T10 PM Advances in Bioaccumulation Assessment
Tuesday, 15 November 2005: 1:50 PM - 5:30 PM in 341-342

(MCE-1117-774861) Influence of metabolism on organic contaminant bioaccumulation–How should we be addressing this?

McElroy, A¹, Rust, A¹, Brownawell, B¹, ¹ Stony Brook University, Stony Brook, NY, USA

ABSTRACT- It is well known that many sediment-associated contaminants are bioavailable to benthic organisms, and that some of these contaminants can be transferred through aquatic food chains, thus posing both ecological and human health risks. Early efforts to predict bioaccumulation based on octanol water partitioning behavior, sediment organic carbon, and organism lipid provide a good first approximation for potential bioaccumulation , but recent work has pointed out the important influence of factors such as soot (or black) carbon, and gut surfactancy in influencing bioavailability. Another often overlooked process is the role of in vivo metabolism of target chemical in affecting observed bioaccumulated levels. We have shown highly species-specific rates of PAH metabolism that are inversely correlated with biota sediment bioaccumulation factors in benthic invertebrates. Further, we have shown that PAH metabolites in tissues are available for food chain transfer to aquatic consumers. The influence of metabolism should be taken into account in the choice of species used for bioaccumulation tests, and in predicting the fate and risk of bioavailable contaminants. Future needs in this area should include development of paradigms to predict metabolic susceptibility of contaminants, indices of metabolic competence in guilds of exposed organisms, methods for directly measuring metabolite body burdens in infaunal and consumer organisms, and an assessment of the toxicological significance of metabolites.

Key words: bioaccumulation, metabolism, PAHs, invertebrates