CHEEC Seed Grants: FY 1990

Ultraviolet phototoxicity of some non-steroidal anti-inflammatory (NSAIDS) agents on the retina of the eye 
TK Shires, Department of Pharmacology; JS Pulido, Department of Ophthalmology, The University of Iowa

Teratogenic potential of Fusarium moniliforme mycotoxins 
S Hendrich, P Murphy, Department of Food Science and Human Nutrition, Iowa State University; G Osweiler, Veterinary Diagnostic Laboratory, Iowa State University; F Ross, T Wilson, National Veterinary Services Laboratory

Development of an immunoassay for the detection of glyphosate in water 
GM Breuer, SL Berberich, University Hygienic Laboratory, The University of Iowa

An assessment of infant exposure to nitrate/nitrite in breast milk and rural well water 
CI Dungy, LB Dusdieker, Department of Pediatrics; BC Kross, Department of Preventive Medicine and Environmental Health, The University of Iowa

Urban-rural differences in cancer incidence and mortality among Iowa residents 
CF Lynch, LF Burmeister, Department of Preventive Medicine and Environmental Health, The University of Iowa

Biotransformation and transport of monoaromatic hydrocarbons under stimulated denitrifying conditions in soil columns 
GF Parkin, ME Vermace, Department of Civil and Environmental Engineering, The University of Iowa

Birth defects in Iowa: Effects of surface water pollution in the Rathbun Lake area 
RW Munger, Department of Preventive Medicine and Environmental Health; JW Hanson, Department of Pediatrics, The University of Iowa

Investigation of the feasibility of adapting immunoassay tests for detection of minute amounts of pesticides in water 
JM Cowan, SL Berberich, University Hygienic Laboratory, The University of Iowa

Analysis of aflatoxins in grain dust 
MI Selim, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, The University of Iowa

 


Ultraviolet phototoxicity of some non-steroidal anti-inflammatory agents (NSAIDS) on the retina of the eye 
Investigators: TK Shires, Department of Pharmacology; JS Pulido, Department of Ophthalmology, The University of Iowa 
Progressive global stratospheric ozone depletion and the resulting elevation in ultraviolet radiation presents the prospect of a significant human health hazard. In the eye, the cornea, lens, and retina have well-established UV radiation pathologies. Increased UV exposures may also intensify the UV-phototoxicity in some therapeutic agents widely used by the general public. This study examined a number of anti-inflammatory analgesics know to be UV-phototoxic in the skin, but with as yet unreported effects in the eye. Study investigators hypothesize that these widely used drugs compound the risk of retinal damage in people who have outdoor occupations.

Teratogenic potential of Fusarium moniliforme mycotoxins
Investigators: S Hendrich, P Murphy, Department of Food Science and Human Nutrition, Iowa State University; G Osweiler, Veterinary Diagnostic Laboratory, Iowa State University; F Ross, T Wilson, National Veterinary Services Laboratory 
This study looked at the teratogenic potential of Fusarium mycotoxins in animal models. Pregnant rats were exposed to F. moniliforme corn culture material and purified fumonisins B1 (FB1). Researchers then analyzed the uterus for fetal resorption, and the pups for gross anomalies, weight, and corpora lutea were counted. Additionally, corn containing foods were sample assayed for fumonisin content. Results found that under experimental conditions, teratogenic potential exists for FB1, but not for F. moniliforme contaminated corn. This suggests that either F. moniliforme is not as bioavailable as purified FB1 or that crude culture material contains antiteratogens. Human exposure to fumonisins in yellow and white corn meal were measured at 0.75 mg-7.5 mg/55 kg woman per day or about 14-140 ug/kg body weight. This suggests fumonisins might be teratogenic to humans, but do not pose a severe risk. Fumonisins may be very useful in understanding mechanisms of growth-related signal transduction.

