Scrubbing Earth of per- and polyfluoroalkyl substances—a.k.a. PFAS or forever chemicals—could eliminate a list of woes for people and planet. Used for decades in everything from nonstick pans to firefighting foams, PFAS have been linked to increased risks of fertility challenges, developmental delays , cancer , and reduced immune response . They are known for a strong bond between carbon and fluorine, which the environment struggles to break down.

The sticking points

PFAS are everywhere: They spew from factories and slough off products and into water with normal use. Scientists have found them in everything from human blood to Antarctic snow . One 2022 report found that 89% of the US population had PFAS in excess of two nanograms per milliliter of blood plasma, a common threshold for potential adverse health effects, and 9% of the population had passed the riskier level of 20 nanograms per milliliter.

The PFAS monster is also a moving target. New compounds are still being created and used.…