PM05 Aquatic Vertebrate/Invertebrate Toxicology
Exhibit Hall
8:00 AM - Monday, 10 November 2003
(PM081) Trinitrotoluene transfer from water and food sources to channel catfish (Ictalurus punctatus).
Ownby, D1, Lotufo, G2, Lydy, M1, 1 Southern Illinois University Carbondale, Carbondale, IL, USA2 U.S. Army Corps of Engineers Research and Development Center, Vicksburg, MS, USA
ABSTRACT- The toxicokinetics of explosive compounds, including trinitrotoluene (TNT), in aquatic organisms is poorly understood. Channel catfish are an ideal species for evaluating the transfer and metabolism of TNT, since they are exposed to compounds via dermal contact with sediment, eating contaminated prey items, and water borne exposure. In the present study, juvenile channel catfish (1.0-3.0 g) were exposed to 14C-labeled TNT via either water or feed. Water uptake, feeding, and organ distribution experiments have been performed. Uptake and elimination models from aqueous exposures yield fast uptake and transformation of TNT to its breakdown metabolites (2-amino-4,6-dinitotoluene, 4-amino-2,6-dinitotoluene, 2,4-diamino-6-nitrotoluene and 2,6-diamino-4-nitrotoluene). Feeding experiments show incorporation of radiolabeled compound into the organism. Fast metabolism of TNT suggests that any potential toxic effects at environmental concentrations would likely come from metabolites. Organ distribution experiments showed similar trends to previous fathead minnow studies, with the majority of the radiolabeld material residing in the internal organs.
Key words: trophic transfer, trinitrotoluene,, bioaccumulation, Ictalurus punctatus