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

The aim of this study was to assess polycyclic aromatic hydrocarbon (PAH) contamination of the Bilina River (Czech Republic) by measuring three PAH biliary metabolites in fish and 16 PAHs in passive samplers. Sixty-one fish were collected; the indicator species were Leuciscus cephalus (n = 25), Rutilus rutilus (n = 17) and Salmo trutta m. fario (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 of 1-OHP was found at Usti nad Labem, while the lowest median value of 27.6 ng/mg was found in the control site, Brezenec. No significant differences among the sites were found. The highest concentration of PAH was detected in Litvinov-Zaluzi (172.0 ng/L) and the lowest concentration (7.9 ng/L) was detected in Brezenec. 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 Bilina River, especially at Litvinov-Zaluzi. We confirmed 1-OHP is the most prevalent PAH biliary metabolite in fish. It 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.