Per- and polyfluoroalkyl substances in plasma and feathers of nestling birds of prey from northern Norway

Plasma samples from nestlings of two top predators, White-tailed eagle (Haliaeetus albicilla) and Northern goshawk (Accipiter gentilis) from northern Norway were analysed for a wide range of per- and polyfluoroalkyl substances (PFASs). Body feathers from the White-tailed eagles were also analysed and significant associations between specific PFASs in blood plasma and body feathers were found (0.36 < R-2 < 0.67; all p < 0.05). This result suggests that analysing body feathers of White-tailed eagle could potentially be a useful non-invasive strategy to monitor PFASs exposure in nestlings of this species. White-tailed eagles showed significantly higher levels of contaminants than Northern goshawks (plasma EPFASs Median = 45.83 vs 17.02 ng(-1), p < 0.05). The different exposure between both species seemed to be related to different dietary input, as quantified by stable carbon and nitrogen isotope analysis of body feathers. A priori, the bird of prey populations studied are not at risk for PFASs, since the levels in plasma of both species were hundreds to thousand times lower than the toxic reference values reported for predatory birds. However, further studies on larger sample sizes are needed to confirm this hypothesis since toxic thresholds for nestling birds of prey are not established.