Work

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

Year: 2026

Type: article

Abstract: Per- and polyfluoroalkyl substances (PFASs) are widely used in diverse industrial and consumer applications. In this study, we have investigated 16 PFASs in waters along urban and suburban/rural transects of seven major rivers in southern India. PFASs have been analysed using Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). Mean ∑ 16 PFASs in river water along the urban transect (96.9±84.8 ng/L) was 7-fold higher than the suburban/rural transect (13.5±22.2 ng/L). Sources apportionment using compositional profiles, statistical models, and diagnostic ratios revealed domestic and commercial wastewater as major contributors, along with agricultural surface runoff, landfill leachate, plastic-associated chemicals, and atmospheric inputs. Overall, Short-Chain (SC) perfluoroalkyl carboxylic acids were more abundant in urban transects, while SC-perfluoroalkyl sulfonic acids were relatively higher in suburban/rural transects. This pattern suggests increasing use and environmental persistence of short-chain PFASs as replacements for long-chain compounds. Total Organic Carbon (TOC) showed stronger significant correlations (R 2 >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.

Source: Environmental Pollution

DOI: 10.1016/j.envpol.2026.128131