Chlorinated insecticide and PCB residues in fish and mussels of east coastal waters of the middle and north Adriatic Sea, 1974--75.

Concentrations of chlorinated pesticides and polychlorinated biphenyls (PCBs) were determined in mussels (Mytilus galloprovincialis) and goby fish (Gibius sp.) collected in four areas located in eastern coastal waters of the middle and north Adriatic Sea. Most samples were collected in early spring and late summer of 1974 and 1975. The compounds p,p'-DDT, p,p'-DDE, p,p'-TDE, and PCBs were detected most frequently. In about 60 percent of the samples dieldrin was also detected. Average wet-weight concentrations of sigmaDDT and PCBs in mussels from the four areas sampled were: Istrian coast, 65 and 76 ppb; Rijeka Bay, 58 and 75 ppb; Zadar, 36 and 128 ppb; Losinj Island, 167 and 133 ppb. Average concentrations in fish samples were: Istrian coast, 124 and 144 ppb; Rijeka Bay, 37 and 82 ppb; Losinj Island, 166 and 157 ppb. Dieldrin concentrations were in the low ppb range. Although major Italian rivers discharge chlorinated hydrocarbons into the north Adriatic, sampling of biota from Istrian coastal waters indicates no significant effect on the pollution level. However, waste waters from small coastal settlements evidently do contribute significantly to chlorinated hydrocarbon contamination of that ocean. Marine samples from Losinj Island had high chlorinated hydrocarbon concentrations, indicating uptake of pollutants from the north Adriatic.