You are here:
Reconnaissance of Mixed Organic and Inorganic Chemicals in Private and Public Supply Tapwaters at Selected Residential and Workplace Sites in the United States
Citation:
Bradley, P., D. Kolpin, K. Romanok, K. Smalling, M. Focaszio, J. Brown, M. Cardon, K. Carpenter, S. Corsi, L. DeCicco, J. Dietze, N. Evans, E. Furlong, C. Givens, J. Gray, D. Griffin, C. Higgins, M. Hladik, L. Iwanowicz, C. Journey, K. Kuivila, J. Masoner, C. McDonough, M. Meyer, J. Orlando, M. Strynar, C. Weis, AND V. Wilson. Reconnaissance of Mixed Organic and Inorganic Chemicals in Private and Public Supply Tapwaters at Selected Residential and Workplace Sites in the United States. Environmental Science & Technology Letters. American Chemical Society, Washington, DC, , 13972-13985, (2018). https://doi.org/10.1021/acs.est.8b04622
Impact/Purpose:
This pilot study provides new information of relevant interest to risk assessors, the states and consumers. Several issues contribute to current concerns regarding the safety and long-term sustainability of US drinking water. These issues include, but are not limited to, increased dependence on water reuse to meet demand, the presence of mixtures of contaminants in drinking water supply sources and the necessary treatment thereof, aging drinking water infrastructure and high visibility water quality failures. Further there is a paucity of information on drinking water exposures at the tap especially exposures in US self-supplied (private well) tapwater. To address these knowledge gaps, USGS, EPA, and NIH/NIEHS conducted a nationally distributed, pilot-scale, synoptic assessment of chemical exposures in home and workplace point of use drinking waters (26 total) in 11 US states. Herein we assess TW exposures based on 482 unique organics and 19 inorganics; along with bioassay results for ER, AR and GR mediated activity. The multiple lines-of-evidence approach employed in this manuscript indicates the potential for adverse effects of only those compounds detected in the sampled TW is relatively low. Because those detections are fractional markers of a largely uncharacterized contaminant space, however, the observed effects potential argues for prioritized assessment of cumulative human impacts of trace-level TW exposures.
Description:
In a pilot study, tapwater (TW) from 13 home (7 municipal sources and 6 private wells) and 12 workplace locations in 11 US states was assessed for 482 organics and 19 inorganics. Only uranium (61.9 µg L-1, private well) exceeded a Safe Drinking Water maximum contaminant level (MCL: 30 µg L-1). Lead was detected in 23 samples (MCL Goal: 0 µg L-1). Seventy-three organics were detected at least once, with median detections of 5 and 17 for self-supply and public-supply samples, respectively (corresponding maxima: 12 and 29). Disinfection byproducts predominated in public-supply samples, comprising 16 (22%) of all detected and 6 of the 10-most-frequently detected. Designed bioactive chemicals (26 pesticides; 10 pharmaceuticals) comprised 49% of detected organics. Site-specific cumulative exposure activity ratios (∑EAR) were calculated for the 37 detected organics with Toxicity Forcaster (ToxCastTM) effects data. Because these detections are fractional indicators of a largely uncharacterized contaminant space, ∑EAR in excess of 0.001 and 0.01 in 15 and 8, respectively, of 19 public-supply samples raise concern for potential effects in vulnerable populations and argue for prioritized assessment of cumulative human impacts of trace-level TW exposures.
URLs/Downloads:
DOI: Reconnaissance of Mixed Organic and Inorganic Chemicals in Private and Public Supply Tapwaters at Selected Residential and Workplace Sites in the United States