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(16-10) Metabolism and genotoxicity of sediment-associated PAH in a deposit-feeding polychaete. Palmqvist, Annemette*,1, Selck, Henriette1, Forbes, Valery1, 1 Roskilde University, Roskilde, DK ABSTRACT- Polycyclic aromatic hydrocarbons (PAHs) tend to partition to and persist in sediments, where they may pose a risk to aquatic organisms. Some PAHs show mutagenic and/or carcinogenic activity, and these are of special concern since little is known about the extent to which bioaccumulation and trophic transfers of these compounds occur. Some marine invertebrates are able to metabolise high molecular weight PAHs, but rarely have the resulting metabolites been identified, and little is known about the genotoxicity of the metabolites compared to the parent compound. We investigated the genotoxicity of the PAH, fluoranthene (Flu) as well as the metabolites produced by the sediment-dwelling polychaete Capitella capitata sp. I. We exposed worms to a nominal sediment Flu concentration of 30 Key words: fluoranthene, metabolites, genotoxicity, comet assay |
g Flu/g dry wt sediment. During a 5-day exposure period and a subsequent 5-day depuration period the concentrations of 14C-labelled Flu, polar metabolites, nonpolar metabolites and tissue-bound residues were measured. Single-cell gel electrophoresis, more commonly known as the Comet Assay, was used to test for potential mutations, and even at the relatively low Flu concentration used, we saw a significant increase in DNA damage compared to the control groups, with the highest level of damage occurring after 48 hours of exposure. The overall pattern of the DNA damage over time was compared to the development in metabolite composition over time. The Flu exposure concentrations resulting in DNA damage are a factor of three or more lower than those at which effects on feeding, growth, or reproduction have been observed in this species. Ingestion and metabolism of PAH by Capitella sp. I may be important for other members of marine benthic communities in areas contaminated with these compounds.