The aim of our study was to assess the occurrence and to determine the concentrations of organochlorine pesticides and indicator PCB congeners in muscle tissue of freshwater fish species and, additionally, in sediments collected from three sampling sites of the Vistula River in the vicinity of Cracow. The determinations of HCH isomers, HCB, DDTs (p,p'-DDE, p,p'-DDD, o,p'-DDT and p,p'-DDT), and six indicator PCB congeners (28, 52, 101, 138, 153, and 180) were carried out in 52 fish samples and 35 sediments samples using capillary gas chromatography.
The mean concentration of DDTs in fish was 281 μg/kg wet weight (11.8-1921 μg/kg) and PCBs 83 μg/kg wet weight (10.5-790 μg/kg). The highest levels of contaminants were detected in the muscles of bream. The high levels of DDT and its metabolites, exceeding the PEL values (probable effect levels) were also detected in sediments (mean 270 μg/kg dry weight, range 12.9-927 μg/kg). In fish and sediments from Cracow and downstream from Cracow the levels of DDTs were higher than upstream of the Vistula River. The levels of contaminants remain of concern due to the potential risk to fish consumers and the ecological risk they pose, and indicate a need for a continuous monitoring.