Assessment of perfluoroalkyl substances concentration levels in wild bat guano samples

Perfluoroalkyl substances (PFASs) are substances commonly used in the production of various everyday objects, including among others kitchen dishes, cosmetics, or clothes. They penetrate to the environment and living organisms causing disturbances in the functioning of many internal organs and systems. Due to environmental pollution, wildlife is also exposed to PFASs, but the knowledge about this issue is rather limited. The aim of this study was to evaluate the exposure of wild greater mouse-eared bats (Myotis myotis), living in Poland, to six selected PFASs: five perfluoroalkyl carboxylic acids (perfluorobutanoic acid-PFBuA, perfluoropentanoic acid-PFPeA, perfluorohexanoic acid-PFHxA, perfluoroheptanoic acid-PFHpA, perfluorooctanoic acid-PFOA) and perfluorooctane sulfonic acid (PFOS) through the analysis of guano samples with liquid chromatography with tandem mass spectrometry (LC-MS-MS) method. To our knowledge this is the first study concerning the PFASs levels in bats, as well as using guano samples to evaluate the exposure of wild mammals to these substances. A total of 40 guano samples were collected from 4 bats summer (nursery) colonies located in various parts of Poland. The presence of PFASs mentioned were detected in all colonies studied, and concentration levels of these substances were sampling dependent. The highest concentration levels were observed in the case of PFPeA [1.34 and 3060 ng/g dry weight (dw)] and PFHxA (8.30-314 ng/g dw). This study confirms the exposure of wild bats to PFASs.