Grantee Research Project Results
2011 Progress Report: Transport and Transformation of Natural and Synthetic Steroid Hormones at Beef Cattle and Dairy Concentrated Animal Feeding Operations (CAFOs)
EPA Grant Number: R833422Title: Transport and Transformation of Natural and Synthetic Steroid Hormones at Beef Cattle and Dairy Concentrated Animal Feeding Operations (CAFOs)
Investigators: Sedlak, David L. , Kolodziej, Edward P. , Harter, Thomas
Institution: University of California - Berkeley , University of Nevada - Reno , University of California - Davis
Current Institution: University of California - Berkeley , University of California - Davis , University of Nevada - Reno
EPA Project Officer: Aja, Hayley
Project Period: October 1, 2007 through September 30, 2010 (Extended to September 30, 2012)
Project Period Covered by this Report: October 1, 2010 through September 30,2011
Project Amount: $698,103
RFA: Fate and Effects of Hormones in Waste from Concentrated Animal Feeding Operations (CAFOS) (2006) RFA Text | Recipients Lists
Research Category: Endocrine Disruptors , Human Health , Safer Chemicals
Objective:
The objective of our research is to assess the occurrence, fate and transport of natural and synthetic steroid hormones at beef and dairy cattle confined animal feeding operations (CAFOs). As part of our project, we are focusing on steroid hormone transport through surface water runoff and groundwater.
Progress Summary:
During the first year, we developed analytical methods, designed experiments to assess these two pathways, collected samples from several field sites and met with extension agents, ranchers and dairymen to learn more about current waste handling practices. During the second year, we finished analytical method development for synthetic steroids, developed a method for measuring particle-associated steroid hormones, and began experiments analyzing steroid transport and transformation in manure, soil, and simulated runoff from a research feedlot in Davis, CA and collected samples from commercial feedlots in Northern California and Iowa. During the third year, we analyzed the results from those experiments and began runoff microcosm experiments to assess steroid stability and transformation in feedlot runoff. During the fourth year, we conducted experiments at a commercial feedlot to determine the effect of time on TBA metabolite excretion, transformation kinetics in soil, and leaching to runoff. We also continued the runoff microcosm experiments to determine the steroid stability and partitioning in runoff.
Although TBA implants are designed to provide a constant release of the steroid to the blood of the implanted animal over a 100-day period, excretion rates were not constant. Concentrations of 17αTBOH in the soil from pens containing implanted animals were, with one exception, highest (14 ng/g) in the pens where animals were implanted most recently. After 100 days, the concentrations had decreased to 2 ng/g. Other TBA metabolite concentrations in the soil also decreased throughout the 100-day lifetime of the implant. This suggests that implantation time could be a controlling factor in determining TBA metabolite concentration in soil on feedlots.
Another reason the soil concentrations of TBA metabolites decreased with time is transformation by microbes in the soil. In our experiments, we observed a half life of approximately 25 days 17αTBOH in feedlot soil. This is much slower than reported half lives in aerobic soil of 4-50 hours, but faster than reported half lives in anaerobic soil of 260-270 days. This recalcitrance of the TBA metabolites confirms what was observed in the research feedlot experiments where the synthetic steroids were stable over the 21 day experiment even after rainfall. Time since implantation and soil transformation time could be the two most important variables in determining TBA metabolite concentrations in soil, and therefore, runoff from feedlots.
To investigate the water-extractable fraction of soil-associated steroids on CAFO surfaces, some soil samples were concurrently extracted with methanol and water. Approximately 60% of methanol-extractable steroids also were water-extractable, suggesting the existence of a strongly bound or otherwise unavailable fraction of steroids in soils. Steroids strongly associated with organic matter phases and on soil particles in locations far from water- soil interfaces are likely not available for leaching or microbial transformation.
Results from runoff microcosm experiments using endogenous steroids showed that the steroids added to the microcosms were rapidly transformed in the first several hours, but then were stable for the next 7 days. Background steroid concentrations which came from the manure were also stable over the 7 days of the experiment, although most of the concentrations are low. Androstenedione concentrations increased dramatically, increasing approximately 100%. This confirms both the production of androstenedione and the stability of the steroids observed in the previous rainfall simulator experiments on the research feedlot. The runoff, of course, has plenty of moisture which suggests the steroids are either unavailable to the microbes, or there is limited biological activity after the initial few hours. Further experiments are ongoing to determine the reason for this behavior.
Future Activities:
During the coming year, we plan to continue our efforts to understand the transport of steroid hormones in surface runoff and groundwater. Additional runoff microcosm experiments will be conducted to observe the effect of higher manure concentrations, equilibration time, and microbial community on endogenous steroid stability. Experiments observing the effects of moisture and shade on synthetic steroid stability in feedlot soil are also being conducted. An additional experiment observing TBA metabolite excretion in various breeds of cattle as a function of time also is being conducted. Data analysis for these experiments is ongoing.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
| Other project views: | All 21 publications | 3 publications in selected types | All 3 journal articles |
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Mansell DS, Bryson RJ, Harter T, Webster JP, Kolodziej EP, Sedlak DL. Fate of endogenous steroid hormones in steer feedlots under simulated rainfall-induced runoff. Environmental Science & Technology 2011;45(20):8811-8818. |
R833422 (2011) R833422 (Final) |
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Webster JP, Kover SC, Bryson RJ, Harter T, Mansell DS, Sedlak DL, Kolodziej EP. Occurrence of trenbolone acetate metabolites in simulated confined animal feeding operation (CAFO) runoff. Environmental Science & Technology 2012;46(7):3803-3810. |
R833422 (2011) R833422 (Final) |
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Supplemental Keywords:
estradiol, estrogen, endocrine disruption, trenbolone acetate, steroid, CAFO, progesterone, androstenedione, estrone, trendione, trenbolone, Health, RFA, Scientific Discipline, Environmental Chemistry, Endocrine Disruptors - Human Health, endocrine disruptors, Biochemistry, Endocrine Disruptors - Environmental Exposure & Risk, concentrated animal feeding operations, EDCs, animal feeding operations, endocrine disrupting chemicals, CAFOsProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.