You might not have heard of “forever chemicals,” but you’ve certainly been exposed to them. This large family of molecules can be found in everything from the wrapper on your take-out burger to the stain-resistant fabric on your couch. You might unwittingly encounter them when you floss your teeth, apply your mascara, or fry an egg in your nonstick pan.
Known to scientists as PFAS (shorthand for perfluoroalkyl and polyfluoroalkyl substances), these pervasive chemicals can linger for many years in soil and water — and in our bodies, where they have been linked to a range of diseases. They’ve been found in the drinking water in many parts of the US, particularly areas near chemical plants that currently or previously made them. So much of this stuff is out there that researchers recently detected unsafe levels in rainwater.
Now, there might be a way to strike the “forever” from those chemicals. Scientists at Northwestern University have come up with a simple and cheap method of breaking down some of these molecules into benign parts. That feat, and, more realistically, others it might inspire, has the potential to play a critical role in the massive and costly effort to eradicate these chemicals from the environment. The discovery is far from an immediate solution to the world’s PFAS problem. But it arrives at a time when the US is starting to put real money into efforts to pull these contaminants out of the water supply, which would create a lot of PFAS waste with nowhere good to go.
Forever chemicals exist to add durability during manufacturing and enable consumer-friendly features like water- and grease-resistance. The problem is that the carbon-fluorine bonds that endow these qualities also make these chemicals annoyingly stable. Getting rid of them is a massive and expensive headache. One community in North Carolina spent some $50 million to upgrade its water treatment plant to filter out PFAS each year and is on the hook for several million more dollars to change the filter and get rid of the chemicals it captured.
Northwestern professor William Dichtel is one of many scientists working on methods to pull these chemicals out of water. But a question has always lingered, he said. “What do you do with the PFAS after you’ve removed them from contaminated water?” Prying apart those carbon-fluorine bonds currently requires brute force — think energy-intensive measures like incineration at extreme temperatures. And even that doesn’t always break everything down.
The team from Northwestern team struck upon a simple alternative. Certain types of PFAS (ones featuring carboxylic acids) can be dissolved in mild conditions using just water, a widely used solvent called DMSO, and sodium hydroxide. What’s left in the end is benign. The lab also partnered with scientists at other universities to do a deep dive into how these chemicals fall apart. Those details may not seem as exciting as an easy recipe for PFAS destruction but are just as important in that they help inform future research.
Such efforts will be needed. The Northwestern team’s findings have not been proven on an industrial scale. DMSO, for example, is not typically used at an industrial scale. The reaction also only works on some kinds of PFAS, so other approaches need to be explored.
Progress in addressing those questions is urgently needed. A lot of forever chemicals could soon be pulled out of our water. The Biden administration’s infrastructure bill included $1 billion to address PFAS contamination as part of an overall $5 billion commitment, with a particular focus on aiding remediation efforts in small or disadvantaged communities.
As part of the plan, the Environmental Protection Agency proposed lowering the acceptable level in drinking water to practically zero for two older chemicals (PFOA and PFOS), and issued a health advisory for two others. Last week, the agency proposed adding PFOA and PFOS to its list of hazardous substances, a move that could put some of the clean-up cost back on the chemical companies.
Companies keep churning out forever chemicals, and consumers keep buying products made more convenient because of them. Unfortunately, that cycle doesn’t seem to be changing any time soon. And although the Northwestern team’s discovery won’t fix the world’s PFAS problems anytime soon, it could help with the clean-up and inspire other inventions that bring safer drinking water closer to reality.
Bloomberg
