PFAS, also known as “forever chemicals,” are a large group of synthetic chemicals that break down very slowly over time and are linked to harmful effects on human health. They’re used in a vast array of products, from pots and pans to computers and even dental floss. Laurel Schaider, senior scientist at the Silent Spring Institute in Massachusetts, studies the spread of PFAS chemicals in the drinking water and their effects on human health. She discussed ways that people can take steps to reduce exposure to PFAS in their daily lives. “There are some things that we can do, such as avoiding buying Teflon-coated pans, skipping stain resistant or waterproof items where they're not needed,” she told Horizons host William Brangham. Schaider noted that, while formulations of food packaging have changed, her past advice has been to avoid microwave popcorn and other types of grease-proof food packaging which might contain PFAS. “People are surprised to learn that Glide dental floss is made of Teflon," she said. "There are cosmetics with PFAS." But there is a challenge, Schaider said, because the products don’t include labels that disclose if they contain these chemicals. Horizons from PBS News, dives into the science, health, technology and environmental issues making headlines each week. Visit the PBS News website to watch this week's episode.