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Dissipation and transformation of 17β-estradiol-17-sulfate in soil-water systems

Author:
Bai, Xuelian, Casey, Francis X. M., Hakk, Heldur, DeSutter, Thomas M., Oduor, Peter G., Khan, Eakalak
Source:
Journal of hazardous materials 2013 v.260 pp. 733
ISSN:
0304-3894
Subject:
agricultural soils, animal manures, biodegradation, carbon, conjugated estrogens, environmental fate, estrone, half life, hydroxylation, oxidation, runoff, soil organic carbon, soil water, subsurface soil layers, topsoil
Abstract:
In the environment, estrogen conjugates can be precursors to the endocrine-disrupting free estrogens, 17-estradiol (E2) and estrone (E1). Compared to other estrogen conjugates, 17-estradiol-17-sulfate (E2-17S) is detected at relatively high concentrations and frequencies in animal manure and surface runoff from fields receiving manure. To elucidate the lifecycle of manure-borne estrogens and their conjugates in the environment, the fate of radiolabelled E2-17S in agricultural soils was investigated using laboratory batch studies with soils of different organic carbon (OC) content (1.29% for topsoil versus 0.26% for subsoil). E2-17S was found relatively persistent in the aqueous phase throughout the duration of the 14 d experiment. The aqueous E2-17S persisted longer in the subsoil (half-lives (DT50) = 64–173 h) than the topsoil (DT50 = 4.9–26 h), and the aqueous persistence of E2-17S depended on its initial concentration. The major transformation pathway was hydroxylation, yielding mono- and di-hydroxy-E2-17S (OH-E2-17S and diOH-E2-17S). Free estrogens, E2 and E1, were only observed in the sorbed phase of the soil at low concentrations (∼1% of applied dose), which demonstrated that deconjugation and subsequent oxidation had occurred. Although deconjugation was not a major pathway, E2-17S could be a precursor of free estrogens in the environment.
Agid:
59342
Handle:
10113/59342