Temporal trends and spatial differences of perfluoroalkylated substances in livers of harbor porpoise (Phocoena phocoena) populations from Northern Europe, 1991-2008

Long-term temporal trends (1991–2008) and spatial differences of perfluoroalkylated substances (PFASs)
were investigated in harbor porpoise (Phocoena phocoena) liver samples of juvenile females from the Baltic
and North Sea. Additionally, spatial differences between the populations in the Baltic Sea and Atlantic
Ocean (i.e. Iceland and Norway) and the influence of the body mass, age and sex on the PFAS concentrations
were examined. Perfluorooctane sulfonate (PFOS) was the predominant compound with a concentration
range of 160–2425 ng/g wet weight (ww), followed by perfluorooctane sulfonamide (PFOSA, 1–237 ng/g
ww) and perfluoroundecanoate (PFUnA, 3–124 ng/g ww). In terms of temporal trends, perfluoroalkyl sulfonates
(PFSAs) and PFOSA concentrations decreased over time, while, conversely, the C9–C13 perfluoroalkyl
carboxylate (PFCA) concentrations increased. Spatial distribution of the contaminant concentrations showed
consistently higher concentrations in the Baltic Sea and lowest concentrations in the Icelandic population of
the Atlantic Ocean.