Fate of Endogenous Steroid Hormones in Steer Feedlots Under Simulated Rainfall-Induced Runoff

Abstract

Steroid hormones pose potential risks to fish and other aquatic organisms at extremely low concentrations. To assess the factors affecting the release of endogenous estrogenic and androgenic steroids from feedlots during rainfall, runoff, and soil samples were collected after simulated rainfall on a 14-steer feedlot under different rainfall rates and aging periods and analyzed for six steroid hormones. While only 17α-estradiol, testosterone, and progesterone were detected in fresh manure, 17β-estradiol, estrone, and androstenedione were present in the surficial soil after two weeks. In the feedlot surficial soil, concentrations of 17α-estradiol decreased by approximately 25% accompanied by an equivalent increase in estrone and 17β-estradiol. Aging of the feedlot soils for an additional 7 days had no effect on estrogen and testosterone concentrations, but androstenedione concentrations decreased substantially, and progesterone concentrations increased. Androstenedione and progesterone concentrations in the surficial soil were much higher than could be accounted for by excretion or conversion from testosterone, suggesting that other potential precursors, such as sterols, were converted after excretion. The concentration of androgens and progesterone in the soil were approximately 85% lower after simulated rainfall, but the estrogen concentrations remained approximately constant. The decreased masses could not be accounted for by runoff, suggesting the possibility of rapid microbial transformation upon wetting. All six steroids in the runoff, with the exception of 17β-estradiol, were detected in both the filtered and particle-associated phases at concentrations well above thresholds for biological responses. Runoff from the aged plots contained less 17α-estradiol and testosterone, but more estrone, androstenedione, and progesterone relative to the runoff from the unaged plots, and most of the steroids had a lower particle-associated fraction.

Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields

“…The overall low frequency of detection of hormones in surface runoff samples was also observed in previous studies [14,20,45]. Mansell et al [20] estimated that 37% to 99% of hormones can be associated with the organic matter of the suspended sediment depending on the dissolved organic carbon in runoff, whereas the current study analyzed the liquid potion of the runoff samples after filtering the suspended sediment.…”

“…Mansell et al [20] estimated that 37% to 99% of hormones can be associated with the organic matter of the suspended sediment depending on the dissolved organic carbon in runoff, whereas the current study analyzed the liquid potion of the runoff samples after filtering the suspended sediment. However, the increase in frequency of detections at 30 DAT agrees with results from the previous study by Mansell et al [20]. Overall, among the hormones and metabolites, estrone and estriol were the two most commonly detected metabolites, occurring in 9% of the runoff samples (n = 216, 30 DAT) irrespective of tillage and manure treatments (data not shown).…”

“…Soil microbiology and surrounding physio-chemical characteristics are major factors controlling transformation among the steroid hormones and their metabolites. For example, Mansell et al [20] reported the presence of parent hormones such as 17␣-estradiol, 17␤-estradiol, and testosterone (ranging from 5 to 175 ng L −1 ) in runoff from feedlot surface during a rainfall simulation event conducted immediately after the animals were removed from the pens but they found the presence of metabolites such as estrone, androstenedione, and progesterone (ranging from 50 to 250 ng L −1 ) in runoff when they conducted another rainfall simulation 7 days later. They concluded that the dominant forms of hormones and metabolites were determined by changing soil microbial composition along with surrounding physio-chemical properties of the soil.…”

Effect of Growth Promotants on the Occurrence of Endogenous and Synthetic Steroid Hormones on Feedlot Soils and in Runoff from Beef Cattle Feeding Operations

“…Endogenous steroids were detected in runoff at biologically active concentrations. 17 To date, no studies have concurrently investigated the occurrence of a large suite of endogenous and exogenous steroid hormones in feedlot surface soils, manure and in runoff from beef feedlot surfaces. Although much speculation exists regarding the effect of growth promotants on the occurrence of endogenous and exogenous steroid hormones in wastes from beef cattle production facilities, there is relatively little data available to document their occurrence in feedlot surface runoff.…”

Steroid Hormone Runoff from Agricultural Test Plots Applied with Municipal Biosolids

“…In these studies, runoff concentration appeared strongly dependent on the litter application rate and frequency. 24,25 Mansell et al 10 investigated soil and runoff concentrations in simulated rainfall experiments from steer feedlots. Whereas only three of the six hormones they measured were detected in fresh manure, all six were detected in surficial soil after two weeks.…”