Dana W. Kolpin Kristin M. Romanok Kelly L. Smalling Michael J. Focazio Juliane B. Brown Mary C. Cardon Kurt D. Carpenter Steven R. Corsi Laura A. DeCicco Julie E. Dietze Nicola Evans Edward T. Furlong Carrie E. Givens James L. Gray Dale W. Griffin Christopher P. Higgins Michelle L. Hladik Luke R. Iwanowicz Celeste A. Journey Kathryn Kuivila Jason R. Masoner Carrie A. McDonough Michael T. Meyer James L. Orlando Mark J. Strynar Christopher P. Weis Vickie S. Wilson Paul M. Bradley 2018 <p><span>Safe drinking water at the point-of-use (tapwater, TW) is a United States public health priority. Multiple lines of evidence were used to evaluate potential human health concerns of 482 organics and 19 inorganics in TW from 13 (7 public supply, 6 private well self-supply) home and 12 (public supply) workplace locations in 11 states. Only uranium (61.9 μg L</span>^–1<span>, private well) exceeded a National Primary Drinking Water Regulation maximum contaminant level (MCL: 30 μg L</span>^–1<span>). Lead was detected in 23 samples (MCL goal: zero). Seventy-five organics were detected at least once, with median detections of 5 and 17 compounds in self-supply and public supply samples, respectively (corresponding maxima: 12 and 29). Disinfection byproducts predominated in public supply samples, comprising 21% of all detected and 6 of the 10 most frequently detected. Chemicals designed to be bioactive (26 pesticides, 10 pharmaceuticals) comprised 48% of detected organics. Site-specific cumulative exposure–activity ratios (∑</span>_EAR<span>) were calculated for the 36 detected organics with ToxCast data. Because these detections are fractional indicators of a largely uncharacterized contaminant space, ∑</span>_EAR<span>&nbsp;in excess of 0.001 and 0.01 in 74 and 26% of public supply samples, respectively, provide an argument for prioritized assessment of cumulative effects to vulnerable populations from trace-level TW exposures.</span></p> application/pdf 10.1021/acs.est.8b04622 en American Chemical Society Reconnaissance of mixed organic and inorganic chemicals in private and public supply tapwaters at selected residential and workplace sites in the United States article