Grantee Research Project Results
Final Report: Fate of Hormones in Waste from Concentrated Broiler Feeding Operations
EPA Grant Number: R833419Title: Fate of Hormones in Waste from Concentrated Broiler Feeding Operations
Investigators: Cabrera, Miguel L. , Hassan, Sayed , Fairchild, Brian D. , Hartel, Peter G. , Kissel, David E. , Radcliffe, David E. , Vencill, William K. , Endale, Dinku
Institution: University of Georgia , USDA
EPA Project Officer: Aja, Hayley
Project Period: July 1, 2007 through June 30, 2010 (Extended to June 30, 2012)
Project Amount: $695,620
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:
Each year, the U.S. broiler industry generates about 13 million Mg of broiler litter, a mixture mostly of bird excreta and bedding material. Broiler litter is typically applied to grasslands as fertilizer because it contains nutrients such as nitrogen, phosphorus, and potassium. In addition to plant nutrients, however, broiler litter also contains the sex hormones estrone, 17β-estradiol and testosterone, which may be transported in surface runoff and contaminate surface waters. Information on factors that affect the concentration of these sex hormones in broiler litter, their fate in soil, and their transport in surface runoff is limited.
The objectives of our work were to: a) determine concentrations of estrone, 17β-estradiol, and testosterone in different classes of broiler litter; b) evaluate the effect of stacking broiler litter on the dynamics of hormone concentrations; c) evaluate the decomposition, sorption, and transport of radio-labeled hormones mixed with broiler litter and applied on the soil surface; and d) evaluate the effect of runoff occurring at different times after broiler litter application, as well as the effect of mechanical aeration, on the concentration of estradiol and testosterone in surface runoff from grassed plots.
Summary/Accomplishments (Outputs/Outcomes):
Objective a) Determine concentrations of estrone, 17β-estradiol, and testosterone in different classes of broiler litter.
Broiler growers use a bedding material (typically wood shavings) to absorb moisture from the bird excreta and maintain an environment with low water availability. In addition, to reduce the level of ammonia in the air, some growers apply chemicals such as aluminum sulfate (alum) or sodium bisulfate (PLT) to the bedding material. When broiler houses are cleaned, either all the litter is removed (full cleanout) or only the caked litter (cake cleanout) is cleaned. In our study, we analyzed 240 broiler litter samples that included full and cake cleanouts as well as none, alum and PLT amendments. These samples were collected after 1, 3, or 5 flocks or birds were raised on the same bedding material.
Our results showed that cake cleanout from untreated bedding or from bedding treated with alum had 94 to 230% greater estrone and testosterone concentrations than full cleanout. Cake cleanout from untreated bedding or from bedding treated with PLT had 54 to 175% greater concentration of estradiol than full cleanout. Thus, cake cleanout would pose a greater risk of contaminating surface runoff with hormones than full cleanout when cake cleanout is surface applied to land as fertilizer
While some poultry integrators require that their growers remove broiler litter from the houses after each flock, other integrators allow growers to clean the houses after several flocks are raised. Our results showed that when the bedding material was not treated with chemicals, concentrations of estrone and estradiol in cake cleanout increased by 147 to 160% from 1 to 3 flocks. Thus, in untreated bedding, cake cleanout from 3 flocks would pose a greater risk of surface runoff contamination than cake cleanout from 1 flock. In contrast, when the bedding material was treated with sodium bisulfate (PLT), sex hormones did not increase as the number of flocks increased from 1 to 5.
Objective b) Evaluate the effect of stacking broiler litter on the dynamics of hormone concentrations.
When broiler litter is removed from broiler houses it sometimes is placed in stack houses until time or weather allows application to the fields. We collected broiler litter samples from six stack houses immediately after stacking and 4 to 8 weeks later. Our results showed that stacking litter for 4 to 8 weeks can reduce estradiol by 35 to 50% and testosterone by 37 to 64%.
This effect apparently was due to microbial activity in the stack as evidenced by temperature increasing up to 60oC during stacking. Thus, stacking may be a good management practice to reduce sex hormones in broiler litter.
