Pesticide and PCB levels in fish from Alberta (Canada)

Pesticide and PCB analyses were completed on fat and muscle samples of 750 fish collected from 11 major lakes and rivers in Alberta. Although phenoxy and organophosphate residues were always below detectable limits, traces of chlorinated pesticides and their derivatives, particularly DDE, DDD and chlordane, were detected in most fat samples. PCB levels exceeded 25 mg/kg in the fat of several species from the North Saskatchewan River but were generally lower in the other systems. Analysis of 160 sediment samples from the North Saskatchewan River revealed no point source of PCB contamination.