Occurrence and patterns of legacy and emerging per- and polyfluoroalkyl substances (PFAS) in bones of white-beaked dolphin (Lagenorhynchus albirostris) using target, suspect, and non-target screening.

Per- and polyfluoroalkyl substances (PFAS) are widespread, resistant to degradation, and bioaccumulative in food webs, raising environmental concerns due to their toxic effects. This growing concern highlights the need for effective biomonitoring for PFAS contamination, including exploration of complementary matrices, to enable long-term retrospective analyses. This study aimed to demonstrate the potential usefulness of white-beaked dolphin bones from 32 individuals stranded along the Danish coasts during the period 1981-2019 in assessing PFAS pollution in marine environments, employing target analysis and non-target screening approaches. Perfluorooctanesulfonic acid (PFOS, 28.4 ng/g) and perfluorooctanesulfonamide (FOSA, 6.3 ng/g) were the dominant PFAS, consistent with prior findings from other tissues and environmental samples in the study area. Non-target screening revealed the presence of semifluorinated n-alkanes, indicating potential transport from terrestrial PFAS sources, such as ski waxes, to marine ecosystems. Spearman rank correlations among biological factors and PFAS classes highlight complementary findings on age-related and sex-associated bioaccumulation tendencies, suggesting PFAS offload to offspring, while results of temporal analysis align with shifts in global PFAS production. This study demonstrates the first screening of dolphin bones using target and non-target analysis to assess bioaccumulation patterns of PFAS in a marine apex predator, providing baseline data on the potential of using marine mammal bones in monitoring long-term environmental pollution trends.