Assessment of polycyclic aromatic hydrocarbon contamination of the Bílina River (Czech Republic) using passive water samplers and fish biliary metabolites

The aim of the study was to assess polycyclic aromatic hydrocarbon (PAH) contamination on the Bílina River (the Czech Republic) by measurement of three PAH biliary metabolites in fish and 16 PAHs in passive samplers. A total of sixty-one fish were collected; the indicator species were chub (Leuciscus cephalus L.; n = 25), roach (Rutilus rutilus L.; n = 17) and brown trout (Salmo trutta m. fario L.; n = 19). Three biliary PAH metabolites were measured: 1-hydroxypyrene (1-OHP), 2-naphtol, and 1-hydroxyphenanthrene, but only 1-OHP was detected in all fish. The highest median value of 32.3 ng·mg-1of 1-OHP was found at Ústí nad Labem, while the lowest median value of 27.6 ng·mg-1was found in the control site, Březenec. No significant differences (P < 0.05) among the sites were found. The highest concentration of PAH was detected in Litvínov-Záluží (172.0 ng·l-1) and the lowest concentration (7.9 ng·l-1) was detected in Březenec. A positive, but non-significant correlation (rs = 0.8) was confirmed between biliary 1-OHP and total PAH in passive samplers. These results indicate the highest pollution in the middle stretches of the Bílina River, especially at Litvínov-Záluží. We confirmed 1-OHP as the most prevalent PAH biliary metabolite in fish that could be used as a biomarker for assessment of PAH pollution of the aquatic ecosystem. The main importance of the present study is in the combination of biochemical and chemical monitoring that provides complex evaluation of aquatic environment contamination. It was the first study on the Bílina River, in which the assessment of PAH contamination in the aquatic ecosystem was realized using combination of biotic and abiotic monitoring.