Biomonitoring of PAH pollution in high-altitude mountain lakes through the analysis of fish bile

Polycyclic aromatic hydrocarbon (PAH) exposure of fish in high-altitude mountain lakes was assessed by measuring bile PAH metabolites. Trout were caught in several regions in Europe, and hydrolyzed bile samples were analyzed by (a) HPLC fluorescence at the excitation/ emission wavelength pairs of naphthol (290/335 nm) and pyrenol (345/395 nm) and (b) gas chromatography-mass spectrometry (GC-MS) for the determination of individual PAHs. The obtained results showed a good correlation between both detection techniques and showed the usefulness of the first one as a screening method. Quantitative differences among lakes were recorded; biliary levels of hydroxylated PAHs ranged from 69 ng/mL bile in trouts from Redó Lake (Spanish Pyrenees) to 990 ng/mL bile in those sampled in Bedøichov Lake (Czech Jizera Mountains). Qualitative differences were also evident, e.g., 1-pyrenol represented 76% of PAH metabolites detected in trouts from Gossenköllesee Lake (Austrian Alps) whereas it was undetected in fish from Redó Lake. The obtained results confirm the long-range transport of PAHs to mountain lakes and subsequent exposure of organisms inhabiting those lakes.