Research and Guidance on Drinking Water Contaminant Mixtures

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Accurate assessment of potential human health risk(s) from multiple-route exposures to multiple chemicals in drinking water is needed because of widespread daily exposure to this complex mixture. Hundreds of chemicals have been identified in drinking water with the mix of chemicals varying with geographic location, source waters, disinfection scenarios and surrounding land uses and industries. Mixtures in drinking water can consist of many chemical classes, e.g., pesticides, pharmaceuticals, metals, polychlorinated biphenyls, and disinfection by-products (DBPs). In some cases, positive data from epidemiological or toxicological studies raise concerns for human health. Depending on the chemical properties of these contaminants, they may be present in liquid, vapor, or aerosol form(s) and can enter the body via ingestion, respiration, or dermal penetration. DBPs are a particularly important class of chemicals that are formed as a consequence of chemical reactions among the disinfectant used to treat the water, naturally occurring organic matter and bromide. Listed below are a number of reports and journal publications that address human health risk assessment and toxicology of drinking water contaminant mixtures.

Research on Drinking Water Disinfection By-Products (DBPs)

Other Drinking Water Contaminants and Single Chemical Information

Guidance on Health Risk Assessment of Chemical Mixtures


U.S. EPA. Research and Guidance on Drinking Water Contaminant Mixtures. U.S. Environmental Protection Agency, Washington, D.C.

This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.