Pygoscelis penguins as indicators of perfluoroalkyl substances pollution and global health risks - case study from King George Island (Western Antarctic).

Rapid warming in the Antarctic Peninsula not only affects ecosystem structure and species distributions but may also alter the transport, bioavailability, and effects of persistent pollutants - heightening the urgency of understanding contaminant dynamics in this vulnerable region. Per- and polyfluoroalkyl substances (PFAS) are globally recognized persistent organic pollutants, yet their occurrence in Antarctic biota remains poorly constrained. We quantified 15 PFAS in feathers, eggshells and guano of Pygoscelis penguins collected at three colonies on King George Island (2021-2022). Most analytes were < LOQ; only perfluorooctane sulfonate (PFOS) and perfluoropentane sulfonate (PFPeS) were detected, at 2.14-2.74 ng/g dw in guano. Crucially, all positive PFAS detections were observed in samples collected from a penguin colony situated in the inner part of Admiralty Bay, an area hosting active operations of five national Antarctic programs, whereas samples from a colony located near the entrance to the bay, at Patelnia Point, contained no detectable PFAS. Given the rapid environmental change and increasing human presence in parts of Antarctica, understanding both local and broader-scale sources of chemical exposure in top predators such as penguins is vital. Our results highlight that even low-background polar ecosystems can exhibit sharply elevated PFAS levels in the immediate vicinity of human infrastructure. Continued monitoring and strict pollution-control measures are therefore essential to safeguard Antarctic biodiversity.