Chlorinated hydrocarbon residues in fish from Nove Mlyny reservoirs along Dyje river, Czech republic

The aim of this work was to monitor levels of chlorinated hydrocarbons in muscle of fish from Nove Mlyny reservoirs. Fish muscle was investigated for the content of DDT and its metabolites and polychlorinated biphenyls (Delor 106 and 7 indicator congeners of PCBs) in common carp (Cyprinus carpio, L.), bream (Abramis brama, L.) and pike perch (Stizostedion lucioperca, L.). Samples were collected and analysed by gas chromatography annually during 1995-2002. Residues of DDT and PCBs were found in all samples. The sum of DDT and its metabolites in fish muscle was determined in range of 0.001 to 0.672 mg(.)kg(-1), Delor 106 in range of 0.047 to 0.476 mg(.)kg(-1) and the sum of 7 indicator congeners of PCB in range of 0.00 1 to 0.133 mg(.)kg(-1). DDT and PCB values did not exceed valid statutory limits of the Czech Ministry of Health except for a single case. The time course of DDT values was assessed. DDT values showed a significant decrease during the monitoring period. Decrease of DDT values was 91% for pike perch and 75% for bream. Significant correlations (p < 0.05) were found between concentrations of DDT and PCB and the content of fat in fish muscle. Our results confirm predominance of metabolite DDE and higher chlorinated congeners of PCB. Results are comparable with those of other authors.