Per- and polyfluoroalkyl substances (PFAS) contamination in soils can pose adverse effects to plants due to their persistence and bioaccumulative nature, including physiological and morphological toxicity, biochemical effects, molecular toxicity, etc. However, the toxic effects normally occur at high level of PFAS, e.g. EC50 values for various measurement (emergence, growth, biomass, survival, etc.) could range from around 1 mg/kg to several hundreds of mg/kg. Most of the contaminated sites are with low level of PFAS (µg/Kg – several mg/Kg) [1, 2], which requires proper treatment and reuse methods due to challenges when applying other destruction methods. At the same time, the uptake of PFAS depending on the bioavailability of PFAS in soils, can be influenced by various parameters including PFAS chain length and chemistry, the soil condition, the microbial community, etc. Thus, the bioaccumulation of PFAS varies from plants, soil conditions, and PFAS compounds, and currently no hyperaccumulation plants are identified for PFAS.
The mobility and bioavailability of PFAS in soils vary according to the soil properties, PFAS molecular properties, the chemistry of soil pore water, the presence and activity of microorganisms [3], which influence the accumulation and toxic effects of PFAS to plants. The existing literature indicated lower pH is beneficial for the retention of PFAAs in soils while dissolved organic matter could complex and compete with anionic PFAAs [4, 5]. However, the interaction of plant roots and the soil particles might alter the sorption and mobility of PFAAs. Thus, reducing the mobility and bioavailability of PFAS via systematic approach with PFAS-Soil-Plant system might be beneficial for the remediation of low-level PFAS contaminated soils.