Organic pollutant contamination of the River Elbe as assessed by biochemical markers

The aim of the study was to assess contamination of the River Elbe basin using selected biochemical markers. Biochemical markers selected were enzymes of the first stage of xenobiotic transformation, namely cytochrome P450 (CYP 450) and ethoxyresorufin-O-deethylase (EROD). The results were correlated with the most important inducers of the enzymes, i.e. polychlorinated biphenyls (PCB) concentrations in muscle tissue of fish, polyaromatic hydrocarbons (PAH) values in bottom sediments and 1-hydroxypyrene (1-OHPY) values in fish bile (terminal metabolite of PAH, or, rather, of one of them, i.e. pyrene), which were determined during the chemical monitoring of the River Elbe basin. The indicator species selected was chub (Leuciscus cephalus L.), which was captured at ten locations in the River Elbe basin. A comparison between the EROD activity and the CYP 450 content along the longitudinal profile of the Elbe showed a significant correlation at the level of significance of p < 0.05. The highest EROD activity levels in the liver were ascertained in Zelcin (341 pmol center dot min(-1)center dot mg(-1)), Valy (263.2 pmol center dot min(-1)center dot mg(-1)) and Lysa nad Labem (179.17 pmol center dot min1 center dot mg(-1)). In Blanice (control location), EROD activity was significantly lower than in any of the other locations studied (p < 0.05). The study failed to produce an unambiguous proof of any correlations between detoxification enzyme activity (CYP 450 and EROD) in the liver and their two important inducers (PCB and PAHs). The possibility that other substances causing activation or inhibition of detoxification enzymes were in play is also discussed.