Persistence of estrogenic hormones in agricultural soils: II. 17Alpha-ethynylestradiol.

The persistence of 17alpha-ethynylestradiol in agricultural soil was established in laboratory microcosm studies. The hormone was rapidly dissipated in loam, sandy loam, and silt loam soils under a range of moisture and temperature conditions. Dissipation of 17alpha-ethynylestradiol correlated closely with removal of total estrogenicity determined with a recombinant yeast bioassay, indicating that extractable estrogenic transformation products did not accumulate. The stability of 17alpha-ethynylestradiol in sterile soil, decreased removal in the absence of oxygen, and the response of dissipation kinetics to variation in temperature and moisture suggested that the removal was microbially mediated. We conclude that 17alpha-ethynylestradiol is rapidly dissipated in agricultural soils under a range of conditions typical of a temperate growing season.