toxicology and Chemistry

    Abstract:

    Atrazine is a well-known contaminant of surface waters and has been implicated in point-source pollution at agrochemical dealerships in the Midwest. Although the fate of atrazine has been well documented in soil and water, little is known about the fate of this contaminant and its metabolites within a grassed system. In the present study, [U-ring-14C]atrazine was added to soil in closed systems to determine the fate of the parent compound and its metabolites in soil, including degradation and movement into plants and air. Soil was treated with 25 mg/kg [14C]labeled atrazine and allowed to age for 5 d. Four systems then were amended with a mixture of prairie grasses, and the remaining four chambers were maintained as unvegetated controls. Dissipation and distribution of parent compound and metabolites were recorded for 21 d. Plant uptake of [14C]residue was less than 0.5% of applied radioactivity. Approximately 2% of total applied [14C]atrazine was mineralized to [14C]CO2, with no differences between vegetated and unvegetated systems. Mass balance recoveries were 76% for grassed systems and 77.5% for unvegetated controls. Approximately 40% of applied radioactivity remained bound to the soil following extraction. The most prevalent extractable compound detected in the soil was the parent, atrazine; major metabolites in soil were deethylatrazine (DEA) and didealkylatrazine (DDA). Leaf tissue contained concentrations of atrazine and key metabolites, i.e., DEA, DDA, and deisopropylatrazine (DIA), above those allowed in forage grasses by the U.S. Environmental Protection Agency; another key metabolite, hydroxyatrazine, was the most prevalent compound identified in both leaf and root tissue.


    CHEEC Project:

    Citation:

    Henderson, Keri L., Jason B. Belden, and Joel R. Coats. "Fate of atrazine in a grassed phytoremediation system." Environmental toxicology and chemistry 26, no. 9 (2007): 1836-1842.

  • Tuesday, March 27, 2007

    Synthesis and characterization of deoxynivalenol glucuronide: Its comparative immunotoxicity with deoxynivalenol

    Author(s):
    Xianai Wu
    Patricia Murphy
    Joan Cunnick
    Suzanne Hendrich

    Journal Title:
    Food and Chemical Toxicology

    Abstract:

    Deoxynivalenol (DON) is a mycotoxin commonly contaminating wheat, barley and corn. DON glucuronide (DONGLU) is a major DON metabolite. We synthesized and purified DONGLU and tested its immunotoxicity, hypothesizing that DONGLU would be much less toxic to K562 cells compared with DON. DONGLU was synthesized using rat liver microsomes, uridine-50-diphosphoglucuronic acid and DON, and purified with a Sephadex LH-20 column and reverse phase HPLC. b-Glucuronidase hydrolysis formed a product with retention time and UV spectrum identical with DON. Using atmospheric pressure chemical ionization in negative mode, the molecular mass (M1) of purified DONGLU was 471 g/mol; in agreement with an expected molecular weight of 472 g/mol. MS and NMR indicated that the glucuronide moiety was conjugated with the carbon-3-hydroxyl group of DON. The cytotoxicity of DON and DONGLU were compared in cell culture using human erythroleukemia cell line K562. Fifty percent inhibition of cell number was observed with a DON concentration of 1.31 lM using a methylthaizol tetrazolium (MTS) cell viability assay whereas no significant cytotoxicity was observed for DONGLU at up to 270 lM. DONGLU did not influence DON toxicity at 0.5 lM, 1.3 lM and 8.4 lM concentration combinations of each compound. These data verified that DONGLU is a detoxification product of DON.


    CHEEC Project:

    Citation:

    Wu, Xianai, Patricia Murphy, Joan Cunnick, and Suzanne Hendrich. "Synthesis and characterization of deoxynivalenol glucuronide: its comparative immunotoxicity with deoxynivalenol." Food and Chemical Toxicology 45, no. 10 (2007): 1846-1855.

     

  • Friday, October 1, 2010

    Arsenic Speciation in the Presence of Anoxic Mixed Valent Iron Systems

    Author(s):
    Angela M. Brown

    Journal Title:
    MS Thesis

    Abstract:

    Iron is ubiquitous in the environment, ranking fourth in abundance in the earth's crust. Iron is responsible for many environmental mechanisms including the distribution of plant nutrients and pollutants. Iron can exist in several minerals, including iron oxides. Arsenic is a naturally occurring metalloid which has been confirmed by the EPA as a carcinogen. Recently, an arsenic epidemic has unfurled in Bangladesh, poisoning an estimated 70 million people. Arsenic contamination does not exist only in the third world, but also in the United States, including Iowa. Due to the widespread distribution of arsenic and the potential for it to be leached into groundwater supplies, there has been a growing interest in establishing removal mechanisms.

    Atomic absorption (AA) spectroscopy and inductively coupled plasma optical emission spectrometry (ICP-OES) have been used. There has been a shift in arsenic analysis methods with the advent of more sensitive methods such as the inductively coupled plasma mass spectrometer (ICP-MS). The geology department recently acquired a Thermo Scientific XSERIES ICP-MS, so an arsenic analysis method was developed in preparation for the research conducted in this study. The ICP-MS, however, only measures total arsenic concentration. As this study focused on the oxidation state of arsenic, an alternative means for determining oxidation state was developed. As(V)-selective cartridges were used to adsorb arsenate, while letting arsenite run through. This method was checked for effectiveness and used to determine aqueous arsenic oxidation state. X-ray absorption spectroscopy (XAS) was used to determine the oxidation state of arsenic adsorbed onto the surface of iron oxide.

    Goethite (α-FeOOH) and magnetite (Fe3O4) are both known to strongly adsorb arsenic. In this work, the potential for As(III) oxidation and As(V) reduction by goethite was studied. As documented by Amstaetter et al., there was some evidence for adsorbed As(III) oxidation by an Fe(II)/goethite system. This study, however, also showed some evidence for oxidation of adsorbed arsenite in the presence of goethite alone. As(V) reduction by magnetite was also studied. Magnetite is capable of having different stoichiometries, or ratios of Fe(II) to Fe(III). Both an oxidized, x=0.27, and a near-stoichiometric, x=0.49, magnetite were studied for their ability to reduce arsenate. There was no evidence for As(V) reduction in the aqueous or adsorbed phase for either system.


    CHEEC Project:

    Citation:

    Brown, Angela Meagan. "Arsenic speciation in the presence of anoxic mixed valent iron systems." MS (Master of Science) thesis, University of Iowa, 2010. https://doi.org/10.17077/etd.28kafekx

  • Friday, June 30, 2006

    Surface acoustic wave (SAW) microsensor array for measuring VOCs in drinking water

    Author(s):
    W. A. Groves
    A. B. Grey
    P. T. O’Shaughnessy

    Journal Title:
    Journal of Environmental Monitoring

    Abstract:

    Exposure to volatile organic chemicals (VOCs) in drinking water has been linked to a number of adverse health effects including cancer, liver, and kidney damage. However, the large number of potential contaminants and the cost and complexity of existing analytical methods limits the extent to which water quality is routinely characterized. This project focused on the laboratory development and evaluation of an instrument for field analysis of VOCs in drinking water. The instrument is based on an array of six polymer-coated surface-acoustic-wave microsensors. A test-set consisting of dichloromethane, chloroform, 1,1,1-trichloroethane, perchloroethylene, and m-xylene was used in a series of experiments designed to optimize the purge–trap preconcentration system, calibrate the instrument over the concentration range of 0.2–2 times the USEPA maximum contaminant levels (MCLs), and compare results to those of a reference laboratory. The primary goal was to develop a cost-effective alternative for on-site evaluation of VOCs in water. Calibration and evaluation test results for spiked water samples demonstrate adequate sensitivity for 19 of the 21 regulated VOCs considered using a ten minute sampling and analysis cycle. Monte Carlo simulations characterized the performance of trained artificial neural networks (ANNs) which had correct classification rates of 99%, 90%, and 80% for the five individual test-set vapors and their binary and ternary mixtures, respectively. These results demonstrate the excellent potential of this technology for addressing the need for improved VOC field-screening methods for water supplies.


    CHEEC Project:

    Citation:

    Groves, W. A., A. B. Grey, and P. T. O’shaughnessy. "Surface acoustic wave (SAW) microsensor array for measuring VOCs in drinking water." Journal of Environmental Monitoring 8, no. 9 (2006): 932-941.

     

  • Saturday, May 5, 2007

    Mass Balance of Metolachlor in a Grassed Phytoremediation System

    Author(s):
    Keri L. Henderson
    Jason B. Belden
    Joel R. Coats

    Journal Title:
    Environmental Science and Technology

    Abstract:

    Metolachlor is a point-source pollutant at agrochemical dealerships in the Midwest, as well as a non point-source contaminant of surface waters caused by runoff. Prairie grasses have been used in filter strips to control runoff and are also useful for phytoremediation; however, little is known about the fate of metolachlor and its metabolites within a grassed system. Effects of uptake by prairie grasses on the formation and fate of degradation products are not known. In this study, [U-ring-14C]metolachlor was added to enclosed systems to determine the fate of the parent compound and its metabolites in soil and plants. Mineralization and volatilization were monitored over the 97 day study and found to be 1.05 and 0.2%, respectively, for vegetated systems. At the end of the study, soil and plant material was evaluated for the presence of parent metolachlor and selected metabolites, as well as bound residues. Metolachlor ethane sulfonic acid was the dominant metabolite in soil and plant tissue. Over 7% of applied radioactivity was taken up by the grasses, and plant uptake/metabolism appeared to be the main mechanism for phytoremediation of metolachlor. Vegetation significantly reduced the amount of metolachlor in soil by 9%, indicating potential success as a remediation tool.


    CHEEC Project:

    Citation:

    Henderson, Keri L., Jason B. Belden, and Joel R. Coats. "Mass balance of metolachlor in a grassed phytoremediation system." Environmental science & technology 41, no. 11 (2007): 4084-4089.

     

  • Saturday, July 21, 2007

    Passive sampling of ambient coarse particulate matter, PM(10-2.5)

    Author(s):
    Darrin K. Ott

    Journal Title:
    PhD Thesis

    Abstract:

    This effort serves to improve the protection of the public from airborne PM10-2.5 by aiding in the recognition of the hazard and in its prevention by improving exposure assessment. Recognizing that the spatial variability o f ambient coarse particulate matter, PM10-2.5, has limited researcher’s ability to properly and convincingly determine its health effects with current exposure assessment capabilities, the overall goal o f this study was to create a novel approach to PM 10-2.5 sampling that would capture this important characteristic.

    To achieve this goal, a passive particulate sampler, already described for use indoors, was modified for ambient use and tested to establish performance criteria.  Modifications included optical microscopy for analysis and simpler strategies to determine the values of particle shape factors that alter calculated results. The method had a CV of 11.6% in the field study. The samplers also had a Pearson correlation coefficient of 0.97 with dichotomous samplers in the field and a ratio of passive sampler to the dichotomous samplers of 1.29. The limit of detection for a seven-day sample, based on the degree of contamination on the blanks was 1.7 pg/m . Since the passive sampler was to be protected from precipitation by a shelter, wind induced turbulent deposition as a source of error was a concern. An investigation of turbulent deposition was performed by testing various shelter designs in a wind tunnel. Shelters that caused turbulence near the airflow entry point also caused the particles, especially the larger ones, to deposit at a much higher rate and overestimate PM10-2.5 mass concentration.

    A shelter, with the passive sampler set between two parallel flat plates, was chosen for implementation as it had little effect on deposition at various wind speeds.  The sheltered passive samplers were used in the field to characterize PM 10-2.5 variability across a Midwestern city. PM 10-2.5 concentrations in the city were found to he spatially non-uniform, CV’s > 20%, minimum R was 0.37 and the maximum coefficient of divergence was 0.36 among the 33 sites, with notable spatial trends further supporting the need for this highly spatially resolved sampling technique.


    CHEEC Project:

    Citation:

    Ott, Darrin Kohl. Passive sampling of ambient coarse particulate matter, PM (10-2.5). The University of Iowa, 2007.

     

  • Wednesday, November 7, 2007

    Nanocrystalline Zeolites and Zeolite Structures:  Synthesis, Characterization, and Applications

    Author(s):
    Sarah C. Larsen

    Journal Title:
    The Journal of Physical Chemistry C

    Abstract:

    Nanocrystalline zeolites are porous nanomaterials with crystal sizes of less than 100 nm that possess unique external and internal surface reactivity. Nanocrystalline zeolites, such as silicalite, ZSM-5 and Y, were synthesized and extensively characterized by powder X-ray diffraction, nitrogen adsorption isotherms, dynamic light scattering, and electron microscopy. Spectroscopic characterization of the nanocrystalline zeolites by FTIR and solid-state NMR provided detailed structural information about internal and external surface sites. The nanocrystalline zeolites were also used as building blocks to form larger, hollow zeolite structures with encapsulated metal or organic species. The surface properties of nanocrystalline zeolites and hollow zeolite structures were tailored through functionalization of surface silanol groups. Applications of nanocrystalline zeolites and zeolite structures in the selective catalytic reduction of NOx and the photoreduction of Cr(VI) to Cr(III) in aqueous solution were investigated. The unique properties and reactivity of nanocrystalline zeolites and the potential for future applications of these materials will also be discussed.


    CHEEC Project:

    Citation:

    Larsen, Sarah C. "Nanocrystalline zeolites and zeolite structures: synthesis, characterization, and applications." The Journal of Physical Chemistry C 111, no. 50 (2007): 18464-18474.

     

     

  • Saturday, March 15, 2008

    Identification of Tylosin Photoreaction Products and Comparison of ELISA and HPLC Methods for Their Detection in Water

    Author(s):
    Dingfei Hu
    Bruce Fulton
    Keri Henderson
    Joel Coats

    Journal Title:
    Environmental Science and Technology

    Abstract:

    Tylosin is a widely used macrolide antibiotic for therapeutics and growth promotion in swine, beef cattle, and poultry production. Through various routes such as manure application, emission, inappropriate disposal, etc., tylosin enters the environment. The fate of tylosin in the environment is not yet fully understood. In this study, two photoreaction products of tylosin in water were identified as isotylosin A alcohol (E,Z) and isotylosin A aldol (E,Z). Tylosin A, B, C, D, isotylosin A alcohol, and isotylosin A aldol were purified, and immunological cross-reactivities of these tylosin-related compounds were tested with a specificity of 26% for tylosin B, 19% for tylosin C, 106% for tylosin D, 121% for isotylosin A alcohol, and 46% for isotylosin A aldol, compared to 100% for tylosin A. Competitive direct enzyme-linked immunosorbent assay (ELISA) for tylosin detection in water was compared with a high-performance liquid chromatography (HPLC) method by analyzing the same water samples from a study of tylosin dissipation in water. ELISA kits detect the other tylosin-related compounds besides tylosin A, which can result in differences in tylosin determination in water.


    CHEEC Project:

    Citation:

    Hu, Dingfei, Bruce Fulton, Keri Henderson, and Joel Coats. "Identification of tylosin photoreaction products and comparison of ELISA and HPLC methods for their detection in water." Environmental science & technology 42, no. 8 (2008): 2982-2987.

     

  • Friday, October 31, 2008

    Supercritical fluid extraction of aflatoxin B1 from soil

    Author(s):
    James M. Starr
    Mustafa I. Selim

    Journal Title:
    Journal of Chromatography A

    Abstract:

    This research describes the development of a supercritical fluid extraction (SFE) method to recover aflatoxin B1 from fortified soil. The effects of temperature, pressure, modifier (identity and percentage), and extraction type were assessed. Using the optimized SFE conditions, the mean recovery from air dried soil was 72%. The variables associated with changes in recovery of aflatoxin were co-solvents, static extraction, and temperature. Acetonitrile–2% acetic acid, used both in-cell and on-line, provided the most efficient recovery. The results indicate that desorption from the soil was the limiting factor in recovery and that the static phase was more important than the dynamic.

     


    CHEEC Project:

    Citation:

    Starr, James M., and Mustafa I. Selim. "Supercritical fluid extraction of aflatoxin B1 from soil." Journal of Chromatography A 1209, no. 1-2 (2008): 37-43.

     

  • Thursday, October 1, 2009

    Subacute exposure to N-ethyl perfluorooctanesulfonamidoethanol results in the formation of perfluorooctanesulfonate and alters superoxide dismutase activity in female rats

    Author(s):
    Wei Xie
    Qian Wu
    Izabela Kania-Korwel
    Job C. Tharappel
    Sanjay Telu
    Mitchell C. Coleman
    Howard P. Glauert
    Kurunthachalam Kannan
    S.V.S. Mariappan
    Douglas R. Spitz
    Jamie Weydert
    Hans-Joachim Lehmler

    Journal Title:
    Archives of Toxicology

    Abstract:

    Perfluorooctanesulfonamides, such as N-ethyl perfluorooctanesulfonamidoethanol (N-EtFOSE), are large scale industrial chemicals but their disposition and toxicity are poorly understood despite significant human exposure. The hypothesis that subacute exposure to N-EtFOSE, a weak peroxisome proliferator, causes a redox imbalance in vivo was tested using the known peroxisome proliferator, ciprofibrate, as a positive control. Female Sprague–Dawley rats were treated orally with N-EtFOSE, ciprofibrate or corn oil (vehicle) for 21 days, and levels of N-EtFOSE and its metabolites as well as markers of peroxisome proliferation and oxidative stress were assessed in serum, liver and/or uterus. The N-EtFOSE metabolite profile in liver and serum was in good agreement with reported in vitro biotransformation pathways in rats and the metabolite levels decreasing in the order perfluorooctanesulfonate ≫ perfluorooctanesulfonamide ~ N-ethyl perfluorooctanesulfonamidoacetate ≫ perfluorooctanesulfonamidoethanol ~ N-EtFOSE. Although N-EtFOSE treatment significantly decreased the growth rate, increased relative liver weight and activity of superoxide dismutases (SOD) in liver and uterus (total SOD, CuZnSOD and MnSOD), a metabolic study revealed no differences in the metabolome in serum from N-EtFOSE-treated and control animals. Ciprofibrate treatment increased liver weight and peroxisomal acyl Co-A oxidase activity in the liver and altered antioxidant enzyme activities in the uterus and liver. According to NMR metabolomic studies, ciprofibrate treated animals had altered serum lipid profiles compared to N-EtFOSE-treated and control animals, whereas putative markers of peroxisome proliferation in serum were not affected. Overall, this study demonstrates the biotransformation of N-EtFOSE to PFOS in rats that is accompanied by N-EtFOSE-induced alterations in antioxidant enzyme activity.


    CHEEC Project:

    Citation:

    Xie, Wei, Qian Wu, Izabela Kania-Korwel, Job C. Tharappel, Sanjay Telu, Mitchell C. Coleman, Howard P. Glauert et al. "Subacute exposure to N-ethyl perfluorooctanesulfonamidoethanol results in the formation of perfluorooctanesulfonate and alters superoxide dismutase activity in female rats." Archives of toxicology 83, no. 10 (2009): 909-924.

     

  • Tuesday, January 24, 2012

    An Optimal Spatial Configuration of Sample Sites for Air Pollution Monitoring

    Author(s):
    Naresh Kumar
    Veronica Nixon
    Kaushik Sinha
    Xiaosen Jiang
    Sarah Ziegenhorn
    Thomas Peters

    Journal Title:
    Journal of the Air and Waste Management Association

    Abstract:

    A novel sampling design is proposed that optimizes the spatial configuration of sampling sites and captures maximum intraurban variability in ambient air pollution with a minimum sample size. Unlike the classical sampling design, a deterministic approach is adopted and the redundancy in the site selection is minimized by controlling for spatial autocorrelation. The proposed design was tested and implemented in a medium-sized midwestern city. The analysis suggested that 32 sites were adequate to capture more than 95% of the total variance in airborne particulate 10 µm or less in aerodynamic diameter (PM10). A list of 20 households was prepared around each of the 32 sites. Households were approached in order of their distance from these sites until one was recruited for intensive indoor and outdoor air pollution monitoring from spring through fall of 2008. Finally, 30 households located around the optimal sites participated in the study. One set of four photometric and gravimetric samplers was deployed for each indoor and outdoor environment. The average ambient PM10 concentration (monitored from April to September 2008) at the selected locations was lower but statistically insignificant as compared with the PM10 (computed using the data from mobile sampling in 2006) at the optimal sites.


    CHEEC Project:

    Citation:

    Kumar, Naresh, Veronica Nixon, Kaushik Sinha, Xiaosen Jiang, Sarah Ziegenhorn, and Thomas Peters. "An optimal spatial configuration of sample sites for air pollution monitoring." Journal of the Air & Waste Management Association 59, no. 11 (2009): 1308-1316.

     

  • Monday, March 23, 2009

    Synthetic Musk Fragrances in a Conventional Drinking Water Treatment Plant with Lime Softening

    Author(s):
    William D. Wombacher
    Keri C. Hornbuckle

    Journal Title:
    Journal of Environmental Engineering

    Abstract:

    Synthetic musk fragrances are common personal care product additives and wastewater contaminants that are routinely detected in the environment. This study examines the presence of eight synthetic musk fragrances [7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), 1,3,4,6,7,8-hexahydro-4,6,6,7,8-hexamethylcyclopenta-γ γγ -2-benzopyran (HHCB), 5-acetyl-1,1,2,6-tetramethyl-3-iso-propylindane (ATII), 4-acetyl-1,1-dimethyl-6-tert-butylindane (ADBI), 6-acetyl-1,1,2,3,3,5-hexamethylindane (AHMI), 6,7-dihydro-1,1,2,3,3,-pentamethyl-4-(5H)-indanone (DPMI), 1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene (musk xylene), and 4-tert-butyl-3,5-dinitro-2,6-dimethylacetophenone (musk ketone)] in source water and the removal of these compounds as they flow through a Midwestern conventional drinking water plant with lime softening. The compounds were measured in water, waste sludge, and air throughout the plant. HHCB and AHTN were detected in 100% of the samples and at the highest concentrations. A mass balance on HHCB and AHTN was performed under warm and cold weather conditions. The total removal efficiency for HHCB and AHTN, which averaged between 67–89%, is dominated by adsorption to water softener sludge and its consequent removal by sludge wasting and media filtration. Volatilization, chlorine disinfection, and the disposal of backwash water play a minor role in the removal of both compounds. As a result of inefficient overall removal, HHCB and AHTN are a constant presence at low levels in finished drinking water.


    CHEEC Project:

    Citation:

    Wombacher, William D., and Keri C. Hornbuckle. "Synthetic musk fragrances in a conventional drinking water treatment plant with lime softening." Journal of Environmental Engineering 135, no. 11 (2009): 1192-1198.

     

  • Thursday, March 6, 2008

    Reduction of Lead Oxide (PbO2) by Iodide and Formation of Iodoform in the PbO2/I−/NOM System

    Author(s):
    Yi-Pin Lin
    Michael P. Washburn
    Richard L. Valentine

    Journal Title:
    Environmental Science and Technology

    Abstract:

    Lead oxide (PbO2) can be an important form of lead mineral scale occurring in some water distribution systems. It is believed to be formed by the oxidation of lead-containing plumbing materials by free chlorine. Its reactivity in water, however, has not been well studied. Iodide is also found in source drinking waters, albeit at low concentrations. Consideration of thermodynamics suggests that iodide can be oxidized by PbO2. In this investigation, iodide ion was used as a probe compound to study the reduction of PbO2 and the formation of iodoform, which has been predicted to be a carcinogen, in the presence of natural organic matter (NOM). The reduction of PbO2 by iodide can be expressed as PbO2 + 3I + 4H+ → Pb2+ + I3 + 2H2O, and the reaction kinetics has been determined in this study. In the presence of NOM, I3 reacts with NOM to form iodoform and its concentration is proportional to the NOM concentration. Our results indicate that PbO2 is a very powerful oxidant and can possibly serve as an oxidant reservoir for the formation of iodinated disinfection byproduct through a novel reaction pathway.


    CHEEC Project:

    Citation:

    Lin, Yi-Pin, Michael P. Washburn, and Richard L. Valentine. "Reduction of lead oxide (PbO2) by iodide and formation of iodoform in the PbO2/I−/NOM system." Environmental science & technology 42, no. 8 (2008): 2919-2924.

  • Sunday, December 20, 2009

    Environmental fate and chemistry of a veterinary antibiotic—tylosin

    Author(s):
    Dingfei Hu
    Keri D. Henderson
    Joel R. Coats

    Journal Title:
    Entomology Publications

    Abstract:

    Aerobic degradation, photolysis, and mobility of tylosin were investigated in the laboratory. Tylosin A is degraded with a half-life of 200 d in water, while it is stable in the dark. Tylosin C and D are relatively stable except in ultrapure water in the light. Slight increases of tylosin B and formation of two photoreaction products, isotylosin A alcohol (E,Z) and isotylosin A aldol (E,Z), were observed under exposure to light. In soil tylosin A and D has a dissipation half-life of about 1 wk. Sorption and abiotic degradation are the major factors influencing the loss of tylosin in the environment. No biotic degradation was observed at the test concentration of 50 μg/ml or μg/g either in pond water or in an agronomic soil, as determined by comparing dissipation profiles in sterilized and unsterilized conditions. At 7.5 ng/ml, biotransformation may play an important role in degradation of tylosin in water. Tylosin has strong sorption to various soils, and leachbility is dependent on soil properties and manure amendment. Adsorbed tylosin in surface soil might run off to water bodies through soil erosion. In the end, pathways were proposed for tylosin degradation in the environment.


    CHEEC Project:

    Citation:

    Hu, Dingfei, Keri LD Henderson, and Joel R. Coats. "Environmental fate and chemistry of a veterinary antibiotic—tylosin." (2009): 93.

  • Tuesday, January 1, 2008

    Impact of veterinary antibiotics in the environment

    Author(s):
    Keri Lynn Deppe Henderson

    Journal Title:
    PhD Thesis

    Abstract:

    The focus of this dissertation is assessment of the potential impact of livestock production practices on terrestrial and aquatic ecosystems by studying the environmental fate and effects of two classes of veterinary antibiotics: macrolides (represented by tylosin) and sulfonamides (represented by sulfamethazine). These antibiotics are widely used in livestock production for disease treatment and prevention, as well as growth promotion. Each has also been widely detected in surface waters in the U.S. The work presented utilized laboratory experiments to study the fate (mobility, dissipation, binding,
    and degradation) in soil columns and aquatic microcosms, and bioavailability to benthic invertebrates. Additionally, methodologies were developed for using a passive sampling, or biomimetic, device to estimate bioavailability in aquatic ecosystems. Results suggest the potential persistence of some antibiotic residues in sediments, and the level of bioaccumulation in Lumbriculus variegatus, an aquatic oligochaete, indicates that uptake by sediment-dwelling invertebrates may be a concern.


    CHEEC Project:

    Citation:

    Henderson, Keri Lynn Deppe, "Impact of veterinary antibiotics in the environment" (2008). Retrospective Theses and Dissertations. 15662. https://lib.dr.iastate.edu/rtd/15662 

  • Wednesday, June 23, 2010

    Nanoparticle Dissolution from the Particle Perspective: Insights from Particle Sizing Measurements

    Author(s):
    Sherrie Elzey
    Vicki H. Grassian

    Abstract:

    In this study, the dissolution of copper nanoparticles in aqueous low-pH suspensions is examined. The dissolution phenomenon is examined using both bulk measurements of copper ion production, as detected by inductively coupled plasma-optical emission spectroscopy (ICP/OES), and a decrease in nanoparticle size using particle-sizing instruments. For size measurements, an electrospray atomizer coupled to a scanning mobility particle sizer (ES-SMPS) was used to monitor changes in the particle size distribution (PSD) of the copper nanoparticles as they dissolved in hydrochloric acid solution in real time. Measured PSDs show interesting changes during the dissolution process, including a change in modality (mono to multi) with time. Although there may be several causes for the observed modality changes upon dissolution, it is clear that only through direct measurements of nanoparticles and nanoparticle PSDs can these dynamic details be captured as these particles change size, thus providing important insights into nanoscale processes.


    CHEEC Project:

    Citation:

    Elzey, Sherrie, and Vicki H. Grassian. "Nanoparticle dissolution from the particle perspective: insights from particle sizing measurements." Langmuir 26, no. 15 (2010): 12505-12508.

     

     

  • Friday, January 21, 2011

    Formation of paratacamite nanomaterials via the conversion of aged and oxidized copper nanoparticles in hydrochloric acidic media

    Author(s):
    Sherrie Elzey
    Jonas Baltrusaitis
    Shaowei Bian
    Vicki H. Grassian

    Journal Title:
    Journal of Materials Chemistry

    Abstract:

    Nanoparticles and nanostructured aggregates of paratacamite are prepared in acidic solutions through the conversion of copper-based nanoparticles. Aged and oxidized copper nanoparticles with an average primary particle size of ∼15 nm, when combined with hydrochloric acid solutions in the range of 0.025 to 0.1 M, show interesting behavior yielding both a change in nanoparticle primary size, as measured by an electrospray scanning mobility particle sizer, and in chemical composition to produce a copper chloride hydroxide mineral identified as paratacamite (γ-Cu2(OH)3Cl) by powder X-ray diffraction of the dehydrated solid sample. Taken together, these data suggest that paratacamite nanoparticles in solution can aggregate to yield microporous paratacamite materials. Microporous paratacamite was characterized by several techniques including X-ray diffraction, transmission electron microscopy, energy dispersive X-ray analysis, electron energy loss spectroscopy, X-ray photoelectron spectroscopy and surface area measurements. Oxidation of these copper-based nanoparticles with molecular oxygen and the role of the oxidized layer in the formation of paratacamite have been investigated. Comparison to microscale copper particles showed there is unique oxidation behavior of nanoscale copper particles that results in unique reaction chemistry of oxidized nanoscale copper particles with hydrochloric acid solutions to form paratacamite. This study provides a new route for the formation of paratacamite nanomaterials that can be used in a wide range of chemically interesting applications including hydrogen storage materials and as a heterogeneous catalyst for the synthesis of green solvents such as dimethyl and diethyl carbonates. Additionally, this study suggests a potentially new pathway for the degradation of art objects and ancient artifacts as well as other cultural heritage materials containing small copper particles that has not been previously considered.


    CHEEC Project:

    Citation:

    Elzey, Sherrie, Jonas Baltrusaitis, Shaowei Bian, and Vicki H. Grassian. "Formation of paratacamite nanomaterials via the conversion of aged and oxidized copper nanoparticles in hydrochloric acidic media." Journal of Materials Chemistry 21, no. 9 (2011): 3162-3169.

  • Friday, July 1, 2011

    Slow Disease Progression in a C57BL/6 Pten-Deficient Mouse Model of Prostate Cancer

    Author(s):
    Robert U. Svensson
    Jessica M. Haverkamp
    Daniel R. Thedens
    Michael B. Cohen
    Timothy L. Ratliff
    Michael D. Henry

    Journal Title:
    The American Journal of Pathology

    Abstract:

    Prostate-specific deletion of Pten in mice has been reported to recapitulate histological progression of human prostate cancer. To improve on this model, we introduced the conditional ROSA26 luciferase reporter allele to monitor prostate cancer progression via bioluminescence imaging and extensively backcrossed mice onto the albino C57BL/6 genetic background to address variability in tumor kinetics and to enhance imaging sensitivity. Bioluminescence signal increased rapidly in Ptenp -/- mice from 3 to 11 weeks, but was much slower from 11 to 52 weeks.  Changes in bioluminescence signal were correlated with epithelial proliferation. Magnetic resonance imaging revealed progressive increases in prostate volume, which were attributed to excessive fluid retention in the anterior prostate and to expansion of the stroma. Development of invasive prostate cancer in 52-week-old Ptenp -/-  mice was rare, indicating that disease progression was slowed relative to that in previous reports. Tumors in these mice exhibited a spontaneous inflammatory phenotype and were rapidly infiltrated by myeloid-derived suppressor cells.  Although Ptenp -/-  tumors responded to androgen withdrawal, they failed to exhibit relapsed growth for up to 1 year. Taken together, these data identify a mild prostate cancer phenotype in C57BL/6 prostate-specific Pten-deficient mice, reflecting effects of the C57BL/6 genetic background on cancer progression.  This model provides a platform for noninvasive assessment of how genetic and environmental risk factors may affect disease progression.


    CHEEC Project:

    Citation:

    Svensson, Robert U., Jessica M. Haverkamp, Daniel R. Thedens, Michael B. Cohen, Timothy L. Ratliff, and Michael D. Henry. "Slow disease progression in a C57BL/6 pten-deficient mouse model of prostate cancer." The American journal of pathology 179, no. 1 (2011): 502-512.

  • Tuesday, May 22, 2012

    Immunomodulatory Effect Of A Glucan Derivative In Lung Inflammation

    Author(s):
    N. Metwali
    S. Hadina
    P.S. Thorne

    Journal Title:
    Poster - American Thoracic Society

    Abstract:

    Rationale: β-D-Glucans are fungal cell wall polysaccharides that stimulate innate immune responses and are responsible for bioaerosol-induced respiratory symptoms in both indoor and occupational environments.

    Methods: C3HeB/FeJ mice were exposed to pustulan (1®6)-β-D-linear glucan in the scheme shown in the Table below. At days 0 and 7 mice were injected intraperitoneally (i.p.) with bovine serum albumin conjugates (pustulan-BSA) with an adjuvant (25μg/ml of pustulan emulsified with 1mg/ml of alum in saline) or saline with/without alum. Negative control mice were injected with saline or alum. At days 14-16, 21-23, and 28-30 mice were challenged intranasally (i.n.) with pustulan (25 μg/mouse in 50μl). Control mice received saline.  Inflammation induced by pustulan was evaluated at day 31 by lung histology and evaluation of bronchoalveolar lavage fluid (BALF).

    Results: Lung histology showed the highest degree of inflammation in mice pretreated with pustulan-BSA conjugate and i.n.-exposed to pustulan. Total BALF cells and cell types, are summarized below. Alum injection followed by pustulan or saline instillation produced an influx of monocytic cells to the lung. Pustulan instillation following saline injection also induced recruitment of monocytes. Significant neutrophilic influx was seen in all mice exposed to i.n. pustulan.

    Conclusion: Pre-exposure to pustulan-protein conjugate is necessary for induction of neutrophilic inflammation upon inhalation of pustulan in mice.


    CHEEC Project:

    Citation:

    Metwali, Nervana, Suzana Hadina, and Peter S. Thorne.  "Immunomodulatory Effect of a Glucan Derivative In Lung Inflammation."  In C31.  Regulation of Lung Inflammation, pp. A4152-A4152.  American Thoracic Society, 2012.

     

  • Tuesday, May 22, 2012

    Coal Fly Ash Induces Bacterial Growth And Virulence And Inhibits Antimicrobial Peptide Activity

    Author(s):
    J. Borcherding
    J. Caraballo
    H. Chen
    L. Stebounova
    A. Pezzulo
    J. Zabner
    V. Grassian
    A.Comellas

    Journal Title:
    Poster - American Thoracic Society

    Abstract:

    Background: Coal Fly Ash (CFA) is a byproduct of coal combustion and is a potential source of iron released into the atmosphere. Iron is a key nutrient for bacterial growth and virulence. Airway surface liquid has different mechanisms to lower iron to prevent bacterial
    colonization and infection. Since air pollution is correlated with increases in respiratory infections, we hypothesize that iron content in CFA will induce an increase in bacterial growth and virulence and inhibit antimicrobial peptide activity (AMP).

    Methods: P. Aeruginosa strain, PAO1 cultures were grown in iron depleted media (M9), CFA from various sources (10μg/mL), and aluminum oxide particles (Al2O3). Growth was measured by recording OD600. In order to test virulence, Drosophila Melanogaster was poked with PAO1 with or without 10μg/mL CFA and survival was recorded over time. CFA was also incubated with pysiologically relevant concentrations of AMPs in the airway surface liquid (lysozyme, lactoferrin and β-Defensins 1 & 2) and combined with bacteria. Growth was recorded to determine AMP activity.

