Global ecological and health risks of PFAS in surface soil

Per- and polyfluoroalkyl substances (PFAS) are highly persistent and potentially toxic, making them a growing global concern. Yet, the large-scale ecological and human health risks of PFAS contamination in soils remain poorly understood. In this study, we synthesized about 2,000 PFAS concentration data points from surface soil samples reported in 106 peer-reviewed studies to evaluate global contamination patterns and associated risks. A probabilistic approach showed that long-chain legacy PFAS, particularly perfluorooctane sulfonic acid (PFOS), were the dominant contaminants in soil (median concentration 1.03 ng g^-1), with 30.32 % of the grids exceeding safety threshold. We identified geographic hotspots that include Central Europe, the northeastern United States, and southeastern China. Notably, health risks linked to perfluorohexane sulfonic acid (PFHxS) are elevated in both Europe and the U.S (exceeded global median by a factor of 26.77). Moreover, short-chain PFAS exhibit higher mobility, suggesting a greater potential for groundwater leaching. These findings highlight the urgent need to establish global soil quality standards for PFAS and offer critical insights to guide public health policy and soil management strategies.