CHEEC Seed Grants: FY 2011

Pesticide Exposure and Risk of Endometriosis
Investigators: E. Smith, L. Rubenstein, Department of Epidemiology: B. Stegmann, Department of Obstetrics and Gynecology; L. Fuortes, Deaprtment of Occupational and Environmental Health, The University of Iowa; D. Sandler, J. Hoppin, National Institute of Environmental Health Sciences

Using Human Enteric Viruses to Track Groundwater Contaminants to a Municipal Drinking Water Supply in an Alluvial Aquifer
Investigator:  W. Simpkins, Department of Geological and Atmospheric Sciences, Iowa State University

Enantiospecific Disposition of Chlordane in a Mouse Model Lacking NADPH-Dependent Cytochrome 450 Reductase
Investigators: E.D. Oldham, I. Kania-Korwel, H.J. Lehmler, Department of Occupational and Environmental Health, University of Iowa

Establishing a Methodology for the Detection of Silica Particles in Lung Cancer Tissue Using Computer-Controlled Scanning Electron Microscopy
Investigators:  K. Coleman, R.W. Field, Department of Occupational and Environmental Health, University of Iowa

 


Pesticide Exposure and Risk of Endometriosis
Investigators:  E. Smith, L. Rubenstein, Department of Epidemiology ; B. Stegmann, Department of Obstetrics and Gynecology; L. Fuortes, Department of Occupational and Environmental Health, The University of Iowa; D. Sandler, J. Hoppin, National Institute of Environmental Health Sciences
Endometriosis is a chronic disease affecting ~15% of US reproductive-aged women, and is a significant cause of infertility. One suggested risk factor is exposure to organochlorines (OC). Diagnosed cases of endometriosis have been detected with longer exposure or higher serum concentrations than controls for OCs (PCDD, PCDF, and PCB/dioxin); however, study results have been inconsistent due partly to small numbers of cases/controls and limited exposure history. Analyses using the Agricultural Health Study will provide a significantly larger sample size for a case-control study and detailed measures of pesticide and environmental exposure to common agricultural pesticides and to these OCs. Study results will be used as pilot data for an National Institute of Child Health & Human Development (NICHD) proposal of clinic-based case-control study. In 2010, an NICHD Fertility Preservation Research Program, sought grants to characterize occupational and environmental exposures that may be associated with risks of infertility. This exposure and infertility issue continues to be of interest to NICHD. 

Using Human Enteric Viruses to Track Groundwater Contaminants to a Municipal Drinking Water Supply in an Alluvial Aquifer
Investigator:  W. Simpkins, Department of Geological and Atmospheric Sciences, Iowa State University
Alluvial aquifers are the most productive and widely used groundwater source for drinking water in Iowa. They are also the most vulnerable to contamination due to their shallow water table, hydraulic interchange with streams, and the potential for flooding. The Ames aquifer in Ames, Iowa is such an aquifer that is potentially vulnerable to contamination. The hypothesis that human enteric viruses enter the Ames aquifer from the South Skunk River and are transported to the municipal well field that supplies the Ames drinking water will be tested by analyzing river water and groundwater in piezometers and wells for viruses and stable isotopes along a groundwater flow path. The results will provide unique information about the extent and temporal variability of human enteric viruses in drinking water and demonstrate an innovative method (i.e., presence of viruses) to assess Groundwater under the Direct Influence of Surface Water (GWUDISW) in alluvial aquifers.

Enantiospecific Disposition of Chlordane in a Mouse Model Lacking NADPH-Dependent Cytochrome 450 Reductase
Investigators: E.D. Oldham, I. Kania-Korwel, H.J. Lehmler, Department of Occupational and Environmental Health, University of Iowa 
The  pesticide  chlordane  is  a  mixture  of  structurally  related,  highly chlorinated hydrocarbons and is a persistent environmental contaminant linked to a range of adverse health effects in animals. Most of the isomers are chiral, and may be metabolized in an enantiospecific manner. This type of metabolism has been shown for other chiral pollutants. We hypothesize that chiral chlordane isomers are metabolized enantioselectively by cytochrome P450 enzymes. To test this hypothesis we will take advantage of  a knockout mouse model lacking the  NADPH-dependent cytochrome P450 reductase, a critical enzyme in the catalytic cycle of P450 oxidation, and measure levels and enantiomeric fractions of chlordane and its metabolites in tissue from wild- type and knockout mice. This research will provide key mechanistic information about enantiospecific metabolism of chlordane, and can be extended to other pesticides commonly found in Iowa.

Publications:  Kania-Korwel I, Lehmler HJ. Chlordane and heptachlor are metabolized enantioselectively by rat liver microsomes. Environ Sci Technol 2013; 47:8913-8922.

Wu X, Barnhart C, Lein PJ Lehmler HJ. Hepatic metabolism affects the atropselective disposition of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) in mice. Environ Sci Technol 2015; 49:616-625.

Establishing a Methodology for the Detection of Silica Particles in Lung Cancer Tissue Using Computer-Controlled Scanning Electron Microscopy
Investigators:  K. Coleman, R.W. Field, Department of Occupational and Environmental Health, University of Iowa
Crystalline silica has long been recognized as an occupational hazard of the dusty trades with exposures resulting in silicosis. As recently as 1997, IARC categorized the respirable portion of crystalline silica as a Grade 1 human carcinogen indicating that silica may be implicated in the development of lung cancer. Evidence in the literature indicates that silica may be not only an occupational hazard, but an environmental hazard as well, with patients with no known exposure showing measurable quantities of silica within cancerous tissue samples. The primary goal of this study is to establish a methodology using Computer-Controlled Scanning Electron Microscopy to examine silica content in lung cancer tissue. Demonstrating that silica is not evenly distributed within the tissue will establish the need to use automated full scanning techniques, such as CCSEM, to guarantee that the analysis is not subject to random sampling error or researcher error, which may be rendering the traditional random sampling of zones for analysis under-representative of silica concentration in the tissue.