Reconnaissance of Mixed Organic and Inorganic Chemicals in Private and Public Supply Tapwaters at Selected Residential and Workplace Sites in the United States

Abstract

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−1, private well) exceeded a National Primary Drinking Water Regulation maximum contaminant level (MCL: 30 μg L−1). 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 (ΣEAR) were calculated for the 36 detected organics with ToxCast data. Because these detections are fractional indicators of a largely uncharacterized contaminant space,ΣEAR 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.

Exposure and potential effects of pesticides and pharmaceuticals in protected streams of the US National park Service southeast region

“…All samples were shipped on ice overnight to the USGS National Water Quality Laboratory (NWQL) in Denver, Colorado for analysis of 113 human-use pharmaceuticals, pharmaceutical metabolites, and polar organic compounds (Furlong et al, 2014) and 224 pesticides and pesticide metabolites (Sandstrom et al, 2016) by direct aqueous injection (DAI) liquid chromatography tandem mass spectrometry (LC-MS/MS). Surface-water extracts (solid phase extraction [SPE] into methanol) were screened for estrogenic, androgenic and glucogenic activity (Bradley et al, 2018b;Conley et al, 2017). Sediment grab samples were collected from select water sample locations in 125-mL combusted (500°C), amber glass jars, as described previously (Weissinger et al, 2018), extracted using an accelerated solvent extraction (ASE) system followed by SPE to reduce matrix interferences, and analyzed for 119 pesticides by gas chromatography mass spectrometry (GC-MS), as described in detail (Hladik and McWayne, 2012).…”

“…Sediment pesticide (119 unique analytes) concentrations were also assessed once (2017) in select locations. Two lines of evidence were employed to assess the potential for cumulative contaminant effects (hazard) to in-stream biota: 1) occurrence and cumulative concentrations of designed-bioactives, and 2) cumulative Exposure Activity Ratios ( P EAR ) (Blackwell et al, 2017;Bradley et al, 2019;Bradley et al, 2018b) based on high-throughput screening data in Toxicity Forecaster (ToxCast TM , U.S. Environmental Protection Agency, 2019). Table 1 2.…”

Pilot-scale expanded assessment of inorganic and organic tapwater exposures and predicted effects in Puerto Rico, USA

“…TW contaminant mixtures and potential drivers/controls (e.g., source-water quality, treatment, premise plumbing) in a range of source-water vulnerability settings are acknowledged public-health data gaps globally ( Doria, 2010 ; Doria et al, 2009 ; Villanueva et al, 2014 ), in the US mainland ( Allaire et al, 2018 ; Pierce and Gonzalez, 2017 ; Sedlak, 2020 ) and in PR (e.g., Natural Resources Defense Council, 2017 ; U.S. Environmental Protection Agency, 2021c ) and are the foci of ongoing TW exposure research by U.S. Geological Survey (USGS), U.S. Environmental Protection Agency (EPA), NIEHS, Colorado School of Mines (Mines) and others (e.g., Bradley et al, 2020 ; Bradley et al, 2018 ; Bradley et al, 2021 ). In August 2018, the USGS, EPA, NIEHS, Mines, and University of Puerto Rico Mayaguez (UPR-M) conducted a spatial pilot assessment of expanded TW exposures (524 organic and 37 inorganic analytes) in 14 homes and commercial locations distributed across PR, including in the northern karst region to: 1) complement and expand on previous and ongoing efforts to identify potential additional TW contaminants that may contribute to adverse health outcomes and 2) continue to inform TW exposures and cumulative risk (exposure, toxicity/hazard: e.g., Moretto et al, 2017 ; National Research Council, 1983 ; U.S. Environmental Protection Agency, 2003 ) to human health across the US.…”

“…A follow-up assessment of TW exposure temporal variability, conducted in December 2018 at two of the synoptic locations (1 home, 1 commercial), included daily pre- and post-flush samples collected over 3 consecutive days. For both synoptic and temporal assessments, the potential human-health risks of individual and cumulative TW exposures were explored based on multiple lines of evidence, comprising: 1) cumulative detections and concentrations of chemicals (e.g., pesticides, pharmaceuticals) with designed, molecular bioactivities ( Bradley et al, 2020 ; Bradley et al, 2018 ), 2) individual (RQ) and cumulative contaminant risk quotients ( Goumenou and Tsatsakis, 2019 ; U.S. Environmental Protection Agency, 2003 ; U.S. Environmental Protection Agency, 2011 ) based on human-health benchmarks, including Safe Drinking Water Act (SDWA) National Primary Drinking Water Regulations (NPDWR) public-health advisories ( U.S. Environmental Protection Agency, 2017 ; U.S. Environmental Protection Agency, 2021a ), and 3) cumulative Exposure-Activity Ratio(s) ( Blackwell et al, 2017 ). The same general sampling protocol and analytical toolbox employed previously ( Bradley et al, 2020 ; Bradley et al, 2018 ; Bradley et al, 2021 ) were preserved herein to inform TW chemical and biological exposures in PR, while supporting inter-study comparisons.…”

Monitoring the human right to water in California: development and implementation of a framework and data tool

“…Large-scale agriculture that contaminates aquifers, wildfires that compromise distribution lines (Proctor et al, 2020), saltwater intrusion from the overuse of coastal aquifers (Barlow & Reichard, 2010) and governance failures (Hanna-Attisha et al, 2015) are but a few pressures affecting water quality. Widespread violations of the SDWA are well documented (Fedinick et al, 2017), and emerging contaminants, such as pharmaceuticals and perfluoroalkyl substances present additional challenges, as these are neither systematically monitored nor regulated in the US (Bradley et al, 2018;Domingo & Nadal, 2019). approaches from existing international monitoring efforts and complements existing California drinking water efforts by being the first US (and state) effort to comprehensively and explicitly monitor the HRTW under one umbrella.…”