Linking Vegetable Per- and Polyfluoroalkyl Substance Accumulation with Root Chemical Traits.

Abstract

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous, persistent organic pollutants increasingly detected in food crops, yet their accumulation capacities and regulatory factors across various plant species remain poorly resolved. Here, we investigated the bioaccumulation patterns of PFAS in 20 vegetable species and their relations with root chemical traits in farmland irrigated with treated wastewater. Leafy vegetables (e.g., <i>Lactuca sativa</i> and <i>Spinacia oleracea</i>) accumulated substantially higher PFAS concentrations (mean: 9.24 ng/g) than the root vegetable <i>Daucus carota</i>, with the short-chain perfluorobutanoic acid (PFBA) identified as the dominant species for all vegetables. PFBA showed the strongest mobility and tended to accumulate in edible aerial tissues of leafy vegetables, whereas long-chain PFASs were largely retained in roots. Across vegetable species, root PFBA concentration increased with the proportion of alkyl carbon and decreased with the proportion of <i>O</i>-alkyl carbon in roots, whereas the long-chain perfluorononanoic acid concentration increased with dissolved organic carbon concentration in roots. PFAS exposure could be decreased by up to 90% by consuming low-concentration vegetable varieties instead of high-concentration ones. These findings highlight the critical role of plant traits and rhizosphere chemistry in governing PFAS uptake pathways and suggest that crop selection and rhizosphere management can inform risk mitigation.