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

TL;DR

This study shows how different vegetables absorb harmful PFAS chemicals, with leafy greens accumulating more than root vegetables, and suggests crop choices can reduce exposure.

Contribution

The study identifies PFBA as the dominant PFAS in vegetables and links root chemical traits to PFAS accumulation patterns.

Findings

Leafy vegetables accumulate significantly higher PFAS concentrations than root vegetables.

PFBA is the dominant PFAS species in all tested vegetables and shows strong mobility to aerial tissues.

Root PFBA concentration correlates with alkyl carbon proportion and inversely with O-alkyl carbon proportion.

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., Lactuca sativa and Spinacia oleracea) accumulated
substantially higher PFAS concentrations (mean: 9.24 ng/g) than the
root vegetable Daucus carota, 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 O-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.

Figures