Per- and Perfluoroalkyl Substances (PFAS) in Five Major Rivers in Kerala, India: A Growing Threat to Water Quality

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous chemicals widely used in industrial manufacturing and consumer goods. Their prevalence is driven by long-range atmospheric transport and global trade in products containing PFAS. In this study, rivers Periyar, Bharathapuzha, Meenachil, Pamba, and Puzhakkal are significant sources of drinking water in Kerala. River samples were collected from July to August 2024 and analyzed for 77 different target PFAS. The study found that total PFAS contamination was highest in the Periyar River, followed by Bharathapuzha, Pamba, Meenachil, and Puzhakkal. A total of 43 individual PFAS compounds were identified across the five river sites. A 100% detection frequency was observed for perfluorooctanesulfonate (PFOS), perfluorobutanesulfonate (PFBS), perfluorohexanesulfonic acid (PFHxS), and perfluorobutanesulfonate (PFBA). The highest concentration of ∑77 PFAS was found in the Periyar River (558 ng/L). The statistical analysis revealed distinct patterns in PFAS composition across different rivers, suggesting that industrial and urban effluents are significant sources of contamination in these rivers. The conventional drinking water treatment used in this area would not remove PFAS, and the resulting estimation of daily intakes suggests that PFAS may pose a health risk to the people depending on these rivers for their drinking water.