Bioconcentration of polychlorinated biphenyls (PCBs) in chironomid larvae, oligochaete worms and fish from contaminated lake sediment

Abstract

Values were determined for PCB bioconcentration factors (BCFs) for fish and BSF (ratio of organism-to-sediment PCB concentration) for fish, oligochaete worms and chironomid larvae, collected in a PCB-contaminated lake in the south of Sweden. Generally, the BCF and BSF increased slightly with increasing PCB lipophilicity. This was not the case for PCBs with a log octanol/water partitioning coefficient of >7, for which the BCF and BSF values levelled off or decreased. The BSF curves for PCBs were similar for the two benthic organisms but different for fish. There was a variation in PCB domain patterns for the benthic organisms between sampling points. This could be an effect of varying bioavailability of the PCBs in the different sediment types.

Despite the similarity in BSF patterns for the benthic organisms, the PCB concentration in chironomids was about twice that in oligochaete worms. The chironomid lipids contained more than twice the amount of non-polar lipid components than did the lipids in oligochaete worms, which probably influenced the lipid/sediment equilibrium of PCB.