FATE OF THE ENDOGENOUS HORMONES, 17 BETA-ESTRADOL AND TESTOSTERONE, IN COMPOSTED POULTRY MANURE

Authors: Hakk, Heldur; MILLNER, PATRICIA - USDA ARS SUSTAINABLE AG; Larsen, Gerald

Submitted to: Pharmaceuticals and Endocrine Disrupting Chemicals in Water Conference
Publication Type: Proceedings
Publication Acceptance Date: 8/20/2001
Publication Date: 10/1/2001
Citation: N/A

Interpretive Summary: Mammals produce and excrete potent hormones naturally. Among the most com- mon are 17 beta-estradiol & testosterone. These hormones are more potent than man-made environmental contaminants of concern that also interact with the estrogen or androgen receptors. The purpose of this study was measure the concentrations of estradiol and testosterone in a poultry manure composting operation in order to access the effectiveness of composting in reducing or eliminating these hormones. Poultry layer manure was obtained from a commercial producer. Commercial kits were utilized to measure concentrations of both hormones. Both hormones were degraded by the microbes present in compost. Estradiol concentrations began at an average of 95 ng/g, and was slowly degraded over the 83 day study period to about half the starting concentration. Testosterone was degraded at a rate approximately three times faster than estradiol. Testosterone concentrations began at 198 ng/g and ended at 32 ng/g at 83 days. Neither hormone was degraded to background levels by the conclusion of the study. The addition of clay, a common texturing agent, to the compost did not affect the rate of decay of either hormone significantly. Two commercial soil amendments produced by microbial digestion of cattle and swine waste were also analyzed. They both contained measurable levels of both hormones, although the swine was much higher. This indicated that there exist many environmental sources of these hormones. The results of the study demonstrated that composting of poultry manure was an effective means of reducing, but not eliminating, the introduction of the potent hormones estradiol and testosterone into the environment.

Technical Abstract: The purpose of this study was to measure the concentrations of the potent hormones, estradiol and testosterone, in a poultry manure composting operation in order to access the effectiveness of composting in reducing these hormones. Poultry layer manure was obtained from a commercial producer and amended with hay, straw, leaves, and starter compost. Commercial enzyme immunoassay kits were utilized to measure concentrations of both hormones. During the first 21 days of the study thermophilic conditions were maintained (>60 degrees C.), while mesophilic conditions (35-55 degrees C.) were maintained for the last 62 days. Both hormones were degraded by the microbes present in compost and could be modeled by a first order with time degradation rate constant. Estradiol concentrations began at an average of 95 ng/g and were slowly degraded to 42 ng/g over the 83 day study period. Estradiol in poultry manure compost had a degradation nrate constant of -0.0086/day. Testosterone was degraded at a rate approximately three times faster than estradiol, i.e. -0.0291/day. Testosterone concentrations began at 198 ng/g and finished at 32 ng/g at 83 days. Neither hormone was degraded to background levels by the conclusion of the study. The addition of Christiana clay to the compost did not affect the rate of decay of either hormone significantly. Two commercial soil amendments produced by microbial digestion of animal wastes were also analyzed. They both contained measurable concentrations of estradiol & testosterone, i.e. 18-144 ng estradiol/g & 5-53 ng testosterone /g. The results of the study demonstrated that composting of poultry manure was an effective means of reducing, but not eliminating, the introduction of the potent hormones, estradiol and testosterone, into the environment.