title: Sorption and mineral-promoted transformation of synthetic hormone growth promoters in soil systems.
abstract: This work examines the fate of synthetic growth promoters (trenbolone acetate, melengestrol acetate, and zeranol) in sterilized soil systems, focusing on their sorption to organic matter and propensity for mineral-promoted reactions. In organic-rich soil matrices (e.g., Pahokee Peat), the extent and reversibility of sorption did not generally correlate with compound hydrophobicity (e.g., K(ow) values), suggesting that specific binding interactions (e.g., potentially hydrogen bonding through C17 hydroxyl groups for the trenbolone and melengestrol families) can also contribute to uptake. In soils with lower organic carbon contents (1-5.9% OC), evidence supports sorption occurring in parallel with surface reaction on inorganic mineral phases. Subsequent experiments with pure mineral phases representative of those naturally abundant in soil (e.g., iron, silica, and manganese oxides) suggest that growth promoters are prone to mineral-promoted oxidation, hydrolysis, and/or nucleophilic (e.g., H2O or OH(-)) addition reactions. Although reaction products remain unidentified, this study shows that synthetic growth promoters can undergo abiotic transformation in soil systems, a previously unidentified fate pathway with implications for their persistence and ecosystem effects in the subsurface.
authors.affiliation: Department of Civil and Environmental Engineering, University of Iowa , 4105 Seamans Center, Iowa City, Iowa 52242, United States.
authors.forename: Shen
authors.initials: S
authors.lastname: Qu
authors.forename: Edward P
authors.initials: EP
authors.lastname: Kolodziej
authors.forename: David M
authors.initials: DM
authors.lastname: Cwiertny
mesh_terms: D000327:Adsorption; D013006:Growth Hormone / Q000138:chemical synthesis / Q000737:chemistry*; D007700:Kinetics; D008552:Melengestrol Acetate / Q000737:chemistry; D008903:Minerals / Q000737:chemistry*; D010084:Oxidation-Reduction; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000138:chemical synthesis / Q000737:chemistry*; D014204:Trenbolone Acetate / Q000737:chemistry; D015029:Zeranol / Q000737:chemistry
chemical_list: D008903:Minerals; D012987:Soil; D012989:Soil Pollutants; D008552:Melengestrol Acetate; D015029:Zeranol; D013006:Growth Hormone; D014204:Trenbolone Acetate
keywords: adsorption; animal agriculture; endocrine disruptors; environmental fate; transformation products