Per- and polyfluoroalkyl substances (PFAS) are known as “forever chemicals” due to their ability to persist in the environment and bioaccumulate in living organisms, including humans. Some PFAS pose a health concern, and the use of PFAS in products such as non-stick coatings, water-repellent fabrics and firefighting foams has come under scrutiny as new regulations seek to mitigate their impact. Researchers at France’s National Research Institute for Agriculture, Food and Environment (INRAE) looked at another potential source of PFAS contamination in a recent study, using ultra high performance liquid chromatography-mass spectrometry (UHPLC-MS) techniques to gauge PFAS levels in different types of fertilizers that could be used to grow food crops.
The researchers tested 47 samples of organic waste products intended for use on agricultural fields in France between 1976 and 2018. This included livestock manure, sewage sludge and composts, and industrial wastes. The results of the target and nontarget testing screening showed that more than 90% of the samples contained at least one PFAS, with up to 113 PFAS being present within one sample. Additionally, the researchers found that wastes originating from urban areas, such as wastewater products, industrial waste and household waste composts, contained more types and higher levels of PFAS than livestock manure.
In the urban wastes, the team found high levels of PFAS compounds that are not commonly monitored, which suggests that previous studies may have underestimated total PFAS levels. Older urban samples contained higher levels of PFAS that have since been banned or phased out, while contemporary samples predominantly contained fluorotelomers. The results show that urban waste could be a significant repository through which PFAS can make their way further into the environment. This study was published in Environmental Science & Technology.
“Humans and livestock can ingest PFAS and excrete them in their feces, or the compounds can leach into domestic sewage and end up in treated municipal wastewater effluent,” said Sébastien Sauvé, a Université de Montréal researcher who led the study. “When these residues are applied to agricultural fields as fertilizer, PFAS could contaminate groundwater and bioaccumulate in food crops.”
Sauvé noted that the research team had access to a valuable bank of historical and contemporary samples to analyze at INRAE, and that environmental research observatories are continuing to conduct long-term monitoring of PFAS in waste products recycled for agricultural use.