Biomagnification of polychlorinated biphenyls (PCBs) in freshwater fish

A total of 19 PCB congeners were determined in muscle of 2 European roach (Rutilus rutilus) and in muscle and liver of 3 pike (Esox lucius) of a small rural lake in the southern Black Forest (Germany) to examine the biomagnification in freshwater fish. The lake is known for a relatively high PCB contamination of its sediments due to past local emissions. The presence of a structure dependent biomagnification in these freshwater fish of two different trophical levels is confirmed. The relative contents of PCB congeners with vicinal H-atoms in m,p- and to a lesser extent, o,m-positions become smaller from roach to pike indicating a stronger induction of PCB metabolizing isoenzymes in the predatory fish. This could also be shown by application of the metabolic slope concept.