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United States Department of Agriculture

Agricultural Research Service

Research Project: WATER QUALITY IMPROVEMENT FROM MANAGEMENT PRACTICES IN AGRICULTURAL WATERSHEDS Title: Fate and Bioavailability of Sulfamethazine in Freshwater Ecosystems

Authors
item Henderson, Keri - IA STATE UNIVERSITY
item Moorman, Thomas
item Coats, Joel - IA STATE UNIVERSITY

Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: January 12, 2009
Publication Date: December 20, 2009
Citation: Henderson, K.L., Moorman, T.B., Coats, J.R. 2009. Fate and Bioavailability of Sulfamethazine in Freshwater Ecosystems. American Chemical Society Symposium Series. 1018:121-131.

Interpretive Summary: The antibiotic sulfamethazine (SMZ) is widely used in swine production and can be transported from manured fields to surface water bodies. We investigated the degradation, fate, and bioavailability of sulfamethazine in microcosms designed to simulate farm ponds. Pond sediment was collected and placed in jars and covered with pond water. Sulfamthazine was added to the water and measured in water and sediment over 63 days. Sulfamethazine dissipated rapidly in the water, with the majority of sulfamethazine moving into the sediment. Sediment-bound sulfamethazine accounted for 40 to 60% of the total added antibiotic. The bioavailability of sulfamethazine in these microcosms was evaluated using the aquatic worm, Lumbriculus variegatus. The worms were incubated in treated water for several timepoints. At the end of the study, worms were extracted and uptake of sulfamethazine was determined. Bioconcentration factors during the exposure were similar to that of persistent hydrophobic contaminants such as polycyclic aromatic hydrocarbons. Our results indicate the need for further assessment of the bioaccumulation potential of SMZ residues as a result of sediment exposure of benthic invertebrates. This basic research is of interest to environmental scientists and engineers seeking to understand the impact of pharmaceuticals in our national water supplies.

Technical Abstract: The antibiotic sulfamethazine can be transported from manured fields to surface water bodies. We investigated the degradation, fate, and bioavailability of sulfamethazine in surface water using 14C-phenyl-sulfamethazine in small pond water microcosms. Sulfamethazine dissipated exponentially from the water column, with the majority of loss occurring via movement into the sediment phase. Sulfamethazine was transformed mainly into non-extractable sediment-bound residue (40 to 60% of applied radioactivity) Manure input significantly increased sorption and binding of sulfamethazine residues to the sediment. These results indicate sediment is a potential sink for sulfamethazine and sulfamethazine-related residues, having important implications for benthic organisms. Understanding the bioavailability of pharmaceuticals in environmental matrices is particularly important considering they are often in an active form. The bioavailability of sulfamethazine in surface water microcosms was evaluated using Lumbriculus variegatus in a bioassay. The worms were incubated in treated water for several timepoints. At the end of the study, worms were extracted and uptake of radioactivity was determined. Bioconcentration factors (BCFs) were calculated, and a significant inverse relationship between exposure concentration and BCF was observed with log BCF of 2.17 at 0.05 mg/l during aquatic exposure, which is on the order of persistent hydrophobic contaminants such as polycyclic aromatic hydrocarbons. Our results indicate the need for further assessment of the bioaccumulation potential of SMZ residues as a result of sediment exposure of benthic invertebrates.

Last Modified: 11/20/2014
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