    Results: After eight hours, PAO1 cultures in the presence of CFA grew more than PAO1 in the absence of iron (Al2O3). CFA also decreased survival in a Drosophila model of virulence when compared with control conditions (M9 alone and Al2O3). When incubated with physiologically relevant concentrations of AMPs, CFA inhibited AMP activity.

    Conclusion: This study provides clear evidence that CFA is a potential source of iron for bacterial growth and virulence and inhibits AMP activity. These results provide a mechanism by which ambient particulate matter increases the risk of respiratory infections.


    CHEEC Project:

    Citation:

    Borcherding, Jennifer, Juan Carlos Caraballo, Haihan Chen, Larissa Stebounova, Alejandro Pezzulo, Joseph Zabner, Vicki H. Grassian, and Alejandro P. Comellas. "Coal Fly Ash Induces Bacterial Growth And Virulence And Inhibits Antimicrobial Peptide Activity." In C58. ENVIRONMENTAL EXPOSURES: MECHANISMS, pp. A4672-A4672. American Thoracic Society, 2012.

  • Sunday, May 15, 2011

    Particulate Matter Induces Bacterial Growth

    Author(s):
    J. Borcherding
    J.C. Caraballo
    H. Chan
    L. Stebounova
    A.A. Pezzulo
    V. Grassian
    J. Zabner
    A.P. Comellas

    Journal Title:
    Poster - American Thoracic Society

    Abstract:

    Rationale: Iron induces growth in bacteria such as P. Aeruginosa. This is the most abundant transition metal in ambient particulate matter (PM). Since it has been reported that air pollution increases chronic obstructive pulmonary disease (COPD) exacerbations, we hypothesize that iron content in PM will induce an increase in bacterial growth.

    Methods: P. Aeruginosa strain, PAO1 cultures were grown in the presence of different iron-containing particles and iron chelators. More specifically, iron-containing particles of various sizes, composition and iron solubility were used. These included alpha and gamma Fe2O3, metallic iron nanoparticles, Fly Ash and various iron chelators such as lactoferrin. Growth was observed over time by sampling cultures and determining colony forming units (cfu).

    Results: After six hours, PAO1 cultures in the presence of iron-containing particles grew one log more than PAO1 in the presence of particles without iron. Iron chelation prevented the iron-containing particles from induced PAO1 growth increase. Furthermore, smaller iron-containing particles induced greater increased growth in PAO1 compared to larger particles

    Conclusion: This study provides clear evidence that PM is a potential source of iron for bacteria. In addition, it seems that particle size affects the PM induced bacterial growth. These results are significant since 75% of COPD exacerbations are considered bacterial and they show that PM is a potential source of iron for bacterial growth.


    CHEEC Project:

    Citation:

    Borcherding, Jennifer, Juan C. Caraballo, Haihan Chan, Larissa Stebounova, Alejandro A. Pezzulo, Vicki Grassian, Joseph Zabner, and Alejandro P. Comellas. "Particulate Matter Induces Bacterial Growth." In A36. EARLY EXPOSURES AND ENVIRONMENTAL EXPOSURES THAT INFLUENCE ALLERGY AND LUNG DISEASE, pp. A1416-A1416. American Thoracic Society, 2011.

  • Tuesday, January 1, 2013

    Cellular effects of metolachlor exposure on human liver (HepG2) cells

    Author(s):
    Sean Hartnett
    Sadiatu Musah
    Kavita R. Dhanwada

    Journal Title:
    Chemosphere

    Abstract:

    Metolachlor is one of the most commonly used herbicides in the United States. Protein synthesis is inhibited when roots and shoots of susceptible plants absorb this synthetic herbicide. While quite effective in killing weeds, several studies have shown that exposure to metolachlor results in decreased cell proliferation, growth and reproductive ability of non-target organisms. However, the mode of metolachlor action in non-target organisms has not yet been elucidated. The current study assessed effects of metolachlor exposure on immortalized human liver (HepG2) cells. Results from cell proliferation assays showed that a 72-h exposure to 50 parts per billion (ppb) metolachlor significantly inhibited growth of these cells compared to untreated controls while a decrease in the cell division rate required exposure to 500 ppb metolachlor for 48 h. Flow cytometry analysis of cell cycle distribution revealed that 500 ppb metolachlor treatment resulted in fewer HepG2 cells in G2/M phase after 72 h. Real-time PCR analysis showed a significant decrease in the abundance of the cyclin A transcripts after 12 h in cells exposed to 300 ppb metolachlor. These results suggest metolachlor may affect progression through the S phase of the cell cycle and entrance into the G2 phase.


    CHEEC Project:

    Citation:

    Hartnett, Sean, Sadiatu Musah, and Kavita R. Dhanwada. "Cellular effects of metolachlor exposure on human liver (HepG2) cells." Chemosphere 90, no. 3 (2013): 1258-1266.

  • Wednesday, December 5, 2012

    Low concentrations of negatively charged sub-micron particles alter the microstructure of DPPC at the air–water interface

    Author(s):
    Amir M. Farnoud
    Jennifer Fiegel

    Journal Title:
    Colloids and Surfaces A: Physicochemical and Engineering Aspects

    Abstract:

    The function of dipalmitoyl phosphatidylcholine (DPPC) Langmuir monolayers was studied after exposure to various concentrations of 200 nm carboxyl-modified polystyrene particles by a combination of surface pressure and surfactant microstructure studies. The presence of particles in the subphase at the lowest concentrations tested (10−5 to 10−4 g/L) did not influence the πA isotherms. However, at the highest concentration (10−3 g/L), changes in the hysteresis areas of the isotherms were observed. The formation of LC domains during compression was significantly altered by the presence of the particles, resulting in the formation of smaller but more numerous domains. Fluorescence and atomic force microscopy images suggested that particles remained in the subphase but were closely associated with the condensed domains.


    CHEEC Project:

    Citation:

    Farnoud, Amir M., and Jennifer Fiegel. "Low concentrations of negatively charged sub-micron particles alter the microstructure of DPPC at the air–water interface." Colloids and Surfaces A: Physicochemical and Engineering Aspects415 (2012): 320-327.

  • Thursday, August 1, 2013

    Cyclic siloxanes in air, including identification of high levels in Chicago and distinct diurnal variation

    Author(s):
    Rachel A. Yucuis
    Charles O. Stanier
    Keri C. Hornbuckle

    Journal Title:
    Chemosphere

    Abstract:

    The organosilicon compounds octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) are high production volume chemicals that are widely used in household goods and personal care products. Due to their prevalence and chemical characteristics, cyclic siloxanes are being assessed as possible persistent organic pollutants. D4, D5, and D6 were measured in indoor and outdoor air to quantify and compare siloxane concentrations and compound ratios depending on location type. Indoor air samples had a median concentration of 2200 ng m−3 for the sum of D4, D5, and D6. Outdoor sampling locations included downtown Chicago, Cedar Rapids, IA, and West Branch, IA, and had median sum siloxane levels of 280, 73, and 29 ng m−3respectively. A diurnal trend is apparent in the samples taken in downtown Chicago. Nighttime samples had a median 2.7 times higher on average than daytime samples, which is due, in part, to the fluctuations of the planetary boundary layer. D5 was the dominant siloxane in both indoor and outdoor air. Ratios of D5 to D4 averaged 91 and 3.2 for indoor and outdoor air respectively.


    CHEEC Project:

    Citation:

    Yucuis, Rachel A., Charles O. Stanier, and Keri C. Hornbuckle. "Cyclic siloxanes in air, including identification of high levels in Chicago and distinct diurnal variation." Chemosphere 92, no. 8 (2013): 905-910.

  • Thursday, February 28, 2013

    Coal Fly Ash Impairs Airway Antimicrobial Peptides and Increases Bacterial Growth

    Author(s):
    Jennifer A. Borcherding
    Haihan Chen
    Juan C. Caraballo
    Jonas Baltrusaitis
    Alejandro A. Pezzulo
    Joseph Zabner
    Vicki H. Grassian
    Alejandro P. Comellas

    Journal Title:
    PLOS One

    Abstract:

    Air pollution is a risk factor for respiratory infections, and one of its main components is particulate matter (PM), which is comprised of a number of particles that contain iron, such as coal fly ash (CFA). Since free iron concentrations are extremely low in airway surface liquid (ASL), we hypothesize that CFA impairs antimicrobial peptides (AMP) function and can be a source of iron to bacteria. We tested this hypothesis in vivo by instilling mice with Pseudomonas aeruginosa (PA01) and CFA and determine the percentage of bacterial clearance. In addition, we tested bacterial clearance in cell culture by exposing primary human airway epithelial cells to PA01 and CFA and determining the AMP activity and bacterial growth in vitro. We report that CFA is a bioavailable source of iron for bacteria. We show that CFA interferes with bacterial clearance in vivo and in primary human airway epithelial cultures. Also, we demonstrate that CFA inhibits AMP activity in vitro, which we propose as a mechanism of our cell culture and in vivo results. Furthermore, PA01 uses CFA as an iron source with a direct correlation between CFA iron dissolution and bacterial growth. CFA concentrations used are very relevant to human daily exposures, thus posing a potential public health risk for susceptible subjects. Although CFA provides a source of bioavailable iron for bacteria, not all CFA particles have the same biological effects, and their propensity for iron dissolution is an important factor. CFA impairs lung innate immune mechanisms of bacterial clearance, specifically AMP activity. We expect that identifying the PM mechanisms of respiratory infections will translate into public health policies aimed at controlling, not only concentration of PM exposure, but physicochemical characteristics that will potentially cause respiratory infections in susceptible individuals and populations.


    CHEEC Project:

    Citation:

    Borcherding, Jennifer A., Haihan Chen, Juan C. Caraballo, Jonas Baltrusaitis, Alejandro A. Pezzulo, Joseph Zabner, Vicki H. Grassian, and Alejandro P. Comellas. "Coal fly ash impairs airway antimicrobial peptides and increases bacterial growth." PLoS One 8, no. 2 (2013): e57673.

  • Sunday, August 18, 2013

    Mechanism of metolachlor action due to alterations in cell cycle progression

    Author(s):
    Dana M. Lowry
    Donovan Greiner
    Michelle Fretheim
    Macy Ubben
    Kavita R. Dhanwada

    Journal Title:
    Cell Biology and Toxicology

    Abstract:

    Metolachlor, a commonly used herbicide in the Midwestern USA, functions by inhibiting chlorophyll and protein synthesis in target plants. Herbicide exposure has led to detrimental effects in several organisms, affecting their growth and behavior; however, its mechanism of action in nontarget organisms is not yet clear. The EPA does not currently have enforceable regulations for maximal limits allowed in drinking water. Previous growth studies from our lab have demonstrated that increasing metolachlor concentrations and increasing time of exposure results in decreased growth of liver cells. The objective of this study was to elucidate a mechanism for this decrease of HepG2 cell growth after herbicide exposure. Results show that metolachlor at environmentally relevant levels (50–100 ppb) that previously led to decreased cell number does not lead to cell death by either necrosis or apoptosis. However, it was demonstrated that the levels of the retinoblastoma protein including two of its hyperphosphorylated forms are decreased in metolachlor exposed cells possibly leading to cell cycle arrest. The levels of another protein involved in cell cycle progression, p53, a mediator in the DNA damage response of cells, was not significantly altered except at the highest level of metolachlor (1,000 ppb) and after a 72-h exposure. These results suggest that the decrease in cell number after low-level metolachlor exposure is most likely due to an alteration in the cell cycle and not due to cell death in human liver cells.


    CHEEC Project:

    Citation:

    Lowry, Dana M., Donovan Greiner, Michelle Fretheim, Macy Ubben, and Kavita R. Dhanwada. "Mechanism of metolachlor action due to alterations in cell cycle progression." Cell biology and toxicology 29, no. 4 (2013): 283-291.

  • Wednesday, March 12, 2014

    Chronic Chlorpyrifos Exposure Does Not Promote Prostate Cancer in Prostate Specific PTEN Mutant Mice

    Author(s):
    Robert U. Svensson
    Nadine L. Bannick
    Maximo J. Marin
    Larry W. Robertson
    Charles F. Lynch
    Michael D. Henry

    Journal Title:
    ournal of environmental pathology, toxicology and oncology: official organ of the International Society for Environmental Toxicology and Cancer

    Abstract:

    Environmental factors are likely to interact with genetic determinants to influence prostate cancer progression. The Agricultural Health Study has identified an association between exposure to organophosphorous pesticides including chlorpyrifos, and increased prostate cancer risk in pesticide applicators with a first-degree family history of this disease. Exploration of this potential gene-environment interaction would benefit from the development of a suitable animal model. Utilizing a previously described mouse model that is genetically predisposed to prostate cancer through a prostate-specific heterozygous PTEN deletion, termed C57/Luc/Ptenp+/−, we used bioluminescence imaging and histopathological analyses to test whether chronic exposure to chlorpyrifos in a grain-based diet for 32 weeks was able to promote prostate cancer development. Chronic exposure to chlorpyrifos in the diet did not promote prostate cancer development in C57/Luc/Ptenp+/− mice despite achieving sufficient levels to inhibit acetylcholinesterase activity in plasma. We found no significant differences in numbers of murine prostatic intraepithelial neoplasia lesions or disease progression in chlorpyrifos versus control treated animals up to 32 weeks. The mechanistic basis of pesticide-induced prostate cancer may be complex and may involve other genetic variants, multiple genes, or nongenetic factors that might alter prostate cancer risk during pesticide exposure in agricultural workers.


    CHEEC Project:

    Citation:

    Svensson, Robert U., Nadine L. Bannick, Maximo J. Marin, Larry W. Robertson, Charles F. Lynch, and Michael D. Henry. "Chronic chlorpyrifos exposure does not promote prostate cancer in prostate specific PTEN mutant mice." Journal of environmental pathology, toxicology and oncology: official organ of the International Society for Environmental Toxicology and Cancer 32, no. 1 (2013): 29.

  • Sunday, December 1, 2013

    Detection of silica particles in lung tissue of non-occupationally exposed individuals by computer controlled scanning electron microscopy

    Author(s):
    Kristen Coleman

    Journal Title:
    MS Thesis

    Abstract:

    For years crystalline silica has been recognized as an occupational hazard of the dusty trades with exposures resulting in silicosis. As recently as 1997, IARC categorized the respirable portion of crystalline silica as a Grade 1 human carcinogen indicating that silica may be implicated in the development of lung cancer. Evidence in the literature indicates that silica may be not only an occupational hazard, but an environmental hazard as well, with patients with no known exposure showing measurable quantities of silica within cancerous tissue samples.

    This study aims to establish a methodology using computer-controlled scanning electron microscopy to examine silica content in lung cancer tissue. Furthermore, demonstrating that silica is not evenly distributed within the tissue will establish the need to use automated full scanning techniques, such as CCSEM, in order to guarantee that the analysis is not subject to random sampling error or researcher driven error, which may be rendering the traditional random sampling of zones for analysis under-representative of silica concentration in the tissue.


    CHEEC Project:

    Citation:

    Coleman, Kristen. "Detection of silica particles in lung tissue of non-occupationally exposed individuals by computer controlled scanning electron microscopy." MS (Master of Science) thesis, University of Iowa, 2013. 
    https://doi.org/10.17077/etd.9nt9ofsi

  • Friday, August 23, 2013

    Interaction of Dipalmitoyl Phosphatidylcholine Monolayers with a Particle-Laden Subphase

    Author(s):
    Amir M. Farnoud
    Jennifer Fiegel

    Journal Title:
    The Journal of Physical Chemistry

    Abstract:

    Recent interest in using submicrometer particles for industrial and therapeutic purposes has led to concerns about their interactions with biological membranes. The mechanisms of particle–membrane interactions are not well understood resulting in contradictory reports on the effects of particles on membrane interfacial properties. In this study, the interactions between negatively charged polystyrene particles (200 nm) and monolayers of dipalmitoyl phosphatidylcholine (DPPC) were investigated. Surface pressure, surface potential, and surfactant microstructure studies were conducted to monitor the interfacial properties of DPPC monolayers spread on a subphase in which particles were dispersed. At a concentration of 0.1 g/L, particles caused a partial collapse of the monolayer. DPPC monolayers spread on a particle-laden subphase also exhibited higher surface potential and increased ratio of ordered domains supporting the presence of a more compact monolayer. These results suggest that particles penetrated the air–water interface thereby altering monolayer packing at the interface. These findings are contrary to our previous work where particles injected into the subphase beneath a DPPC monolayer did not penetrate the interface confirming that the sequence of particle and monolayer addition can alter particle–monolayer interactions. These studies may partially explain the varying results reported in previous studies.


    CHEEC Project:

    Citation:

    Farnoud, Amir M., and Jennifer Fiegel. "Interaction of dipalmitoyl phosphatidylcholine monolayers with a particle-laden subphase." The Journal of Physical Chemistry B 117, no. 40 (2013): 12124-12134.

  • Wednesday, May 8, 2019

    Iron oxide nanoparticles induce Pseudomonas aeruginosa growth, induce biofilm formation, and inhibit antimicrobial peptide function

    Author(s):
    Jennifer Borcherding
    Jonas Baltrusaitis
    Haihan Chen
    Larissa Stebounova
    Chia-Ming Wu
    Gayan Rubasinghege
    Imali A. Mudunkotuwa
    Juan Carlos Caraballo
    Joseph Zabner
    Vicki H. Grassian
    Alejandro P. Comellas

    Journal Title:
    Environmental Science: Nano

    Abstract:

    Given the increased use of iron-containing nanoparticles in a number of applications, it is important to understand any effects that iron-containing nanoparticles can have on the environment and human health. Since iron concentrations are extremely low in body fluids, there is potential that iron-containing nanoparticles may influence the ability of bacteria to scavenge iron for growth, affect virulence and inhibit antimicrobial peptide (AMP) function. In this study, Pseudomonas aeruginosa (PA01) and AMPs were exposed to iron oxide nanoparticles, hematite (α-Fe2O3), of different sizes ranging from 2 to 540 nm (2 ± 1, 43 ± 6, 85 ± 25 and 540 ± 90 nm) in diameter. Here we show that the greatest effect on bacterial growth, biofilm formation, and AMP function impairment is found when exposed to the smallest particles. These results are attributed in large part to enhanced dissolution observed for the smallest particles and an increase in the amount of bioavailable iron. Furthermore, AMP function can be additionally impaired by adsorption onto nanoparticle surfaces. In particular, lysozyme readily adsorbs onto the nanoparticle surface which can lead to loss of peptide activity. Thus, this current study shows that co-exposure of nanoparticles and known pathogens can impact host innate immunity. Therefore, it is important that future studies be designed to further understand these types of impacts.


    CHEEC Project:

    Citation:

    Borcherding, Jennifer, Jonas Baltrusaitis, Haihan Chen, Larissa Stebounova, Chia-Ming Wu, Gayan Rubasinghege, Imali A. Mudunkotuwa et al. "Iron oxide nanoparticles induce Pseudomonas aeruginosa growth, induce biofilm formation, and inhibit antimicrobial peptide function." Environmental Science: Nano 1, no. 2 (2014): 123-132.

  • Thursday, April 17, 2014

    Zeolite and mesoporous silica nanomaterials: greener syntheses, environmental applications and biological toxicity

    Author(s):
    Sean E. Lehman
    Sarah C. Larsen

    Journal Title:
    Environmental Science: Nano

    Abstract:

    Zeolites and mesoporous silica nanoparticles are silicate or aluminosilicate nanomaterials with well-defined pore networks. Zeolites are widely used in industry for applications such as catalysis, separations and gas adsorption. Mesoporous silica nanomaterials have not been as extensively applied relative to zeolites due to the cost and reduced thermal stability, but are being intensively investigated for potential environmental and biomedical applications. In this article, zeolite and mesoporous silica nanomaterials are reviewed with emphasis on connections to the environment. Specifically, the topics of greener syntheses, environmental applications and biological toxicity will be addressed. Both of these materials are typically synthesized with a template, which is then removed to produce the pore volume. Synthetic strategies for the “greening” of the syntheses of zeolites and mesoporous silica will be discussed. Environmental applications including the adsorption of environmental contaminants and environmental catalysis will also be presented. Finally, the toxicity of zeolite and mesoporous silica nanomaterials will be considered.


    CHEEC Project:

    Citation:

    Lehman, Sean E., and Sarah C. Larsen. "Zeolite and mesoporous silica nanomaterials: greener syntheses, environmental applications and biological toxicity." Environmental Science: Nano 1, no. 3 (2014): 200-213.

  • Friday, August 15, 2014

    Reach-scale predictions of the fate and transport of contaminants of emerging concern at Fourmile Creek in Ankeny, Iowa

    Author(s):
    Joseph A. Cullin

    Journal Title:
    MS Thesis

    Abstract:

    Contaminants of emerging concern (CECs) are an unregulated suite of constituents frequently detected in environmental waters, which possess the potential to cause a host of reproductive and developmental problems in humans and wildlife. Degradation pathways of several CECs are well-characterized in idealized laboratory settings, but CEC fate and transport in complex field settings is poorly understood. In the present study I use a multi-tracer solute injection to study and quantify physical transport and photodegradation in a wastewater effluent-impacted stream in Ankeny, Iowa. Conservative tracers are used to quantify physical transport processes in the stream. Use of reactive fluorescent tracers allows for isolation of the relative contribution of photodegradation within the system. Field data were used to calibrate a one-dimensional transport model, and forward modeling was then used to predict the transport of sulfamethoxazole, an antibiotic in the effluent which is susceptible to photolysis. Results show that accurate predictions of reactive CECs at the scale of stream reaches can be made using the fate and transport model based on field tracer studies. Results of this study demonstrate a framework that can be used to couple field tracer and laboratory CEC studies to accurately predict the transport and fate of CECs in streams.


    CHEEC Project:

    Citation:

    Cullin, Joseph Albert. "Reach-scale predictions of the fate and transport of contaminants of emerging concern at Fourmile Creek in Ankeny, Iowa." MS (Master of Science) thesis, University of Iowa, 2014. 
    https://doi.org/10.17077/etd.wwrwtj93

  • Thursday, July 2, 2015

    Chemical Insight into the Adsorption of Chromium(III) on Iron Oxide/Mesoporous Silica Nanocomposites

    Author(s):
    Shani Egodawatte
    Ashish Datt
    Eric A. Burns
    Sarah C. Larsen

    Journal Title:
    Langmuir

    Abstract:

    Magnetic iron oxide/mesoporous silica nanocomposites consisting of iron oxide nanoparticles embedded within mesoporous silica (MCM-41) and modified with aminopropyl functional groups were prepared for application to Cr(III) adsorption followed by magnetic recovery of the nanocomposite materials from aqueous solution. The composite materials were extensively characterized using physicochemical techniques, such as powder X-ray diffraction, thermogravimetric and elemental analysis, nitrogen adsorption, and zeta potential measurements. For aqueous Cr(III) at pH 5.4, the iron oxide/mesoporous silica nanocomposite exhibited a superior equilibrium adsorption capacity of 0.71 mmol/g, relative to 0.17 mmol/g for unmodified mesoporous silica. The aminopropyl-functionalized iron oxide/mesoporous silica nanocomposites displayed an equilibrium adsorption capacity of 2.08 mmol/g, the highest adsorption capacity for Cr(III) of all the materials evaluated in this study. Energy-dispersive spectroscopy (EDS) with transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) experiments provided insight into the chemical nature of the adsorbed chromium species.


    Citation:

    Egodawatte, Shani, Ashish Datt, Eric A. Burns, and Sarah C. Larsen. "Chemical insight into the adsorption of chromium (III) on iron oxide/mesoporous silica nanocomposites." Langmuir31, no. 27 (2015): 7553-7562.

  • Tuesday, March 1, 2016

    Partitioning of naturally-occurring radionuclides (NORM) in Marcellus Shale produced fluids influenced by chemical matrix

    Author(s):
    Andrew W. Nelson
    Adam J. Johns
    Eric S. Eitrheim
    Andrew W. Knight
    Madeline Basile
    E. Arthur Bettis III
    Michael. K. Schultz
    Tori Z. Forbes

    Journal Title:
    Environmental Science: Processes & Impacts

    Abstract:

    Naturally-occurring radioactive materials (NORM) associated with unconventional drilling produced fluids from the Marcellus Shale have raised environmental concerns. However, few investigations into the fundamental chemistry of NORM in Marcellus Shale produced fluids have been performed. Thus, we performed radiochemical experiments with Marcellus Shale produced fluids to understand the partitioning behavior of major radioelements of environmental health concern (uranium (U), thorium (Th), radium (Ra), lead (Pb), and polonium (Po)). We applied a novel radiotracer, 203Pb, to understand the behavior of trace-levels of 210Pb in these fluids. Ultrafiltration experiments indicated U, Th, and Po are particle reactive in Marcellus Shale produced fluids and Ra and Pb are soluble. Sediment partitioning experiments revealed that >99% of Ra does not adsorb to sediments in the presence of Marcellus Shale produced fluids. Further experiments indicated that although Ra adsorption is related to ionic strength, the concentrations of heavier alkaline earth metals (Ba, Sr) are stronger predictors of Ra solubility.


    CHEEC Project:

    Citation:

    Nelson, Andrew W., Adam J. Johns, Eric S. Eitrheim, Andrew W. Knight, Madeline Basile, E. Arthur Bettis III, Michael K. Schultz, and Tori Z. Forbes. "Partitioning of naturally-occurring radionuclides (NORM) in Marcellus Shale produced fluids influenced by chemical matrix." Environmental Science: Processes & Impacts 18, no. 4 (2016): 456-463.

  • Wednesday, July 5, 2017

    Effects of Coal Fly Ash Particulate Matter on the Antimicrobial Activity of Airway Surface Liquid

    Author(s):
    Luis G. Vargas Buonfiglio
    Imali A. Mudunkotuwa
    Mahmoud H. Abou Alaiwa
    Oriana G. Vanegas Calderón
    Jennifer A. Borcherding
    Alicia K. Gerke
    Joseph Zabner
    Vicki H. Grassian
    Alejandro P. Comellas

    Journal Title:
    Environmental Health Perspectives

    Abstract:

    Background:

    Sustained exposure to ambient particulate matter (PM) is a global cause of mortality. Coal fly ash (CFA) is a byproduct of coal combustion and is a source of anthropogenic PM with worldwide health relevance. The airway epithelia are lined with fluid called airway surface liquid (ASL), which contains antimicrobial proteins and peptides (AMPs). Cationic AMPs bind negatively charged bacteria to exert their antimicrobial activity. PM arriving in the airways could potentially interact with AMPs in the ASL to affect their antimicrobial activity.

    Objectives:

    We hypothesized that PM can interact with ASL AMPs to impair their antimicrobial activity.

    Methods:

    We exposed pig and human airway explants, pig and human ASL, and the human cationic AMPs β-defensin-3, LL-37, and lysozyme to CFA or control. Thereafter, we assessed the antimicrobial activity of exposed airway samples using both bioluminescence and standard colony-forming unit assays. We investigated PM-AMP electrostatic interaction by attenuated total reflection Fourier-transform infrared spectroscopy and measuring the zeta potential. We also studied the adsorption of AMPs on PM.

    Results:

    We found increased bacterial survival in CFA-exposed airway explants, ASL, and AMPs. In addition, we report that PM with a negative surface charge can adsorb cationic AMPs and form negative particle–protein complexes.

    Conclusion:

    We propose that when CFA arrives at the airway, it rapidly adsorbs AMPs and creates negative complexes, thereby decreasing the functional amount of AMPs capable of killing pathogens. These results provide a novel translational insight into an early mechanism for how ambient PM increases the susceptibility of the airways to bacterial infection.


    CHEEC Project:

    Citation:

    Vargas Buonfiglio, Luis G., Imali A. Mudunkotuwa, Mahmoud H. Abou Alaiwa, Oriana G. Vanegas Calderón, Jennifer A. Borcherding, Alicia K. Gerke, Joseph Zabner, Vicki H. Grassian, and Alejandro P. Comellas. "Effects of coal fly ash particulate matter on the antimicrobial activity of airway surface liquid." Environmental health perspectives 125, no. 7 (2017): 077003.

  • Monday, February 1, 2016

    The role of L-type amino acid transporters in the uptake of glyphosate across mammalian epithelial tissues

    Author(s):
    Jiaqiang Xu
    Gao Li
    Zhuoyi Wang
    Luqin Si
    Sijie He
    Jialing Cai
    Jiangeng Huang
    Maureen D. Donovan

    Journal Title:
    Chemosphere

    Abstract:

    Glyphosate is one of the most commonly used herbicides worldwide due to its broad spectrum of activity and reported low toxicity to humans. Glyphosate has an amino acid-like structure that is highly polar and shows low bioavailability following oral ingestion and low systemic toxicity following intravenous exposures. Spray applications of glyphosate in agricultural or residential settings can result in topical or inhalation exposures to the herbicide. Limited systemic exposure to glyphosate occurs following skin contact, and pulmonary exposure has also been reported to be low. The results of nasal inhalation exposures, however, have not been evaluated. To investigate the mechanisms of glyphosate absorption across epithelial tissues, the permeation of glyphosate across Caco-2 cells, a gastrointestinal epithelium model, was compared with permeation across nasal respiratory and olfactory tissues excised from cows. Saturable glyphosate uptake was seen in all three tissues, indicating the activity of epithelial transporters. The uptake was shown to be ATP and Na+ independent, and glyphosate permeability could be significantly reduced by the inclusion of competitive amino acids or specific LAT1/LAT2 transporter inhibitors. The pattern of inhibition of glyphosate permeability across Caco-2 and nasal mucosal tissues suggests that LAT1/2 play major roles in the transport of this amino-acid-like herbicide. Enhanced uptake into the epithelial cells at barrier mucosae, including the respiratory and gastrointestinal tracts, may result in more significant local and systemic effects than predicted from glyphosate's passive permeability, and enhanced uptake by the olfactory mucosa may result in further CNS disposition, potentially increasing the risk for brain-related toxicities.


      CHEEC Project:

      Citation:

      Xu, Jiaqiang, Gao Li, Zhuoyi Wang, Luqin Si, Sijie He, Jialing Cai, Jiangeng Huang, and Maureen D. Donovan. "The role of L-type amino acid transporters in the uptake of glyphosate across mammalian epithelial tissues." Chemosphere 145 (2016): 487-494.

    • Thursday, January 28, 2016

      Calf Lung Surfactant Recovers Surface Functionality After Exposure to Aerosols Containing Polymeric Particles

      Author(s):
      Amir M. Farnoud
      Jennifer Fiegel

      Journal Title:
      Journal of Aerosol Medicine and Pulmonary Drug Delivery

      Abstract:

      Background: Recent studies have shown that colloidal particles can disrupt the interfacial properties of lung surfactant and thus key functional abilities of lung surfactant. However, the mechanisms underlying the interactions between aerosols and surfactant films remain poorly understood, as our ability to expose films to particles via the aerosol route has been limited. The aim of this study was to develop a method to reproducibly apply aerosols with a quantifiable particle dose on lung surfactant films and investigate particle-induced changes to the interfacial properties of the surfactant under conditions that more closely mimic those in vivo.

      Methods: Films of DPPC and Infasurf® were exposed to aerosols containing polystyrene particles generated using a Dry Powder Insufflator. The dose of particles deposited on surfactant films was determined via light absorbance. The interfacial properties of the surfactant were studied using a Langmuir-Wilhelmy balance during surfactant compression to film collapse and cycles of surface compression and expansion at a fast cycling rate within a small surface area range.

      Results: Exposure of surfactant films to aerosols led to reproducible dosing of particles on the films. In film collapse experiments, particle deposition led to slight changes in collapse surface pressure and surface area of both surfactants. However, longer interaction times between particles and Infasurf® films resulted in time-dependent inhibition of surfactant function. When limited to lung relevant surface pressures, particles reduced the maximum surface pressure that could be achieved. This inhibitory effect persisted for all compression-expansion cycles in DPPC, but normal surfactant behavior was restored in Infasurf® films after five cycles.

      Conclusions: The observation that Infasurf® was able to quickly restore its function after exposure to aerosols under conditions that better mimicked those in vivo suggests that particle-induced surfactant inhibition is unlikely to occur in vivodue to an aerosol exposure.


      CHEEC Project:

      Citation:

      Farnoud, Amir M., and Jennifer Fiegel. "Calf lung surfactant recovers surface functionality after exposure to aerosols containing polymeric particles." Journal of aerosol medicine and pulmonary drug delivery 29, no. 1 (2016): 10-23.

    • Sunday, October 1, 2017

      A model system to mimic environmentally active surface film roughness and hydrophobicity

      Author(s):
      Jacob S. Grant
      Scott K. Shaw

      Journal Title:
      Chemosphere

      Abstract:

      This work presents the development and initial assessment of a laboratory platform to allow quantitative studies on model urban films. The platform consists of stearic acid and eicosane mixtures that are solution deposited from hexanes onto smooth, solid substrates. We show that this model has distinctive capabilities to better mimic a naturally occurring film's morphology and hydrophobicity, two important parameters that have not previously been incorporated into model film systems. The physical and chemical properties of the model films are assessed using a variety of analytical instruments. The film thickness and roughness are probed via atomic force microscopy while the film composition, wettability, and water uptake are analyzed by Fourier transform infrared spectroscopy, contact angle goniometry, and quartz crystal microbalance, respectively. Simulated environmental maturation is achieved by exposing the film to regulated amounts of UV/ozone. Ultimately, oxidation of the film is monitored by the analytical techniques mentioned above and proceeds as expected to produce a utile model film system. Including variable roughness and tunable surface coverage results in several key advantages over prior model systems, and will more accurately represent native urban film behavior.


      CHEEC Project:

      Citation:

      Grant, Jacob S., and Scott K. Shaw. "A model system to mimic environmentally active surface film roughness and hydrophobicity." Chemosphere 185 (2017): 772-779.

    • Saturday, April 22, 2017

      Solvent-dependent transformation of aflatoxin B1 in soil

      Author(s):
      James M. Starr
      Blake R. Rushing
      Mustafa I. Selim

      Journal Title:
      Mycotoxin Research

      Abstract:

      To date, all studies of aflatoxin B1 (AFB1) transformation in soil or in purified mineral systems have identified aflatoxins B2 (AFB2) and G2 (AFG2) as the primary transformation products. However, identification in these studies was made using thin layer chromatography which has relatively low resolution, and these studies did not identify a viable mechanism by which such transformations would occur. Further, the use of methanol as the solvent delivery vehicle in these studies may have contributed to formation of artifactual transformation products. In this study, we investigated the role of the solvent vehicle in the transformation of AFB1 in soil. To do this, we spiked soils with AFB1 dissolved in water (93:7, water/methanol) or methanol and used HPLC-UV and HPLC-MS to identify the transformation products. Contrasting previous published reports, we did not detect AFB2 or AFG2. In an aqueous-soil environment, we identified aflatoxin B2a (AFB2a) as the single major transformation product. We propose that AFB2a is formed from hydrolysis of AFB1 with the soil acting as an acid catalyst. Alternatively, when methanol was used, we identified methoxy aflatoxin species likely formed via acid-catalyzed addition of methanol to AFB1. These results suggest that where soil moisture is adequate, AFB1 is hydrolyzed to AFB2a and that reactive organic solvents should be avoided when replicating natural conditions to study the fate of AFB1 in soil.


      CHEEC Project:

      Citation:

      Starr, James M., Blake R. Rushing, and Mustafa I. Selim. "Solvent-dependent transformation of aflatoxin B 1 in soil." Mycotoxin research 33, no. 3 (2017): 197-205.

