The Effects of Soil Organic Carbon Content on Plant Uptake of Soil PFAAs and its Potential Regulatory Implications
By Steven Lasee, Seenivasan Subbiah, Sanjit Deb, Adcharee Karnjanapiboonwong, Paxton Payton, and Todd A Anderson
Environ. Toxicol. Chem.
June 2, 2020
DOI: 10.1002/etc.4786
Perfluoro alkyl acids (PFAAs) are known to bioconcentrate in plants grown in contaminated soils; the potential risk from consuming these plants is currently less understood. We determined that the USEPA's current RfDs could be met by consuming a single radish grown in soils with a PFOA concentration of 9.7 ng/g or a PFOS concentration of 90.5 ng/g. Using a combination of our own research and literature data on plant uptake of PFAAs from soil, we developed equations for predicting PFAA bioconcentration factors (BCFs) for plant shoot and root tissues grown in soils with a known percent organic carbon. This calculated BCF was then applied to six scenarios with measured soil PFAA concentrations to estimate PFAA concentrations in plants and potential exposure to humans and animals consuming harvested vegetation. Five of the six scenarios showed potential for surpassing USEPA PFAA RfDs at soil concentrations as low as 24 ng/g PFOA and 28 ng/g PFOS.
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