PFAS, these toxic fluorinated substances qualified as “eternal pollutants”, are present everywhere: both in water and in the ground. Recent studies also show that wastewater treatment plant sludge (WWTP) used for agricultural fertilization is likely to contain it and that the microbes that help break down this sludge play a crucial role in the accumulation of PFAS in the floors.
Per- and polyfluoroalkyl substances, or PFAS, form a family of more than 4,000 chemical compounds that have been used since the 1950s. industrial. They are thus used in the composition of a wide variety of products: non-stick pans, textiles, food packaging, cosmetics, etc.
Unfortunately, these compounds are also toxic and, due to their chemical composition, very persistent.[1] in the environment. Too long ignored by the authorities, this insidious pollution, because invisible, is nevertheless making more and more noise. At the end of 2021, the United States thus announced that it was seriously tackling the problem of PFAS[2]while 80% of American waterways are contaminated!
Microbes would promote the release of PFAS
If the practice of spreading sludge from wastewater treatment plants is considered virtuous, it is unfortunately responsible for an involuntary accumulation of pollutants in agricultural soils and in particular PFAS (and also microplastics), despite the treatments of depollution carried out upstream.
Researchers from Drexel University’s College of Engineering wanted to understand the reasons. In a study published in the journal Environmental Science Processes & Impacts[3]they explain how PFAS are able to “leak out” of fertilizers made from recycled waste, thanks to microbial decomposition.
In a press release, one of the co-authors, Dr. Asa Lewis states: “As it is currently not possible to eliminate PFAS from the environment, it is important to understand all we can about how they are able to persist and accumulate so widely in the natural world. »
The accumulation of PFAS in the environment: a global problem!
Although this study concerns the United States, Europe and France are also largely concerned by PFAS pollution and by the question of sludge treatment.
At the end of February 2023, an investigation by the newspaper The world revealed the extent of PFAS contamination in Europe. Europe thus has more than 20 producing chemical plants, 232 users of PFAS and contamination has been detected at more than 17,000 sites.
In recent years, however, the problem of PFAS has begun to be taken seriously by the public authorities. In view of the growing concerns, the French authorities have also recently launched a ministerial action plan led by the Ministry of Ecological Transition and Territorial Cohesion. This action plan contains 6 axes.
A few days after the announcement of this action plan, it was Europe’s turn to tackle the problem of PFAS head-on, with five Member States having proposed an outright ban on PFAS. An assessment that will soon lead to a recommendation to the European Commission, with a view to regulations by 2025.
[1] According to ANSES, the more carbon atoms they contain, the more persistent they are in the environment.
[2] While the risks posed by PFAS have been known since 1998!
[3] Royal Society of Chemistry