    • Saturday, May 25, 1996

      Enhanced degradation of pesticide wastes in soil: Implications for bioremediation of agrochemical dealer sites

      Author(s):
      Ellen Louise Kruger

      Journal Title:
      PhD Thesis

      Abstract:

      The overall objective of my research is to contribute evidence supporting the following hypotheses: 1) Enhanced degradation of herbicides or degradation products can occur in soils with long-term exposure to the chemical; 2) enhanced degradation of herbicide wastes can occur in rhizosphere soils from contaminated sites; 3) the presence of plants at pesticide-contaminated sites enhances the dissipation of pesticide wastes as a result of increased degradation by microbial communities in the rhizosphere. Specific objectives my research are:

      1. To test pesticide-contaminated soils in radiotracer studies for their degradative capabilities on freshly applied mixtures of herbicides

      2. To quantify specific herbicide degraders

      3. To compare degradation of an aged mixture of herbicides in vegetated and nonvegetated soil

      4. To test for enhanced degradation of a major herbicide metabolite in soils that have had long-term exposure of the parent compound


      CHEEC Project:

      Citation:

      Kruger, Eiien L., Jennifer C. Anhalt, Todd A. Anderson, and Joel R. Coats. ". ENHANCED DEGRADATION OF DEETHYLATRAZINE IN AN." Enhanced degradation of pesticide wastes in soil: implications for bioremediation of agrochemical dealer sites: 59.

    • Thursday, December 1, 2016

      Development of electrospun nanofiber composites for point-of-use water treatment

      Author(s):
      Katherine T. Peter

      Journal Title:
      PhD Thesis

      Abstract:

      A range of chemical pollutants is present in drinking water sources, including organic compounds, (e.g., pharmaceuticals and pesticides) and heavy metals (e.g., arsenic and lead). To protect the health of consumers, particularly those with private drinking water wells and in urban areas with aging water distribution systems, drinking water treatment at the point of use (POU) is essential. Next-generation POU technologies must require minimal energy, efficiently remove a range of pollutants, and be simple enough to permit broad application across users. Nanomaterials are ideal candidates for such technologies, as they exhibit high reactivity within small physical footprints. However, concerns regarding pressure requirements and material release challenge their application in traditional reactor designs. To bridge the gap between potential and practical application of nanomaterials, this study utilizes electrospinning to fabricate composite nanofiber filters. In electrospinning, a high voltage draws a polymer precursor solution (which can contain nanomaterial additives) from a needle, depositing a non-woven nanofiber filter on a collector. Using electrospinning, we develop an optimized carbon nanotube-carbon nanofiber composite that achieves a key balance between material strength and reactivity towards organic pollutants. Additionally, we develop two optimized polymer nanocomposites with embedded iron oxide nanoparticles and/or ion exchange groups, and demonstrate their application for removal of a range of metal contaminants (e.g., arsenic, chromium, lead, copper, and cadmium). Outcomes of this work establish novel methods for nanocomposite fabrication, contributing to the responsible and effective deployment of nanomaterials in POU drinking water treatment.


      CHEEC Project:

      Citation:

      Peter, Katherine T.. "Development of electrospun nanofiber composites for point-of-use water treatment." PhD (Doctor of Philosophy) thesis, University of Iowa, 2016. 
      https://doi.org/10.17077/etd.ga58rdni

    • Sunday, May 1, 2016

      Bacteriophages on paper for the colorimetric detection of Escherichia coli in lake water

      Author(s):
      Miguel Israel Chavez-Santoscoy

      Journal Title:
      MS Thesis

      Abstract:

      Outbreaks of diseases in recreational waters are frequent and cause death worldwide. The EPA established the water quality standard for the fecal indicator bacteria (FIB), Escherichia coli, to determine when there is a risk to public health in the U.S. However, a quick method to detect and quantify E. coli in situ is needed. In this work, we developed a paper-based device for pathogen detection with a focus on FIB E. coli. T4 bacteriophages were physically adsorbed on paper and able to capture E. coli in 5 minutes. For the first time, metabolic changes of bacteria in lake water were considered for designing two colorimetric assays for detection. The limit of detection (LOD) was 104 colony forming units (CFU) (p<0.05) and the color could be observed by the naked eye on the paper within an hour at room temperature. A pre-concentration was coupled to this technology achieving a LOD 5 X 105 CFU in 100 milliliters filtered. The conditions of assays are field-friendly for testing even in remote places and developing countries.


      CHEEC Project:

      Citation:

      Chavez-Santoscoy, Miguel Israel, "Bacteriophages on paper for the colorimetric detection of Escherichia coli in lake water" (2016). Graduate Theses and Dissertations. 15675. 
      https://lib.dr.iastate.edu/etd/15675

    • Tuesday, July 11, 2017

      A delayed proinflammatory response of human preadipocytes to PCB126 is dependent on the aryl hydrocarbon receptor

      Author(s):
      Francoise A. Gourronc
      Larry W. Robertson
      Aloysius J. Klingelhutz

      Journal Title:
      Environmental Science and Pollution Research

      Abstract:

      Inflammation in adipose tissue is recognized as a causative factor in the development of type II diabetes. Adipocyte hypertrophy as well as bacterial and environmental factors have been implicated in causing inflammation in mature adipocytes. Exposure to persistent organic pollutants such as polychlorinated biphenyls (PCBs) has been associated with the development of type II diabetes. We show here that PCB126, a dioxin-like PCB, activates a robust proinflammatory state in fat cell precursors (preadipocytes). The response was found to be dependent on aryl hydrocarbon receptor (AhR) activation, although induction of the response was delayed compared to upregulation of CYP1A1, a classic AhR-responsive gene. Treatment of preadipocytes with a nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) inhibitor partially attenuated the PCB126-induced inflammatory response and partly, but not completely, ameliorated disruption of adipogenesis caused by PCB126. Our results indicate a role for PCB126 in mediating an inflammatory response through AhR in preadipocytes that interferes with adipogenesis.


      CHEEC Project:

      Citation:

      Gourronc, Francoise A., Larry W. Robertson, and Aloysius J. Klingelhutz. "A delayed proinflammatory response of human preadipocytes to PCB126 is dependent on the aryl hydrocarbon receptor." Environmental Science and Pollution Research 25, no. 17 (2018): 16481-16492.

    • Tuesday, April 9, 2019

      Synergistic Association of House Endotoxin Exposure and Ambient Air Pollution with Asthma Outcomes

      Author(s):
      Angelico Mendy
      Jesse Wilkerson
      Pӓivi M. Salo
      Charles H. Weir
      Lydia Feinstein
      Darryl C. Zeldin
      Peter S. Thorne

      Journal Title:
      American Journal of Respiratory and Critical Care Medicine

      Abstract:

      House endotoxin and ambient air pollution are risk factors for asthma; however, the effects of their co-exposure on asthma are not well characterized. Objectives: To examine potential synergistic associations of co-exposure to house dust endotoxin and ambient air pollutants with asthma outcomes. Methods: We analyzed data from 6,488 participants in National Health and Nutrition Examination Survey (NHANES) 2005-2006. Dust from bedding and bedroom floor was analyzed for endotoxin content. The Community Multiscale Air Quality (CMAQ) and Downscaler (DS) data were used to determine annual average particulate matter ≤2.5 μm (PM2.5), ozone (O3), and nitrogen dioxide (NO2) exposures at participants’ residential locations. The associations of the co-exposures with asthma outcomes were assessed and tested for synergistic interaction. Results: In adjusted analysis, PM2.5 (CMAQ) (OR 1.12, 95% CI: 1.07-1.18), O3 (DS) (OR 1.07, 95% CI: 1.02-1.13), and log1010-NO2 (CMAQ) (OR 3.15, 95% CI: 1.33-7.45) were positively associated with emergency room (ER) visits for asthma in the past 12 months. Co-exposure to elevated levels of house dust endotoxin and PM2.5 (CMAQ) was synergistically associated with the outcome, increasing the odds by 5-fold (OR 5.01, 95% CI: 2.54-9.87). A synergistic association was also found for co-exposure to higher concentrations of endotoxin and NO2 in children (OR 3.45, 95% CI: 1.65-7.18). Conclusions: Co-exposure to elevated levels of residential endotoxin and ambient PM2.5 in all participants and NO2 in children is synergistically associated with increased ER visits for asthma. Therefore, decreasing exposure to both endotoxin and air pollution may help reduce asthma morbidity.


      CHEEC Project:

      Citation:

      Mendy, Angelico, Jesse Wilkerson, Pӓivi M. Salo, Charles H. Weir, Lydia Feinstein, Darryl C. Zeldin, and Peter S. Thorne. "Synergistic Association of House Endotoxin Exposure and Ambient Air Pollution with Asthma Outcomes." American journal of respiratory and critical care medicine ja (2019).

    • Friday, December 21, 2018

      Temporal Dynamics of Bacterial Communities in Soil and Leachate Water After Swine Manure Application

      Author(s):
      Elizabeth L. Rieke
      Michelle L. Soupir
      Thomas B. Moorman
      Fan Yang
      Adina C. Howe

      Journal Title:
      Frontiers in Microbiology

      Abstract:

      Application of swine manure to agricultural land allows recycling of plant nutrients, but excess nitrate, phosphorus and fecal bacteria impact surface and drainage water quality. While agronomic and water quality impacts are well studied, little is known about the impact of swine manure slurry on soil microbial communities. We applied swine manure to intact soil columns collected from plots maintained under chisel plow or no-till with corn and soybean rotation. Targeted 16S-rRNA gene sequencing was used to characterize and to identify shifts in bacterial communities in soil over 108 days after swine manure application. In addition, six simulated rainfalls were applied during this time. Drainage water from the columns and surface soil were sampled, and DNA was extracted and sequenced. Unique DNA sequences (OTU) associated with 12 orders of bacteria were responsible for the majority of OTUs stimulated by manure application. Proteobacteria were most prevalent, followed by Bacteroidetes, Firmicutes, Actinobacteria, and Spirochaetes. While the majority of the 12 orders decreased after day 59, relative abundances of genes associated with Rhizobiales and Actinomycetales in soil increased. Bacterial orders which were stimulated by manure application in soil had varied responses in drainage waters over the course of the experiment. We also identified a “manure-specific core” of five genera who comprised 13% of the manure community and were not significantly abundant in non-manured control soils. Of these five genera, Clostridium sensu stricto was the only genus which did not return to pre-manure relative abundance in soil by day 108. Our results show that enrichment responses after manure amendment could result from displacement of native soil bacteria by manure-borne bacteria during the application process or growth of native bacteria using manure-derived available nutrients.


      CHEEC Project:

      Citation:

      Rieke, Elizabeth Luby, Michelle Lynn Soupir, Thomas B. Moorman, Fan Yang, and Adina Chuang Howe. "Temporal dynamics of bacterial communities in soil and leachate water after swine manure application." Frontiers in microbiology 9 (2018): 3197.

    • Tuesday, January 22, 2019

      Physical and Chemical Morphology of Passively Sampled Environmental Films

      Author(s):
      Jacob S. Grant
      Zihua Zhu
      Christopher R. Anderton
      Scott K. Shaw

      Journal Title:
      ACS Earth and Space Chemistry

      Abstract:

      This work presents spatially resolved physical and chemical surface characterization of passively sampled environmental films developed in urban, suburban, and metropolitan locations. Environmental surface films are important mediators of atmospheric particulate matter (PM) and persistent organic pollutants (POPs) fate and transport. The films are developed via dry deposition onto silicon wafer substrates for time scales ranging from 1 to 52 weeks. Spatial and chemical morphologies of the films are analyzed by bright-field, scanning electron, and atomic force microscopies. Surface feature sizes span 6 orders of magnitude, from the millimeter to nanometer regimes, indicative of super- and sub-micrometer PM as well as conformal films of nanoscale PM and semivolatile molecules. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging data are analyzed to report the films’ chemical morphology and speciation which include a range of organic and inorganic species. Increases in surface coverages (ca. 5% for 1 week and ca. 98% for 52 weeks) reflect accumulation of mineral dust and biogenic organics, and the presence of biological species in the films. SIMS imaging reveals diverse and sometimes segregated chemical domains of organics, inorganics, and proteinaceous macromolecules.


      CHEEC Project:

      Citation:

      Grant, Jacob S., Zihua Zhu, Christopher R. Anderton, and Scott K. Shaw. "The Physical and Chemical Morphology of Passively Sampled Environmental Films." ACS Earth and Space Chemistry (2019).

    • Saturday, March 10, 2018

      Airway surface liquid from smokers promotes bacterial growth and biofilm formation via iron-lactoferrin imbalance

      Author(s):
      Luis G. Vargas Buonfiglio
      Jennifer A. Borcherding
      Mark Frommelt
      Gavin J. Parker
      Bryce Duchman
      Oriana G. Vanegas Calderón
      Ruth Fernandez-Ruiz
      Julio E. Noriega
      Alicia K. Gerke
      Joseph Zabner
      Alejandro P. Comellas

      Journal Title:
      Respiratory Research

      Abstract:

      Background

      Smoking is a leading cause of respiratory infections worldwide. Tobacco particulate matter disrupts iron homeostasis in the lungs and increases the iron content in the airways of smokers. The airway epithelia secrete lactoferrin to quench iron required for bacteria to proliferate and cause lung infections. We hypothesized that smokers would have increased bacterial growth and biofilm formation via iron lactoferrin imbalance.

      Methods

      We collected bronchoalveolar lavage (BAL) samples from non-smokers and smokers. We challenged these samples using a standard inoculum of Staphylococcus aureus and Pseudomonas aeruginosa and quantified bacterial growth and biofilm formation. We measured both iron and lactoferrin in the samples. We investigated the effect of supplementing non-smoker BAL with cigarette smoke extract (CSE) or ferric chloride and the effect of supplementing smoker BAL with lactoferrin on bacterial growth and biofilm formation.

      Results

      BAL from smokers had increased bacterial growth and biofilm formation compared to non-smokers after both S. aureus and P. aeruginosa challenge. In addition, we found that samples from smokers had a higher iron to lactoferrin ratio. Supplementing the BAL of non-smokers with cigarette smoke extract and ferric chloride increased bacterial growth. Conversely, supplementing the BAL of smokers with lactoferrin had a concentration-dependent decrease in bacterial growth and biofilm formation.

      Conclusion

      Cigarette smoking produces factors which increase bacterial growth and biofilm formation in the BAL. We propose that smoking disrupts the iron-to-lactoferrin in the airways. This finding offers a new avenue for potential therapeutic interventions to prevent respiratory infections in smokers.


      CHEEC Project:

      Citation:

      Buonfiglio, Luis G. Vargas, Jennifer A. Borcherding, Mark Frommelt, Gavin J. Parker, Bryce Duchman, Oriana G. Vanegas Calderón, Ruth Fernandez-Ruiz et al. "Airway surface liquid from smokers promotes bacterial growth and biofilm formation via iron-lactoferrin imbalance." Respiratory Research 19, no. 1 (2018): 42.

    • Wednesday, February 27, 2019

      Isolation of ligand-centered borocations in molybdenum complexes containing a triaminoborane-bridged diphosphorus ligand

      Author(s):
      Kyounghoon Lee
      Chan Woo Kim
      Jimmy L. Buckley
      Bess Vlaisavljevich
      Scott R. Daly

      Journal Title:
      Dalton Transactions

      Abstract:

      Metal complexes that form isolable, ligand-centered borenium ions (i.e. reactive three-coordinate boron cations) are rare, especially with highly-versatile diphosphorus ligands. Here we report the first structurally-characterized examples of ligand-centered borocations in a class of diphosphorus ligands derived from the bicyclic triaminoborane 1,8,10,9-triazaboradecalin (TBD). Treating (PhTBDPhos)Mo(CO)4 (1) with HOTf or HNTf2 resulted in protonation of the bridgehead α-nitrogen on the TBD backbone and formation of ligand-centered borenium ions (1-HOTf and 1-HNTf2, respectively), whereas reaction of 1 with HBF4·Et2O resulted in protonation of two α-nitrogen atoms and fluoride abstraction from BF4to form a four-coordinate borocation in [1-H2F][BF4]. Single-crystal XRD data confirmed the formation of the borocations, and multinuclear NMR and IR spectroscopy studies were used to interrogate the electronic environment at molybdenum and boron. The 11B NMR resonances for the borenium ions in 1-HOTf and 1-HNTf2 (δ 29.5 and 29.6 ppm) were more deshielded than the resonance for 1 (δ 25.9 ppm), consistent with the decreased electron density at boron. The 31P NMR data revealed similar trends in response to increasing protonation on the TBD backbone, and aligned well with small, stepwise increases in Mo–CO stretching frequencies that followed the order borane (1) < borenium (1-HOTf and 1-HNTf2) < boronium ([1-H2F][BF4]). Density functional theory calculations conducted on 11-HOTf, and [1-H2F][BF4]revealed subtle changes in boron and nitrogen atomic charges consistent with those calculated for more well-established borenium ions in metal-free systems. Overall, the results confirm previous observations of latent borenium ion reactivity in TBDPhos complexes.


      CHEEC Project:

      Citation:

      Lee, Kyounghoon, Chan Woo Kim, Jimmy L. Buckley, Bess Vlaisavljevich, and Scott R. Daly. "Isolation of ligand-centered borocations in molybdenum complexes containing a triaminoborane-bridged diphosphorus ligand." Dalton Transactions (2019).

    • Friday, December 9, 2016

      Differentiating Pseudomonas sp. strain ADP cells in suspensions and biofilms using Raman spectroscopy and scanning electron microscopy

      Author(s):
      Victoria A. Henry
      Julie L. P. Jessop
      Tonya L. Peeples

      Journal Title:
      Analytical and Bioanalytical Chemistry

      Abstract:

      High quality spectra of Pseudomonas sp. strain ADP in the planktonic and biofilm state were obtained using Raman microspectroscopy. These spectra enabled the identification of key differences between free and biofilm cells in the fingerprint region of Raman spectra in the nucleic acid, carbohydrate, and protein regions. Scanning electron microscopy (SEM) enabled detailed visualization of ADP biofilm with confirmation of associated extracellular matrix structure. Following extraction and Raman analysis of extracellular polymeric substances, Raman spectral differences between free and biofilm cells were largely attributed to the contribution of extracellular matrix components produced in mature biofilms. Raman spectroscopy complemented with SEM proves to be useful in distinguishing physiological properties among cells of the same species.


      CHEEC Project:

      Citation:

      Henry, Victoria A., Julie LP Jessop, and Tonya L. Peeples. "Differentiating Pseudomonas sp. strain ADP cells in suspensions and biofilms using Raman spectroscopy and scanning electron microscopy." Analytical and bioanalytical chemistry 409, no. 5 (2017): 1441-1449. DOI: 10.1007/s00216-016-0077-9

    • Monday, January 14, 2019

      Chlorinated Byproducts of Neonicotinoids and Their Metabolites: An Unrecognized Human Exposure Potential?

      Author(s):
      Kathryn L. Klarich Wong
      Danielle T. Webb
      Matthew R. Nagorzanski
      Dana W. Kolpin
      Michelle L. Hladik
      David M. Cwiertny
      Gregory H. LeFevre

      Journal Title:
      Environmental Science & Technology Letters

      Abstract:

      We recently reported the initial discovery of neonicotinoid pesticides in drinking water and their potential for transformation through chlorination and alkaline hydrolysis during water treatment. The objectives of this research were: (1) to determine if neonicotinoid metabolites are relevant to drinking water exposure and (2) to identify the products formed from chlorination of neonicotinoids and their metabolites. Desnitro-imidacloprid and imidacloprid-urea, two known metabolites of imidacloprid, are documented for the first time in drinking water. Desnitro-imidacloprid was present above the lower level of detection (0.03 ng/L) in 67% of samples (six of nine) from drinking water systems but detectable in all samples (up to 0.6 ng/L). Although concentrations of desnitro-imidacloprid were lower than concentrations of the parent neonicotinoids, desnitro-imidacloprid exhibits significantly greater mammalian toxicity than imidacloprid. Using LC-HR-ToF-MS/MS analysis of  results from laboratory experiments, we propose structures for novel transformation products resulting from the chlorination of clothianidin, imidacloprid, desnitro-imidacloprid, imidacloprid-urea, and hydrolysis products of thiamethoxam. Formation of chlorinated neonicotinoid byproducts occurs at time scales relevant to water treatment and/or distribution for the imidacloprid metabolites (t1/2 values from 2.4 min to 1.0 h) and thiamethoxam hydrolysis products (4.8 h). Neonicotinoid metabolites in finished drinking water and potential formation of novel disinfection byproducts during treatment and/or distribution are relevant to evaluating the exposure and potential impacts of neonicotinoids on human health.


      CHEEC Project:

      Citation:

      Klarich Wong, Kathryn L., Danielle T. Webb, Matthew R. Nagorzanski, Dana Ward Kolpin, Michelle L. Hladik, David M. Cwiertny, and Gregory H. LeFevre. "Chlorinated Byproducts of Neonicotinoids and their Metabolites: An Unrecognized Human Exposure Potential?." Environmental Science & Technology Letters (2019).

    • Monday, January 1, 2001

      RDX degradation using an integrated Fe(0)-microbial treatment approach

      Author(s):
      MJ Wildman
      PJ Alvarez

      Journal Title:
      Water Science and Technology

      Abstract:

      RDX is a persistent and highly mobile groundwater contaminant that represents a major remediation challenge at numerous munitions manufacturing and load-assemblage-package facilities. This work presents proof of concept that permeable reactive iron barriers might be a viable approach to intercept and degrade RDX plumes. Specifically, RDX was rapidly reduced in aquifier microcosms amended with Fe(0) powder, and in flow-through columns packed with steel wool. The rate and extent of RDX degradation in microcosms was enhanced by anaerobic bacteria that feed on cathodic hydrogen (i.e., H2 produced during anaerobic Fe(0) corrosion by water). Apparently, the hydrogenotrophic consortium that exploits Fe(0) corrosion as a metabolic niche participated in the further degradation of heterocyclic intermediates produced by the reaction of RDX with Fe(0). Reductive treatment of RDX with Fe(0) also reduced its toxicity to microorganisms and enhanced its subsequent biodegradability under either anaerobic or anaerobic conditions. Therefore, a combined or sequential Fe(0)-biological treatment approach might improve treatment efficiency.


      Citation:

      Wildman, M. J., and P. J. Alvarez. "RDX degradation using an integrated Fe (0)-microbial treatment approach." Water Science and Technology 43, no. 2 (2001): 25.

    • Thursday, July 9, 2009

      Laboratory evaluation of mobility and sorption for the veterinary antibiotic, tylosin, in agricultural soils

      Author(s):
      Dingfei Hu
      Joel R. Coats

      Journal Title:
      Journal of Environmental Monitoring

      Abstract:

      Veterinary medicines, including antibiotics, are utilized in large quantities in intensive livestock farming. It is evidenced that tylosin, one of the most frequently used antibiotics, is only partially metabolized in animals and not completely degraded in the manure storage stage before application to the farmland. In order to assess the mobility of tylosin in soil, a soil-column leaching study and a simple batch sorption experiment were conducted in the laboratory. Tylosin had strong sorption to various soils, with sorption distribution coefficients ranging from 42 to 65 ml/g. The range of concentrations in leachate was detected from non-detectable to 0.27 ng/mL after four simulated rainfall events in one month, and leachability of tylosin is dependent on soil properties and manure amendment. Percentage of clay, organic matter, cation exchange capacity, and manure amendment were positively correlated with sorption, and negatively correlated with mobility of tylosin in soil. The majority of tylosin was not recovered in the testing system, indicating that tylosin was most likely mineralized, or irreversibly bound to solid particles since no major degradation products were detected. Some trace level tylosin residues from manure-applied farmlands may be the major source to surface water systems through soil erosion and preferential flow processes.


      Citation:

      Hu, Dingfei, and Joel R. Coats. "Laboratory evaluation of mobility and sorption for the veterinary antibiotic, tylosin, in agricultural soils." Journal of Environmental Monitoring 11, no. 9 (2009): 1634-1638. DOI: 10.1039/B900973F

    • Friday, August 12, 1994

      Biological Degradation of Pesticide Wastes in the Root Zone of Soils Collected at an Agrochemical Dealership

      Author(s):
      Todd A Anderson
      Ellen L. Kruger
      Joel R. Coats

      Journal Title:
      Entomology

      Abstract:

      Evidence for enhanced microbial degradation of xenobiotic chemicals in the rhizosphere, a zone of increased microbial activity at the root-soil interface, continues to accrue, suggesting that vegetation may play an important role in facilitating bioremediation of contaminated surface soils. For sites tainted with pesticide wastes, such as at agrochemical dealerships, establishing vegetation may be problematic because of the presence of herbicide mixtures at concentrations severalfold above field application rates. Nonetheless, herbicide-tolerant plants exist that can survive in these environments, and they are ideal candidates for testing the influence of rhizosphere microbial communities on the degradation of pesticide wastes. Experiments in this laboratory have tested whether a commodity plant such as soybean could survive in soil from a pesticide-contaminated site containing a mixture of three predominant herbicides, atrazine, metolachlor, and trifluralin, and if its presence could enhance biodegradation. Although soybean survival in this soil was high, its presence did not enhance the degradation of the chemicals. Tests with nonvegetated soils and rhizosphere soils from Kochia sp., a herbicide-tolerant plant, showed enhanced degradation of these chemicals in rhizosphere soil. Also, Kochia sp. seedlings have emerged from rhizosphere soils spiked with additional concentrations of the three test chemicals, indicating the ability of these plants to survive in soils containing high concentrations of herbicide mixtures.


      Citation:
    • Tuesday, March 1, 2005

      Synthesis of environmentally relevant fluorinated surfactants—a review

      Author(s):
      Hans-Joachim Lehmler

      Journal Title:
      Chemosphere

      Abstract:

      In the past years there has been a growing interest in fluorinated persistent organic pollutants such as perfluorooctanesulfonic acid, perfluorooctanesulfonamides, perfluorinated carboxylic acids and fluorotelomer alcohols. Although these compounds have probably been present in the environment for many decades, we are only now beginning to realize that these environmental contaminants may have serious environmental and health effects. This article gives a state-of-the-art review of synthetic approaches that have been employed for the synthesis of these environmentally relevant fluorinated compounds. Perfluorooctanesulfonic acid derivatives, in particular, pose a problem because only a few perfluorooctanesulfonic acid derivatives are available from commercial sources—a fact that limits the ability of researchers worldwide to further study these compounds. Because of the limited literature available, this article also describes synthetic approaches for shorter chain homologues or perfluoroether analogues that can potentially be applied for the synthesis of perfluorooctanesulfonic acid derivatives. The preparation of typical starting materials for the synthesis of perfluorooctanesulfonic acid derivatives such as the perfluoroalkanesulfonyl fluorides and chlorides will be discussed. Subsequently, their conversion into relevant perfluoroalkane sulfonate salts (RFSO3M), sulfonamides (RFSO2NH2), N-alkyl sulfonamides (RFSO2NHR, R = alkyl), N,N-dialkyl sulfonamides (RFSO2NR2, R = alkyl), sulfonamidoethanol (RFSO2NRCH2CH2OH, R = –H, –CH3 or –C2H5) and sulfonamidoacetates (RFSO2NRCH2CO2H, R = –H, –CH3 or –C2H5) will be described. Many perfluorinated carboxylic acids and fluorotelomer alcohols are available from commercial sources. The review of the synthesis of these two classes of fluorinated compounds includes a review of their industrial synthesis and the synthesis of relevant degradation products.


      Citation:

      Lehmler, Hans-Joachim. "Synthesis of environmentally relevant fluorinated surfactants—a review." Chemosphere 58, no. 11 (2005): 1471-1496. DOI: 10.1016/j.chemosphere.2004.11.078

    • Tuesday, August 1, 2006

      Mixing of perfluorooctanesulfonic acid (PFOS) potassium salt with dipalmitoyl phosphatidylcholine (DPPC)

      Author(s):
      Hans-Joachim Lehmler
      W Xie
      GD Bothun
      PM Bummer
      BL Knutson

      Journal Title:
      Colloids and Surfaces B: Biointerfaces

      Abstract:

      Perfluorooctane-1-sulfonic acid (PFOS) is emerging as an important persistent environmental pollutant. To gain insight into the interaction of PFOS with biological systems, the mixing behavior of dipalmitoylphosphatidylcholine (DPPC) with PFOS was studied using differential scanning calorimetry (DSC) and fluorescence anisotropy measurements. In the DSC experiments the onset temperature of the DPPC pretransition (Tp) decreased with increasing PFOS concentration, disappearing at XDPPC ≤ 0.97. The main DPPC phase transition temperature showed a depression and peak broadening with increasing mole fraction of PFOS in both the DSC and the fluorescence anisotropy studies. From the melting point depression in the fluorescence anisotropy studies, which was observed at a concentration as low as 10 mg/L, an apparent partition coefficient of K = 5.7 × 104 (mole fraction basis) was calculated. These results suggest that PFOS has a high tendency to partition into lipid bilayers. These direct PFOS–DPPC interactions are one possible mechanism by which PFOS may contribute to adverse effects, for example neonatal mortality, in laboratory studies and possibly in humans.


      CHEEC Project:

      Citation:

      Lehmler HJ, Xie W, Bothun GD, Bummer PM, Knutson BL. Mixing of perfluorooctanesulfonic acid (PFOS) potassium salt with dipalmitoyl phosphatidylcholine (DPPC). Colloids and Surfaces B: Biointerfaces. 2006 Aug 1;51(1):25-9. DOI: 10.1016/j.colsurfb.2006.05.013

    • Friday, November 7, 1997

      Determinants of Culturable Bioaerosol Concentrations in Dairy Barns

      Author(s):
      Jeffrey L. Lange
      Peter S. Thorne
      Gregory J. Kullman

      Journal Title:
      Annals of Agricultural and Environmental Medicine

      Abstract:

      The concentration of bioaerosols to which dairy farmers are exposed is potentially related to environmental factors, such as climatic conditions and individual management practices. An unprecedented heavy rainfall that was 250% of normal during the growing season of feed and bedding materials provided an unique opportunity for study. Individual dairy management practices differ as to barn construction, type of ventilation system, storage moisture of feed rations, quality of bedding materials, and animal density. The aim of this study was to identify the nvironmental factors affecting the concentrations of culturable bioaerosols in dairy barns. In this cross-sectional study of 48 dairy barns, area samples were collected using all-glass impingers. Culturable bioaerosols were analyzed to determine airborne concentrations of yeasts, molds, mesophilic bacteria, and thermophilic bacteria. The time-weighted geometric mean concentrations of these bioaerosols collected over the work-shift were 1.8x104 cfu/m3 for yeasts, 0.8x104 cfu/m3 for molds, 81.1x104cfu/m3 for mesophilic bacteria, and 0.4x104 cfu/m3 for thermophilic bacteria. These concentrations ranged from two to three orders of magnitude among the different barns. Bioaerosol concentrations did not differ between barns that used feed and bedding grown during extremely high rainfall and barns that used feed and bedding grown during normal rainfall. Multiple regression analyses were used to describe which environmental factors exhibited the strongest correlation with the concentration of bioaerosols. From these analyses, we conclude that efforts to reduce exposure to bioaerosols in dairy barns should focus on ventilation and storage moisture of feed rations.


      CHEEC Project:

      Citation:

      Lange JL, Thorne PS, Kullman GJ. Determinants of culturable bioaerosol concentrations in dairy barns. Annals of Agricultural and Environmental Medicine. 1997 Nov 7;4(2):187-94.

    • Friday, February 1, 2008

      Passive sampling to capture spatial variability in PM10–2.5

      Author(s):
      Darrin K. Ott
      Naresh Kumar
      Thomas M. Peters

      Abstract:

      This work applied inexpensive passive sampling to measure airborne coarse particles with aerodynamic diameters between 2.5 and 10 μm (PM10–2.5) over three 7-day periods at 33 sites in a medium-sized Midwest City (Iowa City, IA). The number of sites and their locations were selected using an optimal sampling design that captured 95% of the total variance in PM10–2.5 as measured with real-time sampling equipment on a mobile sampling platform. Weekly averages of PM10–2.5 were 15.9 μg m−3 (coefficient of variation between sites, CV=23%), 17.9 μg m−3 (CV=24%), and 6.1 μg m−3 (CV=30%). ANOVA showed that these means were statistically different (p<0.001), and that the spatial variability plus random error accounted for 29% of the total variability. The maximum coefficient of divergence between sites—a relative measure of uniformity—ranged from 0.21 to 0.36. These values indicate that PM10–2.5 was heterogeneous even on the fine spatial resolution studied in this work (average distance between sites was 4.4 km). The spatial patterns of PM10–2.5 measured with the passive samplers closely matched with those of mobile mapping and corresponded with known coarse particle sources in the area. This work demonstrates that passive sampling coupled with effective sampling design may enhance our ability to assess exposure to PM10–2.5 at a local scale. Compared to exposure estimates made with data from centrally located, filter-based samplers, these highly spatially resolved estimates should reduce exposure misclassification errors in epidemiological studies.


      CHEEC Project:

      Citation:

      Ott, Darrin K., Naresh Kumar, and Thomas M. Peters. "Passive sampling to capture spatial variability in PM10–2.5." Atmospheric Environment 42, no. 4 (2008): 746-756. DOI: 10.1016/j.atmosenv.2007.09.058

    • Friday, February 1, 2002

      Kinetics of Nitrate, Nitrite, and Cr(VI) Reduction by Iron Metal

      Author(s):
      Michael J. Alowitz
      Michelle M. Scherer

      Journal Title:
      Environmental Science and Technology

      Abstract:

      The kinetics of nitrate, nitrite, and Cr(VI) reduction by three types of iron metal (Fe0) were studied in batch reactors for a range of Fe0 surface area concentrations and solution pH values (5.5−9.0). At pH 7.0, there was only a modest difference (2−4×) in first-order rate coefficients (kobs) for each contaminant among the three Fe0 types investigated (Fisher, Peerless, and Connelly). The kobs values at pH 7.0 for both nitrite and Cr(VI) reduction were first-order with respect to Fe0 surface area concentration, and average surface area normalized rate coefficients (kSA) of 9.0 × 10-3 and 2.2 × 10-1 L m-2 h-1 were determined for nitrite and Cr(VI), respectively. Unlike nitrite and Cr(VI), Fe0 surface area concentration had little effect on rates of nitrate reduction (with the exception of Connelly Fe0, which reduced nitrate at slower rates at higher Fe0 surface areas). The rates of nitrate, nitrite, and Cr(VI) reduction by Fisher Fe0 decreased with increasing pH with apparent reaction orders of 0.49 ± 0.04 for nitrate, 0.61 ± 0.02 for nitrite, and 0.72 ± 0.07 for Cr(VI). Buffer type had minimal effects on reduction rates, indicating that pH was primarily responsible for the differences in rate. At high pH values, Cr(VI) reduction ceased after a short time period, and negligible nitrite reduction was observed over 48 h.


      CHEEC Project:

      Citation:

      Alowitz, Michael J., and Michelle M. Scherer. "Kinetics of nitrate, nitrite, and Cr (VI) reduction by iron metal." Environmental Science & Technology 36, no. 3 (2002): 299-306. DOI: 10.1021/es011000h

    • Thursday, October 1, 1998

      Retrospective Temporal and Spatial Mobility of Adult Iowa Women

      Author(s):
      R. William Field
      Brian J. Smith
      Christine P. Brus
      Charles F. Lynch
      John S. Neuberger
      Daniel J. Steck

      Journal Title:
      Risk Analysis

      Abstract:

      Human exposure assessments require a linkage between toxicant concentrations in occupied spaces and the receptor's mobility pattern. Databases reporting distinct populations' mobility in various parts of the home, time outside the home, and time in another building are scarce. Temporal longitudinal trends in these mobility patterns for specific age and gender groups are nonexistent. This paper describes subgroup trends in the spatial and temporal mobility patterns within the home, outside the home, and in another building for 619 Iowa females that occupied the same home for at least 20 years. The study found that the mean time spent at home for the participants ranged from a low of 69.4% for the 50–59 year age group to a high of 81.6% for the over 80-year-old age group. Participants who lived in either one- or two- story homes with basements spent the majority of their residential occupancy on the first story. Trends across age varied for other subgroups by number of children, education, and urban/rural status. Since all of these trends were nonlinear, they indicate that error exists when assuming a constant, such as a 75% home occupancy factor, which has been advocated by some researchers and agencies. In addition, while aggregate data, such as presented in this report, are more helpful in deriving risk estimates for population subgroups, they cannot supplant good individual-level data for determining risks.


