Researchers announced Thursday, August 18, that they had found a method to destroy certain pollutants, called “eternal,” because of their extreme resistance and toxicity, which are present in many everyday objects and can cause serious health problems.
The technology, which requires relatively low temperatures and so-called common reagents, was developed by chemists in the United States and China, whose work was published in the journal Science, offering a potential solution to a persistent problem for the environment, livestock and humans.
Eternal pollutants, discovered during World War II and decayed extremely slowly, are found in packaging, shampoos, non-stick pans and makeup. Over time, they have spread into our environment: water, soil, air, groundwater, lakes and rivers. A Swedish study showed last week that rainwater was unfit for consumption everywhere on Earth due to high levels of PFAS.
According to some reports, exposure to PFAS can affect fertility and fetal development. It can also lead to increased risk of obesity or certain cancers (prostate, kidney and testicles) and increased cholesterol levels. The current methods to degrade these pollutants require potent treatments, such as incineration at very high temperatures or irradiation by ultrasound.
Their almost indestructible characteristic is linked to the long carbon-fluorine bonds that compose them, among the strongest in organic chemistry. However, the researchers identified a weakness in some types of PFAS. At one end of their molecule, a group of oxygen atoms can be targeted by a common solvent and reagent at temperatures averaging 80 to 120 degrees Celsius.
When this happens, “it causes the entire molecule to collapse in a cascade of complex reactions,” explains William Dichtel of Northwestern University, one of the study’s authors. The scientists also used powerful computational methods to map the quantum mechanics behind these chemical reactions. Work that can eventually be used to improve the technique.
The current report focused on 10 PFAS, including a significant pollutant called GenX, which contaminated the Cape Fear River in North Carolina. But there are more than 12,000 “eternal chemicals,” according to the U.S. Environmental Protection Agency.
“There are other types (of PFAS) that don’t have the same Achilles heel, but each has its weakness,” William Dichtel points out. “If we can identify it, we will know how to activate it to destroy it.”
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