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STAR Grant R833421: Assessing Occurrence, Persistence, and Biological Effects of Hormones Released from Livestock Waste 2007 - 2010

Project Purpose:
This study seeks to characterize the transport, fate, and effects of the natural and synthetic hormones released into the environment by CAFOs, and to evaluate the effects of different waste disposal practices on hormone fate and activity.

Project Description(s):

The overall goal is to determine the presence, persistence and biological effects of natural and synthetic hormones that may be released into the environment from CAFOs, and evaluate the effects of different animal waste disposal practices on the fate and activity of these compounds. This research will help to evaluate whether CAFO waste is an important source of endocrine disrupting chemicals in the environment. The specific objectives are to:

The objectives of the study will be achieved by sampling representative cattle, dairy, swine and poultry operations. Waste loading will be estimated by measuring hormones in manure and urine. Transport/fate will be monitored in several environmental and engineered reservoirs such as tile drains, groundwater, soils, waste storage facilities and field-applied manure slurry. Steroids will be analyzed using LC-MS-MS. To evaluate potential biological activity of the CAFO waste, a suite of molecular and cellular-based bioassays (e.g. E- and A-screens and transfected yeast assays) will be used on extracts of collected samples. These bioassay results will be compared with compounds measured in the samples to determine if specific compounds present in CAFO waste samples can account for the endocrine activity measured by cellular/molecular bioassays. Additionally, full and partial life-cycle fathead minnow assays will be conducted using a suite of developmental and reproductive endpoints. The whole animal effects will be correlated with specific molecular and cellular-based bioassays to identify biomarkers of CAFO-associated endocrine disruption.

Project Outcomes:
The project will determine the potential for environmental release of hormones under various waste management practices, degradation of hormones and associated activities in these practices, the persistence of residuals in transport from CAFOs, and the relative importance of different natural and synthetic hormones to the biological activity of CAFO wastes and effluents. The results will assist CAFO operators to optimize management practices that mitigate environmental problems associated with hormones discharged from CAFOs, and help regulators with risk assessment as biologically relevant chemicals will be identified, quantified, and ranked. Ultimately, the proposed project will help protect sensitive aquatic environments, native species, and humans from wastes associated with CAFOs.

More Information
NCER Star Grant site: Assessing Occurrence, Persistence, and Biological Effects of Hormones Released from Livestock Waste

Susan Laessig at laessig.susan@epa.gov

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