Microplastics as carriers of per- and polyfluoroalkyl substances (PFAS) in aquatic environment: interactions and ecotoxicological effects

MPs act as carriers of organic pollutants, including per- and polyfluoroalkyl substances (PFASs) in aquatic environments and exhibit harmful effects on organisms. Although there has been extensive research on the abundance and distribution MPs and PFASs individually, their co-occurrence and combined ecotoxicological effects have been poorly understood. In this context, the present review aims to present an up-to-date understanding of PFAS sorption onto MPs and their bioaccumulation in different organisms. The combined sources and prevalence of MPs and PFASs are summarized, with some daily-use products identified as important sources of both pollutants. MPs occurrence indicates considerable diversity in their levels, with concentrations ranging from 0-7 particles/m3 (air), 1-4712 particles/kg (soil), 1-26 particles/L (aquatic matrices), and 0-199 particles/organism (species) worldwide. Further, the literature survey provides evidence of PFAS concentrations ranging from < 0.0011 to 95.378 ng/m3 in the air, 6.90 to 294000 ng/kg in soil, 4 to 268 ng/L in aquatic environments, and 0.0014 to 796 ng/g in species. Additionally, the review investigates MPs-PFAS interaction in the aquatic system, thereby highlighting the factors that influence PFAS sorption onto MPs. Various mechanisms of PFAS sorption onto MPs have been examined and compared. Moreover, the review covers the ecological consequences of ingesting PFAS-contaminated MPs and their synergistic effects on aquatic biota. Conclusively, more research is needed to evaluate the combined exposure to MPs and PFAS, particularly under environmentally relevant concentrations to understand the significance of MPs as a vector for emerging contaminants in the environment.