Occurrence and In Vitro Bioactivity of Estrogen, Androgen, and Glucocorticoid Compounds in a Nationwide Screen of United States Stream Waters

• Published in: Environmental science & technology Vol. 51; no. 9; pp. 4781 - 4791
• Main Authors: Conley, Justin M, Evans, Nicola, Cardon, Mary C, Rosenblum, Laura, Iwanowicz, Luke R, Hartig, Phillip C, Schenck, Kathleen M, Bradley, Paul M, Wilson, Vickie S
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02.05.2017
• Subjects: Androgens; Bioassays; Biochemistry; Biocompatibility; Biological activity; Biological Assay; Chemical compounds; Chemicals; Creeks & streams; Environmental monitoring; Environmental science; Estrogen receptors; Estrogens; Glucocorticoids; In vitro methods and tests; Receptors, Estrogen - metabolism; Rivers; Surface water; United States; Water Pollutants, Chemical; Water quality; Water quality assessments; Water quality management; United States > US; Puerto Rico
• ISSN: 0013-936X; 1520-5851; 1520-5851
• DOI: 10.1021/acs.est.6b06515

In vitro bioassays are sensitive, effect-based tools used to quantitatively screen for chemicals with nuclear receptor activity in environmental samples. We measured in vitro estrogen (ER), androgen (AR), and glucocorticoid receptor (GR) activity, along with a broad suite of chemical analytes, in streamwater from 35 well-characterized sites (3 reference and 32 impacted) across 24 states and Puerto Rico. ER agonism was the most frequently detected with nearly all sites (34/35) displaying activity (range, 0.054–116 ng E2Eq L–1). There was a strong linear relationship (r 2 = 0.917) between in vitro ER activity and concentrations of steroidal estrogens after correcting for the in vitro potency of each compound. AR agonism was detected in 5/35 samples (range, 1.6–4.8 ng DHTEq L–1) but concentrations of androgenic compounds were largely unable to account for the in vitro activity. Similarly, GR agonism was detected in 9/35 samples (range, 6.0–43 ng DexEq L–1); however, none of the recognized GR-active compounds on the target-chemical analyte list were detected. The utility of in vitro assays in water quality monitoring was evident from both the quantitative agreement between ER activity and estrogen concentrations, as well as the detection of AR and GR activity for which there were limited or no corresponding target-chemical detections to explain the bioactivity. Incorporation of in vitro bioassays as complements to chemical analyses in standard water quality monitoring efforts would allow for more complete assessment of the chemical mixtures present in many surface waters.