      Citation:

      Field, R. William, Brian J. Smith, Christine P. Brus, Charles F. Lynch, John S. Neuberger, and Daniel J. Steck. "Retrospective temporal and spatial mobility of adult Iowa women." Risk Analysis 18, no. 5 (1998): 575-584. DOI: 10.1023/B:RIAN.0000005932.47880.34

    • Friday, February 1, 2008

      Passive measurement of coarse particulate matter, PM 10 - 2.5

      Author(s):
      Darrin K. Ott
      William Cyrs
      Thomas M. Peters

      Journal Title:
      Journal of Aerosol Science

      Abstract:

      This work developed a passive sampling method to measure ambient PM10–2.5 . The coefficient of variation (CV) of PM10–2.5 measured with collocated passive samplers was 20.1% in laboratory tests and 11.6% in field tests. PM10–2.5 measured passively deviated from that measured with a filter-based dichotomous sampler by 29% in field tests. The strong correlation between PM10–2.5 derived passively with the dichotomous sampler (r=0.97 ) suggests that the bias observed in field tests was systematic and may be empirically corrected. The limit of detection of the method was determined to be   for a 5-day sample. A bootstrap analysis suggests that at least 300 particles should be imaged to stabilize the analytical variability of the method. Repeated analysis suggests that the CV for the analytical method is 5%. This method offers an inexpensive means to assess PM10–2.5 that may be incorporated into compliance networks or epidemiological studies.


      CHEEC Project:

      Citation:

      Ott, Darrin K., William Cyrs, and Thomas M. Peters. "Passive measurement of coarse particulate matter, PM10–2.5." Journal of Aerosol Science 39, no. 2 (2008): 156-167. DOI: 10.1016/j.jaerosci.2007.11.002

    • Wednesday, December 9, 2009

      Aerobic degradation and photolysis of tylosin in water and soil

      Author(s):
      Dingfei Hu
      Joel R. Coats

      Journal Title:
      Environmental Toxicology and Chemistry

      Abstract:

      Veterinary antibiotics enter the environment through the application of organic fertilizers to cropland. In this study, the aerobic degradation of tylosin, a widely used antibiotic in the production of livestock and poultry, was conducted in water and in soil in an effort to further investigate its environmental fate. Tylosin is a macrolide antibiotic, which consists of four factors (A, B, C, D). Water and soil were sampled at selected times and analyzed for tylosin and its degradation products by high‐performance liquid chromatography (HPLC), with product identification confirmed by HPLC‐mass spectrometry. Tylosin A is degraded with a half‐life of 200 d in the light in water, and the total loss of tylosin A in the dark is 6% of the initial spiked amount during the experimental period. Tylosin C and D are relatively stable except in ultrapure water in the light. Slight increases of tylosin B after two months and formation of two photoreaction isomers of tylosin A were observed under exposure to light. However, tylosin probably would degrade faster if the experimental containers did not prevent ultraviolet transmission. In soil, tylosin A has a dissipation half‐life of 7 d, and tylosin D is slightly more stable, with a dissipation half‐life of 8 d in unsterilized and sterilized soil. Sorption and abiotic degradation are the major factors influencing the loss of tylosin in the environment, and no biotic degradation was observed at the test concentration either in pond water or in an agronomic soil, as determined by comparing dissipation profiles in sterilized and unsterilized conditions.


      Citation:

      Hu, Dingfei, and Joel R. Coats. "Aerobic degradation and photolysis of tylosin in water and soil." Environmental Toxicology and Chemistry 26, no. 5 (2007): 884-889. DOI: https://doi.org/10.1897/06-197R.1

    • Wednesday, January 28, 2009

      Concentrations of Bioaerosols, Odors, and Hydrogen Sulfide Inside and Downwind from Two Types of Swine Livestock Operations

      Author(s):
      Peter S. Thorne
      Anne C. Ansley
      Sarah Spencer Perry

      Journal Title:
      Journal of Occupational and Environmental Hygiene

      Abstract:

      Few data on in-barn and downwind concentrations of endotoxin, bioaerosols, and odors from livestock facilities are available, and no studies have compared conventional confinement operations with the more animal-friendly hoop operations. Hoops are open to the environment and use a composted bedding system rather than housing pigs on slatted floors over pits holding manure slurry as in conventional confinements. We assessed airborne toxicants upwind, in barns, and downwind and evaluated determinants of exposure. Inhalable particulate matter, endotoxin, odor threshold, hydrogen sulfide, culturable mesophilic bacteria, culturable fungi, and total airborne microbes, along with wind speed, temperature, and humidity were measured at separate midsized livestock facilities (one hoop, one confinement) in Central Iowa on 10 occasions over 2 years. Significant differences in contaminants were observed between hoops and confinement buildings and across seasons for endotoxin, odors, airborne microorganisms, and hydrogen sulfide. For hoops and confinements, respectively, geometric mean in-barn concentrations were 3250 and 3100 EU/m3 for endotoxin; 1400 and 1910 μg/m3 for particulates; 19.6 and 146 ppb for hydrogen sulfide; 137 and 428 dilutions for odor threshold; and 3.0 × 106 and 1.5 × 106 organisms/m3 for total microbes. Endotoxin, odor, and culturable microorganisms exceeded recommended exposure limits. Reduced analysis of variance models for these contaminants demonstrated differences by barn type, season, number of pigs, and, in some cases, temperature and humidity. Both types of swine operations produced high airborne concentrations of endotoxin, odor, hydrogen sulfide, bacteria, and fungi. Endotoxin and odors were found downwind at concentrations previously associated with adverse health effects.


      Citation:

      Thorne, Peter S., Anne C. Ansley, and Sarah Spencer Perry. "Concentrations of bioaerosols, odors, and hydrogen sulfide inside and downwind from two types of swine livestock operations." Journal of occupational and environmental hygiene 6, no. 4 (2009): 211-220. DOI: 10.1080/15459620902729184

    • Friday, June 4, 2010

      Bioaerosol Concentrations in Noncomplaint, Complaint, and Intervention Homes in the Midwest

      Author(s):
      Jeannine A. DeKoster
      Peter S. Thorne

      Journal Title:
      American Industrial Hygiene Association Journal

      Abstract:

      Forty-one homes of conventional design were studied to investigate the relationship between bioaerosols, building parameters, and season, and to determine if differences existed across health-based home categories. The homes were categorized as: those for which no indoor air problems were known (noncomplaint homes), noncomplaint homes of allergy patients (intervention homes), and complaint “sick” homes (complaint homes). Carbon dioxide and relative humidity were measured in the basement and main floor areas. CO2 concentrations were elevated for complaint homes (mean 1190 ppm) but less than 1000 ppm for all noncomplaint homes (mean 550 ppm). Relative humidity was significantly lower for intervention homes than for complaint or noncomplaint homes. Viable and nonviable bioaerosol sampling was performed on the main floor, the basement, and outside. Outdoor viable fungi exhibited an 8.4-fold range when plotted by month, but respirable and nonrespirable indoor fungal concentrations did not differ significantly by season. Basement geometric mean concentrations of fungi exceeded twice outdoor levels for complaint homes but were half the outdoor concentration for noncomplaint homes. Analysis of variance of bioaerosol concentrations revealed higher contamination in complaint than in noncomplaint homes, and concentrations in intervention homes were significantly lower than the other two groups. Overall, 80% of total viable fungi and 55% of bacteria were respirable. The predominant genera were Cladosporium in noncomplaint and intervention homes, while Penicillium and Aspergillus dominated in basements of complaint homes. The presence of pets, having an unfinished basement, absence of central air conditioning, and decreased use of air conditioning were significantly associated with elevated levels of fungi. High-efficiency furnace filters and increased use of central air conditioning contributed significantly to lower fungal levels in intervention homes.


      Citation:

      DeKoster, Jeannine A., and Peter S. Thorne. "Bioaerosol concentrations in noncomplaint, complaint, and intervention homes in the Midwest." American Industrial Hygiene Association Journal 56, no. 6 (1995): 573-580. DOI: 10.1080/15428119591016809              

    • Thursday, June 1, 2000

      Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study

      Author(s):
      R. William Field
      Daniel J. Steck
      Brian J. Smith
      Christine P. Brus
      Eileen L. Fisher
      John S. Neuberger
      Charles E. Platz
      Robert A. Robinson
      Robert F. Woolson
      Charles F. Lynch

      Journal Title:
      American Journal of Epidemiology

      Abstract:

      Exposure to high concentrations of radon progeny (radon) produces lung cancer in both underground miners and experimentally exposed laboratory animals. To determine the risk posed by residential radon exposure, the authors performed a population-based, case-control epidemiologic study in Iowa from 1993 to 1997. Subjects were female Iowa residents who had occupied their current home for at least 20 years. A total of 413 lung cancer cases and 614 age-frequency-matched controls were included in the final analysis. Excess odds were calculated per 11 working-level months for exposures that occurred 5–19 years (WLM610J prior to diagnosis for cases or prior to time of interview for controls. Eleven WLM619 is approximately equal to an average residential radon exposure of 4 pCI/liter (148 Bq/m3) during this period. After adjustment for age, smoking, and education, the authors found excess odds of 0.50 (95% confidence interval: 0.004, 1.81) and 0.83 (95% percent confidence interval: 0.11, 3.34) using categorical radon exposure estimates for all cases and for live cases, respectively. Slightly lower excess odds of 0.24 (95 percent confidence interval: -0.05, 0.92) and 0.49 (95 percent confidence interval: 0.03, 1.84) per 11 WLM519 were noted for continuous radon exposure estimates for all subjects and live subjects only. The observed risk estimates suggest that cumulative ambient radon exposure presents an important environmental health hazard.


      CHEEC Project:

      Citation:

      Field, R. William, Daniel J. Steck, Brian J. Smith, Christine P. Brus, Eileen L. Fisher, John S. Neuberger, Charles E. Platz, Robert A. Robinson, Robert F. Woolson, and Charles F. Lynch. "Residential radon gas exposure and lung cancer: the Iowa Radon Lung Cancer Study." American Journal of Epidemiology 151, no. 11 (2000): 1091-1102. DOI: 10.1093/oxfordjournals.aje.a010153

    • Tuesday, August 1, 2006

      Avian Influenza among Waterfowl Hunters and Wildlife Professionals

      Author(s):
      James S. Gill
      Richard Webby
      Mary JR Gilchrist
      Gregory C. Gray

      Journal Title:
      Emerging Infectious Diseases

      Abstract:

      We report serologic evidence of avian influenza infection in 1 duck hunter and 2 wildlife professionals with extensive histories of wild waterfowl and game bird exposure. Two laboratory methods showed evidence of past infection with influenza A/H11N9, a less common virus strain in wild ducks, in these 3 persons.

      Wild ducks, geese, and shorebirds are the natural reservoir for influenza A virus (); all 16 hemagglutinin (H) and 9 neuraminidase (N) subtypes are found in these wild birds (,). Recently, the rapid spread of influenza A/H5N1 virus to new geographic regions, possibly by migrating waterfowl, has caused concern among public health officials who fear an influenza pandemic. Until now, serologic studies of the transmission of subtype H5N1 and other highly pathogenic strains of avian influenza have focused on humans who have contact with infected domestic poultry (,). In this cross-sectional seroprevalence study, we provide evidence of past influenza A/H11 infection in persons who were routinely, heavily exposed to wild ducks and geese through recreational activities (duck hunting) or through their employment (bird banding). To our knowledge, this study is the first to show direct transmission of influenza A viruses from wild birds to humans.


      CHEEC Project:

      Citation:

      Gill, James S., Richard Webby, Mary JR Gilchrist, and Gregory C. Gray. "Avian influenza among waterfowl hunters and wildlife professionals." Emerging infectious diseases 12, no. 8 (2006): 1284. DOI: 10.3201/eid1208.060492

    • Wednesday, October 21, 2009

      Agglomeration, isolation and dissolution of commercially manufactured silver nanoparticles in aqueous environments

      Author(s):
      Sherrie Elzey
      Vicki H. Grassian

      Journal Title:
      Journal of Nanoparticle Research

      Abstract:

      The increasing use of manufactured nanoparticles ensures these materials will make their way into the environment. Silver nanoparticles in particular, due to use in a wide range of applications, have the potential to get into water systems, e.g., drinking water systems, ground water systems, estuaries, and/or lakes. One important question is what is the chemical and physical state of these nanoparticles in water? Are they present as isolated particles, agglomerates or dissolved ions, as this will dictate their fate and transport. Furthermore, does the chemical and physical state of the nanoparticles change as a function of size or differ from micron-sized particles of similar composition? In this study, an electrospray atomizer coupled to a scanning mobility particle sizer (ES-SMPS) is used to investigate the state of silver nanoparticles in water and aqueous nitric acid environments. Over the range of pH values investigated, 0.5–6.5, silver nanoparticles with a bimodal primary particle size distribution with the most intense peak at 5.0 ± 7.4 nm, as determined from transmission electron microscopy (TEM), show distinct size distributions indicating agglomeration between pH 6.5 and 3 and isolated nanoparticles at pH values from 2.5 to 1. At the lowest pH investigated, pH 0.5, there are no peaks detected by the SMPS, indicating complete nanoparticle dissolution. Further analysis of the solution shows dissolved Ag ions at a pH of 0.5. Interestingly, silver nanoparticle dissolution shows size dependent behavior as larger, micron-sized silver particles show no dissolution at this pH. Environmental implications of these results are discussed.


      CHEEC Project:

      Citation:

      Elzey, Sherrie, and Vicki H. Grassian. "Agglomeration, isolation and dissolution of commercially manufactured silver nanoparticles in aqueous environments." Journal of Nanoparticle Research 12, no. 5 (2010): 1945-1958. DOI: 10.1007/s11051-009-9783-y

    • Sunday, January 1, 2006

      Are Swine Workers in the United States at Increased Risk of Infection with Zoonotic Influenza Virus?

      Author(s):
      kendall P. Myers
      Christopher W. Olsen
      Sharon F. Setterquist
      Ann W. Capuano
      Kelley J. Donham
      Eileen L. Thacker
      James A. Merchant
      Gregory C. Gray

      Journal Title:
      Clinical Infectious Diseases

      Abstract:

      Background

      Pandemic influenza strains originate in nonhuman species. Pigs have an important role in interspecies transmission of the virus. We examined multiple swine-exposed human populations in the nation' number 1 swine-producing state for evidence of previous swine influenza virus infection.

      Methods

      We performed controlled, cross-sectional seroprevalence studies among 111 farmers, 97 meat processing workers, 65 veterinarians, and 79 control subjects using serum samples collected during the period of 2002–2004. Serum samples were tested using a hemagglutination inhibition assay against the following 6 influenza A virus isolates collected recently from pigs and humans: A/Swine/WI/238/97 (H1N1), A/Swine/WI/R33F/01 (H1N2), A/Swine/Minnesota/593/99 (H3N2), A/New Caledonia/20/99 (H1N1), A/Panama/2007/99 (H3N2), and A/Nanchang/933/95 (H3N2).

      Results

      Using multivariable proportional odds modeling, all 3 exposed study groups demonstrated markedly elevated titers against the H1N1 and H1N2 swine influenza virus isolates, compared with control subjects. Farmers had the strongest indication of exposure to swine H1N1 virus infection (odds ratio [OR], 35.3; 95% confidence interval [CI], 7.7–161.8), followed by veterinarians (OR, 17.8; 95% CI, 3.8–82.7), and meat processing workers (OR, 6.5; 95% CI, 1.4–29.5). Similarly, farmers had the highest odds for exposure to swine H1N2 virus (OR, 13.8; 95% CI, 5.4–35.4), followed by veterinarians (OR, 9.5; 95% CI, 3.6–24.6) and meat processing workers (OR, 2.7; 95% CI, 1.1–6.7).

      Conclusions

      Occupational exposure to pigs greatly increases workers' risk of swine influenza virus infection. Swine workers should be included in pandemic surveillance and in antiviral and immunization strategies.


      CHEEC Project:

      Citation:

      Myers, Kendall P., Christopher W. Olsen, Sharon F. Setterquist, Ana W. Capuano, Kelley J. Donham, Eileen L. Thacker, James A. Merchant, and Gregory C. Gray. "Are swine workers in the United States at increased risk of infection with zoonotic influenza virus?." Clinical infectious diseases 42, no. 1 (2006): 14-20. DOI: 10.1086/498977

    • Friday, February 27, 1998

      Hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine translocation in poplar trees

      Author(s):
      Phillip L. Thompson
      Liz A. Ramer
      Jerald L. Schnoor

      Journal Title:
      Environmental Toxicology and Chemistry

      Abstract:

      This article evaluates the translocation of the explosive hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX) in hybrid poplar trees (Populus deltoides × nigra, DN34) grown in hydroponic solutions. Mass balances with [U‐14C]RDX were used to assess RDX translocation. Up to 60% of the RDX uptaken by the tree accumulated in leaf tissues. Analysis of plant extracts by high‐performance liquid chromatography equipped with radiochemical detection indicated that RDX was not significantly transformed during exposure periods of up to 7 d. The bioaccumulation of RDX may be an important concern for phytoremediation efforts.


      CHEEC Project:

      Citation:

      Thompson, Phillip L., Liz A. Ramer, and Jerald L. Schnoor. "Hexahydro‐1, 3, 5‐trinitro‐1, 3, 5‐triazine translocation in poplar trees." Environmental toxicology and chemistry 18, no. 2 (1999): 279-284.DOI: https://doi.org/10.1002/etc.5620180226

    • Monday, January 27, 1997

      Decreased transpiration in poplar trees exposed to 2,4,6‐trinitrotoluene

      Author(s):
      Phillip L. Thompson
      Liz A. Ramer
      Aaron P. Guffey
      Jerald L. Schnoor

      Journal Title:
      Environmental Toxicology and Chemistry

      Abstract:

      This article discusses the effects of various concentrations of the explosive 2,4,6‐trinitrotoluene (TNT) on the transpiration of hybrid poplar trees growing in hydroponic media. Transpiration was measured daily by gravimetric means. The rapid removal of TNT from hydroponic solutions was a result of plant uptake and required a daily dosage of TNT to ensure a relatively constant exposure over time. Transpiration decreased with increasing TNT concentrations ≥5 mg/L. Decreases in transpiration were accompanied by leaf chlorosis and abscission. A comparison between a laboratory study and a pilot‐scale experiment showed good scale‐up potential.


      CHEEC Project:

      Citation:

      Thompson, Phillip L., Liz A. Ramer, Aaron P. Guffey, and Jerald L. Schnoor. "Decreased transpiration in poplar trees exposed to 2, 4, 6‐trinitrotoluene." Environmental toxicology and chemistry 17, no. 5 (1998): 902-906. DOI: https://doi.org/10.1002/etc.5620170519

    • Monday, April 1, 1996

      Enhanced Mineralization of [14C]Atrazine in Kochia scoparia Rhizospheric Soil from a Pesticide‐Contaminated Site

      Author(s):
      Brenda S. Perkovich
      Todd A. Anderson
      Ellen L. Kruger
      Joel R. Coats

      Journal Title:
      Pesticide Science

      Abstract:

      Mineralization of atrazine (6‐chloro‐N2‐ethyl‐N4‐isopropyl‐1,3,5‐ triazine‐2,4‐diamine) in soil treated with a mixture of atrazine and metolachlor (2‐chloro‐6′‐ethyl‐N‐(2‐methoxy‐1‐methylethyl)acet‐o‐toluidide at concentrations typical of point‐source contamination (50 μg g−1 each) was significantly greater (P<0·001) in rhizospheric soil from Kochia scoparia (L.) Roth., a herbicide‐resistant plant, than in non‐vegetated and control soils. Soils were collected from an agrochemical dealership contaminated with several herbicides, including atra‐zine, metolachlor, trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine and pendimethalin (N‐(1‐ethylpropyl)‐2,6‐dinitro‐3,4‐xylidene), at concentrations well exceeding the field application rates. Mineralization rates of ring‐labeled atrazine in both rhizospheric and non‐vegetated soils were quite high (>47% of the initial 14C applied after 36 days) compared to literature values. These results suggest that plants such as Kochia might be managed at pesticide‐contaminated sites to help facilitate microbial degradation of wastes such as atrazine in soil.


      CHEEC Project:

      Citation:

      Perkovich, Brenda S., Todd A. Anderson, Ellen L. Kruger, and Joel R. Coats. "Enhanced mineralization of [14C] atrazine in Kochia scoparia rhizospheric soil from a pesticide‐contaminated site." Pesticide Science 46, no. 4 (1996): 391-396. DOI: 10.1002/(SICI)1096-9063(199604)46:4<391::AID-PS374>3.0.CO;2-L

    • Wednesday, January 1, 1997

      A Control Study of the Physical and Mental Health of Residents Living Near a Large-scale Swine Operation

      Author(s):
      K Thu
      K Donham
      R Ziegenhorn
      S Reynolds
      PS Thorne
      P Subramanian
      P Whitten
      J Stookesberry

      Journal Title:
      Journal of Agricultural Safety and Health

      Abstract:

      This article presents the results of a study assessing the physical and mental health of residents living in the vicinity of a large-scale swine confinement operation. Physical and mental health data were collected via personal interviews from a sample (n = 18) of all neighbors living within a two-mile radius of a 4,000-sow swine production facility. Results were compared to similar data collected from a random sample of demographically comparable rural residents (n = 18) living near minimal livestock production. Results indicate that neighbors of the large-scale swine operation reported experiencing significantly higher rates of four clusters of symptoms known to represent toxic or inflammatory effects on the respiratory tract. These clusters of symptoms have been well-documented among swine confinement workers. There was no evidence to suggest that neighbors of the large-scale swine operation suffered higher rates of psychological health problems manifested as anxiety or depression. A larger population-based study is needed to test the hypothesis that neighbors of large-scale swine operations experience elevated rates of physical health symptoms comparable to interior confinement workers.


      CHEEC Project:

      Citation:

      Thu, Kendall, Kelley Donham, Randy Ziegenhorn, Stephen Reynolds, Peter S. Thorne, Peryasamy Subramanian, Paul Whitten, and J. Stookesberry. "A control study of the physical and mental health of residents living near a large-scale swine operation." Journal of agricultural safety and health 3, no. 1 (1997): 13-26. DOI: 10.13031/2013.17747

    • Monday, July 31, 1995

      Review: The Application of GIS in Environmental Health Sciences: Opportunities and Limitations

      Author(s):
      U. Sunday Tim

      Journal Title:
      Environmental Research

      Abstract:

      Understanding the complex spatio-temporal relationships between environmental pollution and disease and identifying exposures to environmental hazards in high-risk populations are essential elements of an effective environmental and public health management program. Modern computer technologies, such as geographic information systems (GIS), provide cost effective tools for evaluating interventions and policies potentially affecting health outcomes. GIS analysis or display of environmental health data is also helpful in explaining disease patterns in terms of relationships with social, institutional, technological, and natural environments. This paper examines major issues related to the application of GIS in environmental health sciences. Specifically, the paper presents and discusses the basic principles, potential benefits, and major limitations of GIS in environmental health research. A real-world example application involving development and implementation of a prototype system called EMPHASIS (EnvironMental and Public Health datA analySIs System) to facilitate management, analysis, display, and presentation of environmental, socio-demographic, and health outcome data in Iowa is described. From the discussions and the example application, it is concluded that GIS can significantly add value to environmental and public health data in areas such as exploratory data analysis, hypotheses generation, confirmatory data analysis, and decision-making. The widespread adoption of GIS in these areas, however, is impeded by issues such as inconsistent spatial scales of the data, data quality and currency, lack of appropriate statistical functions for data analysis and interpretation, and data security and confidentiality.


      Citation:

      Tim, U. Sunday. "The application of GIS in environmental health sciences: opportunities and limitations." Environmental Research 71, no. 2 (1995): 75-88. DOI: 10.1006/enrs.1995.1069

    • Monday, October 26, 2009

      Effect of hybrid poplar trees on microbial populations important to hazardous waste bioremediation

      Author(s):
      James L. Jordahl
      Lesley Foster
      Jerald L. Schnoor
      Pedro J.J. Alvarez

      Journal Title:
      Environmental Toxicology and Chemistry

      Abstract:

      Microbial concentrations of denitrifiers, pseudomonads, and monoaromatic petroleum hydrocarbon (BTX) degraders were significantly higher (p < 0.1) in soil samples from the rhizosphere of poplar trees than in adjacent agricultural soils, and atrazine degraders were found only in one rhizosphere sample. The relative abundance of these phenotypes (as a fraction of total heterotrophs) was not significantly different between rhizosphere and surrounding soils. Therefore, the poplar rhizosphere enhanced the growth of microbial populations that participate in natural bioremediation without exerting selective pressure for them.


      Citation:

      Jordahl, James L., Lesley Foster, Jerald L. Schnoor, and Pedro JJ Alvarez. "Effect of hybrid poplar trees on microbial populations important to hazardous waste bioremediation." Environmental Toxicology and Chemistry 16, no. 6 (1997): 1318-1321. DOI: 10.1002/etc.5620160630 

    • Tuesday, September 1, 1992

      The Association of Waterborne Chloroform with Intrauterine Growth Retardation

      Author(s):
      Michael D. Kramer
      Charles F. Lynch
      Peter Isacson
      James W. Hanson

      Journal Title:
      Epidemiology

      Abstract:

      The potential reproductive effects of long-term, low-dose exposure to chloroform have received little attention despite the known, acute toxicity of high exposures and the widespread occurrence of low concentrations in drinking water. We studied the association of waterborne chloroform with low birthweight (<2,500 gm), prematurity (<37 weeks gestation), and intrauterine growth retardation (<5th percentile of weight for gestational age). Cases were not mutually exclusive, but each outcome was analyzed independently. Birth certificates from January 1, 1989, to June 30, 1990, were used to identify cases and randomly selected controls. All were live, singleton infants born to non-Hispanic, white women from Iowa towns with 1,000–5,000 inhabitants. Exposures to chloroform and other trihalomethanes were ecologic variables based on maternal residence and a 1987 municipal water survey. After adjustment for maternal age, parity, adequacy of prenatal care, marital status, education, and maternal smoking by multiple logistic regression, residence in municipalities where chloroform concentrations were ≥10 μg/liter was associated with an increased risk for intrauterine growth retardation (odds ratio = 1.8, 95% confidence interval = 1.1–2.9). The major limitations of this study involve the ascertainment and classification of exposures to trihalomethanes, including such issues as the imprecision of using aggregate municipal measures for classifying exposure at the level of the individual, the potential misclassification due to residential mobility, and the fluctuation of trihalomethane levels.


      Citation:

      Kramer, Michael D., Charles F. Lynch, Peter Isacson, and James W. Hanson. "The association of waterborne chloroform with intrauterine growth retardation." Epidemiology (1992): 407-413.

    • Tuesday, March 1, 1994

      Residential radon exposure and lung cancer: evidence of an urban factor in Iowa.

      Author(s):
      John S. Neuberger
      Charles F. Lynch
      Burton C. Kross
      R. William Field
      Robert F. Woolson

      Journal Title:
      Health Physics

      Abstract:

      An ecological study of lung cancer, cigarette smoking, and radon exposure was conducted in 20 Iowa counties. County-based lung cancer incidence data for white female residents of Iowa were stratified according to radon level and smoking status. Cancer incidence data for the period 1973-1990 were obtained from the State Health Registry of Iowa. Smoking level was determined from a randomly mailed survey. Radon level was determined according to an EPA supported charcoal canister survey. Within low smoking counties, rates for all lung cancer and small cell carcinoma were significantly lower (p < 0.05) in the high radon counties relative to the medium and low radon counties. However, within high smoking counties, rates for all lung cancer, adenocarcinoma, and small cell carcinoma were significantly higher (p < 0.05) in the high radon counties relative to the low radon counties. Variations in socioeconomic data for these counties, available through the 1980 and 1990 census, did not explain these results. Lung cancer rates also were significantly increased in urban counties even after holding smoking status constant. Multivariate analyses revealed significant interactions between smoking, urbanization, radon levels, and lung cancer. The results of this hypothesis generating study will be tested in a case/control study now ongoing in Iowa. Analysis will need to include separate evaluations by smoking status, radon level, and residence in urban or rural areas for the major morphologic types of lung cancer.


      Citation:

      Neuberger, John S., Charles F. Lynch, Burton C. Kross, R. William Field, and Robert F. Woolson. "Residential radon exposure and lung cancer: evidence of an urban factor in Iowa." Health physics 66, no. 3 (1994): 263-269. DOI: 10.1097/00004032-199403000-00005

    • Monday, January 1, 1996

      Residential radon-222 exposure and lung cancer: exposure assessment methodology

      Author(s):
      R. William Field
      Daniel J. Steck
      Charles F. Lynch
      Christine P. Brus
      John S. Neuberger
      Burton C. Kross

      Journal Title:
      Journal of Exposure Analysis and Environmental Epidemiology.

      Abstract:

      Although occupational epidemiological studies and animal experimentation provide strong evidence that radon-222 (222Rn) progeny exposure causes lung cancer, residential epidemiological studies have not confirmed this association. Past residential epidemiological studies have yielded contradictory findings. Exposure misclassification has seriously compromised the ability of these studies to detect whether an association exists between 222Rn exposure and lung cancer. Misclassification of 222Rn exposure has arisen primarily from: 1) detector measurement error; 2) failure to consider temporal and spatial 222Rn variations within a home; 3) missing data from previously occupied homes that currently are inaccessible; 4) failure to link 222Rn concentrations with subject mobility; and 5) measuring 222Rn gas concentration as a surrogate for 222Rn progeny exposure. This paper examines these methodological dosimetry problems and addresses how we are accounting for them in an ongoing, population-based, case-control study of 222Rn and lung cancer in Iowa


      Citation:

      Field RW, Steck DJ, Lynch DF, Brus CP, Neuberger JS, Kross BC. 1996. Residential radon-222 exposure and lung cancer: exposure assessment methodology. Journal of Exposure Analysis and Environmental Epidemiology 6(2): 181-195.

    • Friday, November 1, 1996

      Intercomparison of Waterborne 222Rn Collection Methods: Professional Vs. Homeowner Collection

      Author(s):
      R. William Field
      Burton C. Kross

      Journal Title:
      Groundwater Monitoring & Remediation

      Abstract:

      An intercomparison between trained professional and homeowner water collection techniques was conducted to assess the validity of using both inexperienced homeowner water collectors and mail‐in return of point‐of‐use water samples. The findings indicate that homeowner‐collected water samples obtained at the point of use inside the home and professionally collected water samples collected at an outside tap are comparable, especially if confounders, such as air bubbles in the sampling vials, are minimized.


      Citation:

      Field RW, Kross BC. Intercomparison of Waterborne 222Rn Collection Methods: Professional Vs. Homeowner Collection. Groundwater Monitoring & Remediation. 1996 Nov;16(4):106-12. DOI: 10.1111/j.1745-6592.1996.tb01177.x

    • Sunday, February 1, 1998

      Iowa survey of waterborne 222Rn concentrations in private wells.

      Author(s):
      RW Field
      BC Kross

      Journal Title:
      Health Physics

      Abstract:

      The major objective of the survey was to describe the distribution of waterborne 222Rn concentrations in Iowa's private well-water supplies. Well-water samples were obtained and analyzed for 222Rn from a random sample of 352 Iowa wells. The well-water 222Rn concentrations for the well sites were lognormally distributed and ranged from background concentrations to 87 Bq L-1, with a median value of 12 Bq L-1. The arithmetic mean 222Rn concentration for the sites was 16 Bq L-1 +/- 13 Bq L-1. The geometric mean 222Rn concentration was 12 Bq L-1 with a geometric standard deviation of 2.2. Over half of the samples (52%) exceeded 11 Bq L-1. Both well depth and indoor air 222Rn screening levels correlated with waterborne 222Rn concentrations; however, these correlations had very little predictive value. Glacial drift aquifers tended to have the highest 222Rn concentrations, although there was significant variance of 222Rn concentrations within all the aquifer classifications. In light of the estimate that 370 Bq L-1 of 222Rn in water may lead to 37 mBq L-1 in indoor air, the contribution of well-water derived indoor air 222Rn is minimal compared to ground sources in Iowa.


      Citation:

      Field RW, Kross BC. Iowa survey of waterborne 222Rn concentrations in private wells. Health physics. 1998 Feb;74(2):249. DOI: 10.1097/00004032-199802000-00011

    • Thursday, November 1, 1990

      The Iowa state-wide rural well-water survey water-quality data: Initial analysis.

      Author(s):
      BC Kross
      GR Hallberg
      DR Bruner
      RD Libra
      KD Rex
      LMB Weih
      ME Vermace
      LF Burmeister
      NH Hall
      KL Cherryholmes
      JK Johnson
      MI Selim
      BK Nations
      LS Seigley
      DJ Quade
      AG Dudler
      KD Sesker
      MA Culp
      CF Lynch
      HF Nicholson
      JP Hughes

      Journal Title:
      Technical Information Series 19

      Abstract:

      The State-Wide Rural Well-Water Survey (SWRL) was conducted between April 1988 and June 1989 by the Iowa Department of Natural Resources and the University of Iowa Center for Health Effects of Environmental Contamination. SWRL was designed to provide a statistically valid assessment of the proportion of private rural wells and rural Iowa residents affected by various environmental contaminants. The survey was a systematic sample, stratified by rural population density. SWRL demographic data indicate the sample is clearly representative of rural Iowans.

      Primary samples were analyzed for total coliform bacteria; nitrate (+ nitrite)-N, ammonium-N, and organic-N; major inorganic ions; 27 pesticides, and 5 pesticide metabolites. Existing agency and laboratory USEPA quality assurance, quality control plans were utilized and verified for SWRL. SWRL collected and analyzed 1,048 water samples from 686 sites.

      SWRL was conducted during the driest consecutive two-year period on record in Iowa, with precipitation averaging 14 inches below normal. Monitoring studies indicate the drought limited the movement of contaminants to groundwater. Hence, the SWRL results may present a ‘best-case' water-quality situation because of the temporal coincidence with the drought.

      The SWRL data provide a population-based summary of the drinking water used by rural Iowans, and a cross-section of the quality of Iowa groundwater. The variations in water quality exhibited in the SWRL data, both regionally and particularly with depth, show consistent and predictable geochemical patterns, related to contaminant sources, transport, and age effects. Iowa well waters are near neutral and dissolved ions are dominated by calcium, magnesium, bicarbonate, and in some cases, sulfate. Mean concentrations for all ions, except chloride (Cl) and nitrate (N03-N), increase or remain fairly constant with depth. The higher concentrations of Cl and N03-N at shallow depths are related to their surficial sources. State-wide, 1.3 % of private well waters exceeded the USEPA maximum contaminant level (MCL) for fluoride (F), and 2.5% exceeded the secondary standard of 2 mg/L. Private well water should be analyzed to assess the natural F content before a supplement is prescribed, to avoid problems with dental fluorosis.

      About 18% of Iowa's private, rural drinking-water wells contained N03-N > 10 mg/L, the recommended health advisory level (HAL); 37% of wells have >3 mg/L, typically considered indicative of anthropogenic pollution. Approximately 14% of wells had detections of pesticides: 16 pesticide compounds were detected, including 11 parent compounds and 5 environmental metabolites; 16 pesticides were not detected. Atrazine and its metabolites were found in 8% of wells. Multiple residues were detected in all regions of the state. The mean concentrations were generally < 1 ug/L. Lifetime HALS were exceeded in 1.2 % of private, rural wells in Iowa.

