FIRST HISTOPATHOLOGICAL OBSERVATIONS IN PFAS EXPOSED WORKERS AND DRONES OF APIS MELLIFERA

Per- and Polyfluoroalkyl substances (PFAS) are a broad class of fluorinated synthetic compounds whose carbon–fluorine backbone makes them highly resistant to degradation, leading to long persistence in environmental and biological systems. Exposure to PFAS has been found to affect survival, reproduction, growth, and behaviour of a wide range of animals. Particularly, PFAS can directly affect the endocrine and the reproductive system impairing metabolism and fertility, and alter the regulation of different set of genes affecting the immune system. To date very little is known on the impacts of PFAS on Apis mellifera health, particularly with regard to tissue alterations. In this preliminary study, honey bee workers and drones that survived to PFAS exposure (PFOA, PFOS and PFBA), in an acute oral toxicity test conducted at the IZSVe insectary in August 2025 were analysed by routine histological techniques. Microscopic examination of workers challenged with PFAS revealed a high number of fat-body associated oenocytes presenting accumulation of brown-yellowish granules in their cytoplasm (PFOS 83, 21%; PFOA 78%; PFBA 97,65%) and degeneration of the fat-body, probably due to detoxification attempts. In drones, histological findings included degeneration and increased spaces between the testes seminiferous tubules, confirming targeting of PFAS on the reproductive system also in Apis mellifera. Although based on a limited number of samples, our findings pave the way to further investigations on the possible ecopathological impacts of PFAS on the health of Apis mellifera.