Wednesday, November 4, 2009
Convention Center, Exhibit Hall BC, Second Floor
Presence of reproductive hormones in the environment, even in very low concentrations,has become a growing cause of concern. Land application of poultry litter, animal manures and sewage sludge as fertilizer may increase the amount of hormones in soil and lead to surface or subsurface water contamination. The degree of water contamination will depend on the amount of hormones that are adsorbed by soil, which in turn may depend on the presence of other organic compounds that could compete for adsorption sites. The objective of this study was to evaluate the effect of the organic matter present in poultry litter on testosterone and estradiol adsorption by samples from two soil depths (0-15 and 15-30 cm) in an ultisol from Georgia,USA. Adsorption isotherms were developed for C-14 labeled testosterone and H-3 labeled estradiol in a Cecil soil with and without poultry litter addition. Average linear adsorption coefficients for testosterone without litter were 18.3 mL/g for the 0-15 cm depth and 15.8 mL/g for the 15-30 cm depth. Average linear adsorption coefficients for testosterone with litter were significantly lower at 14.1 mL/g for the 0-15 cm depth and 12.0 mL/g for the 15-30 cm depth. Same trend has also been observed for estradiol. The average linear adsorption coefficients for estradiol without litter were 21.6 mL/g for the 0-15 cm depth and 15.6 mL/g for the 15-30 cm depth. The average adsorption coefficients for estradiol with litter were 19.2 mL/g for 0-15 cm and 13.5 for 15-30 cm. These results suggest that the organic matter in poultry litter may compete with testosterone and estradiol for adsorption sites, leading to less adsorption of both hormones by soil and therefore more hormone left in the soil solution.