Skin sampling as a proxy for screening per- and polyfluoroalkyl substances (PFAS) exposures in endangered sea turtles

Per- and polyfluoroalkyl substances (PFAS) are widespread in the environment, including the ocean. However, information on PFAS exposures in protected and endangered sea turtle species is scarce because sampling liver or blood is invasive and challenging. We assessed, for the first time, whether skin tissue, which is less invasive to collect, can be used to screen for PFAS in sea turtles. We measured concentrations of 20 PFAS in the skin and serum from deceased juvenile green turtles. Perfluorooctane sulfonic acid (PFOS) was the predominant PFAS and was detected in most of the skin (85 %) and serum (100 %). For individuals with paired skin and serum, PFOS concentrations were not significantly different, and thus suggest that skin samples have promising use for screening PFAS in sea turtles. This method may be adapted and optimized in the future to increase data coverage and improve our understanding of sea turtle exposures to PFAS.