Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/6/2007
Publication Date: 3/10/2007
Citation: Accinelli, C., Koskinen, W.C., Becker, J.M., Sadowsky, M.J. 2007. Environmental fate of two sulfonamide antimicrobial agents in soil. Journal of Agricultural and Food Chemistry. 55:2677-2682. Interpretive Summary: Veterinary antimicrobial chemicals have been detected in a number of environmental samples, including agricultural soils. In this study, the persistence and sorption of two sulfonamide antimicrobials, sulfamethazine (SMZ) and sulfachloropyridine (SCP), in soil and their potential effects on soil microorganisms were investigated. Faster dissipation was observed in a silt loam soil as compared to a sandy soil. When liquid swine manure slurry was added to the soils, the sulfonamides degraded faster; the manure likely stimulated microbial activity resulting in greater degradation. SMZ and SPC had no effects on soil microorganisms. Results from these laboratory investigations indicate that because the two sulfonamides, SMZ and SPC, had no potential to persist in a silt loam and sandy soils and had no effect on the soil microbial community, further environmental research on veterinary antimicorbial chemicals should focus on more persistent chemicals. This research will help scientists to focus on chemicals that are more persistent and have a greater potential for adverse environmental effects.
Technical Abstract: Veterinary antimicrobials have been detected in a number of environmental samples, including agricultural soils. In this study, the persistence and sorption of the sulfonamide sulfamethazine (SMZ) and sulfachloropyridine (SCP) in soil and their potential effects on soil microorganisms were investigated. More sulfonamides dissipated from a silt loam than a sandy soil. Average half-lives of SMZ and SPC among the two soils were of 18.6 and 21.3, respectively. Presence of 5% (v/w) of liquid swine slurry (LSS) led to a decrease of sulfonamide persistence in both soils. Lower persistence in LSS-amended soils was likely due to the higher microbial activity than in unammended soils and/or to the greater bioavailability, as estimated by sorption isotherms. Concentrations of SMZ and SPC up to 100 µg/g had no effects on antimicrobials degradation rates and soil microorganisms. These studies suggest that higher sulfonamide concentrations would be eventually necessary to affect the main processes ruling their environmental fate in soil.