Publication: Lebepe-Mazur S, Bal H, Hopmans E, Murphy P, Hendrich S; Fumonisin B is Fetotoxic in Rats. Vet. Human Toxicol. 1995; 37:126-130

Development of an immunoassay for the detection of glyphosate in water 
Investigators: GM Breuer, SL Berberich, University Hygienic Laboratory; The University of Iowa 
The aim of this study was to develop a monoclonal antibody specific for the common herbicide glyphosate (trade name: Roundup), and develop an immunoassay system for the rapid detection of glyphosate in water samples. Immunoassays would dramatically reduce the costs of water sampling for glyphosate as compared to current analytical methods. The glyphosate molecule is quite small, and has only three chemically distinct sites. Because of these few small sites available for attachment, problems have been encountered by other researchers in developing a immunoassay system for glyphosate. The CHEEC researchers, too, encountered similar difficulties and were unsuccessful in their attempts at developing an immunoassy for glyphosate. Researchers on this project theorized devising a scheme for creating an attachment site internal to the glyphosate molecule, thus presenting the molecule in its native form. Researchers determined this was possible, but this synthesis and process was beyond the scope and resources of this seed grant.

Assessment of infant exposure to nitrate/nitrite in breast milk and rural well water
Investigators: CI Dungy, LB Dusdieker, Department of Pediatrics; BC Kross, Department of Preventive Medicine and Environmental Health, The University of Iowa 
The objectives of this study were to determine if the concentration of nitrate/nitrite in human milk is unsafe for consumption by infants under 6 months of age, and to compare the concentration of nitrate/nitrite in private well-water used as a primary source of drinking water to the concentration of nitrate/nitrite in human breast milk. Participants included 20 women who were either exclusively breast feeding or breast and bottle feeding, and 24 women who were formula feeding. Five of the 20 breast feeders indicated rural well-water as their source of drinking water, and 6 of the 24 formula feeders used private well-water supplies. Three of the eleven wells had nitrate levels greater than the Health Advisory Limit (HAL), but none of these 3 women offered their infants supplemental water or prepared formula using the high nitrate content well-water. Nine of the 20 women who reported exclusive or partial breast feeding had analysis of water, breast milk, and urine samples done. The urine nitrate levels were equal to or up to 69 times greater than the nitrate concentration in breast milk. Analyses of the breast milk indicated in all cases the nitrate concentration was markedly below the HAL.

Publication:  Dusdieker D, Stumbo PJ, Kross BC, Dungy CI; Does Increased Nitrate Ingestion Elevate Nitrate Levels in Human Milk? Archives of Pediatrics and Adolescent Medicine. 1996; 150(3):311-314

Urban-rural differences in cancer incidence and mortality among Iowa residents 
Investigators: F Lynch, LF Burmeister, Department of Preventive Medicine and Environmental Health, The University of Iowa 
Urban-rural differences in cancer incidence and mortality rates were evaluated in a descriptive epidemiologic study among Iowa residents (1973-1988). Results were based on two separate definitions of urban and rural-one county boundary based and the other based on application of an address algorithm. Both definitions yielded similar findings. Two different definitions of mortality were used. The first definition included as an eligible death only those cases where cancer was listed as the underlying cause of death , whereas the second definition included all conditions of cancer where cancer was listed on the death certificate as the underlying cause or as a contributing condition. Study findings were 1) Smoking-related cancers were found to be significantly higher in urban areas relative to rural areas for males and females, and mortality from smoking-related cancers was greater in urban areas; 2) Lip cancer in males was the only cancer site with a significantly elevated rate in rural areas relative to urban areas, all other cancers were higher for urban areas, for both males and females; 3) Better sensitivity was established when using the 'all causes of death' definition, and use of the application algorithm proved more sensitive as well; and 4) Cancer mortality rates were generally higher in those urban and rural areas that had higher cancer incidence rates. An additional research project was funded by the National Cancer Institute to investigate these findings further. Technical Report Available.

Biotransformation and transport of monoaromatic hydrocarbons under stimulated denitrifying conditions in soil columns
Investigators: GF Parkin, ME Vermace, Department of Civil and Environmental Engineering, The University of Iowa 
Leaking underground storage tanks and pipelines are some of the largest contributors to point source contamination of groundwater. The monoaromatic hydrocarbons benzene, ethylbenzene, toluene, and xylene (BETX's) are the hardest to manage if groundwater contamination occurs. This research project examined the role of nitrate as an alternate electron acceptor for biologically mediated reactions important to in situ biorestoration. Batch column study results showed no degradation of benzene, ethylbenzene, nor p-xylene observed over a one-hundred day period. No decrease in nitrate was observed as well. Results from the control reactor suggests that abiotic removal mechanisms such as sorption are negligible. Toluene degradation was observed when fed alone and in the mixture, and a concomitant decrease in nitrate was also observed. The research suggests that the presence of the non degraded BETX's has no apparent affect on the degradation of toluene. Additional research was funded by the Iowa State Water Resources Research Institute.

