Sources and transport of per- and polyfluoroalkyl substance (PFAS) in agricultural soil–plant systems
Miao Han, Chao Qin, Yanzheng Gao
Abstract
Per- and polyfluoroalkyl substance (PFAS), a class of new contaminants, have garnered increasing research attention in recent years owing to their environmental persistence and biological toxicity. Agricultural soils influence human health and exhibit marked spatial heterogeneity on a global scale. However, systematic reviews on the sources and transport of PFAS in soil–plant systems, across different regions, remain limited. To bridge this gap, this review focuses on the PFAS loading introduced into agricultural soil through waste and sewage reuse, highlighting biosolids as the primary source of PFAS contaminants. Global waste emission data revealed elevated PFAS risks in Western Europe, Australia, and East Asia. Subsequently, PFAS migration behaviors in soils and plants were examined. The results showed long-chain PFAS have strong adsorption in plant roots and soil, especially in soil rich in organic matter and minerals. In contrast, short-chain PFAS exhibit greater mobility and tend to accumulate in leaves and grains, driven by transpiration and tissue protein content. This raises concern over elevated PFAS risks in high-protein crops, particularly soybeans. The present study proposes that imposing strict limits on PFAS concentrations in waste reuse products is the most effective strategy to control their infiltration into agricultural soils. Additionally, migration models of PFAS in soils and plants are essential for predicting their bioavailability. The prioritized establishment of regional predictive models provides an effective strategy to counteract the complexity of soil properties. Integrating such models with regional soil heterogeneity data is conducive to assessing the global risks of PFAS contamination in agricultural soils in the future.