Residential Tap Water Sampling for Water Contaminants to Determine True Exposure in Human

摘要

Traditionally, epidemiologist and toxicologist rely on the indirect methods of exposure assessment (environmental monitoring, modeling, questionnaire etc.) to determine chronic health risk in humans via drinking water consumption. These methods are limited in scope because of inherent temporal-spatial variability, mixture interactions, and characteristics of water distribution networks. In the absence of good exposure assessment, many toxicological and epidemiological studies remain inconclusive about the toxicity of environmental chemicals. Hence, a precise exposure measurement is needed to determine environmentally realistic concentrations of chemicals in a population and the associated health risks. Precise exposure assessment can be achieved by sampling tap water from residential sites. This method accounts for variability in the exposure assessment and is believed to be the most accurate measure of human exposure via drinking water. Therefore, we have proposed a sampling program to measure pesticides and other urban contaminants in Indianapolis Community Water System (IndyCWS). The seven residential sites are identified to capture the large part of IndyCWS. The samples will be collected weekly, biweekly, and monthly basis during the April-June period. The samples will be analyzed in a certified laboratory using EPA recommended methods. The data from this study will be used to determine temporal-spatial variability of measured chemicals, compare with the exposure levels reported by public agencies, evaluate cumulative exposure of mixtures, and develop association with health outcomes. Currently, this work is in-progress and the results from the study will be discussed in the meeting.