Per- and polyfluoroalkyl substances (PFAS) in little penguins and associations with urbanisation and health parameters

Abstract

Per- and Polyfluoroalkyl substances (PFAS) are increasingly detected in wildlife and present concerning and unknown health risks. While there is a growing body of literature describing PFAS in seabird species, knowledge from temperate Southern Hemisphere regions is lacking. Little penguins (Eudyptula minor) can nest and forage within heavily urbanised coastal environments and hence may be at risk of exposure to pollutants. We analysed scat contaminated nesting soils (n = 50) from 17 colonies in lutruwita/Tasmania for 16 PFAS, plasma samples (n = 45) from nine colonies, and three eggs for 49 PFAS. We detected 14 PFAS across the sample types, with perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) most commonly detected. Mean concentration of PFOS in plasma was 2.56 ± 4.3 ng/mL (<LOD-22.3), soil was 2.92 ± 5.39 μg/kg (<LOD-29.8) and eggs were 11.89 ± 11.30 μg/kg (0.27-22.84). Mean concentration of PFHxS in plasma was 0.9 ± 0.84 ng/mL (<LOD-5.6), soil was 11.4 ± 39.18 μg/kg (<LOD-213.3) and eggs were 0.27 ± 0.11 μg/kg (<LOD-0.38). Urbanisation of breeding sites was positively associated with PFOS and PFHxS concentrations in soils and blood. Phenology appeared to be an important predictor of PFHxS load, with moulting birds having lower levels compared to non-moulting birds. We investigated PFAS associations with health parameters and found that haematocrit and total plasma proteins in females were negatively associated with PFOS and positively associated in males. The number of erythrocytic nuclear abnormalities in males was positively associated with PFOS. Findings are the first to document the presence of PFAS in this resident seabird nesting and foraging close to anthropogenically modified habitats. We demonstrate that even in low concentrations, PFAS may have detectable relationships with penguin health. Ongoing research is needed to investigate foraging ecology and trophic bioaccumulation pathways, as well as understand sublethal consequences from exposure.

Keywords: Ecotoxicology; Genotoxicity; Human impacts; Seabird sentinels; Wildlife health.