2010 Progress Report: Transport and Transformation of Natural and Synthetic Steroid Hormones at Beef Cattle and Dairy Concentrated Animal Feeding Operations (CAFOs)

EPA Grant Number: R833422
Title: 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: Klieforth, Barbara I
Project Period: October 1, 2007 through September 30, 2010 (Extended to September 30, 2012)
Project Period Covered by this Report: October 1, 2009 through September 30,2010
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 , Health , Safer Chemicals


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, built and tested rainfall simulators, and began experiments analyzing steroid transport and transformation in manure, soil, and simulated runoff from a research feedlot in Davis, CA. We also measured the steroid concentration in runoff, groundwater, and soil samples from commercial feedlots in Northern California and Iowa. During the third year, we finished the simulated runoff experiments at the research feedlot, processed several hundred soil and runoff samples to determine steroid concentration and other water quality parameters, and analyzed the data to understand how steroids were being transported and transformed on the feedlot.
Results from the simulated runoff experiments show that all of the endogenous and synthetic steroids analyzed were detected in the soil after the cattle were present at concentrations ranging from <1 ng/g to 60 ng/g. Both the endogenous and synthetic steroids in the soil were surprisingly stable over the 14 day period when the cattle were present and during the 7 days after the cattle were removed with total estrogen, testosterone, and both trenbolone isomer concentrations remaining nearly constant. Previous research has demonstrated half lives for these compounds ranging from hours to a few days, so the steroids were much more stable than expected. It is possible that the dry conditions inhibited or slowed microbial activity, or that the steroids in manure may be strongly bound to organic matter in large particles which could slow biotransformation and limit accessibility to runoff water or microbes.
Although the cattle excreted little androstenedione and progesterone, relatively high concentrations of the steroids were observed in the soil after the 14-day period when the cattle were held on the feedlot suggesting other sources or possible precursors, such as sterols in the manure and soil.
Only a small fraction of the steroids measured in the soil were released to the simulated runoff. Soil estrogen concentrations remained constant after rainfall, and TBA metabolite concentrations changed less than 10%. While the endogenous androgens and progesterone concentrations in the soil were decreased more than 80% after runoff, the mass released to runoff could only account for approximately 10% of the mass lost from the soil suggesting rapid transformation of these compounds either in the wet soil or runoff. Even the small fraction of total steroids released to the runoff caused concentrations that were, in all cases, several orders of magnitude above thresholds for feminization, masculinization, and olfactory interference. Endogenous steroid concentrations ranged between 15 and 225 ng/L with 17α-estradiol, androstenedione, and progesterone the dominant steroids present. TBA metabolite concentrations ranged between 1-390 ng/L with median concentrations of 17α-TBOH, 17β-TBOH, and TBO of 34, 16, and 19 ng/L, respectively. A significant fraction (roughly 50%) of the steroids in the runoff was associated with particles implying that treatment methods relying on particle removal could remove about half of the steroid hormones from feedlot runoff.
Results from an experiment in Iowa where feedlot runoff was treated by passing through a settling basin, vegetated infiltration basin, and a vegetated treatment area showed good removal of the  endogenous steroid hormones after passing through the various treatment steps with only trace concentrations of estrone, androstenedione, and progesterone remaining in the effluent from the vegetated treatment area. These results suggest that each treatment step was effective at removing a portion of the steroid hormones, but a settling basin alone may not lower the concentrations sufficiently without further dilution.

Future Activities:

During the coming year, we plan to continue our efforts to understand the transport of steroid hormones in surface runoff and groundwater. Runoff microcosm experiments will be conducted to observe steroid stability and partitioning in runoff under various scenarios. Experiments observing TBA metabolite concentrations with time in soil samples from feedlot pens containing TBA implanted steers also will be conducted, and leaching experiments with methanol and water will be conducted to determine what fraction of steroids will leach from soil in runoff.

Journal Articles:

No journal articles submitted with this report: View all 21 publications for this project

Supplemental Keywords:

estradiol, estrogen, endocrine disruption, trenbolone acetate, steroid, CAFO, progesterone, androstenedione, estrone, trendione, trenbolone, RFA, Health, Scientific Discipline, Environmental Chemistry, Endocrine Disruptors - Environmental Exposure & Risk, endocrine disruptors, Biochemistry, Endocrine Disruptors - Human Health, CAFOs, EDCs, endocrine disrupting chemicals, animal feeding operations, concentrated animal feeding operations

Progress and Final Reports:

Original Abstract
  • 2008 Progress Report
  • 2009 Progress Report
  • 2011 Progress Report
  • Final Report