PFAS Uptake from Regulatory-Compliant Irrigation Water Exceeds Dietary Limits in Radish and Lettuce: Dose-Response and Activated Carbon Mitigation
Year: 2026
Type: preprint
Abstract: Per- and polyfluoroalkyl substances (PFAS) are regulated primarily in drinking water and soil, yet neither matrix is what consumers ingest. We tested whether irrigation water meeting regulatory thresholds can still produce unsafe PFAS burdens in edible crops. Radish (Raphanus sativus) and lettuce (Lactuca sativa) were irrigated across five arms (0, 16, 152 and 301 ng L −1 total PFAS from five long-chain compounds, plus a 152 ng L −1 activated carbon (AC)-filtered arm); plant and soil PFAS were quantified by liquid chromatography- mass spectrometry. Tissue PFAS accumulated dose-dependently, exceeding the European Food Safety Authority tolerable weekly intake by 2–39×. Critically, at 16 ng L −1 , below the Massachusetts drinking-water maximum contaminant level, tissue exceeded dietary limits by 2–4× while soil PFAS remained below international agricultural screening values, revealing a soil–plant regulatory disconnect. The contamination was undetectable by inspection: growth metrics did not differ across treatments and 67 blinded observers classified contamination at chance. Gravity-column AC pre-filtration reduced tissue PFAS by 84–91% without growth penalty. Compliance in the two monitored matrices does not predict crop burden, supporting direct crop-tissue monitoring and accessible pre-harvest filtration.
Source: ChemRxiv
Authors: Sahana Chaubal, Arjav Shah
Institution: Massachusetts Institute of Technology
Language: English
Subfield: Environmental Chemistry
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7204934136