Exposures and potential health implications of contaminant mixtures in linked source water, finished drinking water, and tapwater from public-supply drinking water systems in Minneapolis/St. Paul area, USA
Kelly L. Smalling, Paul M. Bradley, Kristin M. Romanok, Sarah M. Elliot, Jane de Lambert, Michael J. Focazio, Stephanie E. Gordon, James L. Gray, Leslie K. Kanagy, Michelle L. Hladik, Keith A. Loftin, R. B. McCleskey, Elizabeth Medlock-Kakaley, Mary C. Cardon, Nicola Evans, Christopher Weis
Abstract
estrogen, androgen, and glucocorticoid bioactivities. Mixtures of organic and inorganic contaminants were prevalent in source water, finished water, and tapwater samples, indicating the continued need for broad assessments of mixed contaminant exposures to characterize potential drinking-water human health outcomes. Contaminant concentrations were similar among drinking water sources and no exceedances of Environmental Protection Agency maximum contaminant level(s) (MCL) were observed in any treated sample (finished water or tapwater) in this study. No treated sample contained estrogenic, androgenic, or glucocorticoid activity at concentrations that may cause adverse human health effects. However, there were multiple exceedances of non-enforceable MCL goal(s) (MCLG), and other health advisories combined with frequent exceedances of benchmark-based hazard indices in both finished water and tapwater samples. These results indicate that exposure to contaminant mixtures is a potential public health concern underscoring our continued efforts to assess contaminant mixture exposures at the drinking-water point of consumption using a broad analytical scope.