DIETARY CHARACTERIZATIONS IN A STUDY OF HUMAN EXPOSURES IN THE LOWER RIO-GRANDE VALLEY .2. HOUSEHOLD WATERS

The Lower Rio Grande Valley Environmental Study (LRGVES) was designed to evaluate multiple forms of exposure to Valley residents because of community concerns of possible adverse health effects from environment al conditions. This is the second of two papers that describe the diet ary components of the LRGVES scoping study, conducted in the spring an d summer of 1993 in nine Valley residences. Drinking water and househo ld water samples were collected along with food and beverage samples t o determine potential dietary exposures of the participants. Water sam ples were analyzed for various organic compounds, including volatile o rganic compounds, polycyclic aromatic hydrocarbons, pesticides, haloac etic acids, chlorinated acids, and benzidines. Samples were also analy zed for trace elements, selected anions, and microbial quality. Source s of water available in the residences for drinking and other househol d purposes were public treatment facilities, vended water machines, an d a private well. In general, organic and inorganic chemicals found in commercial sources of drinking water did not exceed federal criteria. However, products of the disinfection process (total trihalomethanes) exceeded the federal regulatory level in one sample. In addition, tap water samples from public water supplies were high in chloride and su lfate anions, often related to poor odor, color, or taste, resulting i n residents of the Valley purchasing water for drinking at local vendi ng machines and storing it in their homes in a variety of containers. Microbiological contamination of these containers was found to be a po tential health problem. Coliform levels exceeding federal criteria for public water supplies were found in the water of several participants who did not regularly disinfect the containers in which they stored t heir drinking water. Water from a private well, which was designated f or purposes other than drinking, was also unsuitable for drinking beca use of microbial contamination. Water sampling in the LRGVES pilot stu dy identified the need for intervention and educational programs to el iminate exposures of Valley residents. Published by Elsevier Science L td.