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Detection of High Levels of Endocrine Activity in Selected Environmental Surface Water Samples Using ER, AR, and GR-mediated In Vitro Bioassays
Citation:
Wilson, V., N. Evans, M. Cardon, P. Hartig, K. Schenck, L. Rosenblum, AND T. Reilly. Detection of High Levels of Endocrine Activity in Selected Environmental Surface Water Samples Using ER, AR, and GR-mediated In Vitro Bioassays. Society of Toxicology (SOT) Meeting, San Diego, CA, March 23 - 27, 2015.
Impact/Purpose:
This abstract will be presented at the Society of Toxicology (SOT) Meeting, March 23-27, 2015, San Diego, CA
Description:
Determining the associated health risks of exposure to complex mixtures in the environment is a recognized challenge. The Chemical Mixtures project, a collaborative effort between USEPA and USGS, is making a step in that direction by examining the co-occurrence of chemicals and biological activity associated with stream waters. The overall study combines comprehensive chemical compositional analysis, which includes direct chemical analysis for over 700 dissolved organic and inorganic chemicals, identification and quantitation of unknown contaminants (environmental diagnostics),and a battery of bioassays to evaluate biological activity and toxicity. Thirty-eight sites were sampled each impacted by known contaminant sources. Herein, extracts of samples were examined for estrogen (ER), androgen (AR) or glucocorticoid (GR) receptor-mediated activity using in vitro transcriptional activation assays. In the ER assay, greater than 65% of the sites had quantifiable estradiol equivalents (EEQ) of 0.1ng/L or greater. Thirteen sites had EEQs above 1ng/ L while only 4 were above 5 ng/L, a concentration expected to cause estrogenic effects in fish. In the GR assay, 7 sites had dexamethasone equivalents (DEQ) ranging from 18-60 ng/L. Low levels of androgen (DHT) equivalents (AEQ) were quantifiable in 4 sites ranging from 1.6-4.8 ng/L. Three sites had activity in all 3 pathways. As analytical results become available, we will compare those to the bioassay results to determine if the chemicals responsible for the endocrine activity can be identified. Combining the comprehensive analytical expertise of the USGS with bioassay testing at the EPA provides a unique opportunity to identify the chemical mixture present in surface waters and to integrate that with potential biological activity. This abstract does not reflect EPA policy.