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COMPARISONS OF PESTICIDE LEVELS AND EXPOSURES IN NHEXAS ARIZONA AND ARIZONA-MEXICO BORDER POPULATIONS
Citation:
Nishioka, M. G., M. C. Brinkman, S. M. Gordon, M. K. O'Rourke, M. D. Lebowitz, S. R. Rogan, D. J. Moschandreas, AND G L. Robertson. COMPARISONS OF PESTICIDE LEVELS AND EXPOSURES IN NHEXAS ARIZONA AND ARIZONA-MEXICO BORDER POPULATIONS. Presented at ISEA 2000 Exposure Analysis in the 21st Century: Integrating Science, Policy and Quality of Life, Monterey Peninsula, CA, October 24-27, 2000.
Impact/Purpose:
The primary objective of the NAFTA Border study was to determine if the population of the U.S./Mexico Border area of Arizona are more highly exposed to environmental contaminants than the residents of the state of Arizona as a whole. The NAFTA Border Study will also demonstrate the feasibility of using these measurement processes in future multimedia-multipathway studies along the U.S./Mexico Border.
Description:
The distributions of organophosphate (OP) insecticides chlorpyrifos and diazinon in exposure matrices such as indoor air, house dust, food, and water have been determined for 416 homes in the general Arizona population, and for 87 homes along the Arizona-Mexico border. The concentrations of the pesticides in these media were compared for the 50th, 75th, 90th, and 95th percentiles of the populations. The levels of diazinon were similar for the two populations, however differences were found in chlorpyrifos distributions for these two populations. In particular, the median values were higher for the border communities, but at the 90-95th percentiles, the concentrations of chlorpyrifos in exposure media were substantially higher in the general population compared to the border area. This may be related to differences in SES and/or housing characteristics. Both OPs appear together in these homes, and the sum of the two OPs by home along the border is 50% higher than would be predicted by simple addition of the individual distribution functions. Given their similar mode of action, pesticide exposures may need to be considered in terms of the sum of OPs rather than individually. Exposure estimates, and comparisons with urinary values, indicate that a significant mode of exposure is not accounted for at this time; this component may be due to a higher than anticipated vapor phase dermal penetration rate or to ingestion of TCPy in food.
The U.S. EPA Office of Research and Development funded this research. The abstract was reviewed and approved. The presentation has not been reviewed.