Scientists may have just found an Achilles' heel for these persistent pollutants. PFAS owe their exceptional resistance to a chemical bond between carbon and fluorine, one of the strongest in existence. This is precisely why they are used everywhere: they resist heat, water, and the test of time.
But this robustness has also become a major problem. For several years, studies have linked PFAS to various health risks, while these substances contaminate soils, rivers, and even drinking water. Researchers worldwide are therefore seeking to develop technologies capable of destroying them.
Plasma, electrochemistry, ultrasound, or even ultraviolet rays. These technologies work differently, but they have one thing in common: they produce reactive species, extremely unstable molecules or particles capable of attacking the famous bonds.
Until now, researchers thought that the main "bond breakers" were primarily hydrated electrons or hydroxyl radicals. But a Danish team has just shown that another actor could play a much more important role than expected: hydrogen radicals, produced when water is exposed to very intense UV light.
This discovery doesn't mean we finally know how to easily destroy PFAS. But it does allow us to better understand which chemical mechanism is actually doing the work. And that's essential for designing more efficient processes.
The advantage of this approach is that it could work without adding chemicals, using only water and light. However, many challenges remain: the process is slow, energy-intensive, and some byproducts formed during the reaction still need to be studied.
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Most importantly, most current technologies do not completely destroy PFAS. Activated carbon filters, for example, remove them from the water but concentrate them in a medium that then requires further treatment. In other words, the problem is often simply shifted rather than solved.
And even with the best available technologies, their impact would remain limited. A study conducted by researchers and journalists from the Forever Pollution Projectcoordinated by the newspaper The Worldestimates that if all of Europe were equipped with these processes, they would allow less than 2 % of annual PFAS emissions to be treated.
That is why the authors of Forever Pollution Project insist on banning its production, replacing it with less persistent substances and also strengthening the polluter-pays principle already enshrined in European law.
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