Legacy and Novel Per- and Polyfluoroalkyl Substances in Tap Water from East China: Impact from Water Sources and Risk Mitigation by Household Purifiers

The growing regulatory focus on per- and polyfluoroalkyl substances (PFAS) in drinking water raises the urgent need for comprehensive monitoring and effective removal strategies. Herein, we analyzed 81 PFAS in tap water produced from three major water bodies in East China, a global PFAS emission hub. Such systematic quantitative analyses detected 64 PFAS, representing the highest reported number to date and including 28 novel species first quantified in Chinese tap water. Owing to the inefficacy of conventional treatments, PFAS levels and compositions in tap water varied collaboratively with raw water sources and seasonal fluctuations. Consequently, any PFAS contamination in raw water directly translated into tap water, with total concentrations reaching up to 8970.3 ng/L. Source apportionment analysis identified emission sources aligned with local industrial activities, highlighting their critical role in shaping PFAS profiles in tap water. Particularly, household reverse osmosis purifiers demonstrated near-complete removal for most PFAS regardless of perfluorocarbon chain length or contamination levels. Monte Carlo simulations further validated significant reductions in health risks of PFAS in purified waters, with most cases complying with U.S. EPA limits. Our findings provide reference data on novel PFAS occurrences in tap water and offer a practical mitigation strategy to inform management efforts.