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 environmental conditions. This is the second of two papers that describe the dietary components of the LRGVES scoping study, conducted in the spring and summer of 1993 in nine Valley residences. Drinking water and household water samples were collected along with food and beverage samples to determine potential dietary exposures of the participants. Water samples were analyzed for various organic compounds, including volatile organic compounds, polycyclic aromatic hydrocarbons, pesticides, haloacetic acids, chlorinated acids, and benzidines. Samples were also analyzed for trace elements, selected anions, and microbial quality. Sources of water available in the residences for drinking and other household purposes were public treatment facilities, vended water machines, and 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 sulfate anions, often related to poor odor, color, or taste, resulting in residents of the Valley purchasing water for drinking at local vending machines and storing it in their homes in a variety of containers. Microbiological contamination of these containers was found to be a potential 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 their drinking water. Water from a private well, which was designated for purposes other than drinking, was also unsuitable for drinking because of microbial contamination. Water sampling in the LRGVES pilot study identified the need for intervention and educational programs to eliminate exposures of Valley residents. Published by Elsevier Science Ltd.