Persistent organic pollutants in feathers of various terrestrial and aquatic bird species: Interspecies difference and source apportionment

Feathers are regarded as important nondestructive biomonitoring tools for bird pollutants. However, external contamination of feathers by different pollutants in different bird species remains unclear. In the present study, the feathers of 16 bird species, including terrestrial, freshwater, and marine birds, were analyzed for persistent organic pollutants (POPs). Bird feathers from an abandoned e-waste recycling site had higher POP concentrations and were more correlated with the POP muscle concentrations than those from the less polluted areas. The significant and positive POP correlations between the feathers and muscles of different species indicate that feathers are a good indicator of inter-species and spatial pollution. For individual species, the most hydrophobic POPs in feathers, such as hepta- to deca-polybrominated diphenyl ethers, had higher proportions than in muscles and worse correlations with muscle POPs compared with other POPs. Results of the chemical mass balance (CMB) model revealed that the gaseous phase, internal pollution, and atmospheric particle phase were the main contributors to low-, medium-, and high-hydrophobicity POPs in feathers, respectively. Overall, this study provides a preliminary but meaningful framework for distinguishing between internal and external contamination in feathers and gives information concerning the fitness of feathers as POP indicators with specific physicochemical properties.