Analysis of Perfluoroalkyl Acids in Swedish Biota  : Temporal trends, tissue distribution and toxicity

Abstract: Perfluorinated alkyl acids (PFAS) are ubiquitous environmental contaminants. They are found in high concentrations in top predators worldwide, with perfluorooctane sulfonate (PFOS) as the predominant compound. Due to concerns regarding toxicity and persistence of PFOS, this compound was included in the Stockholm convention of persistent organic pollutants in 2009.PFAS differ from other persistent organic pollutants in their physicochemical properties and as a result their environmental fate is insufficiently understood. The focus of this thesis was to learn more on the environmental fate of PFAS by analysis of 15 different PFAS in Swedish biota. Analytes included perfluorinated carboxylates (PFCAs; carbon chain lengths C6-C15), perfluorinated sulfonates (PFSAs; C4, C6, C8, C10), and perfluorooctane sulfonamide (PFOSA).Elevated concentrations of PFAS were found in the marine, terrestrial and limnic Swedish environment, exemplified by Baltic common guillemot (Uria aalge), peregrine falcon (Falco peregrinus), and the amphipod Monoporeia affinis. PFOS was the predominant PFAS in the species. Analysis of archived material showed that PFOS concentration had increased 30-fold in guillemot eggs since 1968. PFOS concentration in peregrine falcon eggs had increased from 1974 to the mid 1980s and then leveled off, while PFCA in the falcon eggs showed an exponential increase until recent years. The relation between PFAS concentrations in egg and in tissue from adult guillemot showed that PFAS had different potentials for transfer to the egg, depending on chain length and functional group.The toxicological implications of PFAS pollution in the Swedish environment are not known but the high concentrations of PFOS in the Baltic guillemot eggs are of concern. Recent toxicological studies show toxic effects of PFOS in concentrations close to, or below the concentrations reported in this thesis. The margins of safety seem to be higher for the PFCAs, although toxicity data are scarce.