Persistence of Estrogenic Hormones in Agricultural Soils: I. 17β‐Estradiol and Estrone

Abstract

The persistence and pathways of dissipation of 17β‐estradiol and estrone in soil were established in laboratory microcosm incubations. [4‐¹⁴C]‐17β‐Estradiol dissipation and mineralization rates were determined over a range of temperatures and moistures, and this compound was rapidly removed in soil conditions typical of a temperate growing season. 17β‐Estradiol was oxidized to estrone in both autoclaved and nonsterile loam, silt loam, and sandy loam soils, suggesting an abiological transformation. In contrast, estrone was stable in autoclaved soil, suggesting that its removal was microbially mediated. Both [4‐¹⁴C]‐17β‐estradiol and [4‐¹⁴C]‐estrone formed non‐extractable residues, and soil‐bound residues were only slowly mineralized, suggesting that their bioavailability was low. Determination of total estrogenicity in soil extracts by means of a recombinant yeast assay indicated that there were no other estrogenic compounds produced during 17β‐estradiol dissipation, and that total estrogenicity was rapidly dissipated below the detection limit. We suggest that environmental studies evaluating the movement and persistence of estrogenic hormones from animal wastes should include estrone in their analyses.