What should we know when choosing feather, blood, egg or preen oil as biological samples for contaminants detection? A non-lethal approach to bird sampling for PCBs, OCPs, PBDEs and PFASs

Birds are considered as good bio-monitors and they can provide highly valuable data about the level of contamination in their habitat. During the design of biomonitoring studies one of the first issues after choosing species is the choice of biological material. Non-lethally collected samples have recently been gaining greater attention as they offer several ethical and practical advantages. However, not all sample matrices are suitable for biomonitoring of certain compounds. The main aim of this review is to bring to closer attention the utility of non-lethally collected samples from avian species, based on recent literature. The selected samples are feathers, blood, preen oil and eggs, as these are the types of biological materials most often chosen and may reveal birds' exposure from their diet. It is not my intention to single out one of them as the ultimate tool for organic compound analysis, but rather to present their utility in order to support or advise on future choices, as a single matrix might not be sufficient to fully evaluate birds' exposure. Therefore, this paper presents the current status of the non-lethal approach in avian species for determination of PCBs, OCPs, PBDEs and PFASs.