Per- and polyfluorinated alkyl substances (PFASs) represent a group of highly recalcitrant micropollutants, that continuously endanger the environment. The present work describes the geographical trends of fish contamination by individual PFASs (including new compounds, e.g., Gen-X) assessed by analyzing the muscle tissues of 5 separate freshwater fish species from 10 locations on the Czech section of the Elbe River and its largest tributary, the Vltava River. The data of this study also showed that the majority of the detected PFASs consisted of long-chain representatives (perfluorooctane sulfonate (PFOS), perfluorononanoic acid, perfluorodecanoic acid, and perfluoroundecanoic acid), whereas short-chain PFASs as well as other compounds such as Gen-X were detected in relatively small quantities. The maximum concentrations of the targeted 32 PFASs in fish were detected in the lower stretches of the Vltava and Elbe Rivers, reaching 289.9 ng/g dw, 140.5 ng/g dw, and 162.7 ng/g dw for chub, roach, and nase, respectively. Moreover, the relationships between the PFAS (PFOS) concentrations in fish muscle tissue and isotopic ratios (δ15N and δ13C) were studied to understand the effect of feed composition and position in the river continuum as a proxy for anthropogenic activity. Redundancy analysis and variation partitioning showed that the largest part of the data variability was explained by the interaction of position in the river continuum and δ15N (δ13C) of the fish. The PFAS concentrations increased downstream and were positively correlated with δ15N and negatively correlated with δ13C. A detailed study at one location also demonstrated the significant relationship between δ15N (estimated trophic position) and PFASs (PFOS) concentrations. From the tested physicochemical properties, the molecular mass and number of fluorine substituents seem to play crucial roles in PFAS bioaccumulation.

Department of Zoology Faculty of Science Charles University Viničná 7 CZ 128 44 Prague 2 Czech Republic

Institute for Environmental Studies Faculty of Science Charles University Benátská 2 CZ 128 01 Prague 2 Czech Republic

Institute of Microbiology of the Czech Academy of Sciences Vídeňská 1083 CZ 142 20 Prague 4 Czech Republic

Institute of Microbiology of the Czech Academy of Sciences Vídeňská 1083 CZ 142 20 Prague 4 Czech Republic; Institute for Environmental Studies Faculty of Science Charles University Benátská 2 CZ 128 01 Prague 2 Czech Republic

References provided by Crossref.org

A non-lethal stable isotope analysis of valued freshwater predatory fish using blood and fin tissues as alternatives to muscle tissue