Carolyn Beans

How “forever chemicals” might impair the immune system

Stain-resistant carpets and nonstick pots were once the epitome of “better living through chemistry,” their space-age properties conferred by molecules known as perfluoroalkyl and polyfluoroalkyl substances (PFAS). But in the early 2000s, researchers began to discover that PFAS were somehow reaching the far- thest corners of the planet—from polar bears in Alaska to pilot whales in the Faroe Islands of the North Atlantic. These molecules contain chains of carbon peppered with fluorine atoms, which together form one of the strongest known chemical bonds. That helps these chemicals excel at repelling grease and water but also makes them astonishingly resistant to degradation in the environment.

… People are exposed to forever chemicals through contaminated water, food, and air, as well as countless products including cosmetics and upholstery … US companies no longer manufacture the two best-known PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). But these legacy PFAS persist in the environment, even as thousands of others remain in production.

… After monitoring almost 1,000 children up to age 7, the team reported that exposure to PFOA and another PFAS called per- fluorohexane sulfonic acid (PFHxS) was associated with higher rates of diarrhea or gastric flu. By age 3, children with higher exposure to PFOS, PFOA, PFHxS, or perfluoroheptane sulfonic acid (PFHpS) had higher rates of bronchitis or pneumonia (9). In contrast, other studies have hinted that PFAS may at times over- activate the immune system (10).

… Although researchers are learning more about the toxicity of individual PFAS, they still don’t know how PFAS chemicals interact …