Anthracene Bioconcentration in Rainbow Trout during Single-compound and Complex-mixture Exposures

Rainbow trout were exposed for 72 h to [ 14C]anthracene alone and [ I4C]anthracene in an oil shale retort water. Tissue levels of [I4C]anthracene were analyzed at 24, 48 and 72 h to determine non-steady-state bicconcentration factors (BCFs), and uptake and depuration rates were calculated from anthracene disappearance in exposure waters and metabolite appearance in depuration waters. Uptake rates (14.6 to 16.9 h-') were similar to previously reported values; however, depuration rates (0.00158 to 0.00188 h-') were very low. Consequently, measured non-steadystate BCFs after 72 h (9,OOO to 9,200) for anthracene were higher than expected, probably because fish were not fed and had low excretion rates. Measured and estimated anthracene BCFs were lower in retort water exposures than in single-compound exposures because of slower uptake and faster depuration. We attribute slower uptake during retort water exposures to either decreased bioavailability of anthracene or rate-limiting transport of contaminants from uptake sites to storage and processing sites. Induction of mixed-function oxidases may have increased depuration from fish exposed to retort water. We conclude that bioconcentration of individual compounds from complex chemical mixtures may be difficult to predict based on single-compound kinetics. Keywords[ I4C]Anthracene Oil shale retort water Rainbow trout Uptake Depuration