Publication:  Vermace ME, Christianson RF, Parkin GF, Alvarez PJJ; Relationship Between the Concentration of Denitrifers and Pseudomonas spp. in Soils: Implications for BTX Bioremediation. Water Research. 1996; 30:3139-3145

Birth defects in Iowa: Effects of surface water pollution in the Rathbun Lake area 
Investigators: R Munger, Department of Preventive Medicine and Environmental Health; JW Hanson, Department of Pediatrics, The University of Iowa 
The effects of pesticide contamination of drinking water on human reproductive health are largely unknown. In a statewide survey of 856 Iowa municipal drinking water supplies in 1986-1987, a rural water system supplied by the Rathbun Reservoir was found to have elevated levels of the herbicide atrazine, 2.2 mcg/l vs. 0.6 mcg/l in other Iowa surface water supplies. Rates of low birth weights, prematurity, and intrauterine growth retardation (IUGR) in live singleton births during 1984-1990 in women living in 13 communities served by the Rathbun water system were compared to other Iowa communities. The Rathbun communities had a significantly greater risk of IUGR than southern Iowa communities with other surface sources of drinking water. Multiple linear regression analyses revealed that levels of the herbicides atrazine, metolachlor, and cyanazine 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 correlated. The independent contributions of each to IUGR risk could not be determined.

Publication:  Munger R, Isacson P, Song Hu, Burns T, Hanson J, Lynch CF, Cherryholmes K, Van Dorpe P, Hausler WJ Jr; Intrauterine Growth Retardation in Iowa Communities with Herbicide-Contaminated Drinking Water Supplies. Environ. Health Perspectives. 1997; 105(3):308-314

Investigation of the feasibility of adapting immunoassay tests for detection of minute amounts of pesticides in water 
Investigators: JM Cowan, SL Berberich, University Hygienic Laboratory, The University of Iowa 
The aim of this study was to develop a protocol for the detection of the pesticides atrazine and alachlor in water at concentrations below .1 mg/l using immunochemistry. Detection below these concentrations may be useful in identifying trends of increased pesticide contamination before there is a real health risk. The procedure involved using a sample routinely processed for gas chromatograph (GC) analysis and evaluating by immunoassay after evaporating off the solvent and resuspending the sample in water. The study results found immunoassay is only slightly less reliable than GC analysis. Concentrated organic extracts prepared for GC analysis can also be successfully used for the detection and quantitation of atrazine and alachlor by immunoassay analysis at concentrations significantly below the detection limit of GC. Method detection limits for atrazine were calculated at approximately 0.4 ng/l -a 250 fold improvement over GC, and approximately 0.3 ng/l for alachlor- a 300 fold improvement over GC. This procedure is being used in a study investigating the levels of atrazine and alachlor in rain water.

Analysis of aflatoxins in grain dust 
Investigators: MI Selim, Institute of Agricultural Medicine and Occupational Health, Department of Preventive Medicine and Environmental Health, The University of Iowa 
Aflatoxins are recognized as potent chemical carcinogens, have been associated with liver cancer in animal studies, and may be associated with lung cancer incidence in humans exposed to aflatoxins in contaminated grain dust. This project developed and validated a one-step extraction and analysis technique for the separation and quantitative determination of low levels of aflatoxins in airborne grain dust samples. This technique is faster, more sensitive, more selective, and more reliable than present methods. The method is based on the use of supercritical fluid extraction (SFE) on line with gas chromatography or supercritical fluid chromatography followed by mass spectrometric detection (SFE/GC/MS or SFE/SFC/MS). In addition, preliminary data on the levels of aflatoxins in grain dust generated during harvest and on-farm grain handling operations were collected. Results from this study were used to acquire a grant from the National Institute for Occupational Safety and Health to expand research.

Publication:  Selim MI, Tsuei MH; The Developement and optimization of a supercritical fluid extraction method for the analysis of aflatoxin B1 in grain dust. American Industrial Hygiene Association Journal. 1993; 54(4):135-41