Intercropping minimally influences differences in per- and polyfluoroalkyl substance (PFAS) uptake among three agricultural crops

The widespread presence of per- and polyfluoroalkyl substances (PFAS) in agroecosystems challenges safe and profitable food production. To contribute to the broader understanding of crop-specific PFAS uptake, we cultivated lettuce ( Lactuca sativa L.), tall fescue ( Schedonorus arundinaceus [Schreb.] Dumort.), and tomato ( Solanum lycopersicum L.) in a complete randomized design on a field historically contaminated with PFAS. Bioconcentration factors (BCFs) were evaluated across crops with distinct root, leaf, and fruit traits that have been linked to differential PFAS uptake mechanisms. Our findings indicated edible portion BCFs followed the general trend (highest to lowest): tall fescue > lettuce > tomato fruit. Though tall fescue showed the highest uptake of perfluoropentanoate (PFPeA), perfluorooctanoate (PFOA), and perfluorooctanesulfonate (PFOS) (mean ± SE = 0.75 ± 0.12, 0.09 ± 0.01, 0.03 ± 0.10, respectively), the BCFs remained below the threshold (BCF > 10) that would classify the crop as a ‘hyperaccumulator.’ Tomato fruits translocated only short-chain compounds perfluorobutanoate (PFBA) and PFPeA (BCF mean ± SE = 0.21 ± 0.1, 0.14 ± 0.1). Across all crops, short-chain BCFs were 48 times higher than long-chain BCFs, and carboxylates were more mobile than sulfonates (p ≤ 0.01). Precursor compounds were minimally detected in edible portions despite high concentrations in soils, suggesting biotransformation. Intercropping lettuce or tomato with tall fescue did not reduce BCFs, indicating the limited potential of intercropping for PFAS phytomanagement with the crops tested here. These results highlight the importance of crop selection, species-specific action thresholds, and improvements that can be made to make PFAS research comparable across studies. • Edible portion BCFs generally ranked from highest to lowest: tall fescue > lettuce > tomato fruit. • Short-chain carboxylates were more concentrated in edible portions than long-chain sulfonates and precursors. • Low precursor BCFs in edible portions suggest biotransformation and/or limited mobility. • Intercropping marketable crops with tall fescue increased PFAS uptake into one or both crops, indicating further research is needed to identify effective phytomanagement strategies.