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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

  • 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

  • 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

  • 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