Per- and polyfluoroalkyl substances (PFASs) in rivers of southern India: Spatial distribution, sources, health and ecotoxicological risks

>0.8; p<0.01) with SC-PFASs due to weaker sorption affinity for particulate matter and higher solubility over Long-Chain (LC) PFASs. A low ecotoxicological risk from exposure to PFOA, PFDA, and PFOS was observed for daphnids and PFOA for mysids at selected sites. Furthermore, PFOS concentrations exceeded the European Union Water Framework Directive (EU WFD) Environmental Quality Standard (EQS) for inland surface waters (0.65 ng/L) for over 80% sites in the urban transect and approximately 50% of sites in suburban/rural transects, indicating potential concern for aquatic ecosystem in urban-influenced areas. Human risk quotients (RQ<1) indicate low risk, but chronic exposure may accumulate.