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In Vitro Screening of Environment Samples for Estrogenic and Androgenic Activity: Concentrated Animal Feedlot Operations (beef, dairy, poultry)
Project Purpose:
Effluents from animal operations have been shown to contain chemicals with endocrine activities. The extent of such exposures and their potential impact on human and ecosystem health is unknown. Effluents have been shown to possess endocrine disrupting activity of sufficient potency to adversely impact reproduction in some fish species. In the US, fish living in ecosystems contaminated with human or domestic animal effluents also display reproductive alterations. We are participating in several projects using in vitro transcriptional activation and binding assays to characterize the estrogenicity and androgenicity of these types of environmental samples. These samples include beef and dairy CAFO (concentrated animal feedlot operation) and other animal effluents (poultry, geese, swine) collected in the field and effluents from industrial operations (pulp and paper mill).
Project Description(s):
In this project, we are evaluating environmental samples for EDC activities in order to 1. Identify the potency of the samples. 2. Attempt to identify specific chemicals in samples responsible for the EDC activity. And 3. Try to determine the potential impacts of these chemicals on fish, wildlife and human health. Due to the complex composition of these discharges, the identification of chemicals responsible for hormonal activity can not always be performed using chemical analyses alone. For this reason, chemical identification in most cases will be guided by the cell-based bioassays that can pinpoint hormonally-active sample fractions. EDC activity has been identified in several environmental samples, including androgenic and estrogenic activity. Specific chemicals have been identified in CAFO effluents with androgenic activity and androgens and estrogens have been identified in pulp mill effluents, treated sewage effluents and in combustion by-product samples. Initial studies demonstrated androgenic activity in pulp and paper mill effluents which correlated with the presence of masculinized female fish downstream from the plant. We applied similar techniques to assessing effluents from cattle feedlot operations. Androgens identified in the CAFO have been shown to masculinize fathead minnows in the laboratory at environmental levels. Work has established that beef CAFO discharges from different sites within the U.S. consistently exhibit androgenic activity, and that androgenic metabolites of a synthetic anabolic steroid used to enhance beef production (trenbolone acetate) can be detected in beef CAFO discharges. Further, ORD scientists have shown that trenbolone metabolites are extremely potent in fish, masculinizing females and impacting reproduction at low ng/L (part-per-trillion) concentrations in the water.
Project Outcomes:
In vitro assays can be used to assess EDC activity in environmental samples as a screen for potential effects on fish, wildlife and human health. (Pulp mill effluent, CAFOs (beef, poultry, swine), and avian wildlife effluents, and sewage effluents. Outcomes include: 1. Development of robust in vitro and instrumental analytical methods to identify and quantify compounds responsible for androgenic and estrogenic activity of CAFO discharges originating from dairy and/or beef operations, 2. Established a preliminary strategy and experimental design to assess estrogenicity and androgenicity in environmental samples and 3. Assess the effects of mixtures of the estrogens in these effluents to determine if the behave in a predictable, dose-additive or in a synergistic fashion.
Contact
Vickie Wilson at wilson.vickie@epa.gov