Many millennia from now, when humans are long vanished from the Earth, intergalactic travelers visiting our planet may wonder about this world’s ancient inhabitants and their civilizations. One clue these visitors will be able to use in their investigations will be the presence of a class of manmade chemicals called per- and polyfluoroalkyl substances (PFASs). Dubbed “forever chemicals,” PFASs will likely outlast humanity. PFASs have a wide range of uses thanks to their unique physio-chemical properties. They can be found in stain resistant textiles, greaseproof food packaging, nonstick cookware, firefighting foam, personal care products, pharmaceuticals, pesticides, and in over 200 other applications. Because of their widespread use, coupled with their persistence and mobility, PFASs can now be found everywhere researchers look for them—in our food, in our drinking water, and in our bodies. Contamination of drinking water with one PFAS, called PFOA or C8 (because it contains eight carbon atoms), …