Effects of Manure Application and Site Variation on Soil Estrogen.

17ß-estradiol is a natural estrogenic hormone found in animal manure and urine. While it has been reported to dissipate rapidly in soil laboratory studies, it is frequently detected in the environment at concentrations that could potentially have adverse affects on wildlife. The objective of this study was to assess the relationship between soil hydrology, including localized groundwater flow and vertical water movement within the soil profile, and the persistence and detections of 17ß-estradiol in the soil system.  Soil cores were taken from various locations at a swine (sus scrofa) farm over 2006 and 2007.  The producer applied liquid manure slurry to one of five sites.  Cores were taken to the depth of the water table and separated into 15-cm increments.  Pore water was extracted and analyzed for 17ß-estradiol and its main metabolites, using a combination of mass spectrometry and liquid chromatography (LC/MS-MS).  Estradiol was detected at all sites but was highly variable. Estradiol was detected in 249 out of 589 extractions (42.3%), and concentrations ranged from 0 to 733 ng-estradiol/kg-dry soil. Analysis of variance indicated a statistically significant difference between sites and time (p≤0.05).  Beginning in Spring 2006, concentrations trended upward, reaching a maximum in the Spring of 2007, and then declined. The injection of the manure slurry did not appear to have a significant affect on the amount of estradiol extracted, as mean concentrations taken both immediately before and after the application were not significantly different. A similar range of concentrations was detected on all sites, and non-application site detections followed similar trends to application sites.  Detection trends appeared to be related to climate, possibly to precipitation.  Where estradiol was detected, highest concentrations favored the upper profile, while the greatest frequency of detections were in the lower profile and near the water table.