      Approximately 45% of sites were positive for total coliform bacteria. Total coliforms are ubiquitous constituents of soils, surface water, and shallow groundwater and cannot be equated to fecal coliforms. Only 7% of water systems were positive for fecal coliform bacteria. The only sound, general interpretation of a persistent presence of total coliforms is that the water system is allowing interaction with soil, soil-water, shallow groundwater, or possibly surface water. This can indicate that the system is prone to other forms of contamination.

      Individually, or in combination, nearly 55% of rural water supplies exhibited total coliform positives, N03-N > 10 mg/L, and/or pesticide detections. Using fecal coliforms only, this reduces to about 30% of well-water supplies. Based on 1980 Census data, about 130,000 rural Iowa residents consume drinking water from private wells with > 10 mg/L, N03-N; 94,000 use water with one or more pesticides; 5,400 use water with a pesticide concentration above an HAL.

      Statistical analyses show significant associations between many water-quality parameters but the associations are not strong predictors based on state-wide data. By far the most significant factor explaining water-quality variations is well depth. An apparent relationship among total coliforms, N03-N, and pesticides is primarily a function of their co-occurrence related to well depth. Total coliform bacteria are very poor predictors of these chemical contaminants. If a prediction were based on the presence of total coliform, the probability is better that they would not occur in the water supply.

      Consistent relationships among N03-N, dissolved oxygen, and ammonium-N with well depth suggest that nitrate reduction and/or denitrification occurs with depth in groundwater systems in Iowa. It is not clear from these data if the deeper groundwater system has the capacity to denitrify the nitrate loads currently being delivered to the system, however.

      The effects of sinkholes or agricultural drainage wells are not significant in a state-wide context. Sinkholes were identified in the vicinity of only 2.1% of sites and only 0.6% of sites were near agricultural drainage wells (ADW). No sites reporting ADWs had any pesticide detections or N03-N > 10 mg/L. Non-farm, suburban housing tracts exhibited the most significant association between land use and water quality; proportionately, these areas show substantially fewer wells with > 10 mg/L N03-N and total coliform bacteria. Wells <50 feet from septic systems, showed less nitrate and significantly fewer positives for total and fecal coliform bacteria.

      Point source problems affect only a small proportion of wells state-wide. Wells located in feedlots showed significantly higher concentrations of nitrate, but not bacteria problems. Such sites comprise only about 3% of wells state-wide, and account for only about 1% of the wells with > 10 mg/L, N03-N. Sites where herbicides were mixed within 15 feet of the well showed greater pesticide detections, but again the proportion of wells is low, about 3%, state-wide. Wells located within 15 feet of chemical storage and handling areas are uncommon, occurring at <0.6% of rural sites, and none of these wells contained pesticides or N03-N > 10 mg/L.

      About 5.5% of private water wells in Iowa have experienced a spill or back-siphoning accident with pesticides or fertilizers. These sites exhibit a greater proportion of pesticide detections and high nitrate concentrations than average, as expected, but at the majority of sites the pesticides detected were not those involved in the accident. The sites exceeding HALs for pesticides occurred throughout the state. The sites were dominated by shallow wells; one deep well was involved, and this was a point source case which could affect any depth of well. Two of the sites, 25%, are clearly point source cases, a spill and back-siphoning accident (alachlor and trifluralin); the majority, 62.5%, are probable nonpoint sources related to pesticide occurrences in shallow groundwater (alachlor and atrazine); 1 case, 12.5%, is equivocal (atrazine).

      Well depth is a major variable related to well-water quality, affecting the potential for surficial contaminants to enter a well. The degree of contamination is far greater in shallow wells and significant contamination occurs in wells up to 100 feet deep. Wells < 100 feet deep comprise 50% of wells state-wide and account for 70% of total coliform positives, 80% of fecal coliform positives, 64% of pesticide detections and total atrazine detections, and 89% of wells with N03-N > 10 mg/L. In NE Iowa the depth of contamination is greater because of the deeper groundwater circulation. The greatest proportions of contaminated wells occur in the SC, SW, and NW regions, paralleling regional dependence on shallow wells. In these regions nearly 75% of wells are < 100 feet deep (dominantly seepage wells) because alternative water sources are limited.

      Certain factors of well construction or placement may afford easy entry of shallow, contaminated groundwater. But these factors are not causes of contamination; if the contaminants were not in the environment they would not get into the soil water and groundwater, or the well. Remediation of well construction or replacing current wells with deeper wells would undoubtedly reduce nitrate and pesticide contamination in many locations, but this would not address the cause of the contamination. The sources of contamination must be addressed because these shallow groundwaters will be the recharge for deeper groundwater with time. Sanitary and structural improvements of private water systems are also needed.

      Extrapolating from temporal samples provides an upper limit estimate of wells with likely detections, at sometime over the course of a year: 1. wells > 10 mg/L N03-N 21%; 2. wells with any pesticide detections 30%; 3. wells with atrazine detections 15%. The systematically selected 10% repeat sites provide a consistent representation of the state-wide data, including representative detections of pesticides down to a 1% occurrence interval. These wells can provide a subset for monitoring trends over time.


      Citation:
    • Saturday, March 1, 1997

      Intrauterine growth retardation in Iowa communities with herbicide-contaminated drinking water supplies.

      Author(s):
      Ronald Munger
      Peter Isacson
      Song Hu
      Trudy Burns
      James Hanson
      Charles F. Lynch
      Keith Cherryholmes
      Paul Van Dorpe
      William J. Hausler, jr

      Journal Title:
      Environmental Health Perspectives

      Abstract:

      In a statewide survey of 856 Iowa municipal drinking water supplies in 1986-1987 the Rathbun rural water system was found to contain elevated levels of triazine herbicides. Rates of low birth weight, prematurity, and intrauterine growth retardation (IUGR) in live singleton births during the period 1984-1990 by women living in 13 communities served by the Rathbun water system were compared to other communities of similar size in the same Iowa counties. The Rathbun communities had a greater risk of IUGR than southern Iowa communities with other surface sources of drinking water (relative risk = 1.8; 95% CI = 1.3, 2.7). Multiple linear regression analyses revealed that levels of the herbicides atrazine, metolachlor, and cyanzinc were each significant predictors of community IUGR rates in southern Iowa after controlling for several potentially confounding factors including maternal smoking and socioeconomic variables. The association with IUGR was strongest for atrazine, but all three herbicides were intercorrelated and the independent contributions of each to IUGR risk could not be determined. We conclude that communities in southern Iowa with drinking water supplies contaminated with herbicides have elevated rates of IUGR compared to neighboring communities with different water supplies. Because of the limitations of the ecologic design of this study, including aggregate rather than individual measures of exposure and limited ability to control for confounding factors related to source of drinking water and risk of IUGR, a strong causal relationship between any specific water contaminant and risk of IUGR cannot yet be inferred. The association between the water supplied to the Rathbun communities and the increased risk of IUGR should be considered a preliminary finding that needs to be verified by more detailed epidemiologic studies.


      CHEEC Project:

      Citation:

      Munger R, Isacson P, Hu S, Burns T, Hanson J, Lynch CF, Cherryholmes K, Van Dorpe P, Hausler Jr WJ. Intrauterine growth retardation in Iowa communities with herbicide-contaminated drinking water supplies. Environmental Health Perspectives. 1997 Mar;105(3):308. DOI: 10.1289/ehp.97105308

    • Monday, June 1, 1992

      Birth defects and pesticide-contaminated water supplies in Iowa

      Author(s):
      Ronald Munger
      Peter Isacson
      M Kramer
      James Hanson
      Trudy Burns
      Keith Cherryholmes

      Journal Title:
      American Journal of Epidemiology

      Citation:

      Munger R, Isacson P, Kramer M, Hanson J, Burns T, Cherryholmes K, Hausler Jr W. Birth defects and pesticide-contaminated water supplies in Iowa. Am J Epidemiol. 1992 Jun;136(8):959.

    • Wednesday, September 1, 1993

      Mineralization and Uptake of Triazine Pesticide in Soil-Plant Systems

      Author(s):
      Dhileepan R. Nair
      Joel G. Burken
      Louis A. Licht
      Jerald L. Schnoor

      Journal Title:
      Journal of Environmental Engineering

      Abstract:

      Deep‐rooted trees planted as a buffer zone can intercept runoff and eroded sediments, thus reducing non‐point‐source pollution due to agricultural chemicals. In this study, Populus sp. were grown in bioreactors with an agricultural soil (silt‐loam) and in a silica‐sand media; both were spiked with 14C uniformly ring‐labeled atrazine. The plants took up over 11% of the 14C labeled atrazine applied to the silt‐loam soil and over 91% of that applied to the silica sand media, with the majority of the 14C accumulating as nonphytotoxic metabolites in the leaves. Research suggests that, in addition to nutrient uptake, poplar tree buffer strips may be effective in removing atrazine from agricultural percolation and runoff water.


      CHEEC Project:

      Citation:

      Nair DR, Burken JG, Licht LA, Schnoor JL. Mineralization and uptake of triazine pesticide in soil-plant systems. Journal of Environmental Engineering. 1993 Sep;119(5):842-54. DOI: 10.1061/(ASCE)0733-9372(1993)119:5(842)

    • Thursday, July 1, 1993

      Effect of soil conditions on model parameters and atrazine mineralization rates

      Author(s):
      Dhileepan R. Nair
      Jerald L. Schnoor

      Journal Title:
      Water Research

      Abstract:

      Transformation of pesticides is dependent on soil environmental conditions and knowledge of this is necessary to improve subsurface fate and transport pesticide models. Laboratory experiments were performed using 14C ring and isopropyl side-chain labeled atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) applied to three Iowa soils incubated in batch reactors under different environmental conditions. Mineralization of both the ring and isopropyl side chain carbons was proportional to the organic matter content of the soils and oxygen content. Atrazine ring carbon mineralization also increased with soil water content. Oxygen limitation in soils reduced the bio-transformation rate of atrazine, and mineralization was much slower under denitrifying conditions. Empirical models were developed to represent the mineralization rate of atrazine ring carbon and isopropyl side-chain carbon for varying soil organic matter, soil water content, temperature, and oxygen partial pressure.


      CHEEC Project:

      Citation:

      Nair DR, Schnoor JL. Effect of soil conditions on model parameters and atrazine mineralization rates. Water research. 1994 May 1;28(5):1199-205. DOI: 10.1016/0043-1354(94)90208-9

    • Sunday, August 1, 1993

      Factors Associated With Elevated 222Rn Levels in Iowa

      Author(s):
      R. William Field
      Burton C. Kross
      LeAnn M. Weih
      Laverle J. Vust
      Howard F. Nicholson

      Journal Title:
      Health Physics

      Abstract:

      The University of Iowa, in conjunction with the Environmental Protection Agency's State Radon Survey Assistance Program, performed a 222Rn screening survey of 582 rural households in the winter of 1989. The distribution of maximum indoor 222Rn concentrations throughout Iowa as well as the relationship between 222Rn screening measurements, detector placement, and housing characteristics are summarized. This report is unique in that site-specific home construction characteristics were collected in the field from participants prior to 222Rn monitoring. The findings of the survey indicate that the significance of a particular housing characteristic on a 222Rn screening measurement is dependent on the placement of the radon detector.


      CHEEC Project:

      Citation:

      Field RW, Kross BC, Weih LM, Vust LJ, Nicholson HF. Factors associated with elevated 222Rn levels in Iowa. Health physics. 1993 Aug;65(2):178-84. DOI: 10.1097/00004032-199308000-00008

    • Thursday, April 12, 2018

      High prevalence of elevated blood lead levels in both rural and urban Iowa newborns: Spatial patterns and area-level covariates

      Author(s):
      Margaret Carrel
      David Zahrieh
      Sean G. Young
      Jacob Oleson
      Kelli K. Ryckman
      Brian Wels
      Donald L. Simmons
      Audrey Saftlas

      Journal Title:
      PloS one

      Abstract:

      Lead in maternal blood can cross the placenta and result in elevated blood lead levels in newborns, potentially producing negative effects on neurocognitive function, particularly if combined with childhood lead exposure. Little research exists, however, into the burden of elevated blood lead levels in newborns, or the places and populations in which elevated lead levels are observed in newborns, particularly in rural settings. Using ~2300 dried bloods spots collected within 1–3 days of birth among Iowa newborns, linked with the area of mother’s residence at the time of birth, we examine the spatial patterns of elevated (>5 μg/dL) blood lead levels and the ecological-level predictors of elevated blood lead levels. We find that one in five newborns exceed the 5 μg/dL action level set by the US Centers for Disease Control & Prevention (CDC). Bayesian spatial zero inflated regression indicates that elevated blood lead in newborns is associated with areas of increased pre-1940s housing and childbearing-age women with low educational status in both rural and urban settings. No differences in blood lead levels or the proportion of children exceeding 5 μg/dL are observed between urban and rural maternal residence, though a spatial cluster of elevated blood lead is observed in rural counties. These characteristics can guide the recommendation for testing of infants at well-baby appointments in places where risk factors are present, potentially leading to earlier initiation of case management. The findings also suggest that rural populations are at as great of risk of elevated blood lead levels as are urban populations. Analysis of newborn dried blood spots is an important tool for lead poisoning surveillance in newborns and can direct public health efforts towards specific places and populations where lead testing and case management will have the greatest impact.


      CHEEC Project:

      Citation:

      Carrel M, Zahrieh D, Young SG, Oleson J, Ryckman KK, Wels B, Simmons DL, Saftlas A. Correction: High prevalence of elevated blood lead levels in both rural and urban Iowa newborns: Spatial patterns and area-level covariates. PloS one. 2018 Apr 12;13(4):e0196002. DOI: 10.1371/journal.pone.0177930

    • Friday, March 4, 2016

      Evaluation of a low-cost aerosol sensor to assess dust concentrations in a swine building

      Author(s):
      Samuel Jones
      T. Renee Anthony
      Sinan Sousah

      Journal Title:
      Annals of Occupational Hygiene

      Abstract:

      Exposure to dust is a known occupational hazard in the swine industry, although efforts to measure exposures are labor intensive and costly. In this study, we evaluated a Dylos DC1100 as a low-cost (~$200) alternative to assess respirable dust concentrations in a swine building in winter. Dust concentrations were measured with collocated monitors (Dylos DC1100; an aerosol photometer, the pDR-1200; and a respirable sampler analyzed gravimetrically) placed in two locations within a swine farrowing building in winter for 18–24-h periods. The particle number concentrations measured with the DC1100 were converted to mass concentration using two methods: Physical Property Method and Regression Method. Raw number concentrations from the DC1100 were highly correlated to mass concentrations measured with the pDR-1200 with a coefficient of determination (R2) of 0.85, indicating that the two monitors respond similarly to respirable dust in this environment. Both methods of converting DC1100 number concentrations to mass concentrations yielded strong linear relationships relative to that measured with the pDR-1200 (Physical Property Method: slope = 1.03, R2 = 0.72; Regression Method: slope = 0.72, R2 = 0.73) and relative to that measured gravimetrically (Physical Property Method: slope = 1.08, R2 = 0.64; Regression Method: slope = 0.75, R2 = 0.62). The DC1100 can be used as a reasonable indicator of respirable mass concentrations within a CAFO and may have broader applicability to other agricultural and industrial settings.


      CHEEC Project:

      Citation:

      Jones S, Anthony TR, Sousan S, Altmaier R, Park JH, Peters TM. Evaluation of a low-cost aerosol sensor to assess dust concentrations in a swine building. Annals of Occupational Hygiene. 2016 Mar 4;60(5):597-607. DOI: 10.1093/annhyg/mew009

    • Sunday, February 1, 2015

      PCB126 inhibits adipogenesis of human preadipocytes

      Author(s):
      Gopi Gadupudi
      Francoise A. Gourronc
      Gabriele Ludewig
      Larry W. Robertson
      Aloysius J. Klingelhutz

      Journal Title:
      Toxicology in Vitro

      Abstract:

      Emerging evidence indicates that persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), are involved in the development of diabetes. Dysfunctional adipocytes play a significant role in initiating insulin resistance. Preadipocytes make up a large portion of adipose tissue and are necessary for the generation of functional mature adipocytes through adipogenesis. PCB126 is a dioxin-like PCB and a potent aryl hydrocarbon receptor (AhR) agonist. We hypothesized that PCB126 may be involved in the development of diabetes through disruption of adipogenesis. Using a newly developed human preadipocyte cell line called NPAD (Normal PreADipocytes), we found that exposure of preadipocytes to PCB126 resulted in significant reduction in their subsequent ability to fully differentiate into adipocytes, more so than when the cells were exposed to PCB126 during differentiation. Reduction in differentiation by PCB126 was associated with downregulation of transcript levels of a key adipocyte transcription factor, PPARγ, and late adipocyte differentiation genes. An AhR antagonist, CH223191, blocked this effect. These studies indicate that preadipocytes are particularly sensitive to the effects of PCB126 and suggest that AhR activation inhibits PPARγ transcription and subsequent adipogenesis. Our results validate the NPAD cell line as a useful model for studying the effects of POPs on adipogenesis.


      CHEEC Project:

      Citation:

      Gadupudi G, Gourronc FA, Ludewig G, Robertson LW, Klingelhutz AJ. PCB126 inhibits adipogenesis of human preadipocytes. Toxicology in Vitro. 2015 Feb 1;29(1):132-41. DOI: 10.1016/j.tiv.2014.09.015

    • Friday, October 12, 2018

      Ligand-Centered Borenium Reactivity in Triaminoborane-Bridged Diphosphine Complexes

      Author(s):
      Kyounghoon Lee
      Clara Kirkvold
      Bess Vlaisavljevich
      Scott R. Daly

      Journal Title:
      Inorganic Chemistry

      Abstract:

      Borenium ions (i.e., three-coordinate boron cations) are known to promote a wide variety of stoichiometric and catalytic reactions because of their high Lewis acidity. As demonstrated by the growing number of chemically reactive borane ligands, there is considerable interest in developing ligands with highly electrophilic boron sites that promote multisite reactivity in metal complexes. However, there are currently few examples of ligand-centered borenium ions, especially with ligands that form coordination complexes with a wide range of metals. Here we report borenium-like reactivity on a highly versatile diphosphine ligand. Treating (PhTBDPhos)NiCl2 (1) with strong Bronsted acids such as HBF4·Et2O, HOTf, or HNTf2 resulted in fluoride or chloride abstraction from BF4 or NiCl2, respectively, to form trans N–H and B–X bonds on the ligand backbone. HCl addition to the bridgehead N–B bond is reversible, and the reactivity depends on the identity of the supporting counteranions, as observed when treating [(PhTBDPhos)NiCl]2X2, where X = NTf2 (3), OTf (4), or BArF4 (5), with HCl. The reaction of 4 with HNTf2 instead of HCl yielded NMR evidence of the latent borenium cation in solution and showed how poor nucleophiles such as triflate bind to the borenium ion in the solid state. Remarkably, replacing the chloride ligands in 1 with chelating and less-labile thiolates or catecholates, or changing the phosphorus substituents (phenyl to isopropyl), attenuates the reactivity on the ligand backbone. Density functional theory was used to quantify the reaction free energies, and the theoretical results corroborate the experimental observations. Given the broad utility of diphosphines in homogeneous catalysis and the known benefits of strong Lewis acid promotors in many catalytic reactions, we anticipate that the results will provide new opportunities for dual-site reactivity involving boron ligands and metals.


      CHEEC Project:

      Citation:

      Lee K, Kirkvold C, Vlaisavljevich B, Daly SR. Ligand-Centered Borenium Reactivity in Triaminoborane-Bridged Diphosphine Complexes. Inorganic Chemistry. 2018 Oct 12. DOI: 10.1021/acs.inorgchem.8b01601

    • Tuesday, October 16, 2018

      Triaminoborane-bridged diphosphine complexes with Ni and Pd: coordination chemistry, structures, and ligand-centered reactivity

      Author(s):
      Kyounghoon Lee
      Courtney M. Donahue
      Scott R. Daly

      Journal Title:
      Dalton Transactions

      Abstract:

      The synthesis, coordination chemistry, and reactivity of two diphosphines containing the cyclic triaminoborane 1,8,10,9-triazaboradecalin (TBD) are described. To evaluate the ligand-centered reactivity of PhTBDPhos and iPrTBDPhos, the complexes (PhTBDPhos)MCl2 and (iPrTBDPhos)MCl2, where M = Ni and Pd, were prepared and characterized by elemental analysis, multinuclear NMR spectroscopy (1H, 13C, 31P, and 11B), and single-crystal X-ray diffraction (XRD). Despite very low boron Lewis acidity in the TBD backbone, (PhTBDPhos)NiCl2 (1) and (PhTBDPhos)PdCl2 (3) react with H2O, alcohols, and hydrated fluoride reagents in the presence of NEt3 to yield trans H–O or H–F addition across the bridgehead N–B bond. In contrast, iPrTBDPhos shows no appreciable reactivity when bound to NiCl2 (2) and PdCl2 (4), which is attributed to the sterically-bulky isopropyl substituents blocking substrate access to boron in the TBD backbone. The new complexes {[(PhTBDPhos-H2O)Ni]2(μ-OH)2}Cl2 (5), {[(PhTBDPhos-H2O)Pd]2(μ-OH)2}Cl2 (6), (PhTBDPhos-MeOH)NiCl2 (7), (PhTBDPhos-MeOH)PdCl2 (8), (PhTBDPhos-C3H5OH)PdCl2 (9), and {[(PhTBDPhos-HF)Ni]2(μ-OH)2}Cl2 (10) were isolated, and all but 6 were structurally characterized by single-crystal XRD. Multinuclear NMR studies revealed that isolated, crystallographically-authenticated samples of 5–9 lose ligand-bound water or alcohol with reappearance of starting materials 1 and 3 when dissolved in NMR solvents. Addition of NEt3 attenuated the water and alcohol loss from 5–9 to allow 1H, 13C, 31P, and 11B NMR data to be collected for all the compounds, confirming the determined structures. Additional reactivity experiments with NaOMe and fluoride reagents suggested that participation of the bridgehead nitrogen in the TBD backbone is important for promoting reactivity at boron when PhTBDPhos is bound to Ni and Pd. The term “cooperative ligand-centered reactivity” (CLR) is proposed to define chemical reactions that appear to require participation of more than one atom on the ligand, such as those reported here.


      CHEEC Project:

      Citation:

      Lee K, Donahue CM, Daly SR. Triaminoborane-bridged diphosphine complexes with Ni and Pd: coordination chemistry, structures, and ligand-centered reactivity. Dalton Transactions. 2017;46(29):9394-406. DOI: 10.1039/C7DT02144E.

    • Monday, January 1, 2018

      Distinguishing between metabolically active and dormant bacteria on paper

      Author(s):
      Stephanie A. Hice
      Miguel C. Santoscoy
      Michelle L. Soupir
      Rebecca Cademartiri

      Journal Title:
      Applied Microbiology and Biotechnology

      Abstract:

      Switching between metabolically active and dormant states provides bacteria with protection from environmental stresses and allows rapid growth under favorable conditions. This rapid growth can be detrimental to the environment, e.g., pathogens in recreational lakes, or to industrial processes, e.g., fermentation, making it useful to quickly determine when the ratio of dormant to metabolically active bacteria changes. While a rapid increase in metabolically active bacteria can cause complications, a high number of dormant bacteria can also be problematic, since they can be more virulent and antibiotic-resistant. To determine the metabolic state of Escherichia coli and Salmonella Typhimurium, we developed two paper-based colorimetric assays. The color changes were based on oxidoreductases reducing tetrazolium salts to formazans, and alkaline phosphatases cleaving phosphates from nitrophenyl phosphate salt. Specifically, we added iodophenyl-nitrophenyl-phenyl tetrazolium salt (INT) and methylphenazinium methyl sulfate to metabolically active bacteria on paper and INT and para-nitrophenyl phosphate salt to dormant bacteria on paper. The color changed in less than 60 min and was generally visible at 103 CFU and quantifiable at 106 CFU. The color changes occurred in both bacteria, since oxidoreductases and alkaline phosphatases are common bacterial enzymes. On one hand, this feature makes the assays suitable to a wide range of applications, on the other, it requires specific capture, if only one type of bacterium is of interest. We captured Salmonella or E. coli with immobilized P22 or T4 bacteriophages on the paper, before detecting them at levels of 102 or 104 CFU, respectively. Determining the ratio of the metabolic state of bacteria or a specific bacterium at low cost and in a short time, makes this methodology useful in environmental, industrial and health care settings.


      CHEEC Project:

      Citation:

      Hice SA, Santoscoy MC, Soupir ML, Cademartiri R. Distinguishing between metabolically active and dormant bacteria on paper. Applied microbiology and biotechnology. 2018 Jan 1;102(1):367-75. DOI: 10.1007/s00253-017-8604-y

    • Wednesday, April 5, 2017

      Occurrence of Neonicotinoid Insecticides in Finished Drinking Water and Fate during Drinking Water Treatment

      Author(s):
      Kathryn L. Klarich
      Nicholas C. Pflug
      Eden M. DeWald
      Michelle L. Hladik
      Dana W. Kolpin
      David M. Cwiertny
      Gregory H. LeFevre

      Journal Title:
      Environmental Science & Technology Letters

      Abstract:

      Neonicotinoid insecticides are widespread in surface waters across the agriculturally intensive Midwestern United States. We report for the first time the presence of three neonicotinoids in finished drinking water and demonstrate their general persistence during conventional water treatment. Periodic tap water grab samples were collected at the University of Iowa over 7 weeks in 2016 (May–July) after maize/soy planting. Clothianidin, imidacloprid, and thiamethoxam were ubiquitously detected in finished water samples at concentrations ranging from 0.24 to 57.3 ng/L. Samples collected along the University of Iowa treatment train indicate no apparent removal of clothianidin or imidacloprid, with modest thiamethoxam removal (∼50%). In contrast, the concentrations of all neonicotinoids were substantially lower in the Iowa City treatment facility finished water using granular activated carbon (GAC) filtration. Batch experiments investigated potential losses. Thiamethoxam losses are due to base-catalyzed hydrolysis under high-pH conditions during lime softening. GAC rapidly and nearly completely removed all three neonicotinoids. Clothianidin is susceptible to reaction with free chlorine and may undergo at least partial transformation during chlorination. Our work provides new insights into the persistence of neonicotinoids and their potential for transformation during water treatment and distribution, while also identifying GAC as a potentially effective management tool for decreasing neonicotinoid concentrations in finished drinking water.


      CHEEC Project:

      Citation:

      Klarich KL, Pflug NC, DeWald EM, Hladik ML, Kolpin DW, Cwiertny DM, LeFevre GH. Occurrence of neonicotinoid insecticides in finished drinking water and fate during drinking water treatment. Environmental Science & Technology Letters. 2017 Apr 5;4(5):168-73. DOI: 10.1021/acs.estlett.7b00081

    • Saturday, September 1, 2001

      Tea Consumption and Risk of Cancer of the Colon and Rectum

      Author(s):
      James R. Cerhan
      Shannon D. Putnam
      Greg D. Bianchi
      Alexander S. Parker
      Charles F. Lynch
      Kenneth P. Cantor

      Journal Title:
      Nutrition and Cancer

      Abstract:

      The association between tea consumption and risk of colon and rectal cancers was investigated in a population-based case-control study conducted in Iowa (United States). Colon (n = 685) and rectal (n = 655) cancer cases age 40–85 yr were identified through the Iowa Surveillance, Epidemiology, and End Results (SEER) Cancer Registry (86% response rate); controls (n = 2,434) were frequency matched by sex and 5-yr age group (80% response rate). The usual adult consumption of tea (hot and iced), along with other information including dietary data, was selfreported using a mailed questionnaire. Total tea consumption (cups/day) was categorized as none (reference category), low (3.1), medium (3.1–5.0), and high (5.0), with cut points for tea consumers based on the 75th and 90th percentiles of use among controls. Unconditional logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals. There was no association between total tea consumption and colon cancer (ORs = 1.0, 1.1, 1.3, and 0.7) or rectal cancer (ORs = 1.0, 0.9, 1.4, and 1.0) after adjustment for age, sex, education, physical activity, smoking history, and intake of coffee, fiber, and fruits and vegetables. Results were similar when hot tea and iced tea were evaluated individually. Further adjustment for other colorectal cancer risk factors did not alter these results. There was no association with proximal or distal colon cancer. There was also no interaction between tea consumption and any of the dietary variables or total fluid on risk of colon or rectal cancer, with the exception of a suggestive positive association between an increasing frequency of tea consumption and colon cancer risk among current smokers (multivariate ORs = 1.0, 1.4, 2.0, and 1.8; P for trend = 0.1), but not among never smokers (multivariate ORs = 1.0, 1.0, 1.1, and 0.4; P for trend = 0.3). These data do not support an overall association, either positive or negative, between tea consumption and risk of colon or rectal cancer in this Midwestern US population.


      Citation:

      James R. Cerhan , Shannon D. Putnam , Greg D. Bianchi , Alexander S. Parker , Charles F. Lynch & Kenneth P. Cantor (2001) Tea Consumption and Risk of Cancer of the Colon and Rectum, Nutrition and Cancer, 41:1-2, 33-40, DOI: 10.1080/01635581.2001.9680609

    • Saturday, March 1, 2003

      Nitrate in Public Water Supplies and Risk of Bladder Cancer

      Author(s):
      Mary H Ward
      Kenneth P Cantor
      David Riley
      Shannon Merkle
      Charles F. Lynch

      Journal Title:
      Epidemiology

      Abstract:

      Background. Nitrate is a precursor compound in the formation of N-nitroso compounds, most of which are potent animal carcinogens. N-nitroso compounds and their precursors have not been extensively evaluated as bladder cancer risk factors.

      Methods. We conducted a population-based case-control study of bladder cancer in Iowa. Cases were men and women newly diagnosed with bladder cancer in 1986-1989. Nitrate data for Iowa public water supplies were sparse before the 1960s. To reduce misclassification by unknown nitrate levels, we included only those who used public supplies with nitrate data for 70% or more of their person-years since 1960 (808 cases, 1259 controls).

      Results. Among controls, the median average nitrate level for their Iowa residences with public water supplies was 1.3 mg/liter nitrate-nitrogen (interquartile range = 0.6-3.0). After adjustment for confounders, we found no increased risk of bladder cancer with increasing average nitrate levels in drinking water; the highest quartile odds ratio for women was 0.8 (95% confidence interval = 0.4-0.8), and for men 0.5 (0.4-0.8). We observed no association among those with high water nitrate exposure (>median) and low (
      Conclusions. Our data suggest that long-term exposure to nitrate in drinking water at levels in this study (90th percentile 5.5 mg/liter nitrate-nitrogen) is not associated with risk of bladder cancer.

      Citation:

      Ward, Mary H., Kenneth P. Cantor, David Riley, Shannon Merkle, and Charles F. Lynch. "Nitrate in public water supplies and risk of bladder cancer." Epidemiology 14, no. 2 (2003): 183-190.

    • Monday, November 1, 2004

      Use of Qualitative and Quantitative Information in Neural Networks for Assessing Agricultural Chemical Contamination of Domestic Wells

      Author(s):
      Arabinda Mishra
      Chittaranjan Ray
      Dana W. Kolpin

      Journal Title:
      Journal of Hydrologic Engineering

      Abstract:

      A neural network analysis of agrichemical occurrence in groundwater was conducted using data from a pilot study of 192 small-diameter drilled and driven wells and 115 dug and bored wells in Illinois, a regional reconnaissance network of 303 wells across 12 Midwestern states, and a study of 687 domestic wells across Iowa. Potential factors contributing to well contamination (e.g., depth to aquifer material, well depth, and distance to cropland) were investigated. These contributing factors were available in either numeric (actual or categorical) or descriptive (yes or no) format. A method was devised to use the numeric and descriptive values simultaneously.  Training of the network was conducted using a standard backpropagation algorithm. Approximately 15% of the data was used for testing.  Analysis indicated that training error was quite low for most data. Testing results indicated that it was possible to predict the contamination potential of a well with pesticides. However, predicting the actual level of contamination was more difficult. For pesticide occurrence in drilled and driven wells, the network predictions were good. The performance of the network was poorer for predicting nitrate occurrence in dug and bored wells. Although the data set for Iowa was large, the prediction ability of the trained network was poor, due to descriptive or categorical input parameters, compared with smaller data sets such as that for Illinois, which contained more numeric information.


      Citation:

      Mishra, Arabinda, Chittaranjan Ray, and Dana W. Kolpin. "Use of qualitative and quantitative information in neural networks for assessing agricultural chemical contamination of domestic wells." Journal of Hydrologic Engineering 9, no. 6 (2004): 502-511.

    • Wednesday, September 24, 2008

      Comparison of Farmers in the Agricultural Health Study to the 1992 and 1997 Censuses of Agriculture

      Author(s):
      Charles F. Lynch
      Nancy L. Sprince
      Ellen Heywood
      Joy Pierce
      Nyla Logsden-Sackett
      Margaret Pennybacker
      Michael C. R. Alavanja

      Journal Title:
      Journal of Agromedicine

      Abstract:

      Context: The Agricultural Health Study (AHS) is a large, prospective cohort study in the states of Iowa and North Carolina that has been developed to better understand how pesticides and other agricultural exposures relate to the occurrence of cancer and other diseases.

      Purpose: This report compares the characteristics of AHS farmers to the Census of Agriculture to evaluate the generalizability of AHS findings.

      Methods: We restricted the AHS to private pesticide applicators who enrolled in Iowa (n = 31,065) and in North Carolina (n = 17,239) between 1993 and 1997, and who identified themselves as living or working on a farm. We compared their self-reported data with data from the 1992 and 1997 Censuses of Agriculture.

      Findings: AHS farmers in Iowa are younger; live or work on larger farms; more frequently apply herbicides, insecticides, and fungicides; and are more likely to raise beef cattle and swine, and grow corn, soybeans, hay, and oats. AHS farmers in North Carolina are also younger, live or work on larger farms, more frequently reported growing crops commonly seen in the state, and are more frequent pesticide users. However, animals raised are similar to those in the North Carolina Census of Agriculture.

      Conclusions: AHS farmers likely represent the higher end of pesticide usage in both states in part because AHS farmers have larger farms. Since the health effects of pesticides are best ascertained among pesticide users with the greatest exposure, the AHS cohort should prove to be a valuable resource for health effects research.


      Citation:

      Lynch, C.F., Sprince, N.L., Heywood, E., Pierce, J., Logsden-Sackett, N., Pennybacker, M. and Alavanja, M.C., 2005. Comparison of farmers in the agricultural health study to the 1992 and 1997 censuses of agriculture. Journal of agromedicine, 10(1), pp.13-22.

    • Saturday, January 1, 2005

      In Defense of Clean Water: How Iowa and Its Neighbors Protect Watersheds

      Author(s):
      Peter Weyer

      Journal Title:
      The Iowa Policy Project

      Abstract:

      The U.S. Environmental Protection Agency (EPA) defines watershed as the area of land where all of the water that is under it or drains off of it goes into the same place. The World Bank includes the receiving water body in its definition: A watershed is the specific land area that drains water into a river system or other body of water. Depending on the scale of the receiving water body, watersheds can include thousands of square miles of drainage area (e.g., Mississippi River watershed) or only a few square miles (e.g. Ralston Creek watershed, Johnson County, Iowa). Regardless of the size of any given watershed, receiving water bodies may be highly vulnerable to contamination from a variety of natural as well as anthropogenic sources, and water quality in receiving waters can vary seasonally as well as spatially.  Wildlife populations and domestic animals can negatively impact water quality depending on the number of animals and their proximity to water sources. Human activities and land uses within a watershed may impact water quality in streams and lakes and can affect wildlife habitats as well as humans who use those water sources for recreation (fishing, swimming) and as drinking water sources (for municipal water supplies). In the Midwest, intense agricultural activities including row cropping and livestock production may have impacts on water quality within watersheds over broad geographic areas, depending on seasonal precipitation patterns and conservation practices. Larger metropolitan areas as well as smaller urban areas can contribute significant contaminant loads to surface waters within watersheds.

