Tuesday, November 14, 2006 - 10:40 AM

Nature, Fate and Significance of Natural and Synthetic Hormonal Substances Carried in Livestock Waste and Biosolids.

Ed Topp1, Angela Lorenzen1, Anne-Marie Jacobsen2, John Hendel1, Kent Burnison3, Mark Servos3, and Ralph Chapman1. (1) Agriculture and Agri-Food Canada, Ontario, London, ON N5V 4T3, Canada, (2) Danish Univ of Pharmaceutical Sciences, Universitetsparken, DK-2100, Copenhagen, Denmark, (3) National Water Research Institute, Environment Canada, Burlington, ON L7R 4A6, Canada

Endogenous hormones of human or animal origin are frequently detected in the environment, and at inappropriately high concentrations androgenic and estrogenic hormones can potentially cause endocrine disruption in wildlife. Agriculture could potentially be a source of endocrine-disrupting chemicals (EDCs) through the land application of sewage biosolids, or animal wastes that carry synthetic or natural substances with hormonal activity. Recombinant yeast and mammalian cell line (BG1Luc4E2) hormone receptor gene transcription assays were used to screen crude organic extracts of municipal biosolids and animal manures for estrogen, androgen, and progesterone receptor gene transcription activities. All materials were generally found to have estrogenic and androgenic, but not progestin activity. A toxicity identity evaluation (TIE) approach used to identify the chemical basis for this activity detected phytoestrogenic substances in liquid swine manure, and alkylphenol detergent components in liquid municipal biosolids. Laboratory experiments with radiolabeled substrates have explored the kinetics, mechanisms, and effects of key rate-controlling parameters on the persistence of selected hormonal substances including 4-nonylphenol, ethynylestradiol, estradiol, and testosterone. In general, these chemicals were dissipated in soils with kinetic responses to soil temperature, moisture, and texture typical of mesophilic aerobic microbial biodegradation. Microorganisms carried in swine manure slurry and in aerobically-digested biosolids could hasten the biotransformation of estradiol and of testosterone in soil. A variety of steroidal transformation products were transiently detected during testosterone and estradiol dissipation, but these had significantly lower hormonal activities than the parent compounds as detected using the recombinant yeast assays.  In summary, we have found that these chemicals are dissipated in soils with kinetics implying that they carry little risk to adjacent water if the application of organic fertilizer in commercial agriculture is appropriately managed to avoid preferential flow or runoff.