Objective c) Evaluate the decomposition, sorption, and transport of radio-labeled hormones mixed with broiler litter and applied on the soil surface.
Radiolabeled estradiol and testosterone were added to broiler litter, applied on the surface of four different soils and incubated for 168 days at 10, 20 or 30oC and at water potentials of -0.03 MPa (field capacity) and -1.5 MPa (permanent wilting point). The soil samples were collected from three locations in Georgia, a Cecil sandy loam (fine, kaolinitic, thermic Typic Kanhapludults) from Watkinsville, a Cecil sandy loam from Eatonton, a Sedgefield sandy loam (fine, mixed, active, thermic Aquultic Hapludalfs) from Eatonton, and a Tifton loamy sand (fine-loamy, kaolinitic, thermic Plinthic Kandiudults) from Tifton. Our results showed that temperature and water content (water potential) affected estradiol and testosterone decomposition, but their effect was not very large. As temperature varied from 10 to 30oC and water content varied from -1.5 to -0.03 MPa, mineralization in 168 days ranged from 2 to 14% for estradiol and from 34 to 48% for testosterone. However, our mineralization was higher than that of Hemmings and Hartel (2006), who observed approximately 1% of estradiol and 17% of testosterone mineralized when the labeled hormones were added to broiler litter only (no soil) and were incubated for 175 d at similar temperatures and water contents. Therefore, the mineralization of hormones mixed with broiler litter and applied on the soil surface was greater than mineralization of hormones mixed with broiler litter alone.
Temperature and water content had greater effects on the distribution of the sex hormones remaining in the soil. Increasing temperature from 10 to 30oC and increasing water content from permanent wilting point (-1.5 MPa) to field capacity (-0.03 MPa) decreased the amount of estradiol and testosterone extractable in water and increased the amounts associated with soil organic fractions. These results suggest that better conditions for mineralization also lead to less water-extractable hormones and more incorporation of the remaining hormones into soil organic matter (humification). This effect may result in reduced concentrations in surface runoff as well as reduced biological activity of the hormones remaining in soil. Our results also show that the incorporation of hormones into soil organic fractions increases with time after application.
Contamination of surface runoff with sex hormones as well as movement of hormones through the soil will likely depend on the degree of sorption by soil. Because both estradiol and testosterone are present in broiler litter, sorption of one hormone may be affected by the other hormone. We studied sorption of estradiol and testosterone by soil and broiler litter when applied separately or together. The soil used was a Cecil sandy clay loam (fine, kaolinitic, thermic Typic Kanhapludult), which is a common soil in the Southern Piedmont physiographic region. Batch equilibrium sorption data were fit with the linear and non-linear Freundlich sorption equations. Our results showed that when hormones were applied separately to soil, testosterone sorption was slightly greater than estradiol sorption. When the hormones were applied together, sorption in soil decreased for both hormones but there was a much larger difference between testosterone and estradiol, with testosterone being more strongly sorbed. When broiler litter was added to the soil/hormone mixture, sorption decreased for testosterone and increased for estradiol. These results suggest that the organic matter in broiler litter can affect sorption of hormones by soil and therefore affect their movement. Indeed, in columns packed with aggregated soil (simulating field conditions), the presence of broiler litter accelerated the breakthrough of testosterone although it did not affect the breakthrough curve for estradiol (Figure 1). These findings suggest that to understand sorption of broiler litter-derived hormones, it is necessary to evaluate both hormones together and consider the effect of organic matter in broiler litter. It may be necessary to understand the specific sorption properties of the soil in a given area.
Figure 1. Breakthrough curves of estradiol and testosterone in packed soil columns with
and without poultry litter in the presence of both hormones for three replicate columns.
Figure 2. Ammonia knives used for aerating grassed paddocks.
Objective d) Evaluate the effect of runoff occurring at different times after broiler litter application, as well as the effect of mechanical aeration, on the concentration of hormones in surface runoff from grassed plots.