      Ambient surface water quality in the United States became a national concern during the late 1960s and early 1970s, resulting in grassroots level efforts to identify problems and legislative action to establish watershed protection programs. More than 30 years after the passing of the Federal Water Pollution Control Act (1972), efforts to limit point sources of contaminants to surface water sources have been considered very successful, although some problems remain. Point sources of pollution are defined as “any discernible, confined and discrete conveyance, including but not linked to any pipe, ditch, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. This term does not include agricultural storm water discharges and return flows from irrigated agriculture.” Nonpoint source contaminants include any sources of water pollution that do not fit within the point source definition.  

      Nonpoint contaminants have been more difficult to identify, quantify and prevent than point sources and federal funding is not adequate to tackle the vast number of impacted watersheds across the nation.


      Citation:
    • Saturday, October 15, 2005

      Ecological Wastewater Management in Iowa

      Author(s):
      Scott Wallace
      Gene Parkin
      Brett Ballavance
      Ryan Brandt

      Journal Title:
      The Iowa Policy Project

      Abstract:

      This report summarizes the challenges Iowa is faced with in meeting the wastewater treatment needs of its residents, and explores the opportunities for providing ecologically responsible wastewater services for those with inadequate or nonexistent treatment systems. In Iowa, small- (single-home) and mid-size (those serving a few homes or a commercial development) communities offer the greatest opportunity for improvement. This is mainly due to the fact that Iowa has already provided sewer service to large populations where the conventional big pipe approach has been cost-effective. Many of the wastewater treatment technologies available for single-family homes and mid-size populations offer unique environmental benefits such as water reuse and/or zero-discharge to surface waters. Additionally, small treatment systems can provide higher-quality effluents than conventional large-scale treatment works, reducing the adverse environmental effects caused by excessive release of nutrients and pathogenic organisms.


      Citation:

      Brandt, Ryan. "The Iowa Policy Project." (2005).

    • Wednesday, March 22, 2006

      Risk factors for lung cancer in Iowa women: Implications for prevention

      Author(s):
      John S. Neuberger
      Jonathan D. Mahnken
      Matthew S. Mayo
      R. William Field

      Journal Title:
      Cancer Detection and Prevention

      Abstract:

      Background: Multiple risk factors possibly associated with lung cancer were examined as part of a large-scale residential radon case–control study conducted in Iowa between 1994 and 1997. We were particularly interested in stratifying risk factors by smoking status. Relatively little risk factor information is available for Midwestern rural women. Methods: Four hundred thirteen female lung cancer cases and 614 controls aged 40–84, who were residents of their current home for at least 20 years, were included. Risk factors examined included cigarette smoking, passive smoking, occupation, chemical exposure, previous lung disease, family history of cancer, and urban residence. Multiple logistic regression analysis was conducted after adjusting for age, education, and cumulative radon exposure. Results: As expected, active cigarette smoking was the major risk factor for lung cancer. While cessation of smoking was significantly associated with a reduced risk for lung cancer, the risk remained significantly elevated for 25 years. Among all cases, asbestos exposure was a significant risk. Among ex-smokers, pack-year history predominated as the major risk. Among never smokers, a family history of kidney or bladder cancer were significant risk factors (OR = 7.34, 95% CI = 1.91–28.18; and OR = 5.02, 95% CI = 1.64–15.39, respectively), as was a history of previous lung disease (OR = 2.28, 95% CI = 1.24–4.18) and asbestos exposure. No statistically significant increase in lung cancer risk was found for occupation or urban residence. Conclusions: Smoking prevention activities are urgently needed in rural areas of the United States. Relatives of individuals with smoking-related cancers are potentially at increased risk. Genetic risk factors should be more fully investigated in never smokers.

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      Citation:

      Neuberger, John S., Jonathan D. Mahnken, Matthew S. Mayo, and R. William Field. "Risk factors for lung cancer in Iowa women: implications for prevention." Cancer detection and prevention 30, no. 2 (2006): 158-167.

       

    • Friday, June 30, 2006

      Evaluation of a tungsten coil atomization-laser-induced fluorescence detection approach for trace elemental analysis

      Author(s):
      Muhsin Ezer
      Seth A. Elwood
      Bradley T. Jones
      Josef B. Simeonsson

      Journal Title:
      Analytica Chimica Acta

      Abstract:

      The analytical utility of a tungsten (W)-coil atomization-laser-induced fluorescence (LIF) approach has been evaluated for trace level measurements of elemental chromium (Cr), arsenic (As), selenium (Se), antimony (Sb), lead (Pb), tin (Sn), copper (Cu), thallium (Tl), indium (In), cadmium (Cd), zinc (Zn) and mercury (Hg). Measurements of As, Cr, In, Se, Sb, Pb, Tl, and Sn were performed by laser-induced fluorescence using a single dye laser operating near 460 nm whose output was converted by frequency doubling and stimulated Raman scattering to wavelengths ranging from 196 to 286 nm for atomic excitation. Absolute limits of detection (LODs) of 1, 0.3, 0.3, 0.2, 1, 6, 1, 0.2 and 0.8 pg and concentration LODs of 100, 30, 30, 20, 100, 600, 100, 20, and 80 pg/mL were achieved for As, Se, Sb, Sn, In, Cu, Cr, Pb and Tl, respectively. Determinations of Hg, Pb, Zn and Cd were performed using two-color excitation approaches and resulted in absolute LODs of 2, 30, 5 and 0.6 pg, respectively, and concentration LODs of 200, 3000, 500 and 60 pg/mL, respectively. The sensitivities achieved by the W-coil LIF approaches compare well with those reported by W-coil atomic absorption spectrometry, graphite furnace atomic absorption spectrometry, and graphite furnace electrothermal atomization-LIF approaches. The accuracy of the approach was verified through the analysis of a multielement reference solution containing Sb, Pb and Tl which each had certified performance acceptance limits of 19.6–20.4 μg/mL. The determined concentrations were 20.05 ± 2.60, 20.70 ± 2.27 and 20.60 ± 2.46 μg/mL, for Sb, Pb and Tl, respectively. The results demonstrate that W-coil LIF provides good analytical performance for trace analyses due to its high sensitivity, linearity, and capability to measure multiple elements using a single tunable laser and suggest that the development of portable W-coil LIF instrumentation using compact, solid-state lasers is feasible.


      Citation:

      Ezer, Muhsin, Seth A. Elwood, Bradley T. Jones, and Josef B. Simeonsson. "Evaluation of a tungsten coil atomization-laser-induced fluorescence detection approach for trace elemental analysis." Analytica chimica acta 571, no. 1 (2006): 136-141.

       

    • Thursday, September 20, 2007

      Economics of place-based monitoring under the safe drinking water act, part I: spatial and temporal patterns of contaminants, and design of screening strategies

      Author(s):
      Edwin Brands
      R. Rajagopal

      Journal Title:
      Environmental Monitoring and Assessment

      Abstract:

      The goals of environmental legislation and associated regulations are to protect public health, natural resources, and ecosystems. In this context, monitoring programs should provide timely and relevant information so that the regulatory community can implement legislation in a cost-effective and efficient manner. The Safe Drinking Water Act (SDWA) of 1974 attempts to ensure that public water systems (PWSs) supply safe water to its consumers. As is the case with many other federal environmental statutes, SDWA monitoring has been implemented in relatively uniform fashion across the USA. In this three part series, spatial and temporal patterns in water quality data are utilized to develop, compare, and evaluate the economic performance of alternative place-based monitoring approaches to current monitoring practice. Under the Safe Drinking Water Act (SDWA), a common list of over 90 contaminants is analyzed nationwide using EPA-authorized laboratory procedures. National and state-level summaries of SDWA data have shown that not all contaminants occur in all places at all times. This hypothesis is confirmed and extended by showing that only a few (less than seven) contaminants are of concern in any one of 19 Iowa surface water systems studied. These systems collectively serve about 350,000 people and their sizes vary between 1,200 and 120,000. The distributions of contaminants found in these systems are positively skewed, with many non-detect measurements. A screening strategy to identify such contaminants in individual systems is presented. These findings have significant implications not only for the design of alternative monitoring programs, but also in multi-billion-dollar decisions that influence the course of future drinking water infrastructure, repair, and maintenance investments.


      Citation:

      Brands, Edwin, and R. Rajagopal. "Economics of place-based monitoring under the safe drinking water act, part I: spatial and temporal patterns of contaminants, and design of screening strategies." Environmental monitoring and assessment 143, no. 1-3 (2008): 75-89.

       

    • Sunday, October 12, 2008

      Nitrate Ingestion from Drinking Water and Diet and Cancer Risk

      Author(s):
      P J Weyer
      J R Kantamneni
      X Lu
      M H Ward
      J R Cerhan

      Journal Title:
      Epidemiology

      Abstract:

      Nitrate ingested from drinking water and diet can contribute to the endogenous formation of carcinogenic N-nitroso compounds. Epidemiologic studies of nitrate and cancer have reported mixed findings; a brief overview will be given. We present an updated analysis of The Iowa Women's Health Study (IWHS), which in 2001 reported an increased risk for bladder cancer associated with long-term exposure to nitrate in municipal water supplies. Our reanalysis included an additional six years of bladder cancer cases and exposure assessment for both drinking water and diet nitrate. Nitrate intake was calculated for a cohort of 16,541 Iowa women (ages 55-69 at 1986 baseline) who used the same municipal drinking water supply for >10 years. A total of 112 incident bladder cancers were diagnosed in the cohort through 2004. Nitrate levels in finished (post-treatment) drinking water for all municipal supplies and nitrate levels in raw (pre-treatment) source water for supplies using alluvial groundwater were used to calculate mean nitrate levels (1955-88). Dietary nitrate was estimated using a 126-item food frequency questionnaire. Dietary nitrate was not associated with bladder cancer risk. An increased bladder cancer risk was associated with the highest quartile of exposure to nitrate in drinking water (>2.23 mg/L nitrate-nitrogen, Relative Risk (RR) = 2.16, 95%CI 1.09-4.28); the risk was highest for women in the high water nitrate group who also had higher meat intake and lower vitamin C intake (RR = 4.17, 95%CI 1.46-11.88). Reanalysis of the IWHS showed an increase bladder cancer risk associated with long term exposure to drinking water nitrate levels below the regulatory limit. Other studies have found bladder cancer risk associated with exposure to trihalomethanes (THMs) and haloacetic acids (HAAs), common disinfection by-products (DBPs). We are estimating historical THM and HAA levels in Iowa municipal water supplies based in order to evaluate the separate contributions and possible interactions of nitrate and DBPs to bladder cancer risk. Recent studies on emerging nitrogenous DBPs (halonitromethanes, haloacetonitriles, N-nitrosodimethylamine) document cytotoxic and genotoxic effects in some mammalian species; therefore, research on drinking water exposures to these compounds in human populations is warranted.


      Citation:

      Weyer, P. J., J. R. Kantamneni, X. Lu, M. H. Ward, and J. R. Cerhan. "Nitrate Ingestion from drinking water and diet and cancer risk." Epidemiology 19, no. 6 (2008): S55.

    • Thursday, September 20, 2007

      Economics of place-based monitoring under the safe drinking water act, part II: Design and development of place-based monitoring strategies

      Author(s):
      Edwin Brands
      R. Rajagopal

      Journal Title:
      Environmental Monitoring and Assessment

      Abstract:

      The goals of environmental legislation and associated regulations are to protect public health, natural resources, and ecosystems. In this context, monitoring programs should provide timely and relevant information so that the regulatory community can implement legislation in a cost-effective and efficient manner. The Safe Drinking Water Act (SDWA) of 1974 attempts to ensure that public water systems (PWSs) supply safe water to its consumers. As is the case with many other federal environmental statutes, SDWA monitoring has been implemented in relatively uniform fashion across the United States. In this three part series, spatial and temporal patterns in water quality data are utilized to develop, compare, and evaluate the economic performance of alternative place-based monitoring approaches to current monitoring practice. Part II: Several factors affect the performance of monitoring strategies, including: measurable objectives, required precision in estimates, acceptable confidence levels of such estimates, available budget for sampling. In this paper, we develop place-based monitoring strategies based on extensive analysis of available historical water quality data (1960–1994) of 19 Iowa community water systems. These systems supply potable water to over 350,000 people. In the context of drinking water, the objective is to protect public health by utilizing monitoring resources to characterize contaminants that are detectable, and are close to exceeding health standards. A place-based monitoring strategy was developed in which contaminants were selected based on their historical occurrence, rather than their appearance on the SDWA contaminant list. In a subset of the water systems, the temporal frequency of monitoring for one ubiquitous contaminant, nitrate, was tailored to patterns in its historical occurrence and concentration. Three sampling allocation models (linear, quadratic, and cubic) based on historic patterns in peak occurrence were developed and evaluated. Random and fixed-interval sampling strategies within the context of such models were also developed and evaluated. Strategies were configured to incorporate a variety of options for frequency and number of samples (depending on budget and the desired precision in estimate of peak concentrations).


      Citation:

      Brands, Edwin, and R. Rajagopal. "Economics of place-based monitoring under the safe drinking water act, part II: Design and development of place-based monitoring strategies." Environmental monitoring and assessment 143, no. 1-3 (2008): 91-102.

    • Monday, August 20, 2007

      Economics of place-based monitoring under the safe drinking water act, part III: performance evaluation of place-based monitoring strategies

      Author(s):
      Edwin Brands
      R. Rajagopal

      Journal Title:
      Environmental Monitoring and Assessment

      Abstract:

      The goals of environmental legislation and associated regulations are to protect public health, natural resources, and ecosystems. In this context, monitoring programs should provide timely and relevant information so that the regulatory community can implement legislation in a cost-effective and efficient manner. The Safe Drinking Water Act (SDWA) of 1974 attempts to ensure that public water systems (PWSs) supply safe water to its consumers. As is the case with many other federal environmental statutes, SDWA monitoring has been implemented in relatively uniform fashion across the USA. In this three part series, we present over 30 years of evidence to demonstrate unique patterns in water quality contaminants over space and time, develop alternative place-based monitoring approaches that exploit such patterns, and evaluate the economic performance of such approaches to current monitoring practice. Part III: Place-based (PBA) and current SDWA monitoring approaches were implemented on test datasets (1995–2001) from 19 water systems and evaluated based on the following criteria: percent of total detections, percent detections above threshold values (e.g. 20, 50, 90% of MCL), and cost. The PBA outperformed the current SDWA monitoring requirements in terms of total detections, missed only a small proportion of detections below the MCL, and captured all detections above 50% of the MCL. Essentially the same information obtained from current compliance monitoring requirements can be gained at approximately one-eighth the cost by implementing the PBA. Temporal sampling strategies were implemented on test datasets (1995–2001) from four water systems and evaluated by the following criteria: parameter estimation, percent deviation from “true” 90th, 95th, and 99th percentiles, and number of samples versus accuracy of the estimate. Non event-based (NEB) strategies were superior in estimating percentiles 1–50, but underestimated the higher percentiles. Event-based strategies were superior in estimating 95th and 99th percentiles, and required significantly fewer samples (than NEB strategies) to estimate the “true” 95th and 99th percentiles. Incorporation of place-based information significantly improves the performance of monitoring and temporal sampling strategies in the context of surface-influenced water systems in the state of Iowa. Application of similar methods to other areas and types of water systems would likely produce similar results. Compared to current SDWA monitoring, the place based approach allows for cost-effective, enhanced characterization of local contaminants of concern.


      Citation:

      Brands, Edwin, and R. Rajagopal. "Economics of place-based monitoring under the safe drinking water act, part III: performance evaluation of place-based monitoring strategies." Environmental monitoring and assessment 143, no. 1-3 (2008): 103-120.

       

       

    • Tuesday, September 23, 2014

      Association between arsenic, cadmium, manganese, and lead levels in private wells and birth defects prevalence in North Carolina: a semi-ecologic study

      Author(s):
      Alison P Sanders
      Tania A Desrosiers
      Joshua L Warren
      Amy H Herring
      Dianne Enright
      Andrew F Olshan
      Robert E Meyer
      Rebecca C Fry

      Journal Title:
      BMC Public Health

      Abstract:

      Background

      Toxic metals including arsenic, cadmium, manganese, and lead are known human developmental toxicants that are able to cross the placental barrier from mother to fetus. In this population-based study, we assess the association between metal concentrations in private well water and birth defect prevalence in North Carolina.

      Methods

      A semi-ecologic study was conducted including 20,151 infants born between 2003 and 2008 with selected birth defects (cases) identified by the North Carolina Birth Defects Monitoring Program, and 668,381 non-malformed infants (controls). Maternal residences at delivery and over 10,000 well locations measured for metals by the North Carolina Division of Public Health were geocoded. The average level of each metal was calculated among wells sampled within North Carolina census tracts. Individual exposure was assigned as the average metal level of the census tract that contained the geocoded maternal residence. Prevalence ratios (PR) with 95% confidence intervals (CI) were calculated to estimate the association between the prevalence of birth defects in the highest category (≥90thpercentile) of average census tract metal levels and compared to the lowest category (≤50th percentile).

      Results

      Statewide, private well metal levels exceeded the EPA Maximum Contaminant Level (MCL) or secondary MCL for arsenic, cadmium, manganese, and lead in 2.4, 0.1, 20.5, and 3.1 percent of wells tested. Elevated manganese levels were statistically significantly associated with a higher prevalence of conotruncal heart defects (PR: 1.6 95% CI: 1.1-2.5).

      Conclusions

      These findings suggest an ecologic association between higher manganese concentrations in drinking water and the prevalence of conotruncal heart defects.


      Citation:

      Sanders, Alison P., Tania A. Desrosiers, Joshua L. Warren, Amy H. Herring, Dianne Enright, Andrew F. Olshan, Robert E. Meyer, and Rebecca C. Fry. "Association between arsenic, cadmium, manganese, and lead levels in private wells and birth defects prevalence in North Carolina: a semi-ecologic study." BMC Public Health 14, no. 1 (2014): 955.

    • Tuesday, November 24, 2015

      Phthalate exposure and semen quality in fertile US men

      Author(s):
      S. W. Thurston
      J. Mendiola
      A. R. Bellamy
      H. Levine
      C. Wang
      A. Sparks
      J. B. Redmon
      E. Z. Drobnis
      S. H. Swan

      Journal Title:
      Andrology

      Abstract:

      Several experimental and observational studies have demonstrated the antiandrogenicity of several phthalates. However, there is limited evidence of an association between phthalate exposure in adult life and semen quality. The aim of this study was to examine phthalate exposure during adulthood in relation to semen quality in fertile US men. This multi‐center cross‐sectional study included 420 partners of pregnant women who attended a prenatal clinic in one of five US cities during 1999–2001. Nine phthalate metabolites [mono (2‐ethylhexyl) phthalate (MEHP), mono (2‐ethyl‐5‐hydroxyhexyl) phthalate (MEHHP), mono (2‐ethyl‐5‐oxohexyl) phthalate (MEOHP), and mono (2‐ethyl‐5‐carboxypentyl) phthalate (MECPP)], as well as mono‐n‐butyl phthalate (MBP) and mono‐isobutyl phthalate (MiBP), mono (three carboxypropyl) phthalate (MCPP), monobenzyl phthalate (MBzP), and monoethyl phthalate (MEP)] were measured in urine collected at the same time as the semen sample. We regressed natural log‐transformed (ln) sperm concentration, ln(total sperm count), ln(total motile sperm count), percent motile spermatozoa, and percent spermatozoa with normal morphology on each of the nine natural log‐transformed metabolite concentrations and on the molar‐weighted sum of DEHP metabolites in separate models. We fit unadjusted models and models that adjusted for confounders determined a priori. In unadjusted models, ln(MiBP) was significantly and positively associated with motility and ln(MBzP) significantly negatively associated with ln(total sperm count). In adjusted linear models, urinary metabolite concentrations of DEHP, DBP, DEP, and DOP were not associated with any semen parameter. We found an inverse association between ln(MBzP) concentrations and sperm motility (β = −1.47, 95% CI: −2.61, −0.33), adjusted for ln(creatinine concentration), geographic location, age, race, smoking status, stress, recent fever, time from sample collection and time to complete analysis. Several sensitivity analyses confirmed the robustness of these associations. This study and the available literature suggest that impacts of adult exposure to phthalates at environmental levels on classical sperm parameters are likely to be small.


      Citation:

      Thurston, Sally W., Jaime Mendiola, Abbie R. Bellamy, Hagai Levine, Christina Wang, Amy Sparks, J. Bruce Redmon, Erma Z. Drobnis, and Shanna H. Swan. "Phthalate exposure and semen quality in fertile US men." Andrology 4, no. 4 (2016): 632-638.

    • Monday, December 25, 2017

      Fingerprinting the Refugio oil spill using topographic signal processing of two-dimensional gas chromatographic images

      Author(s):
      Rachel Bruflodt
      Robert K. Nelson
      Eleanor C. Arrington
      David Valentine
      Ananya Sen Gupta
      Karin Lemkau
      Veronika Kivenson
      Christopher M. Reddy

      Journal Title:
      OCEANS 2017 - Anchorage, IEEE Xplore

      Abstract:

      We examine petroleum forensics from a pattern recognition and feature separation perspective in this work. Apportioning the environmental impact of oil spills is important for marine pollution studies. Robust fingerprinting of an unknown sample from a petroleum-rich locale remains a data science challenge. Crude petroleum is a complex mixture, and as such, the fingerprint of a petroleum source can be discovered as the signature profile of hydrocarbon peaks corresponding to the biomarker compounds, which are well-known for their recalcitrance to environmental weathering. In this work, we apply recently proposed peak topography mapping techniques to examine the GCxGC topography of the Archean region based on four representative crude oil samples collected from the locale of the Refugio spill. Specifically, we compare the robustness of match between samples from the leaking pipeline of the Refugio spill against the match between oil samples from other local sources.


      Citation:

      Bruflodt, Rachel, Robert K. Nelson, Eleanor C. Arrington, David Valentine, Ananya Sen Gupta, Karin Lemkau, Veronika Kivenson, and Christopher M. Reddy. "Fingerprinting the Refugio oil spill using topographic signal processing of two-dimensional gas chromatographic images." In OCEANS 2017-Anchorage, pp. 1-4. IEEE, 2017.

    • Monday, May 1, 2017

      Elevated Arsenic in Private Wells of Cerro Gordo County, Iowa: Causes and Policy Changes

      Author(s):
      Douglas J. Schnoebelen
      Sophia Walsh
      Brian Hanft
      Oscar E. Hernandez-Murcia
      Chad Fields

      Journal Title:
      Journal of Environmental Health

      Abstract:

      Private wells are unregulated and often at risk for arsenic contamination. Research objectives included distribution of groundwater arsenic concentrations, identification of arsenic sources, and establishment of best practices for well construction to minimize risk for wells in Cerro Gordo County, Iowa. We sampled 68 wells over 3 years with 393 water samples and 79 rock samples. Geochemical modeling was used to better understand arsenic mobilization. Arsenic in groundwater ranged from 1.0 to less than 10.0 µg/L for 75 water samples and 31 water samples had arsenic concentrations greater than or equal to 10 µg/L. The arsenic source is naturally occurring sulfide minerals (typically pyrite) in the bedrock aquifers. The shallow (100–150 feet) Lime Creek Aquifer was most at risk for arsenic. Arsenic is likely mobilized from the rock into the water in the shallow aquifer under more oxidizing conditions, subject to water level changes. The study resulted in a policy change for arsenic testing and well completion in Cerro Gordo County to better protect domestic well users.


      Citation:

      Schnoebelen, Douglas J., Sophia Walsh, Brian Hanft, Oscar E. Hernandez-Murcia, and Chad Fields. "Elevated Arsenic in Private Wells of Cerro Gordo County, Iowa: Causes and Policy Changes." Journal of environmental health 79, no. 9 (2017).

    • Thursday, August 4, 2016

      Spatially Derived Risk Factors for Cutaneous Melanoma

      Author(s):
      Marvin Langston

      Journal Title:
      PhD Thesis

      Abstract:

      Intermittent sun exposure and sun sensitivity factors are the most well described risk factors for the development of cutaneous melanoma (CM). Other potential environmental risks for CM, such as arsenic, are rarely examined. Total sun exposure has not been a consistent risk factor for CM, but recall bias in self-reporting sun exposure throughout life may limit the ability to detect a true association. Objective measures of sun exposure including remotely sensed ambient ultra-violet radiation (UVR) may allow for better capture of total sun exposure. In three chapters, spatially derived factors (ambient UVR, environmental soil arsenic, drinking water arsenic) were observed to determine their relevance in exposure assessment and subsequent risk for CM.UVR trends were investigated using available satellite data (1978-2014) to generate inferences for UVB changes over time in the United States. We found that UVB changed across the study area, but these changes lack biological relevance based on the magnitude of changes observed. Thus, a more objective measure of lifetime ambient sun exposure may be estimated using 30-year average UVR by month in future studies. The spatial correlation between environmental soil arsenic and drinking water across the state of Iowa was investigated. Arsenic concentrations in soil were not significantly spatially correlated with either municipal public water source or non-municipal water source arsenic concentrations. Based on these findings, soil arsenic may not serve as a valid surrogate marker for arsenic in drinking water.In Chapter 5, we assessed the relationship of spatially derived estimates of lifetime ambient UVR, environmental arsenic exposure from soil and drinking water, and CM in a population-based case-control study. Our findings suggest that total sun exposure is positively associated with CM, while arsenic concentration in environmental soil and drinking water were not associated. Sun exposure measured through ambient UVR exposure may allow for better understanding of the association between cumulative or total sun exposure and CM. Additionally, more studies need to be completed to estimate the potential risks for CM in regions where high arsenic concentrations may not be endemic.


      Citation:

      Langston, Marvin Epolian. "Spatially Derived Risk Factors for Cutaneous Melanoma." (2016).

    • Thursday, December 1, 2016

      Exposure to arsenic and atrazine from drinking water and risk of cancer

      Author(s):
      Taehyun Roh

      Journal Title:
      PhD Thesis

      Abstract:

      Arsenic and atrazine are two water contaminants of high public health concern in Iowa. Arsenic is found in soil from glacier deposits and atrazine is a commonly used herbicide. My questions were whether Iowans are exposed to higher levels of arsenic and atrazine from drinking water, whether Iowans have the same rates of cancers as the rest of the US, and whether higher levels of arsenic is some Iowa counties could lead to a higher risk for prostate cancer.

      I investigated the occurrence of arsenic and atrazine in drinking water from Iowa private wells and public water systems. I found that detection and concentration of atrazine in drinking water decreased over time. However, the percentage of arsenic detections and concentrations higher than the current regulatory level increased over time in the public water systems. Therefore, arsenic was selected as a water contaminant for further study.

      Cancer is the second leading cause of death in the US. However, cancer rates vary by different regions over time. In this study, the trends in cancers related to arsenic and atrazine exposures in Iowa were investigated and compared to 8 other states for white adults. I observed that the number of new overall cancer cases and death from them was lower in Iowa than the US, but different trends in major cancers were found between Iowa and the US. Importantly, prostate cancer was the most frequent type of cancer in men in both Iowa and the US and it was selected as a health outcome for further study.

      Based on what I found in those previous studies, I conducted a county-level study comparing prostate cancer and arsenic in drinking water in Iowa. I estimated the risk of prostate cancer by the three range of arsenic level at a county level. The results of analysis showed that the risk of prostate cancer increased by 16 % and 28 % in the groups of counties with the medium and high arsenic level, compared to the group of counties with low arsenic level.

      Together, these results indicate that the analysis of contaminants and regional occurrence of human diseases like cancer may be able to identify factors, like water contaminants, that have a negative effect on health. This knowledge can then be used to design methods to reduce or remove exposure to these contaminants.


      Citation:

      Roh, Taehyun. "Exposure to arsenic and atrazine from drinking water and risk of cancer." PhD (Doctor of Philosophy) thesis, University of Iowa, 2016. 
      https://doi.org/10.17077/etd.qmk8mmsg

    • Thursday, February 1, 2018

      Economic Benefits of Nitrogen Reductions in Iowa

      Author(s):
      Chuan Tang
      Gabriel E. Lade
      David Keiser
      Catherine Kling
      Yongjie Ji
      Yau-Huo Shr

      Journal Title:
      Center for Agricultural and Rural Development, Iowa State University

      Abstract:

      Iowa agriculture provides tremendous benefits to the state, national, and global economy. The intense nature of the state’s agricultural activities is not without cost. Agricultural industry is a large contributor to water quality problems both within the state as well as in downstream rivers, streams, and the Gulf of Mexico. First released in November 2012, the Iowa Nutrient Reduction Strategy (NRS) lays out a technology-driven framework for reducing nutrient delivery to waterways in Iowa and, ultimately, the Gulf of Mexico. These efforts are part of a broader strategy that includes 11 other states to reduce the size, severity, and duration of hypoxia in the Gulf of Mexico.

      While the Gulf Hypoxic Zone has received a lot of attention, meeting the NRS targets would also have large local benefits. Many water utilities and homes with private wells must treat their water due to high nitrate levels. In a recent court case, Des Moines Water Works (DMWW) unsuccessfully sued three Northwest Iowa drainage districts to compensate for its nitrate removal costs. According to DMWW, the utility spent over $500,000 to remove nitrates in 2016 and plans to expand its nitrate removal capabilities in coming years at an estimated cost of $15 million. Beyond the state capitol, water utilities across the state dedicate substantive resources to remove nitrates. Ensuring nitrates in drinking water remain low is imperative—high nitrate levels in drinking water are associated with adverse human health outcomes for susceptible populations. Beyond drinking water, nitrate pollution also contributes to the poor water quality of Iowa’s rivers and lakes, diminishing the recreational value of these resources.

      This report explores important costs of high nitrates to Iowans and summarizes benefits to the state of meeting its NRS targets. 1 In Section 1, we discuss important factors that determine nitrate levels in the state’s streams, rivers, and lakes.2 We also provide background on drinking water sources in the state and existing nitrate regulations in the United States.

      Section 2 explores nitrate removal costs to public water supply (PWS) systems and private well owners. We first summarize nitrate removal technologies, and their associated operating costs, that are available to PWS systems. Because many Iowans living in rural areas rely on private wells for their home’s drinking water, we also explore trends in nitrate levels in private wells and discuss treatment and avoidance costs to these households. We then provide three case studies of how towns in Iowa manage nitrates in their drinking water. We find that Iowa’s PWSs have invested at least $1.8 million in nitrate treatment equipment since 2000, that many small PWSs cannot afford to meet EPA safe drinking water standards for nitrates, and that many Iowans that rely on private wells are potentially exposed to unsafe nitrate concentrations in their drinking water.

      Section 3 summarizes another cost of nitrates in the state—lost recreation benefits. We discuss the impacts of agricultural runoffs (mainly nitrogen and phosphorous) on Iowa’s lakes. We focus on the contribution of these pollutants to the development of harmful algal blooms (HABs), a noxious form of algae that is harmful to human health. We document an increase in the prevalence of beach advisories and closures in the state from HABs. We then value some of the recreational benefits of meeting Iowa’s NRS targets. Improving the quality of Iowa’s lakes by meeting the NRS targets would increase recreational benefits to all Iowans by approximately $30 million per year.

      In Section 4, we discuss the current state of knowledge on adverse human health impacts from exposure to high nitrates in water. A substantial epidemiologic and public health literature documents associations between nitrate exposure and blue baby syndrome in infants. Other work suggests that long-term exposure to nitrates, even at low levels, may also be associated with other adverse health impacts. We conclude the section by discussing the need for mo


      Citation:

      Tang, Chuan, Gabriel E. Lade, David Keiser, Catherine Kling, Yongjie Ji, and Yau-Huo Shr. "Economic Benefits of Nitrogen Reductions in Iowa." (2018)

    • Monday, March 19, 2018

      Which Water to Drink? Costs and Benefits of Alternatives

      Author(s):
      Edwin Brands
      R Rajagopal

      Journal Title:
      SciFed Journal of Public Health

      Abstract:

      Public water systems’ infrequent violations of United States Environmental Protection Agency’s (US EPA) heath-based water quality standards are highly publicized (and often magnified) by mass media, although waterborne disease outbreaks and deaths have been significantly reduced since the advent of modern public drinking water systems in the U.S. A small number of water systems (e.g. Flint, Michigan) had serious water quality problems in recent years, but all consumers are presented with many alternative products by rapidly growing bottled water and home filtration device industries. We illustrate the problem of consumer decisions regarding drinking water alternatives, in the context of water quality, health, and cost information by investigating and reporting on differences in selected water quality parameters and economics of drinking water alternatives, including public water systems, private wells, bottled water, and home filtration devices. In our historical snapshot dataset, samples were taken from these sources in an Eastern Iowa study area during two different seasons and analyzed for contaminants typically found in highly agricultural areas. In addition to the snapshot data, we also examined the most recent available longitudinal data on study area public water systems and wells. Although there were differences in the numbers and concentrations of contaminants detected, no selected contaminants exceeded US EPA drinking water maximum contaminant levels in any of the drinking water categories. Based on our analysis, public water systems appear to be the most prudent choice for drinking water and therefore deserving of continued investment in associated infrastructure. Water filtration devices are the next best choice, with bottled water by far the most expensive, 280-6,300 times that of public water systems in the study area, without providing additional protection in the context of US drinking water regulations.


      Citation:

      Edwin Brands and Rajagopal R (2018) Which Water to Drink? Costs and Benefits of Alternatives. SF J Pub Health 2:1.

    • Monday, November 1, 2010

      Serum inhibin-b in fertile men is strongly correlated with low but not high sperm counts: a coordinated study of 1,797 European and US men

      Author(s):
      Niels Jorgensen
      Fan Liu
      anna-Maria Andersson
      Matti Vierula
      Stewart Irvine
      Jacques Auger
      Charlene K. Brazil
      Erma Z. Drobnis
      Tina K. Jensen
      Pierre Jounnet
      James W. Overstreet
      J. Bruce Redmon
      Amy Sparks
      Jorma Toppari
      Christina Wang
      Niels E. Skakkebaek
      Shanna H. Swan

      Journal Title:
      Fertility and Sterility

      Abstract:

      Objective

      To describe associations between serum inhibin-b and sperm counts, adjusted for effect of time of blood sampling, in larger cohorts than have been previously reported.

      Design

      Cross-sectonal studies of spermatogenesis markers.

      Setting

      Four European and four US centers.

      Patient(s)

      Fertile men (1,797) were included and examined from October 1996–February 2005.

      Intervention(s)

      The study was observational and therefore without any intervention.

      Main Outcome Measure(s)

      Associations between inhibin-b and semen variables controlled for time of blood sampling and other covariates.

      Result(s)

      Inhibin-b decreased about 2.00% per hour from 8 am–12 pm and then about 3.25% per hour from 12 pm–4 pm. There was a strong positive association between inhibin-b levels less than 150 pg/mL and both sperm concentration and total sperm count (slopes of the regression lines were β = 0.011 and β = 0.013 for natural logarithm-transformed sperm concentration and total sperm count, respectively). For inhibin-b levels of 150–300 pg/mL the associations were not as steep (β = 0.002), but still significant. For inhibin-b levels more than 300 pg/mL there was little association to the sperm counts. Neither sperm motility nor morphology was significantly related to inhibin-b level in any group.

      Conclusion(s)

      Serum inhibin-b levels decrease nonlinearly during the daytime, and are positively correlated with sperm counts, but the predictive power is best when inhibin-b is low.


      Citation:

      Jørgensen N, Liu F, Andersson AM, Vierula M, Irvine DS, Auger J, Brazil CK, Drobnis EZ, Jensen TK, Jouannet P, Overstreet JW. Serum inhibin-b in fertile men is strongly correlated with low but not high sperm counts: a coordinated study of 1,797 European and US men. Fertility and sterility. 2010 Nov 1;94(6):2128-34. DOI: 10.1016/j.fertnstert.2009.12.051

    • Wednesday, December 6, 2000

      Heller, Martin C., and Gregory A. Keoleian. Life cycle-based sustainability indicators for assessment of the US food system. Vol. 4. Ann Arbor, MI: Center for Sustainable Systems, University of Michigan, 2000.

