A fugacity approach for assessing the bioaccumulation of hydrophobic organic compounds from estuarine sediment

The bioavailability of four sediment-spiked hydrophobic organic contaminants (HOCs; chrysene, benzo[a]pyrene, chlordane, and Aroclor 1254) was investigated by comparing bioaccumulation by the amphipod Corophium colo with uptake into a thin film of ethylene/vinyl acetate (EVA) copolymer. The EVA thin film is a solid-phase extraction medium previously identified as effective at measuring the bioavailable contaminant fraction in sediment. The present study presents the results of I I separate treatments in which chemical uptake into EVA closely matched uptake into lipid over 10 d. For all compounds, the concentration in EVA was a good approximation for the concentration in lipid, suggesting that this medium would be an appropriate biomimetic medium for assessing the bioaccumulation of HOCs during risk assessment of contaminated sediment. For chrysene and benZo[a]pyrene, limitations on bioaccumulation and toxicity because of low aqueous solubility were observed. The fugacity of the compounds in lipid (f(lip)) and in the EVA thin film (f(EVA)) also was determined. The ratio of f(lip) to f(EVA) was greater than one for all chemicals, indicating that all chemicals biomagnified over the duration of the exposure and demonstrating the potential for EVA thin-film extraction to assess trophic transfer of HOCs.