You are here:
Use of an In Vitro, Nuclear Receptor Assay Panel to Characterize the Endocrine-Disrupting Activity Load of Wastewater Treatment Plant Effluent Extracts
Citation:
Paul, K., R. Marfil-Vega, M. Mills, Steve Simmons, V. Wilson, AND K. Crofton. Use of an In Vitro, Nuclear Receptor Assay Panel to Characterize the Endocrine-Disrupting Activity Load of Wastewater Treatment Plant Effluent Extracts. Presented at Society for Environmental Toxicology and Chemistry (SETAC), November 11 - 15, 2012.
Impact/Purpose:
This abstract will be presented at the Society of Environmental Toxicology and Chemistry, (SETAC) meeting, November 11-15, 2012, Long Beach, CA
Description:
Use of an In Vitro, Nuclear Receptor Assay Panel to Characterize the Endocrine-Disrupting Activity Load of Wastewater Treatment Plant Effluent Extracts Katie B. Paul 1.2, Ruth Marfil-Vega 1 Marc A. Mills3, Steve 0. Simmons2, Vickie S. Wilson4, Kevin M. Crofton2 10ak Ridge Institute for Science Education Postdoctoral Fellow, ORD, U.S . EPA; 2 Integrated Systems Toxicology Division, and 4Toxicity Assessment Division, NHEERL; 3NRMRL, ORD, U.S. EPA, RTP, NC and Cincinnati, OH The objective of this multi-laboratory project is to characterize the potential endocrine-disrupting activity of wastewater treatment plant (WWTP) effluent extracts from the Assabet River (Boston, MA) using bioassays and analytical chemistry. We tested the hypothesis that estrogen receptor (ER), androgen receptor (AR), and pregnane-X receptor (PXR) assays would provide a sensitive screen for the potential estrogenic, androgenic, and thyroid-disrupting load of samples obtained from WWTP effluents and aid prioritization of further analytical and biological testing ofthese effluent extracts. Effluent samples from 4 WWTP sampling sites and a blank were extracted using 6 different methods, each targeting specific chemical groupings. In order of descending potency, extracts enriched for thyroid hormones, pharmaceuticals, aromatase inhibitors, steroids, and alkylphenols tested positive for estrogenic activity (4- 10 ng/L estradiol equivalents, EEQs), and with greater efficacy than the perfluorinated chemicals extracts (> 1 ng/L EEQ). The potency of ER activation by each extract type was WWTP site-dependent. Several extracts demonstrated modest AR agonist activity, generally coincident with extracts from the site that demonstrated the highest ER activation. Significant AR antagonism was not observed for any extract. Preliminary data obtained with a PXR activity assay suggests that the pharmaceutical extract method may be most appropriate for subsequent assays of potential thyroid-disruptors that up-regulate hepatic catabolism of thyroid hormones. This was consistent with previous work that demonstrated PXR activation 3-fold over vehicle control with whole freeze-dried effluents at environmental concentrations. Continuing work will relate activation of ER, AR, and PXR to identify possible potency relationships between these activities in the effluent extracts. Extracts will also be tested in additional bioassays, - including a thyroid peroxidase inhibition assay, to assess another thyroid disruption target using an emerging medium-throughput technology. These data inform an integrated bioassay and analytical approach to understanding the potential endocrine-disrupting activity of effluents and potential strategies for monitoring EDC activities following changes in treatment technologies. This abstract does not necessarily reflect the policy of the US EPA.