      Author(s):
      Martin C. Heller
      Gregory A. Keoleian

      Abstract:

      The United States food system, from field to table, is at a crossroads for change. Improving the sustainability of this complex system requires a thorough understanding of the relationships between food consumption behaviors, processing and distribution activities, and agricultural production practices. The product life cycle system is a useful framework for studying the links between societal needs, the natural and economic processes involved in meeting these needs, and the associated environmental consequences. The ultimate goal is to guide the development of system-based solutions.

      This report presents a broad set of indicators covering the life cycle stages of the food system. Indicators address economic, social, and environmental aspects of each life cycle stage: origin of (genetic) resource, agricultural growing and production, food processing, packaging and distribution, preparation and consumption, and end of life. The report then offers an initial critical review of the condition of the U.S. food system by considering trends in the various indicators.

      Multiple threats to the long-term vitality of the U.S. food system demonstrate that the current system is not economically, socially, or environmentally sustainable. Key indicators supporting this conclusion include: rates of agricultural land conversion, income and profitability from farming, degree of food industry consolidation, fraction of edible food wasted, diet related health costs, legal status of farmworkers, age distribution of farmers, genetic diversity, rate of soil loss and groundwater withdrawal, and fossil fuel intensity. We suggest that the most effective opportunities to enhance the sustainability of the food system exist in changing consumption behavior, which will have compounding benefits across agricultural production, distribution and food disposition stages.


      Citation:

      Heller, Martin C., and Gregory A. Keoleian. Life cycle-based sustainability indicators for assessment of the US food system. Vol. 4. Ann Arbor, MI: Center for Sustainable Systems, University of Michigan, 2000.

    • Wednesday, October 11, 2006

      The muscular Dystrophy Surveillance Tracking and Research Network (MD STARnet): Surveillance methodology

      Author(s):
      Lisa A. Miller
      Paul A. Romitti
      Christopher Cunniff
      Charlotte Druschel
      Katherine D. Mathews
      F. John Meaney
      Dennis Matthews
      Jiji Kantamneni
      Zhen-Fang Feng
      Nancy Zemblidge
      Timothy M. Miller
      Jennifer Andrews
      Deborah Fox
      Emma Ciafaloni
      Shree Pandya
      April Montgomery
      Aileen Kenneson

      Journal Title:
      Defects Research Part A: Clinical and Molecular Teratology

      Abstract:

      Background

      This report focuses on the common protocol developed by the Muscular Dystrophy Surveillance Tracking and Research Network (MD STARnet) for population‐based surveillance of Duchenne and Becker muscular dystrophy (DBMD) among 4 states (Arizona, Colorado, Iowa, and New York).

      Methods

      The network sites have developed a case definition and surveillance protocol along with software applications for medical record abstraction, clinical review, and pooled data. Neuromuscular specialists at each site review the pooled data to determine if a case meets the case criteria. Sources of potential cases of DBMD include neuromuscular specialty clinics, service sites for children with special healthcare needs, and hospital discharge databases. Each site also adheres to a common information assurance protocol.

      Results

      A population‐based surveillance system for DBMD was created and implemented in participating states.

      Conclusions

      The development and implementation of the population‐based system will allow for the collection of information that is intended to provide a greater understanding of DBMD prevalence and health outcomes. Birth Defects Research (Part A) 2006. © 2006 Wiley‐Liss, Inc.


      CHEEC Project:

      Citation:

      Miller, Lisa A., Paul A. Romitti, Christopher Cunniff, Charlotte Druschel, Katherine D. Mathews, F. John Meaney, Dennis Matthews et al. "The muscular dystrophy surveillance tracking and research network (MD STARnet): Surveillance methodology." Birth Defects Research Part A: Clinical and Molecular Teratology 76, no. 11 (2006): 793-797. DOI: 10.1002/bdra.20279 

    • Wednesday, January 2, 2013

      Urinary Concentrations of Di(2‐ethylhexyl) Phthalate Metabolites and Serum Reproductive Hormones: Pooled Analysis of Fertile and Infertile Men

      Author(s):
      Jaime Mendiola
      John D. Meeker
      Niels Jorgensen
      Anna-Maria Andersson
      Fan Liu
      Antonia M. Calafat
      J. Bruce Redmon
      Erma Z. Drobnis
      Amy E. Sparks
      Christina Want
      Russ Hauser
      Shanna H. Swan

      Journal Title:
      Journal of Andrology

      Abstract:

      Urinary concentrations of metabolites of the anti‐androgenic xenobiotic di‐(2‐ethylhexyl) phthalate (DEHP) were previously shown to be weakly associated with serum levels of several hormones in 2 disparate US populations: partners of pregnant women participating in the Study for Future Families and partners in infertile couples from Massachusetts General Hospital infertility clinic. The observed associations between phthalate metabolites and reproductive hormones were robust and insensitive to the characteristics of the subpopulation or the laboratory in which the hormones were measured, despite the fact that these 2 populations span a range of fertility, urinary phthalate metabolites, and reproductive hormone levels. We therefore examined associations between urinary metabolites of DEHP and reproductive hormones—follicle‐stimulating hormone, luteinizing hormone, testosterone (T), inhibin B, and estradiol (E2)—and sex hormone–binding globulin (SHBG) in the pooled population. The magnitude of the associations seen were similar to those reported for each population separately, but effect estimates were more precise because of the increased sample size and the greater range of phthalate metabolite concentrations and hormone levels. Urinary concentrations of 3 metabolites of DEHP[mono(2‐ethylhexyl) phthalate (MEHP), mono(2‐ethyl‐5‐hydroxyhexyl) phthalate (MEHHP), and mono(2‐ethyl‐5‐oxohexyl) phthalate (MEOHP)] were inversely associated with the free androgen index (FAI = T/SHBG) and calculated free testosterone. Urinary concentrations of MEHHP and MEOHP were positively associated with SHBG, and MEHP was inversely associated with E2. No other phthalate metabolites were associated with serum hormones, consistent with results in each population. Our results in this diverse population suggest that DEHP exposure is robustly associated with some male sex steroid hormones.


      Citation:

      Mendiola, Jaime, John D. Meeker, Niels Jørgensen, Anna‐Maria Andersson, Fan Liu, Antonia M. Calafat, J. Bruce Redmon et al. "Urinary concentrations of di (2‐ethylhexyl) phthalate metabolites and serum reproductive hormones: pooled analysis of fertile and infertile men." Journal of andrology 33, no. 3 (2012): 488-498. DOI: 10.2164/jandrol.111.013557

    • Wednesday, July 1, 1998

      The Association of Drinking Water Source and Chlorination By-Products with Cancer Incidence among Postmenopausal Women in Iowa: A Prospoective Cohort Study

      Author(s):
      TJ Doyle
      W Zheng
      JR Cerhan
      CP Hong
      TA Sellers
      LH Kushi
      AR Folsom

      Journal Title:
      American Journal of Public Health

      Abstract:

      Objectives

      This study assessed the association of drinking water source and chlorination by-product exposure with cancer incidence.

      METHODS

      A cohort of 28,237 Iowa women reported their drinking water source. Exposure to chlorination by-products was determined from statewide water quality data.

      RESULTS

      In comparison with women who used municipal ground-water sources, women with municipal surface water sources were at an increased risk of colon cancer and all cancers combined. A clear dose-response relation was observed between four categories of increasing chloroform levels in finished drinking water and the risk of colon cancer and all cancers combined. The relative risks were 1.00, 1.06, 1.39, and 1.68 for colon cancer and 1.00, 1.04, 1.24, and 1.25 for total cancers. No consistent association with either water source or chloroform concentration was observed for other cancer sites.

      CONCLUSIONS

      These results suggest that exposure to chlorination by-products in drinking water is associated with increased risk of colon cancer.


      Citation:

      Doyle, Timothy J., Wei Zheng, James R. Cerhan, Ching-Ping Hong, Thomas A. Sellers, Lawrence H. Kushi, and Aaron R. Folsom. "The association of drinking water source and chlorination by-products with cancer incidence among postmenopausal women in Iowa: a prospective cohort study." American Journal of Public Health 87, no. 7 (1997): 1168-1176. DOI: 10.2105/AJPH.87.7.1168

    • Monday, February 1, 1999

      Characteristics of Pesticide Use in a Pesticide Applicator Cohort: The Agricultural Health Study

      Author(s):
      Michael CR Alavanja
      Dale P Sandler
      Cheryl J McDonnell
      Charles F Lynch
      Margaret Pennybacker
      Shelia Hoar Zahm
      David T Mage
      William C Steen
      Wendy Wintersteen
      Aaron Blair

      Journal Title:
      Environmental Research

      Abstract:

      Data on recent and historic pesticide use, pesticide application methods, and farm characteristics were collected from 35,879 restricted-use pesticide applicators in the first 2 years of the Agricultural Health Study, a prospective study of a large cohort of private and commercial licensed pesticide applicators that is being conducted in Iowa and North Carolina. (In Iowa, applicators are actually “certified,” while in North Carolina they are “licensed”; for ease of reference the term license will be used for both states in this paper.) Commercial applicators (studied in Iowa only) apply pesticides more days per year than private applicators in either state. When the types of pesticides being used by different groups are compared using the Spearman coefficient of determination (r2), we find that Iowa private and Iowa commercial applicators tend to use the same type of pesticides (r2=0.88). White and nonwhite private applicators tended to use the same type of pesticides (North Carolinar2=0.89), as did male and female private applicators (Iowar2=0.85 and North Carolinar2=0.84). There was less similarity (r2=0.50) between the types of pesticides being used by Iowa and North Carolina private applicators. A greater portion of Iowa private applicators use personal protective equipment than do North Carolina private applicators, and pesticide application methods varied by state. This heterogeneity in potential exposures to pesticides between states should be useful for subsequent epidemiologic analyses using internal comparison groups.


      Citation:

      Alavanja, Michael CR, Dale P. Sandler, Cheryl J. McDonnell, Charles F. Lynch, Margaret E. Pennybacker, Shelia Hoar Zahm, David T. Mage, William C. Steen, Wendy Wintersteen, and Aaron Blair. "Characteristics of pesticide use in a pesticide applicator cohort: the Agricultural Health Study." Environmental research 80, no. 2 (1999): 172. DOI: 10.1006/enrs.1998.3888

    • Tuesday, July 19, 2011

      Associations between urinary metabolites of di(2‐ethylhexyl) phthalate and reproductive hormones in fertile men

      Author(s):
      J. Mendiola
      N. Jorgensen
      AM Andersson
      AM Calafat
      MJ Silva
      JB Redmon
      A Sparks
      EZ Drobnis
      C Wang
      F Liu
      SH Swan

      Journal Title:
      International Journal of Andrology

      Abstract:

      Widely used man‐made chemicals, including phthalates, can induce hormonal alterations through a variety of cellular and molecular mechanisms. A number of rodent and observational studies have consistently demonstrated the anti‐androgenic effect of several phthalates. However, there are only limited data on the relationship between exposure to these chemicals and reproductive hormone levels in men. All men (n = 425) were partners of pregnant women who participated in the Study for Future Families in five US cities and provided urine and serum samples on the same day. Eleven phthalate metabolites were measured in urine and serum samples were analysed for reproductive hormones, including follicle‐stimulating hormone, luteinizing hormone, testosterone, inhibin B and oestradiol and sex hormone‐binding globulin (SHBG). Pearson correlations and parametric tests were used for unadjusted analyses, and multiple linear regression analysis was performed controlling for appropriate covariates. We observed weak or no associations with urinary phthalates other than di(2‐ethylhexyl) phthalate (DEHP). All measures of testosterone [total, calculated free testosterone and the free androgen index (FAI)] were inversely correlated with the urinary concentrations of four DEHP metabolites. After adjustment by appropriate covariates, there was no longer an association between urinary DEHP metabolite concentrations and total testosterone levels; however, FAI was significantly associated with the urinary concentrations of several DEHP metabolites. SHBG was positively related to the urinary concentrations of mono(2‐ethylhexyl) phthalate, but not with other DEHP metabolites, an association that was attenuated after adjustment. Our results suggest that DEHP exposure of fertile men is associated with minor alterations of markers of free testosterone.


      Citation:

      Mendiola, Jaime, N. Jørgensen, A‐M. Andersson, A. M. Calafat, M. J. Silva, J. Bruce Redmon, A. Sparks et al. "Associations between urinary metabolites of di (2‐ethylhexyl) phthalate and reproductive hormones in fertile men." International journal of andrology 34, no. 4pt1 (2011): 369-378. DOI: 10.1111/j.1365-2605.2010.01095.x 

    • Wednesday, October 31, 2018

      The Agricultural Health Study

      Author(s):
      Michael C. R. Alavanja
      Dale P. Sandler
      Suzanne B. McMaster
      Shelia Hoar Zahm
      Cheryl J. McDonnell
      Charles F. Lynch
      Margaret Pennybacker
      Nathaniel Rothman
      Mustafa Dosemeci
      Andrew E. Bond
      Aaron Blair

      Journal Title:
      Environmental Health Perspectives

      Abstract:

      The Agricultural Health Study, a large prospective cohort study has been initiated in North Carolina and Iowa. The objectives of this study are to: 1) identify and quantify cancer risks among men, women, whites, and minorities associated with direct exposure to pesticides and other agricultural agents; 2) evaluate noncancer health risks including neurotoxicity reproductive effects, immunologic effects, nonmalignant respiratory disease, kidney disease, and growth and development among children; 3) evaluate disease risks among spouses and children of farmers that may arise from direct contact with pesticides and agricultural chemicals used in the home lawns and gardens, and from indirect contact, such as spray drift, laundering work clothes, or contaminated food or water; 4) assess current and past occupational and nonoccupational agricultural exposures using periodic interviews and environmental and biologic monitoring; 5) study the relationship between agricultural exposures, biomarkers of exposure, biologic effect, and genetic susceptibility factors relevant to carcinogenesis; and 6) identify and quantify cancer and other disease risks associated with lifestyle factors such as diet, cooking practices, physical activity, smoking and alcohol consumption, and hair dye use. In the first year of a 3-year enrollment period, 26,235 people have been enrolled in the study, including 19,776 registered pesticide applicators and 6,459 spouses of registered farmer applicators. It is estimated that when the total cohort is assembled in 1997 it will include approximately 75,000 adult study subjects. Farmers, the largest group of registered pesticide applicators comprise 77% of the target population enrolled in the study. This experience compares favorably with enrollment rates of previous prospective studies.


      Citation:

      Alavanja, Michael C., Dale P. Sandler, Suzanne B. McMaster, Shelia Hoar Zahm, Cheryl J. McDonnell, Charles F. Lynch, Margaret Pennybacker et al. "The Agricultural Health Study." Environmental health perspectives 104, no. 4 (1996): 362. DOI: 10.1289/ehp.96104362

    • Wednesday, September 1, 2010

      Are Environmental Levels of Bisphenol A Associated with Reproductive Function in Fertile Men?

      Author(s):
      Jaime Mendiola
      Niels Jorgensen
      Anna-Maria Andersson
      Antonia M. Calafat
      Xiaoyun Ye
      J. Bruce Redmon
      Erma Z. Drobnis
      Christina Wang
      Amy Sparks
      Sally W. Thurston
      Fan Liu
      Shanna H. Swan

      Journal Title:
      Environmental Health Perspectives

      Abstract:

      Background

      Rodent and in vitro studies have demonstrated the estrogenicity of bisphenol A (BPA). However, few studies have examined the relationship between human exposure to BPA and male reproductive function.

      Objectives

      We investigated the relationships between environmental BPA exposure and reproductive parameters, including semen quality and male reproductive hormones, in prospectively recruited fertile men.

      Methods

      Participants (n = 375) were partners of pregnant women who participated in the Study for Future Families in four U.S. cities, and all of the men provided blood, semen, and urine samples. BPA was measured in urine. Serum samples were analyzed for reproductive hormones, including follicle-stimulating hormone, luteinizing hormone (LH), testosterone, inhibin B, estradiol, and sex hormone–binding globulin (SHBG), as well as the free androgen index (FAI). Semen analyses were performed according to World Health Organization criteria. Pearson correlations were used for unadjusted analyses, and multiple linear regression analyses were used to examine associations controlling for age, body mass index, smoking, ethnicity, urinary creatinine concentration, time of sample collection, and duration of abstinence.

      >Results

      After multivariate adjustment, we observed no significant associations between any semen parameter and urinary BPA concentration. However, a significant inverse association was found between urinary BPA concentration and FAI levels and the FAI/LH ratio, as well as a significant positive association between BPA and SHBG.

      Conclusions

      Our results suggest that, in fertile men, exposure to low environmental levels of BPA may be associated with a modest reduction in markers of free testosterone, but any effects on reproductive function are likely to be small, and of uncertain clinical significance.


      Citation:

      Mendiola, Jaime, Niels Jørgensen, Anna-Maria Andersson, Antonia M. Calafat, Xiaoyun Ye, J. Bruce Redmon, Erma Z. Drobnis et al. "Are environmental levels of bisphenol A associated with reproductive function in fertile men?." Environmental health perspectives 118, no. 9 (2010): 1286. DOI: 10.1289/ehp.1002037

    • Thursday, January 1, 1998

      Drinking water source and chlorination byproducts I. Risk of bladder cancer

      Author(s):
      Kenneth P. Cantor
      Charles F. Lynch
      Mariana E. Hildesheim
      Mustafa Dosemeci
      Jay Lubin
      Michael Alavanja
      Gunther Craun

      Journal Title:
      Epidemiology

      Abstract:

      We conducted a population-based case-control study of bladder cancer in Iowa in 1986-1989 to evaluate the risk posed by tapwater containing chlorination byproducts. We combined information about residential history, drinking water source, beverage intake, and other factors with historical data from water utilities and measured contaminant levels to create indices of past exposure to chlorination byproducts. The study comprised 1,123 cases and 1,983 controls who had data relating to at least 70% of their lifetime drinking water source. After we adjusted for potential confounders, we calculated odds ratios for duration of chlorinated surface water of 1.0 (referent), 1.0, 1.1, 1.2, and 1.5 for 0, 1-19, 20-39, 40-59, and > or =60 years of use. We also found associations with total and average lifetime byproduct intake, as represented by trihalomethane estimates. Positive findings were restricted to men and to ever-smokers. Among men, odds ratios were 1.0 (referent), 1.1, 1.3, 1.5, and 1.9, and among ever-smokers, 1.0, 1.1, 1.3, 1.8, and 2.2, after adjustment for intensity and timing of smoking. Among nonsmoking men and women, regardless of smoking habit, there was no association. Among men, smoking and exposure to chlorinated surface water mutually enhanced the risk of bladder cancer. The overall association of bladder cancer risk with duration of chlorinated surface water use that we found is consistent with the findings of other investigations, but the differences in risk between men and women, and between smokers and nonsmokers, have not been widely observed.


      Citation:

      Cantor, Kenneth P., Charles F. Lynch, Mariana E. Hildesheim, Mustafa Dosemeci, Jay Lubin, Michael Alavanja, and Gunther Craun. "Drinking water source and chlorination byproducts I. Risk of bladder cancer." Epidemiology (1998): 21-28.

    • Saturday, April 1, 1995

      Radium-bearing pipe scale deposits: implications for national waterborne radon sampling methods.

      Author(s):
      R. William Field
      Eileen L. Fisher
      Richard L. Valentine
      Burton C. Kross

      Journal Title:
      American Journal of Public Health

      Abstract:

      A point-of-use waterborne radon-222 (222Rn) survey of a small Iowa town was performed to determine the cause of unnaturally high waterborne 222Rn concentrations in the municipality. The source of the elevated 222Rn concentrations was a newly discovered reservoir of waterborne 222Rn originating from distribution-system radium-226 (226Ra) adsorbed internal pipe scale deposits. Because the proposed national drinking water regulations for 222Rn require sampling at the origin of the distribution system rather than at the point of use, the proposed scheme for collection of water samples may not represent actual consumer waterborne 222Rn exposure in all cases.


      Citation:

      Field RW, Fisher EL, Valentine RL, Kross BC. Radium-bearing pipe scale deposits: implications for national waterborne radon sampling methods. American journal of public health. 1995 Apr;85(4):567-70.

    • Friday, March 1, 1996

      Does Increased Nitrate Ingestion Elevate Nitrate Levels in Human Milk?

      Author(s):
      Lois B. Dusdieker
      Phyllis J. Stumbo
      Burton C. Kross
      Clairbourne I. dungy

      Journal Title:
      Archives of Pediatrics & Adolescent Medicine

      Abstract:

      Objective:  To determine whether the nitrate content of human milk is influenced by maternal ingestion of water containing elevated nitrate levels.

      Design:  Prospective, nonrandomized, volunteer study.

      Setting:  Clinical Research Center at the University of Iowa Hospitals and Clinics, Iowa City.

      Patients:  Twenty healthy lactating women with infants older than 6 months.

      Interventions:  The mothers were asked to consume a minimum of 1500 mL of water containing 0 mg of nitrate per liter on day 1, 45 mg on day 2, and 100 mg on day 3 in addition to consuming and recording their dietary intake. Breast-feeding was permitted during days 1 and 2, but milk was expressed on day 3 and the infants were given alternate food sources. After each 24-hour study day, maternal urine and milk samples were collected and frozen. A modified cadmium column reduction method was used to determine spot urinary and milk nitrate content.

      Results:  The mean total nitrate intake from diet and water on days 1, 2, and 3, respectively, was 46.6, 168.1, and 272.0 mg. Spot urine nitrate content on days 1, 2, and 3, respectively, was 36.0, 66.0, and 84.0 mg. Nitrate concentration of human milk on days 1, 2, and 3, respectively, was 4.4, 5.1, and 5.2 mg/L.

      Conclusion:  Women who consume water with a nitrate concentration of 100 mg/L or less do not produce milk with elevated nitrate levels.(Arch Pediatr Adolesc Med. 1996;150:311-314)


      Citation:

      Dusdieker, Lois B., Phyllis J. Stumbo, Burton C. Kross, and Claibourne I. Dungy. "Does increased nitrate ingestion elevate nitrate levels in human milk?." Archives of pediatrics & adolescent medicine 150, no. 3 (1996): 311-314. DOI:10.1001/archpedi.1996.02170280081015

    • Monday, September 30, 1991

      Incidence of histologic types of uterine sarcoma in relation to menstrual and reproductive history

      Author(s):
      Stephen M. Schwartz
      Noel S. Weiss
      Janet R. Daling
      Polly A. Newcomb
      Jonathan M. Liff
      Marilee D. Gammon
      W. Douglas Thompson
      Janice D. Watt
      Bruce K. Armstrong
      Peter Weyer
      Peter Isaacson
      Marit Ek

      Journal Title:
      International Journal of Cancer

      Abstract:

      To determine whether the occurrence of one or more histologic types of uterine sarcoma is related to events in a woman's reproductive life, a population‐based case‐control study was conducted. One‐hundred sixty‐seven women newly diagnosed with uterine sarcoma among residents of 6 geographic regions were compared to 208 women selected at random from the same populations with regard to histories of menstruation, pregnancy and childbearing, and breast feeding, as reported during a telephone interview. Compared to women whose menstrual periods began at age 13, women whose menses began earlier were at increased risk of leiomyosarcoma (OR = 2.0, 95% CI 0.9, 4.3); other histologic types were less strongly associated with early age at menarche. Women with leiomyosarcoma and endometrial stromal sarcoma, but not malignant mixed Müllerian tumors, tended to have ceased menstruating 2‐3 years later than controls. None of the histologic types was clearly related to parity or to age at first live birth, but each was inversely related to age at last live birth. Associations were observed between leiomyosarcoma and histories of an induced abortion (OR = 4.2, 95% CI 1.2, 14.2) and of breast feeding after a live birth (OR = 0.5, 95% CI 0.3, 1.0); these relationships were not observed for other morphologic variants. These results suggest possible similarities and differences in menstrual and reproductive risk factors among histologic types of uterine sarcoma, and between these malignancies and the more common breast, endometrial and ovarian carcinomas.


      Citation:

      Schwartz SM, Weiss NS, Daling JR, Newcomb PA, Liff JM, Gammon MD, Douglas Thompson W, Watt JD, Armstrong BK, Weyer P, Isaacson P. Incidence of histologic types of uterine sarcoma in relation to menstrual and reproductive history. International journal of cancer. 1991 Sep 30;49(3):362-7. DOI: 10.1002/ijc.2910490308 

       

    • Monday, January 15, 2018

      Ingested nitrate and nitrite, disinfection by-products, and pancreatic cancer risk in postmenopausal women

      Author(s):
      Arbor J.L. Quist
      Maki Inoue-Choi
      Peter J. Weyer
      Kristin E. Anderson
      Kenneth P. Cantor
      Stuart Krasner
      Laura E. Beane Freeman
      Mary H. Ward
      Rena R. Jones

      Journal Title:
      International Journal of Cancer

      Abstract:

      Nitrate and nitrite are precursors of N‐nitroso compounds (NOC), probable human carcinogens that cause pancreatic tumors in animals. Disinfection by‐products (DBP) exposures have also been linked with digestive system cancers, but few studies have evaluated relationships with pancreatic cancer. We investigated the association of pancreatic cancer with these drinking water contaminants and dietary nitrate/nitrite in a cohort of postmenopausal women in Iowa (1986–2011). We used historical monitoring and treatment data to estimate levels of long‐term average nitrate and total trihalomethanes (TTHM; the sum of the most prevalent DBP class) and the duration exceeding one‐half the maximum contaminant level (>½ MCL; 5 mg/L nitrate‐nitrogen, 40 µg/L TTHM) among participants on public water supplies (PWS) >10 years. We estimated dietary nitrate and nitrite intakes using a food frequency questionnaire. We computed hazard ratios (HR) and 95% confidence intervals (CI) using Cox regression and evaluated nitrate interactions with smoking and vitamin C intake. We identified 313 cases among 34,242 women, including 152 with >10 years PWS use (N = 15,710). Multivariable models of average nitrate showed no association with pancreatic cancer (HRp95vs. Q1 = 1.16, 95% CI: 0.51–2.64). Associations with average TTHM levels were also null (HRQ4vs. Q1 = 0.70, 95% CI:0.42–1.18). We observed no trend with increasing years of exposure to either contaminant at levels >½ MCL. Positive associations were suggested in the highest dietary nitrite intake from processed meat (HRp95vs. Q1 = 1.66, 95% CI 1.00–2.75;ptrend = 0.05). We found no interactions of nitrate with known modifiers of endogenous NOC formation. Our results suggest that nitrite intake from processed meat may be a risk factor for pancreatic cancer.


      Citation:

      Quist AJ, Inoue‐Choi M, Weyer PJ, Anderson KE, Cantor KP, Krasner S, Freeman LE, Ward MH, Jones RR. Ingested nitrate and nitrite, disinfection by‐products, and pancreatic cancer risk in postmenopausal women. International journal of cancer. 2018 Jan 15;142(2):251-61. DOI: 10.1002/ijc.31055 

       

    • Friday, September 1, 2017

      Ingested nitrate, disinfection by-products, and kidney cancer risk in older women

      Author(s):
      Rena R. Jones
      Peter J. Weyer
      Curt T. Dellavalle
      Kim Robien
      Kenneth P. Cantor
      Stuart Krasner
      Laura E. Beane Freeman
      Mary H. Ward

      Journal Title:
      Epidemiology

      Abstract:

      Background
      N-nitroso compounds formed endogenously after nitrate/nitrite ingestion are animal renal carcinogens. Previous epidemiologic studies of drinking water nitrate did not evaluate other potentially toxic water contaminants, including the suspected renal carcinogen chloroform.

      Methods
      In a cohort of postmenopausal women in Iowa (1986–2010), we used historical measurements to estimate long-term average concentrations of nitrate-nitrogen (NO3−N) and disinfection by-products (DBP) in public water supplies. For NO3–N and the regulated DBP (total trihalomethanes [THM] and the sum of five haloacetic acids [HAA5]), we estimated the number of years of exposure above one-half the current maximum contaminant level (>½-MCL NO3–N; >5 mg/L). Dietary intakes were assessed via food frequency questionnaire. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) with Cox models, and evaluated interactions with factors influencing N-nitroso compound formation.

      Results
      We identified 125 incident kidney cancers among 15,577 women reporting using water from public supplies >10 years. In multivariable models, risk was higher in the 95th percentile of average NO3–N (HRp95vsQ1 = 2.3; CI: 1.2, 4.3; P trend = 0.33) and for any years of exposure >½-MCL; adjustment for total THM did not materially change these associations. There were no independent relationships with total THM, individual THMs chloroform and bromodichloromethane, or with haloacetic acids. Dietary analyses yielded associations with high nitrite intake from processed meats but not nitrate or nitrite overall. We found no interactions.

      Conclusions
      Relatively high nitrate levels in public water supplies were associated with increased risk of renal cancer. Our results also suggest that nitrite from processed meat is a renal cancer risk factor.


      Citation:

      Jones RR, Weyer PJ, DellaValle CT, Robien K, Cantor KP, Krasner S, Beane Freeman LE, Ward MH. Ingested nitrate, disinfection by-products, and kidney cancer risk in older women. Epidemiology. 2017 Sep 1;28(5):703-11. DOI: 10.1097/EDE.0000000000000647 

    • Monday, December 1, 2014

      Assessing bottled water nitrate concentrations to evaluate total drinking water nitrate exposure and risk of birth defects

      Author(s):
      Peter J. Weyer
      Jean D. Brender
      Paul A. Romitti
      Jiji R. Kantamneni
      David Crawford
      Joseph R. Sharkey
      Mayura Shinde
      Scott A. Horel
      Ann M. Vuong
      Peter H. Langlois

      Journal Title:
      Journal of Water and Health

      Abstract:

      Previous epidemiologic studies of maternal exposure to drinking water nitrate did not account for bottled water consumption. The objective of this National Birth Defects Prevention Study (NBDPS) (USA) analysis was to assess the impact of bottled water use on the relation between maternal exposure to drinking water nitrate and selected birth defects in infants born during 1997–2005. Prenatal residences of 1,410 mothers reporting exclusive bottled water use were geocoded and mapped; 326 bottled water samples were collected and analyzed using Environmental Protection Agency Method 300.0. Median bottled water nitrate concentrations were assigned by community; mothers' overall intake of nitrate in mg/day from drinking water was calculated. Odds ratios for neural tube defects, limb deficiencies, oral cleft defects, and heart defects were estimated using mixed-effects models for logistic regression. Odds ratios (95% CIs) for the highest exposure group in offspring of mothers reporting exclusive use of bottled water were: neural tube defects [1.42 (0.51, 3.99)], limb deficiencies [1.86 (0.51, 6.80)], oral clefts [1.43 (0.61, 3.31)], and heart defects [2.13, (0.87, 5.17)]. Bottled water nitrate had no appreciable impact on risk for birth defects in the NBDPS.


      Citation:

      Weyer PJ, Brender JD, Romitti PA, Kantamneni JR, Crawford D, Sharkey JR, Shinde M, Horel SA, Vuong AM, Langlois PH. Assessing bottled water nitrate concentrations to evaluate total drinking water nitrate exposure and risk of birth defects. Journal of water and health. 2014 Dec 1;12(4):755-62. DOI: 10.2166/wh.2014.237  

    • Friday, July 1, 2016

      Atrazine in public water supplies and risk of ovarian cancer among postmenopausal women in the Iowa Women’s Health Study

      Author(s):
      Maki Inoue-Choi
      Peter J Weyer
      Rena R Jones
      Benjamin J Booth
      Kenneth P Cantor
      Kim Robien
      Mary H Ward

      Journal Title:
      Occupational and Environmental Medicine

      Abstract:

      Background
      Few studies have evaluated environmental chemical exposures in relation to ovarian cancer. We previously found an increased risk of ovarian cancer among postmenopausal women in Iowa associated with higher nitrate levels in public water supplies (PWS). However, elevated nitrate levels may reflect the presence of other agricultural chemicals, such as atrazine, one of the most commonly detected pesticides in Iowa PWS.

      Methods
      We evaluated the association between atrazine in drinking water and incident ovarian cancer (N=145, 1986–2010) among 13 041 postmenopausal women in the Iowa Women's Health Study who used their PWS for ≥11 years as reported in 1989. Average levels of atrazine (1986–1987), nitrate-nitrogen (NO3-N, 1955–1988) and estimated levels of total trihalomethanes (TTHM, 1955–1988) from PWS monitoring data were linked to the participants' cities of residence. We computed HRs and 95% CIs by categories of the average atrazine level (not detected, ≤ or >0.37 parts per billion=median) using Cox proportional hazards regression adjusting for ovarian cancer risk factors.

      Results
      Atrazine was detected in water samples from 69 cities where 4155 women (32%) lived and levels were moderately correlated with NO3-N (ρ=0.35) and TTHM (ρ=0.24). Atrazine levels were not associated with ovarian cancer risk with or without adjusting for NO3-N and TTHM levels (p-trend=0.50 and 0.81, respectively). Further, there was no evidence for effect modification of the atrazine association by NO3-N or TTHM levels.

      Conclusions
      In our study with low atrazine detection rates, we found no association between atrazine in PWS and postmenopausal ovarian cancer risk


      Citation:

      Inoue-Choi, M., Weyer, P. J., Jones, R. R., Booth, B. J., Cantor, K. P., Robien, K., & Ward, M. H. (2016). Atrazine in public water supplies and risk of ovarian cancer among postmenopausal women in the Iowa Women's health study. Occup Environ Med, oemed-2016. DOI: 10.1136/oemed-2016-103575.

    • Saturday, October 1, 2016

      Assessing the relationship between groundwater nitrate and animal feeding operations in Iowa (USA)

      Author(s):
      Keith W. Zirkle
      Bernard T. Nolan
      Rena R. Jones
      Peter J. Weyer
      Mary H. Ward
      David C. Wheeler

      Journal Title:
      Science of the Total Environment

      Abstract:

      Nitrate-nitrogen is a common contaminant of drinking water in many agricultural areas of the United States of America (USA). Ingested nitrate from contaminated drinking water has been linked to an increased risk of several cancers, specific birth defects, and other diseases. In this research, we assessed the relationship between animal feeding operations (AFOs) and groundwater nitrate in private wells in Iowa. We characterized AFOs by swine and total animal units and type (open, confined, or mixed), and we evaluated the number and spatial intensities of AFOs in proximity to private wells. The types of AFO indicate the extent to which a facility is enclosed by a roof. Using linear regression models, we found significant positive associations between the total number of AFOs within 2 km of a well (p trend < 0.001), number of open AFOs within 5 km of a well (p trend < 0.001), and number of mixed AFOs within 30 km of a well (p trend < 0.001) and the log nitrate concentration. Additionally, we found significant increases in log nitrate in the top quartiles for AFO spatial intensity, open AFO spatial intensity, and mixed AFO spatial intensity compared to the bottom quartile (0.171 log(mg/L), 0.319 log(mg/L), and 0.541 log(mg/L), respectively; all p < 0.001). We also explored the spatial distribution of nitrate-nitrogen in drinking wells and found significant spatial clustering of high-nitrate wells (> 5 mg/L) compared with low-nitrate (≤ 5 mg/L) wells (p = 0.001). A generalized additive model for high-nitrate status identified statistically significant areas of risk for high levels of nitrate. Adjustment for some AFO predictor variables explained a portion of the elevated nitrate risk. These results support a relationship between animal feeding operations and groundwater nitrate concentrations and differences in nitrate loss from confined AFOs vs. open or mixed types.


