Human exposure to per- and poly-fluoroalkyl substances (PFAS) in Asia and contributing factors, with a focus on East Asia.

Abstract

The production and use of PFAS in some countries, coupled with uncertainties about their applications across Asia, underscore the urgent need to assess human exposure-particularly beyond China, Japan, and South Korea, which account for 80-90% of existing environmental PFAS studies. Exposure levels vary significantly across the region, with industrial activities, including textile and automotive manufacturing, contributing to severe contamination, especially in freshwater sources. Studies have detected PFAS in surface and groundwater across 20 Asian countries (∼3000 samples), sometimes at concerning concentrations. Contamination extends to drinking water and food products, further increasing human exposure risks. There is now substantial evidence, particularly from China, South Korea, and Japan, indicating a widespread presence of long-chain PFAS in human serum and breast milk. Additionally, replacement compounds and their degradation products, such as 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) and the dimer and trimer acids of hexafluoropropylene oxide (HFPO-DA, and HFPO-TA), are increasingly detected in human samples in China, where they are produced. Although the situation in the rest of Asia is currently unclear due to limited data, given the widespread PFAS contamination in water and food sources in the studied areas of Asia, human exposure is highly likely. Beyond direct contamination, additional risk factors in certain Asian regions are likely to exacerbate exposure, including industrially impacted freshwater resources, self-supplied and untreated drinking waters, and high reliance on fish and seafood (including wastewater-fed fisheries) in some countries. Conversely, dietary patterns, such as vegetarianism in some regions (e.g. India), may influence PFAS exposure differently. Despite these concerns, PFAS regulations in Asia typically fall behind those in Western countries, resulting in significant gaps in risk assessment and regulat