Sources, Fate, and Plant Uptake in Agricultural Systems of Per- and Polyfluoroalkyl Substances

Abstract

Purpose of Review Per- and polyfluoroalkyl substances (PFAS) are a family of > 4700 recalcitrant compounds, many of which are ubiquitous in the environment. This review aims to (1) identify PFAS sources and fate processes relevant to agricultural systems and (2) expand on plant uptake mechanisms and plant responses to PFAS. Recent Findings The number of PFAS being quantified in studies involving soil, water, and plants is increasing. Transformation of precursors that tend to stay in the rhizosphere can lead to long-term PFAS reservoir to plants. Some PFAS are readily taken up, particularly the shorter-chain PFAS, and can evoke metabolic responses and phytotoxic effects at high concentrations. PFAS translocation from roots to shoots occurs through both active and passive transport mechanisms. Both PFAS uptake and effects vary between and within species. Summary As new PFAS emerge, it will be necessary to continue expanding the list of PFAS quantified in land-applied media and assessing their accumulation potential in plants. While controlled laboratory or greenhouse studies have merit, comprehensive field studies are needed to provide clarity on PFAS fate and their relative risk in agricultural systems. Field studies should include identifying site-specific PFAS sources, quantifying a broader suite of PFAS and identifying potential precursors, evaluating plant uptake of replacement PFAS, reporting of soil properties and climatic conditions, and assessing risk of impacts to source and irrigation waters. This information can be utilized to inform future studies towards evaluating and mitigating risks to our food chain associated with PFAS in agricultural systems.

Bioaccumulation, Biodistribution, Toxicology and Biomonitoring of Organofluorine Compounds in Aquatic Organisms

“…A similar study, taking into account the contamination of flathead mullet (Mugil cephalus), Atlantic mackerel (Scomber scombrus), and European plaice (Pleuronectes Platessa), hake (Merluccius merluccius), and sea bass (Dicentrarchus labrax), has reported PFAS contamination levels that were above the tolerable daily intake for toddlers' diet in Italy [56]. In this context, despite the Organization for Economic Cooperation and Development (OECD) has identified more than 4500 PFAS-related substances [57], only a few of them (<20) are regularly analysed and monitored, thus underestimating the real exposure to PFAS. For example, the percentage of unidentified organofluorine compounds may range from 30 to 90% of the total extracted fluorinated substances in wildlife animals or marine mammals [58,59].…”

A sensitive method for the detection of legacy and emerging per- and polyfluorinated alkyl substances (PFAS) in dairy milk

“…PFAS present in AFFF utilized at fire training areas and military bases may persist in soils and groundwater leachate [17,46,47]. PFAS recalcitrance in soils due to AFFF leachate irrigation or biosolid amendment application pose reasonable concerns for agriculture [48]. Concentration of PFOA and PFOS in plants grown in biosolid-amended soils have previously been found up to 200 ng/g dw and 20 ng/g dw, respectively [49].…”

Perfluoroalkylated acids (PFAAs) accumulate in field-exposed snails (Cepaea sp.) and affect their oxidative status

“…To the best of our knowledge PFAAs have only been studied in crop species (e.g. Blaine et al, 2013Blaine et al, , 2014Costello and Lee, 2020), and studies on native plants species are absent. As in these earlier studies plants were grown on spiked soils or biosolid-amended soils (e.g.…”