Occurrence of Perfluorooctane Sulfonate and Other Perfluorinated Alkylated Substances in Harbor Porpoises from the Black Sea

Perfluorooctane sulfonate (PFOS) and other perfluorinated
alkylated substances (PFAS) were determined in liver,
kidney, muscle, brain, and blubber samples of 31 harbor
porpoises (Phocoena phocoena relicta) of different age and
sex stranded along the Ukrainian coast of the Black
Sea. In all individuals and in all tissues, PFOS was the
predominant PFAS, accounting for on average 90% of the
measured PFAS load. PFOS concentrations were the
highest in liver (327 ± 351 ng/g wet wt) and kidney (147
± 262 ng/g wet wt) tissue, and lower in blubber (18 ± 8 ng/g
wet wt), muscle (41 ± 50 ng/g wet wt), and brain (24 ±
23 ng/g wet wt). No significant differences could be determined
between males and females, nor between juvenile and
adult animals (p > 0.05). Perfluorononanoic acid,
perfluorodecanoic acid, perfluoroundecanoic acid, and
perfluorododecanoic acid could be detected in liver tissue
of approximately 25% of the individuals. Perfluorobutane
sulfonate, perfluorobutanoic acid, and perfluorooctanoic acid
were not detected in any of the porpoise livers. Although
we investigated a potential intraspecies segregation
according to the source of prey, using stable isotopes, no
statistically significant correlation between PFOS concentrations and stable isotopes could be determined. It is,
however, noteworthy that the contamination by PFOS in
the Black Sea harbor porpoises is comparable to levels
found in porpoises from the German Baltic Sea and from
coastal areas near Denmark and, therefore, might pose
a threat to this population.