A first-of-its-kind study has measured the toxicity of several types of per- and polyfluoroalkyl substances (PFAS), better known as "forever chemicals," when mixed together in the environment and in the human body.
The good news: Most of the tested chemicals' individual cytotoxicity and neurotoxicity levels were relatively low.
The bad news: the chemicals acted together to make the entire mixture toxic.
The study is novel in that it assesses the mixture toxicity of PFAS. These synthetic compounds have been widely used in consumer products—from nonstick pans to makeup—for decades, and they can take hundreds to thousands of years to break down, if ever. They are estimated to be in at least 45% of the nation's drinking water and in the blood of practically every American, and they have been linked to cancer and neurodevelopmental disorders.