Assessing Cumulative Exposure to Drinking Water Contaminants. F. Letkiewicz and M. Muller, Abt Associates, Inc., 4800 Montgomery Lane, Bethesda, MD 20814; and J. C. Reinert, U.S. Environmental Protection Agency, Office of Policy, Planning and Evaluation, 401 M St. SW (2123), Washington, DC 20460
EPA is conducting a national analysis of cumulative exposures to contaminants in drinking water. The objective of this analysis is to estimate national average exposure levels for 31 contaminants found in both public and private drinking water supplies, and to characterize the distribution of exposures in selected geographic and demographic groups. Measured concentration data were obtained from URCIS (Unregulated Contaminants Information System) and NIRS (National Inorganic and Radionuclide Survey) and were averaged across all public and private water supplies located in a particular county, weighted according to the population served by the associated water supply. For water systems lacking measured concentration data, imputed concentration values were used based on measurements taken at water supplies of similar size, type, and location. Drinking water consumption data were combined with the concentration data and the resulting intake values were weighted by the number of people residing in each county to determine national average intake values for the different contaminants.
The views expressed in this presentation are those of the authors, and do not necessarily represent those of the U.S. Environmental Protection Agency.
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