Over 75 years, a billion-dollar industry has grown up around a group of toxic chemicals that helps keep carpets clean, makes water roll off of camping equipment, and stops your food from sticking to frying pans. There are nearly 5,000 of these chemicals in a class called PFAS, for perfluoralkyl and polyfluoroalkyl substances.
We’re just beginning to understand the risk they pose. What chemists know is that the tough carbon-fluorine bonds in these “forever chemicals” make them break down very slowly in the environment — posing a persistent risk to water supplies.
PFAS Linked to Liver and Developmental Problems
The Centers for Disease Control has profiled PFAS, which has been studied in people and in animals. Studies have linked to it developmental problems, thyroid disease, harm to the immune system, and impaired liver function. The CDC and Environmental Protection Agency also say some of the chemicals in this class may cause cancer.
PFAS are oil, stain, grease, and water repellent, so they’re found in consumer products like ski goggles and camping gear. What people are worried about now is where the chemicals might have entered drinking water through industrial uses. There’s a firefighting foam used on airport runways because it cleans up fuel spills and oil really well, and from there the PFAS chemicals could leach into soil, and then water.
Environmental Working Group toxicologist Alexis Temkin says that human exposure can come from drinking water and certain types of food, especially seafood.
“We’re now beginning to understand that it can be found in compost, which can be used on other types of vegetables, which can then take up PFAS,” Temkin says. “So we know that the health hazard and the risk can come from a variety of different places.”
Under a federal program, starting a couple of decades ago, companies voluntarily phased out the older versions of these PFAS chemicals. They aren’t made in the U.S. anymore, but some other newer ones are, and these newer chemicals may be less toxic, or may not be.
Thousands of Chemicals and Very Few Rules
Federal rules set a health advisory limit for drinking water at 70 parts per trillion. The CDC’s toxicology review suggests that the for some chemicals the limit should be around one-fifth of that.
