- Scientists are finding ways to destroy "forever" chemicals known to persist in the environment.
- Exposure to PFAS has been linked to increased cancer risk and other health conditions.
- A couple of cheap ingredients can be combined to break down the compounds' tricky structure.
Scientists have found a cheap and effective way to break down a class of chemicals associated with an increased risk of certain cancers, thyroid disease, and low birth weight.
PFAS (per- and polyfluoroalkyl substances) are often called "forever chemicals" because they stick around in the air, water, and human tissue for decades. That durability is precisely what made the chemicals popular additives to grease-resistant takeout boxes, long-lasting makeup, and stain-resistant furniture.
Due to their widespread use, PFAS have permeated the environment and most Americans are believed to have some level of "forever chemicals" in their blood. Previous attempts to destroy PFAS have required hazardous waste incinerators or other expensive disposal methods, so scientists have been searching for a new way to clean up the chemicals.
The latest innovation in PFAS disposal involves just two common ingredients: lye, which is used to make soap; and dimethyl sulfoxide (DMSO), a solvent that can penetrate human skin and other membranes. DMSO has been approved by the Food and Drug Administration for use in a bladder pain medication and some cancer drugs.
When combined in boiling water, the mixture successfully degraded a type of PFAS that's found in nonstick cookware and firefighting foam, according to findings published Thursday in journal Science.
Although the method doesn't work on all types of PFAS, it shows promise for breaking down about 40% of forever chemicals that share a similar chemical signature, Northwestern University researchers Brittany Trang and William Dichtel said in a news release.
This new solution has yet to be tested in the field, but it could be scaled up to treat PFAS chemicals off-site after they are filtered out from drinking water or other contaminated resources.
PFAS linked to worse health outcomes
There are nearly 3,000 sites in the US — including landfills, rivers, and water reservoirs — considered contaminated by PFAS, according to the recent study. Communities that live near contaminated sites have an especially high level of environmental exposure to PFAS, but everyone is exposed to cumulative amounts of the chemicals in their everday lives.
High levels of PFAS in the blood have also been associated with high blood pressure in middle-aged women, which is a risk factor for heart attack and stroke. Other adverse health outcomes related to PFAS include increased cholesterol, thyroid disease, decreased immune response, and infant and fetal growth problems, according to the CDC.
Finding forever chemicals' Achilles heel by chance
Researchers discovered this method for PFAS disposal by chance in a routine toxicity study by the Environmental Protection Agency. The study grouped PFAS into subsets based on their structure and how they reacted to different chemicals, such as DMSO.
The medical solvent was able to break down certain PFAS but not others, which helped the EPA classify the chemicals. This discovery also inspired the Northwestern researchers to try a new way to neutralize PFAS.
They found that the simple mixture of DMSO, lye, and water worked on a type of PFAS that's thought to remain in the environment practically forever, according to a perspective published alongside the study.
Compounds in that subset of PFAS (known as PFCAs) are held together by a chemical signature called a carboxylic acid group, which is essentially the molecule's Achilles heel, researchers wrote in the study. Heating the compounds in the disposal mixture effectively knocks off that key group.
"Once that happens it causes the entire molecule to fall apart in a cascade of reactions," Dichtel said in the news release.
The chain reaction leaves behind a mixture of relatively harmless byproducts that are safe to release into the environment.
While the method won't work for all types of PFAS, it represents a hope that researchers will find more simple and cost-effective solutions for breaking down other forever chemicals in the future.