PFAS forever chemicals broken down by hydrogen radicals under UV light Aarhus University study
PFAS, the "forever chemicals" that build up in water and human blood, may have a weak spot. Aarhus University researchers found hydrogen radicals formed from water under intense UV light strip fluorine from PFAS, breaking down GenX by up to 49 percent in five hours with no added
PFAS, the class of synthetic compounds known as "forever chemicals," resist breaking down in nature and accumulate in soil, drinking water, and human blood. A new study suggests they are not as indestructible as the name implies. Researchers at Aarhus University in Denmark, working through the university's Centre for Water Technology, identified hydrogen radicals as the key to pulling PFAS apart. These radicals are highly reactive fragments that form from water when it is exposed to intense ultraviolet light. According to the team, the radicals attack the PFAS molecules and gradually remove their fluorine atoms, the bonds that make these compounds so stubborn, breaking them into smaller and less persistent substances. The reaction worked best under high-energy UV light at wavelengths below 300 nanometers. In laboratory tests the compound GenX degraded by up to 49 percent and lost about 21 percent of its fluorine within five hours, with no added chemical reagents. That point matters for cost and scale, since many existing PFAS treatments rely on extra inputs that complicate cleanup. The finding, published in the journal Environmental Science and Technology, also corrects an earlier assumption. Previous work had pointed to other reactive species as the main drivers of PFAS breakdown. By naming hydrogen radicals as the central actor, the Aarhus team gives engineers a clearer target as they try to turn a lab result into treatment that works at the scale of a city water supply.