Virtually every living thing on Earth, from Patagonian penguins to newborn human babies, has been touched by the synthetic chemicals known as per- and polyfluoroalkyl substances, or PFAS. In fact, you would be hard pressed to find a sample of human blood, tissue or breast milk without detectable levels of at least one type of PFAS.

Making matters worse, researchers are continually uncovering links between human exposure to PFAS and poor health outcomes, including a weakened immune system, a heightened risk of kidney and testicular cancer, and pregnancy complications, including preeclampsia and reduced birth weight. The levels of some PFAS considered safe in U.S. drinking water are decreasing. Despite this, The Trump administration is in the process of revoking and possibly rewriting proposed regulations for all but PFOA and PFOS, two of the most commonly used PFAS until the early 2000s. U.S. maximum contaminant level goals for PFOA and PFOS are 0 parts per trillion – meaning there are no levels the U.S. Environmental Protection Agency considers safe.

Meanwhile, thousands of PFAS have not been studied and have no regulation or oversight. In many cases, there is no monitoring data on their presence in consumer products, water and food.

As an expert in chemical pollution, I have studied a wide range of synthetic and natural chemicals that can have harmful health effects for humans and wildlife. A major focus of my current research is tracing PFAS from their initial source – including consumer products, contaminated food and water, and the air – to their resulting fingerprint in an organism’s blood and tissues.

By following the journey of how PFAS move into the bodies of living things – including people – scientists like me are working to improve safety recommendations and usage guidelines for these chemicals. First, though, we need to understand how these complex chemical mixtures are transformed as they accumulate in the body.

PFAS are a large class of organic chemicals – meaning........

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