Distribution of perfluoroalkyl compounds and mercury in fish liver from high-mountain lakes in France originating from atmospheric deposition

Abstract : Perfluoroalkyl compounds (PFCs) and total mercury (THg) were investigated in fish liver collected from four high-mountain lakes in the French alps in which the water was fed only by atmospheric deposition. Concentrations of various PFCs, including C9-C15 perfluoroalkyl carboxylates (PFCAs) and perfluorooctane sulfonate (PFOS) were quantified. The PFOS concentration was similar in all high-mountain lakes with mean concentrations ranging from 3.61-4.24 ng g-1 wet weight (ww) indicating homogeneous atmospheric deposition. Conversely, the spatial distribution of PFCAs and THg was strongly influenced from a different emission source, which is probably the city of Grenoble, which resulted in significantly higher concentration levels of ∑PFCAs in three lakes (P < 0.001) and of THg in two lakes (P < 0.05) located easterly from Grenoble. Furthermore, the positive correlation between PFCAs and THg suggest similar transport and bioaccumulation pathways. The contribution of the longer chain PFCAs decreased with increasing distance from the local source area of Grenoble, which could be attributed to their less pronounced transport potential. Results from this study demonstrate that the contamination of PFCs and THg in the fish of the high-mountain lakes originated from atmospheric deposition and subsequent bioaccumulation.