      Citation:

      Zirkle, K. W., Nolan, B. T., Jones, R. R., Weyer, P. J., Ward, M. H., & Wheeler, D. C. (2016). Assessing the relationship between groundwater nitrate and animal feeding operations in Iowa (USA). Science of the Total Environment, 566, 1062-1068. DOI: 10.1016/j.scitotenv.2016.05.130 

       

    • Thursday, November 27, 2014

      Nitrate and nitrite ingestion and risk of ovarian cancer among postmenopausal women in Iowa

      Author(s):
      Maki Inoue-Choi
      Rena R. Jones
      Kristin E. Anderson
      Kenneth P. Cantor
      James R. Cerhan
      Stuart Krasner
      Kim Robien
      Peter J. Weyer
      Mary H. Ward

      Journal Title:
      International Journal of Cancer

      Abstract:

      Nitrate and nitrite are precursors in the endogenous formation of N‐nitroso compounds (NOC), potential human carcinogens. We evaluated the association of nitrate and nitrite ingestion with postmenopausal ovarian cancer risk in the Iowa Women's Health Study. Among 28,555 postmenopausal women, we identified 315 incident epithelial ovarian cancers from 1986 to 2010. Dietary nitrate and nitrite intakes were assessed at baseline using food frequency questionnaire data. Drinking water source at home was obtained in a 1989 follow‐up survey. Nitrate‐nitrogen (NO3‐N) and total trihalomethane (TTHM) levels for Iowa public water utilities were linked to residences and average levels were computed based on each woman's duration at the residence. We computed multivariable‐adjusted hazard ratios (HR) and 95% confidence intervals (CI) using Cox proportional hazards regression. We tested interactions of nitrate with TTHMs and dietary factors known to influence NOC formation. Ovarian cancer risk was 2.03 times higher (CI = 1.22–3.38, ptrend = 0.003) in the highest quartile (≥2.98 mg/L) compared with the lowest quartile (≤0.47 mg/L; reference) of NO3‐N in public water, regardless of TTHM levels. Risk among private well users was also elevated (HR = 1.53, CI = 0.93–2.54) compared with the same reference group. Associations were stronger when vitamin C intake was <median (pinteraction = 0.01 and 0.33 for private well and public supplies, respectively). Dietary nitrate was inversely associated with ovarian cancer risk (ptrend = 0.02); whereas, dietary nitrite from processed meats was positively associated with the risk (ptrend = 0.04). Our findings indicate that high nitrate levels in public drinking water and private well use may increase ovarian cancer risk among postmenopausal women.


      Citation:

      Inoue‐Choi M, Jones RR, Anderson KE, Cantor KP, Cerhan JR, Krasner S, Robien K, Weyer PJ, Ward MH. Nitrate and nitrite ingestion and risk of ovarian cancer among postmenopausal women in Iowa. International journal of cancer. 2015 Jul 1;137(1):173-82. DOI: 10.1002/ijc.29365

    • Sunday, July 1, 2012

      Interaction of nitrate and folate on the risk of breast cancer among postmenopausal women

      Author(s):
      Maki Inoue-Choi
      Mary H. Ward
      James R. Cerhan
      Peter J. Weyer
      Kristin E. Anderson
      Kim Robien

      Journal Title:
      Nutrition and Cancer

      Abstract:

      Ingested nitrate can be endogenously reduced to nitrite, which may form N-nitroso compounds, known potent carcinogens. However, some studies have reported no or inverse associations between dietary nitrate intake and cancer risk. These associations may be confounded by a protective effect of folate, which plays a vital role in DNA repair. We evaluated the interaction of dietary and water nitrate intake with total folate intake on breast cancer risk in the Iowa Women's Health Study. Dietary intake was assessed at study baseline. Nitrate intake from public water was assessed using a historical database on Iowa municipal water supplies. After baseline exclusions, 34,388 postmenopausal women and 2,875 incident breast cancers were included. Overall, neither dietary nor water nitrate was associated with breast cancer risk. Among those with folate intake ≥400 μg/day, breast cancer risk was significantly increased in public water users with the highest nitrate quintile (HR = 1.40, 95% CI = 1.05–1.87) and private well users (HR = 1.38, 95% CI = 1.05–1.82) compared to public water users with the lowest nitrate quintile; in contrast, there was no association among those with lower folate intake. Our findings do not support a previous report of increased risk of breast cancer among individuals with high dietary nitrate but low folate intake.


      Citation:

      Inoue-Choi, M., Ward, M. H., Cerhan, J. R., Weyer, P. J., Anderson, K. E., & Robien, K. (2012). Interaction of nitrate and folate on the risk of breast cancer among postmenopausal women. Nutrition and cancer, 64(5), 685-694. DOI: 10.1080/01635581.2012.687427

    • Saturday, May 1, 2010

      Nitrate Intake and the Risk of Thyroid Cancer and Thyroid Disease

      Author(s):
      Mary H. Ward
      Briseis A. Kilfoy
      Peter J. Weyer
      Kristin E. Anderson
      Aaron R. Folsom
      James R. Cerhan

      Journal Title:
      Epidemiology

      Abstract:

      Background
      Nitrate is a contaminant of drinking water in agricultural areas and is found at high levels in some vegetables. Nitrate competes with uptake of iodide by the thyroid, thus potentially affecting thyroid function.

      Methods
      We investigated the association of nitrate intake from public water supplies and diet with the risk of thyroid cancer and self-reported hypothyroidism and hyperthyroidism in a cohort of 21,977 older women in Iowa who were enrolled in 1986 and who had used the same water supply for >10 years. We estimated nitrate ingestion from drinking water using a public database of nitrate measurements (1955–1988). Dietary nitrate intake was estimated using a food frequency questionnaire and levels from the published literature. Cancer incidence was determined through 2004.

      Results
      We found an increased risk of thyroid cancer with higher average nitrate levels in public water supplies and with longer consumption of water exceeding 5 mg/L nitrate-N (for ≤5 years at >5 mg/L, relative risk [RR] = 2.6 [95% confidence interval (CI) = 1.1–6.2]). We observed no association with prevalence of hypothyroidism or hyperthyroidism. Increasing intake of dietary nitrate was associated with an increased risk of thyroid cancer (highest vs. lowest quartile, RR = 2.9 [1.0–8.1]; P for trend = 0.046) and with the prevalence of hypothyroidism (odds ratio = 1.2 [95% CI = 1.1–1.4]), but not hyperthyroidism.

      Conclusions
      Nitrate may play a role in the etiology of thyroid cancer and warrants further study.


      Citation:

      Ward, M. H., Kilfoy, B. A., Weyer, P. J., Anderson, K. E., Folsom, A. R., & Cerhan, J. R. (2010). Nitrate intake and the risk of thyroid cancer and thyroid disease. Epidemiology (Cambridge, Mass.), 21(3), 389. DOI: 10.1097/EDE.0b013e3181d6201d

    • Thursday, June 25, 1992

      Risk of Leukemia after Chemotherapy and Radiation Treatment for Breast Cancer

      Author(s):
      Rochelle E. Curtis
      John D. Boice, Jr.
      Marilyn Stovall
      Leslie Bernstein
      Raymond S. Greenberg
      John T. Flannery
      Ann G. Schwartz
      Peter J. Weyer
      William C. Moloney
      Robert N. Hoover

      Journal Title:
      New England Journal of Medicine

      Abstract:

      Background Few studies have evaluated the late effects of adjuvant chemotherapy for breast cancer. Moreover, the relation between the risk of leukemia and the amount of drug given and the interaction of chemotherapy with radiotherapy have not been described in detail.

      Methods We conducted a case–control study in a cohort of 82,700 women given a diagnosis of breast cancer from 1973 to 1985 in five areas of the United States. Detailed information about therapy was obtained for 90 patients with leukemia and 264 matched controls. The dose of radiation to the active marrow was estimated from individual radiotherapy records (mean dose, 7.5 Gy).

      Results The risk of acute nonlymphocytic leukemia was significantly increased after regional radiotherapy alone (relative risk, 2.4), alkylating agents alone (relative risk, 10.0), and combined radiation and drug therapy (relative risk, 17.4). Dose-dependent risks were observed after radiotherapy and treatment with melphalan and cyclophosphamide. Melphalan was 10 times more leukemogenic than cyclophosphamide (relative risk, 31.4 vs. 3.1). There was little increase in the risk associated with total cyclophosphamide doses of less than 20,000 mg.

      Conclusions Although leukemia occurs in few patients with breast cancer, significantly elevated risks were linked to treatments with regional radiation and alkylating agents. Melphalan is a more potent leukemogen than cyclophosphamide or radiotherapy. Low risks were associated with the levels of cyclophosphamide in common use today. Systemic drug therapy combined with radiotherapy that delivers high doses to the marrow appears to enhance the risk of leukemia.


      Citation:

      Curtis RE, Boice Jr JD, Stovall M, Bernstein L, Greenberg RS, Flannery JT, Schwartz AG, Weyer P, Moloney WC, Hoover RN. Risk of leukemia after chemotherapy and radiation treatment for breast cancer. New England Journal of Medicine. 1992 Jun 25;326(26):1745-51.  DOI: 10.1056/NEJM199206253262605

    • Monday, July 23, 2018

      Drinking Water Nitrate and Human Health: An Updated Review

      Author(s):
      Mary H. Ward
      Rena R. Jones
      Jean D. Brender
      Theo M. de Kok
      Peter J. Weyer
      Bernard T. Nolan
      Cristina M. Villanueva
      Simone G. van Breda

      Journal Title:
      International Journal of Environmental Research and Public Health

      Abstract:

      Nitrate levels in our water resources have increased in many areas of the world largely due to applications of inorganic fertilizer and animal manure in agricultural areas. The regulatory limit for nitrate in public drinking water supplies was set to protect against infant methemoglobinemia, but other health effects were not considered. Risk of specific cancers and birth defects may be increased when nitrate is ingested under conditions that increase formation of N-nitroso compounds. We previously reviewed epidemiologic studies before 2005 of nitrate intake from drinking water and cancer, adverse reproductive outcomes and other health effects. Since that review, more than 30 epidemiologic studies have evaluated drinking water nitrate and these outcomes. The most common endpoints studied were colorectal cancer, bladder, and breast cancer (three studies each), and thyroid disease (four studies). Considering all studies, the strongest evidence for a relationship between drinking water nitrate ingestion and adverse health outcomes (besides methemoglobinemia) is for colorectal cancer, thyroid disease, and neural tube defects. Many studies observed increased risk with ingestion of water nitrate levels that were below regulatory limits. Future studies of these and other health outcomes should include improved exposure assessment and accurate characterization of individual factors that affect endogenous nitrosation.


      Citation:

      Ward M, Jones R, Brender J, de Kok T, Weyer P, Nolan B, Villanueva C, van Breda S. Drinking Water Nitrate and Human Health: An Updated Review. International journal of environmental research and public health. 2018 Jul 23;15(7):1557.  DOI: 10.3390/ijerph15071557

    • Tuesday, August 8, 2017

      Estimated Maternal Pesticide Exposure from Drinking Water and Heart Defects in Offspring

      Author(s):
      Jihye Kim
      Michael D. Swartz
      Peter H. Langlois
      Paul A. Romitti
      Peter Weyer
      Laura E. Mitchell
      Thomas J. Luben
      Anushuya Ramakrishnan
      Sadia Malik
      Philip J. Lupo
      Marcia L. Feldkamp
      Robert E. Meyer
      Jennifer J. Winston
      Jennita Reefhuis
      Sarah J. Blossom
      Erin Bell
      A. J. Agopian
      the National Birth Defects Prevention Study

      Journal Title:
      International Journal of Environmental Research and Public Health

      Abstract:

      Our objective was to examine the relationship between estimated maternal exposure to pesticides in public drinking water and the risk of congenital heart defects (CHD). We used mixed-effects logistic regression to analyze data from 18,291 nonsyndromic cases with heart defects from the Texas Birth Defects Registry and 4414 randomly-selected controls delivered in Texas from 1999 through 2005. Water district-level pesticide exposure was estimated by linking each maternal residential address to the corresponding public water supply district’s measured atrazine levels. We repeated analyses among independent subjects from the National Birth Defects Prevention Study (NBDPS) (1620 nonsyndromic cases with heart defects and 1335 controls delivered from 1999 through 2005). No positive associations were observed between high versus low atrazine level and eight CHD subtypes or all included heart defects combined. These findings should be interpreted with caution, in light of potential misclassification and relatively large proportions of subjects with missing atrazine data. Thus, more consistent and complete monitoring and reporting of drinking water contaminants will aid in better understanding the relationships between pesticide water contaminants and birth defects.


      Citation:

      Kim, J., Swartz, M. D., Langlois, P. H., Romitti, P. A., Weyer, P., Mitchell, L. E., ... & Feldkamp, M. L. (2017). Estimated Maternal Pesticide Exposure from Drinking Water and Heart Defects in Offspring. International journal of environmental research and public health, 14(8), 889. https://doi.org/10.3390/ijerph14080889

    • Tuesday, November 1, 2016

      Nitrate from Drinking Water and Diet and Bladder Cancer Among Postmenopausal Women in Iowa

      Author(s):
      Rena R. Jones
      Peter J. Weyer
      Curt T. DellaValle
      Maki Inoue-Choi
      Kristin E. Anderson
      Kenneth P. Cantor
      Stuart Krasner
      Kim Robien
      Laura E. Beane Freeman
      Debra T. Silverman
      Mary H. Ward

      Journal Title:
      Environmental Health Perspectives

      Abstract:

      Background
      Nitrate is a drinking water contaminant arising from agricultural sources, and it is a precursor in the endogenous formation of N-nitroso compounds (NOC), which are possible bladder carcinogens.

      Objectives
      We investigated the ingestion of nitrate and nitrite from drinking water and diet and bladder cancer risk in women.

      Methods
      We identified incident bladder cancers among a cohort of 34,708 postmenopausal women in Iowa (1986–2010). Dietary nitrate and nitrite intakes were estimated from a baseline food frequency questionnaire. Drinking water source and duration were assessed in a 1989 follow-up. For women using public water supplies (PWS) > 10 years (n = 15,577), we estimated average nitrate (NO3-N) and total trihalomethane (TTHM) levels and the number of years exceeding one-half the maximum contaminant level (NO3-N: 5 mg/L, TTHM: 40 μg/mL) from historical monitoring data. We computed hazard ratios (HRs) and 95% confidence intervals (CIs), and assessed nitrate interactions with TTHM and with modifiers of NOC formation (smoking, vitamin C).

      Results
      We identified 258 bladder cancer cases, including 130 among women > 10 years at their PWS. In multivariable-adjusted models, we observed nonsignificant associations among women in the highest versus lowest quartile of average drinking water nitrate concentration (HR = 1.48; 95% CI: 0.92, 2.40; ptrend = 0.11), and we found significant associations among those exposed ≥ 4 years to drinking water with > 5 mg/L NO3-N (HR = 1.62; 95% CI: 1.06, 2.47; ptrend = 0.03) compared with women having 0 years of comparable exposure. TTHM adjustment had little influence on associations, and we observed no modification by vitamin C intake. Relative to a common reference group of never smokers with the lowest nitrate exposures, associations were strongest for current smokers with the highest nitrate exposures (HR = 3.67; 95% CI: 1.43, 9.38 for average water NO3-N and HR = 3.48; 95% CI: 1.20, 10.06 and ≥ 4 years > 5 mg/L, respectively). Dietary nitrate and nitrite intakes were not associated with bladder cancer.

      Conclusions
      Long-term ingestion of elevated nitrate in drinking water was associated with an increased risk of bladder cancer among postmenopausal women.


      Citation:

      Jones RR, Weyer PJ, DellaValle CT, Inoue-Choi M, Anderson KE, Cantor KP, Krasner S, Robien K, Beane Freeman LE, Silverman DT, Ward MH. 2016. Nitrate from drinking water and diet and bladder cancer among postmenopausal women in Iowa. Environ Health Perspect 124:1751–1758; DOI: 10.1289/EHP191

    • Tuesday, November 14, 2006

      Impacts of Waste from Concentrated Animal Feeding Operations on Water Quality

      Author(s):
      JoAnn Burkholder
      Bob Libra
      Peter Weyer
      Susan Heathcote
      Dana Kolpin
      Peter S. Thorne
      Michael Wichman

      Journal Title:
      Environmental Health Perspectives

      Abstract:

      Waste from agricultural livestock operations has been a long-standing concern with respect to contamination of water resources, particularly in terms of nutrient pollution. However, the recent growth of concentrated animal feeding operations (CAFOs) presents a greater risk to water quality because of both the increased volume of waste and to contaminants that may be present (e.g., antibiotics and other veterinary drugs) that may have both environmental and public health importance. Based on available data, generally accepted livestock waste management practices do not adequately or effectively protect water resources from contamination with excessive nutrients, microbial pathogens, and pharmaceuticals present in the waste. Impacts on surface water sources and wildlife have been documented in many agricultural areas in the United States. Potential impacts on human and environmental health from long-term inadvertent exposure to water contaminated with pharmaceuticals and other compounds are a growing public concern. This work-group, which is part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards—Searching for Solutions, identified needs for rigorous ecosystem monitoring in the vicinity of CAFOs and for improved characterization of major toxicants affecting the environment and human health. Last, there is a need to promote and enforce best practices to minimize inputs of nutrients and toxicants from CAFOs into freshwater and marine ecosystems.


      Citation:

      Burkholder, J., Libra, B., Weyer, P., Heathcote, S., Kolpin, D., Thorne, P. S., & Wichman, M. (2006). Impacts of waste from concentrated animal feeding operations on water quality. Environmental health perspectives, 115(2), 308-312. DOI: 10.1289/ehp.8839

    • Friday, June 14, 2013

      Prenatal Nitrate Intake from Drinking Water and Selected Birth Defects in Offspring of Participants in the National Birth Defects Prevention Study

      Author(s):
      Jean D. Brender
      Peter J. Weyer
      Paul A. Romitti
      Binayak P. Mohanty
      Mayura U. Shinde
      Ann M. Vuong
      Joseph R. Sharkey
      Dipankar Dwivedi
      Scott A. Horel
      Jiji Kantamneni
      John C. Huber Jr
      Qi Zheng
      Martha M. Werler
      Katherine E. Kelley
      John S. Griesenbeck
      F. Benjamin Zhan
      Peter H. Langlois
      Lucina Suarez
      Mark A. Canfield
      the National Birth Defects Prevention Study

      Journal Title:
      Environmental Health Perspectives

      Abstract:

      Background
      Previous studies of prenatal exposure to drinking-water nitrate and birth defects in offspring have not accounted for water consumption patterns or potential interaction with nitrosatable drugs.

      Objectives
      We examined the relation between prenatal exposure to drinking-water nitrate and selected birth defects, accounting for maternal water consumption patterns and nitrosatable drug exposure.

      Methods
      With data from the National Birth Defects Prevention Study, we linked addresses of 3,300 case mothers and 1,121 control mothers from the Iowa and Texas sites to public water supplies and respective nitrate measurements. We assigned nitrate levels for bottled water from collection of representative samples and standard laboratory testing. Daily nitrate consumption was estimated from self-reported water consumption at home and work.

      Results
      With the lowest tertile of nitrate intake around conception as the referent group, mothers of babies with spina bifida were 2.0 times more likely (95% CI: 1.3, 3.2) to ingest ≥ 5 mg nitrate daily from drinking water (vs. < 0.91 mg) than control mothers. During 1 month preconception through the first trimester, mothers of limb deficiency, cleft palate, and cleft lip cases were, respectively, 1.8 (95% CI: 1.1, 3.1), 1.9 (95% CI: 1.2, 3.1), and 1.8 (95% CI: 1.1, 3.1) times more likely than control mothers to ingest ≥ 5.42 mg of nitrate daily (vs. < 1.0 mg). Higher water nitrate intake did not increase associations between prenatal nitrosatable drug use and birth defects.

      Conclusions
      Higher water nitrate intake was associated with several birth defects in offspring, but did not strengthen associations between nitrosatable drugs and birth defects.


      Citation:

      Citation: Brender JD, Weyer PJ, Romitti PA, Mohanty BP, Shinde MU, Vuong AM, Sharkey JR, Dwivedi D, Horel SA, Kantamneni J, Huber JC Jr., Zheng Q, Werler MM, Kelley KE, Griesenbeck JS, Zhan FB, Langlois PH, Suarez L, Canfield MA, and the National Birth Defects Prevention Study. 2013. Prenatal nitrate intake from drinking water and selected birth defects in offspring of participants in the National Birth Defects Prevention Study. Environ Health Perspect 121:1083–1089; DOI: 10.1289/ehp.1206249.

    • Friday, July 15, 2016

      Hypospadias and maternal exposure to atrazine via drinking water in the National Birth Defects Prevention study

      Author(s):
      Jennifer J. Winston
      Michael Emch
      Robert E. Meyer
      Peter Langlois
      Peter Weyer
      Bridget Mosley
      Andrew F. Olshan
      Lawrence E. Band
      Thomas J. Luben
      the National Birth Defects Prevention Study

      Journal Title:
      Environmental Health

      Abstract:

      Background
      Hypospadias is a relatively common birth defect affecting the male urinary tract. It has been suggested that exposure to endocrine disrupting chemicals might increase the risk of hypospadias by interrupting normal urethral development.

      Methods
      Using data from the National Birth Defects Prevention Study, a population-based case-control study, we considered the role of maternal exposure to atrazine, a widely used herbicide and potential endocrine disruptor, via drinking water in the etiology of 2nd and 3rd degree hypospadias. We used data on 343 hypospadias cases and 1,422 male controls in North Carolina, Arkansas, Iowa, and Texas from 1998–2005. Using catchment level stream and groundwater contaminant models from the US Geological Survey, we estimated atrazine concentrations in public water supplies and in private wells. We assigned case and control mothers to public water supplies based on geocoded maternal address during the critical window of exposure for hypospadias (i.e., gestational weeks 6–16). Using maternal questionnaire data about water consumption and drinking water, we estimated a surrogate for total maternal consumption of atrazine via drinking water. We then included additional maternal covariates, including age, race/ethnicity, parity, and plurality, in logistic regression analyses to consider an association between atrazine and hypospadias.

      Results
      When controlling for maternal characteristics, any association between hypospadias and daily maternal atrazine exposure during the critical window of genitourinary development was found to be weak or null (odds ratio for atrazine in drinking water = 1.00, 95 % CI = 0.97 to 1.03 per 0.04 μg/day increase; odds ratio for maternal consumption = 1.02, 95 % CI = 0.99 to 1.05; per 0.05 μg/day increase).

      Conclusions
      While the association that we observed was weak, our results suggest that additional research into a possible association between atrazine and hypospadias occurrence, using a more sensitive exposure metric, would be useful.


      Citation:

      Winston, J. J., Emch, M., Meyer, R. E., Langlois, P., Weyer, P., Mosley, B., ... & Luben, T. J. (2016). Hypospadias and maternal exposure to atrazine via drinking water in the National Birth Defects Prevention study. Environmental Health, 15(1), 76. DOI: 10.1186/s12940-016-0161-9.

    • Tuesday, May 1, 2001

      Municipal Drinking Water Nitrate Level and Cancer Risk in Older Women: The Iowa Women’s Health Study

      Author(s):
      Peter J. Weyer
      James R. Cerhan
      Burton C. Kross
      George R. Hallberg
      Jiji Kantamneni
      George Breuer
      Michael P. Jones
      Wei Zheng
      Charles F. Lynch

      Journal Title:
      Epidemiology

      Abstract:

      Nitrate contamination of drinking water may increase cancer risk, because nitrate is endogenously reduced to nitrite and subsequent nitrosation reactions give rise to N-nitroso compounds; these compounds are highly carcinogenic and can act systemically. We analyzed cancer incidence in a cohort of 21,977 Iowa women who were 55-69 years of age at baseline in 1986 and had used the same water supply more than 10 years (87% >20 years); 16,541 of these women were on a municipal supply, and the remainder used a private well. We assessed nitrate exposure from 1955 through 1988 using public databases for municipal water supplies in Iowa (quartile cutpoints: 0.36, 1.01, and 2.46 mg per liter nitrate-nitrogen). As no individual water consumption data were available, we assigned each woman an average level of exposure calculated on a community basis; no nitrate data were available for women using private wells. Cancer incidence (N = 3,150 cases) from 1986 through 1998 was determined by linkage to the Iowa Cancer Registry. For all cancers, there was no association with increasing nitrate in drinking water, nor were there clear and consistent associations for non-Hodgkin lymphoma; leukemia; melanoma; or cancers of the colon, breast, lung, pancreas, or kidney. There were positive associations for bladder cancer [relative risks (RRs) across nitrate quartiles = 1, 1.69, 1.10, and 2.83] and ovarian cancer (RR = 1, 1.52, 1.81, and 1.84), and inverse associations for uterine cancer (RR = 1, 0.86, 0.86, and 0.55) and rectal cancer (RR = 1, 0.72, 0.95, and 0.47) after adjustment for a variety of cancer risk/protective factors, agents that affect nitrosation (smoking, vitamin C, and vitamin E intake), dietary nitrate, and water source. Similar results were obtained when analyses were restricted to nitrate level in drinking water from 1955 through 1964. The positive association for bladder cancer is consistent with some previous data; the associations for ovarian, uterine, and rectal cancer were unexpected.


      Citation:

      Weyer, P. J., Cerhan, J. R., Kross, B. C., Hallberg, G. R., Kantamneni, J., Breuer, G., ... & Lynch, C. F. (2001). Municipal drinking water nitrate level and cancer risk in older women: the Iowa Women's Health Study. Epidemiology, 327-338.

    • Thursday, December 12, 2013

      Maternal dietary intake of nitrates, nitrites and nitrosamines and selected birth defects in offspring: a case-control study

      Author(s):
      John C. Huber Jr.
      Jean D Brender
      Qi Zheng
      Joseph R Sharkey
      Ann M Vuong
      Mayura U Shinde
      John S Griesenbeck
      Lucina Suarez
      Peter H Langlois
      Mark A Canfield
      Paul A Romitti
      Peter J Weyer
      National Birth Defects Prevention Study

      Journal Title:
      Nutrition Journal

      Abstract:

      Background
      Dietary intake of nitrates, nitrites, and nitrosamines can increase the endogenous formation of N-nitroso compounds in the stomach. Results from animal studies suggest that these compounds might be teratogenic. We examined the relationship between maternal dietary intake of nitrates, nitrites (including plant and animal sources as separate groups), and nitrosamines and several types of birth defects in offspring.

      Methods
      For this population-based case–control study, data from a 58-question food frequency questionnaire, adapted from the short Willett Food Frequency Questionnaire and administered as part of the National Birth Defects Prevention Study (NBDPS), were used to estimate daily intake of dietary nitrates, nitrites, and nitrosamines in a sample of 6544 mothers of infants with neural tube defects (NTD)s, oral clefts (OC)s, or limb deficiencies (LD)s and 6807 mothers of unaffected control infants. Total daily intake of these compounds was divided into quartiles based on the control mother distributions. Odds ratios (OR)s and 95% confidence intervals (CI)s were estimated using logistic regression; estimates were adjusted for maternal daily caloric intake, maternal race-ethnicity, education, dietary folate intake, high fat diet (> 30% of calories from fat), and state of residence.

      Results
      While some unadjusted ORs for NTDS had 95% (CI)s that excluded the null value, none remained significant after adjustment for covariates, and the effect sizes were small (adjusted odds ratios [aOR] <1.12). Similar results were found for OCs and LDs with the exception of animal nitrites and cleft lip with/without cleft palate (aORs and CIs for quartile 4 compared to quartile 1 =1.24; CI=1.05-1.48), animal nitrites and cleft lip (4th quartile aOR=1.32; CI=1.01-1.72), and total nitrite and intercalary LD (4th quartile aOR=4.70; CI=1.23-17.93).

      Conclusions
      Overall, odds of NTDs, OCs or LDs did not appear to be significantly associated with estimated dietary intake of nitrate, nitrite, and nitrosamines.


      Citation:

      Huber, J. C., Brender, J. D., Zheng, Q., Sharkey, J. R., Vuong, A. M., Shinde, M. U., ... & Romitti, P. A. (2013). Maternal dietary intake of nitrates, nitrites and nitrosamines and selected birth defects in offspring: a case-control study. Nutrition journal, 12(1), 34.  DOI: 10.1186/1475-2891-12-34.

    • Wednesday, June 1, 2016

      Agricultural Compounds in Water and Birth Defects

      Author(s):
      Jean D. Brender
      Peter J. Weyer

      Journal Title:
      Current Environmental Health Reports

      Abstract:

      Agricultural compounds have been detected in drinking water, some of which are teratogens in animal models. The most commonly detected agricultural compounds in drinking water include nitrate, atrazine, and desethylatrazine. Arsenic can also be an agricultural contaminant, although arsenic often originates from geologic sources. Nitrate has been the most studied agricultural compound in relation to prenatal exposure and birth defects. In several case-control studies published since 2000, women giving birth to babies with neural tube defects, oral clefts, and limb deficiencies were more likely than control mothers to be exposed to higher concentrations of drinking water nitrate during pregnancy. Higher concentrations of atrazine in drinking water have been associated with abdominal defects, gastroschisis, and other defects. Elevated arsenic in drinking water has also been associated with birth defects. Since these compounds often occur as mixtures, it is suggested that future research focus on the impact of mixtures, such as nitrate and atrazine, on birth defects.


      Citation:

      Brender, J. D., & Weyer, P. J. (2016). Agricultural compounds in water and birth defects. Current Environmental Health Reports, 3(2), 144-152. DOI: 10.1007/s40572-016-0085-0.

    • Monday, May 1, 2006

      Comparison of nitrate levels in raw water and finished water from historical monitoring data on Iowa municipal drinking water supplies

      Author(s):
      Peter J. Weyer
      Brian J. Smith
      Zhen-Fang Feng
      Jiji R. Kantamneni
      David G. Riley

      Journal Title:
      Environmental Monitoring and Assessment

      Abstract:

      Nitrate contamination of water sources is a concern where large amounts of nitrogen fertilizers are regularly applied to soils. Ingested nitrate from dietary sources and drinking water can be converted to nitrite and ultimately to N-nitroso compounds, many of which are known carcinogens. Epidemiologic studies of drinking water nitrate and cancer report mixed findings; a criticism is the use of nitrate concentrations from retrospective drinking water data to assign exposure levels. Residential point-of-use nitrate data are scarce; gaps in historical data for municipal supply finished water hamper exposure classification efforts. We used generalized linear regression models to estimate and compare historical raw water and finished water nitrate levels (1960s--1990s) in single source Iowa municipal supplies to determine whether raw water monitoring data could supplement finished water data to improve exposure assessment. Comparison of raw water and finished water samples (same sampling date) showed a significant difference in nitrate levels in municipalities using rivers; municipalities using other surface water or alluvial groundwater had no difference in nitrate levels. A regional aggregation of alluvial groundwater municipalities was constructed based on results from a previous study showing regional differences in nitrate contamination of private wells; results from this analysis were mixed, dependent upon region and decade. These analyses demonstrate using historical raw water nitrate monitoring data to supplement finished water data for exposure assessment is appropriate for individual Iowa municipal supplies using alluvial groundwater, lakes or reservoirs. Using alluvial raw water data on a regional basis is dependent on region and decade.


      Citation:

      Weyer, P. J., Smith, B. J., Feng, Z. F., Kantamneni, J. R., & Riley, D. G. (2006). Comparison of nitrate levels in raw water and finished water from historical monitoring data on Iowa municipal drinking water supplies. Environmental monitoring and assessment, 116(1-3), 81-90. DOI: 10.1007/s10661-006-7228-y

    • Tuesday, August 1, 2017

      Case study approach to modeling historical disinfection byproduct exposure in Iowa drinking waters

      Author(s):
      Stuart W. Krasner
      Kenneth P. Cantor
      Peter J. Weyer
      Mariana Hildesheim
      Gary Amy

      Journal Title:
      Journal of Environmental Sciences

      Abstract:

      In the 1980s, a case control epidemiologic study was conducted in Iowa (USA) to analyze the association between exposure to disinfection by-products (DBPs) and bladder cancer risk. Trihalomethanes (THMs), the most commonly measured and dominant class of DBPs in drinking water, served as a primary metric and surrogate for the full DBP mixture. Average THM exposure was calculated, based on rough estimates of past levels in Iowa. To reduce misclassification, a follow-up study was undertaken to improve estimates of past THM levels and to re-evaluate their association with cancer risk. In addition, the risk associated with haloacetic acids, another class of DBPs, was examined. In the original analysis, surface water treatment plants were assigned one of two possible THM levels depending on the point of chlorination. The re-assessment considered each utility treating surface or groundwater on a case-by-case basis. Multiple treatment/disinfection scenarios and water quality parameters were considered with actual DBP measurements to develop estimates of past levels. The highest annual average THM level in the re-analysis was 156 µg/L compared to 74 µg/L for the original analysis. This allowed the analysis of subjects exposed at higher levels (>96 µg/L). The re-analysis established a new approach, based on case studies and an understanding of the water quality and operational parameters that impact DBP formation, for determining historical exposure.


      Citation:

      Krasner, S. W., Cantor, K. P., Weyer, P. J., Hildesheim, M., & Amy, G. (2017). Case study approach to modeling historical disinfection by-product exposure in Iowa drinking waters. Journal of Environmental Sciences, 58, 183-190.https://doi.org/10.1016/j.jes.2017.03.007

    • Thursday, November 30, 2017

      Low-level arsenic exposure from drinking water is associated with prostate cancer in Iowa

      Author(s):
      Taehyun Roh
      Charles F. Lynch
      Peter Weyer
      Kai Wang
      Kevin M. Kelly
      Gabriele Ludewig

      Journal Title:
      Environmental Research

      Abstract:

      Inorganic arsenic is a toxic naturally occurring element in soil and water in many regions of the US including the Midwest. Prostate cancer is the second most common type of cancer in men in Iowa, surpassed only by nonmelanotic skin cancer. Epidemiology studies have evaluated arsenic exposure from drinking water and prostate cancer, but most have focused on high-level exposures outside the US. As drinking water from groundwater sources is a major source of arsenic exposure, we conducted an ecologic study to evaluate prostate cancer and arsenic in drinking water from public water sources and private wells in Iowa, where exposure levels are low, but duration of exposure can be long.

      Arsenic data from public water systems were obtained from the Iowa Safe Drinking Water Information System for the years 1994-2003 and for private wells from two Iowa Well Water Studies, the Iowa Community Private Well Study (ICPWS, 2002-2003) and Iowa Statewide Rural Well Water Survey Phase 2 (SWIRL2, 2006-2008) that provided data for 87 Iowa counties. Prostate cancer incidence data from 2009 to 2013 for Iowa were obtained from Surveillance, Epidemiology and End Results' SEER*Stat software. County averages of water arsenic levels varied from 1.08 to 18.6 ppb, with three counties above the current 10 ppb limit. Based on the tertiles of arsenic levels, counties were divided into three groups: low (1.08-2.06 ppb), medium (2.07-2.98 ppb), and high (2.99-18.6 ppb).

      Spatial Poisson regression modeling was conducted to estimate the risk ratios (RR) of prostate cancer by tertiles of arsenic level at a county level, adjusted for demographic and risk factors. The RR of prostate cancer were 1.23 (95% CI, 1.16-1.30) and 1.28 (95% CI, 1.21-1.35) in the medium and high groups, respectively compared to the low group after adjusting for risk factors. The RR increased to 1.36 (95% CI, 1.28-1.45) in the high group when analyses were restricted to aggressive prostate cancers (Gleason score >7). This study shows a significant dose-dependent association between low-level arsenic exposure and prostate cancer, and if this result is replicated in future individual-level studies, may suggest that 10 ppb is not protective for human health.p>


      Citation:

      Roh, T., Lynch, C. F., Weyer, P., Wang, K., Kelly, K. M., & Ludewig, G. (2017). Low-level arsenic exposure from drinking water is associated with prostate cancer in Iowa. Environmental research, 159, 338-343. https://doi.org/10.1016/j.envres.2017.08.026