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In vitro assessment of estrogenic bioactivity in complex environmental effluents
Citation:
CARDON, M. C., P. C. HARTIG, V. S. WILSON, L. Yonkos, AND S. R. HUTCHINS. In vitro assessment of estrogenic bioactivity in complex environmental effluents. Presented at Society of Toxicology (SOT) Annual Meeting, San Francisco, CA, March 11, 2011 - March 15, 2012.
Impact/Purpose:
Environmental effluents contain a diversity of chemicals, can originate from a variety of sources, and have been found to contain estrogenic and/or androgenic activity. In this study, samples were collected from targeted sites or as runoff from an agriculture field that was sprayed with poultry manure/litter.
Description:
Environmental effluents contain a diversity of chemicals, can originate from a variety of sources, and have been found to contain estrogenic and/or androgenic activity. In this study, samples were collected from targeted sites or as runoff from an agriculture field that was sprayed with poultry manure/litter. These collections were made after initial manure/litter application, then days after application or when there had been a significant amount of rain to produce runoff. Estrogenic activity of environmental water samples was determined in an estrogen-dependent luciferase assay. T47D-KBluc cells are human breast cancer cells that express both estrogen receptor (ER) alpha and ER beta and are stably transfected with a triplet estrogen response element promoter and a luciferase reporter gene construct (Wilson et al.,2004). This reporter gene assay is sensitive, specific, and has a short turn around time for determining estrogenic activity. Estrogen equivalents (EEQs) are used to standardize relative estrogen activity for comparison within and between studies. Over a 3-year period estrogenicity of litter-influenced runoff / receiving water increased for approximately 4-9 days after each application before declining. In vitro bioactivity was consistent with analytical chemistry results for estrone (E1) and estradiol (E2). Increases in estrogens between day 0 and day 9 were hypothesized to occur due to microbial deconjugation of glucuronide and sulfate groups to produce bioactive E1 and E2 which then were further degraded to inactive forms. The biological activity of the samples based on our EEQ data corresponded well with the analytical chemistry data (GC/MS/MS analysis). Analytical chemistry results and EEQ results were consistent with vitellogenin induction in male fish. Disclaimer: This work does not necessarily reflect U.S. EPA policy.