Perfluoroalkyl and polyfluoroalkyl (PFAS) in tap water in the southern key economic region

Abstract

Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) are durable, artificial chemicals used widely in household products. Over time, they accumulate in the environment - contaminating water sources, air, and drinking water and pose potential health risks. This study investigates PFAS concentrations in tap water from Vietnam's Southern Key Economic Region (SKER), including Binh Duong, Long An, Tien Giang, Dong Nai, Ba Ria - Vung Tau, Binh Phuoc, Tay Ninh, and Ho Chi Minh City. Between May and August 2022, researchers collected 24 tap water samples from households and analyzed them using solid - phase extraction and UPLC - MS/MS. The analysis revealed that PFAS were detected in 21 out of 24 samples, with the number of compounds identified per sample varying between zero and six and an average of five. Among them, PFOS was the most frequently detected, appearing in 87.5% of the samples. Six compounds - PFHxA, PFHpA, PFOA, PFDA, PFBS, and PFOS – co - occurred in 4.2% of samples. Total PFAS concentrations ranged from undetectable levels to 6.83 ng/L, with an average of 1.12 ± 1.42 ng/L. The most prominent compounds - PFBS, PFOS, and PFOA - accounted for 36.4%, 26.6%, and 15.2% of total PFAS levels, respectively. Concentrations of PFOA and PFOS were below the U.S. EPA's 2023 Health Advisory Level of 4 ng/L, indicating low exposure risk (HQ < 0.1). Nevertheless, the potential for PFAS bioaccumulation suggests possible long - term health risks, highlighting the need for continuous monitoring of water sources in Vietnam to safeguard public health.