Occurrence and health risk assessment of per- and Polyfluoroalkyl Substances (PFAS) in household tap water in Ho Chi Minh City, Vietnam

ABSTRACT

Diagram showing PFAS occurrence in tap water in Ho Chi Minh City and their contribution to cumulative human health risk, with PFOS, PFOA, and PFBS identified as dominant contributors.

Per- and polyfluoroalkyl substances (PFAS) are persistent and bioaccumulative contaminants of emerging concern in drinking water, posing potential risks to human health. This study evaluated the occurrence, concentration levels, and health risks of 12 PFAS compounds in household tap water from 24 districts in Ho Chi Minh City (HCMC), Vietnam, along with influent water from three major water supply plants. Between May and August 2022, a total of 72 tap water and 12 influent samples were collected and analyzed using solid-phase extraction and UPLC-MS/MS. Eight PFAS compounds were detected, with PFOS, PFBS, and PFOA found in all tap water samples. Total PFAS concentrations ranged from 0.74 to 6.01 ng/L (mean: 1.79 ± 1.41 ng/L). In several cases, treated water showed higher PFAS levels than influent water, suggesting contamination during treatment or distribution. Estimated daily intake (EDI) and hazard index (HI) calculations indicated PFOS as the dominant contributor to health risk, though HI values were below 1. Descriptive HQi-based contribution analysis identified PFBS, PFOS, and PFOA as the major contributors to cumulative non-carcinogenic risk. This study emphasizes the need for continued monitoring, regulatory action, and improved treatment processes to reduce PFAS exposure through tap water in urban environments.