Given that most of the mineralization of estradiol and testosterone occurs during the first 30 to 60 days, and that incorporation into soil organic matter fractions increases with time, it is expected that the risk of contaminating surface runoff with sex hormones will decrease with time. We applied broiler litter to grassed plots and conducted rainfall simulations at 0, 1, 2, 3, or 4 weeks after application. Plots that did not receive rainfall immediately after application were protected with clear plastic suspended 50 cm above the soil to prevent natural rain from reaching the plots. Our results did not show differences in concentrations and mass losses of estradiol and testosterone in runoff as a function of time. Therefore, broiler litter applied on the soil surface may contaminate surface runoff with hormones for at least 4 weeks following application if rains that do not cause runoff do not occur during that time.
Grassland aeration is a mechanical treatment that has been shown to reduce the concentration of broiler litter-derived phosphorus in surface runoff and may therefore reduce the concentration of sex hormones (Franklin, et al., 2007). We applied broiler litter to six 0-8-ha grassed paddocks and aerated three of them with ammonia knives (30 cm apart) in a direction perpendicular to the slope. The other three paddocks were used as controls. Ammonia knives are thin knives that penetrate about 15-20 cm into the soil and form a thin trench without much disruption of the soil surface (Figure 2). Our results showed that aerating grasslands with ammonia knives may reduce concentrations of estradiol and testosterone in surface runoff when runoff events occur soon after litter application. However, aeration may not reduce concentrations in later runoff events.
Conclusions:
- Cake cleanout would pose a greater risk of contaminating surface runoff with hormones than full cleanout, and in untreated bedding, cake cleanout from three flocks would pose a greater risk of surface runoff contamination than cake cleanout from one flock.
- Stacking broiler litter for 4 to 8 weeks is likely to reduce (although not eliminate) estradiol and testosterone concentrations.
- The percentage of hormone decomposition when surface applied to soil is lower for estradiol (about 10%) than for testosterone (about 40%).
- The effect of temperature and water content on decomposition of estradiol and testosterone applied to the soil surface is relatively small.
- Increasing temperature from 10 to 30oC and increasing water content from permanent wilting point (-1.5 MPa) to field capacity (-0.03 MPa) may decrease the amount of estradiol and testosterone extractable in water and increase the amounts associated with soil organic fractions. These results suggest that better conditions for mineralization also may lead to less water-extractable hormones and more incorporation of remaining sex hormones into soil organic matter (humification).
- The incorporation of hormones into soil organic fractions increases with time after application.
- Sorption of estradiol and testosterone by soil decreases when both hormones are added together when compared to hormones added separately.
- The organic matter present in broiler litter can affect sorption of estradiol and testosterone by soil.
- Broiler litter applied on the soil surface may contaminate surface runoff with estradiol and testosterone for at least 4 weeks following application.
- Aerating grasslands with ammonia knives may reduce concentrations of estradiol and testosterone in surface runoff for runoff events that occur soon after litter application, but is not likely to have an effect in later runoff events.
References:
Franklin, D.H., M.L. Cabrera, L.T. West, V.H. Calvert, and J.A. Rema. 2007. Aerating grasslands: effects on runoff and phosphorus losses from applied broiler litter. J. Environ. Qual. 36:208-215.
Hemmings, S.N.J., and P.G. Hartel. 2006. Mineralization of hormones in breeder and broiler litters at different water potentials and temperatures. J. Environ. Qual. 35:701-706.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 9 publications | 1 publications in selected types | All 1 journal articles |
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Bera M, Radcliffe DE, Cabrera ML, Vencill WK, Thompson A, Hassan S. 17-β estradiol and testosterone sorption in soil with and without poultry litter. Journal of Environmental Quality 2011;40(6):1983-1990. |
R833419 (2011) R833419 (Final) |
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Supplemental Keywords:
broiler litter, mineralization, hormones, aeration, grasslands, sorption, surface runoff, stacking, RFA, Scientific Discipline, Health, Environmental Chemistry, Endocrine Disruptors - Environmental Exposure & Risk, endocrine disruptors, Ecology and Ecosystems, Ecological Risk Assessment, Endocrine Disruptors - Human Health, CAFOs, EDCs, endocrine disrupting chemicals, animal feeding operations, concentrated animal feeding operationsProgress 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.