| Abstract: | Investigations were made of 212 fish samples of eight fish species from 29 lakes of the Schwerin county. Determinations were made gas-chromatographically after chemical derivatization. In lakes with a low anthropogenic load the following concentrations were found: 0.05 mg/kg DDT, 0.03 mg/kg PCB. In lakes with higher pollution, the concentrations were 0.21 mg/kg DDT and 0.42 mg/kg PCB. The limit of tolerance for foodstuffs was never exceeded and predatory fish did not show higher concentrations than non-predacious fish. For ten eels, however, the mean contents were 1.6 mg/kg DDT and 0.36 mg/kg PCB. The total content of DDT in all fishes was composed as follows: 70 … 75% p,p′-DDE, 15 … 20% p,p′-DDD and 5 … 10% p,p′-DDT. Trout from an intensive-breeding plant contained 0.16 mg/kg DDT and 0.04 mg/kg PCB from the contaminated feed. By means of a change-over to different feed the contents were reduced to 0.03 mg/kg DDT and 0.04 mg/kg PCB. |
