Beginning in the early 2000s, some of the most common and well-studied PFAS were phased out through a combination of industry shifts and international regulations. A new study from Harvard has found that since that phaseout, North Atlantic pilot whales have 60% lower concentrations of these chemicals in their bodies. PFAS, or per- or polyfluoroalkyl substances, are ubiquitous in modern life. First produced at the end of World War II, these chemicals are in everything from furniture and cosmetics to food packaging, nonstick pans and clothing. They have also infiltrated our water, soil, and food, making PFAS a major concern for human and ecological health.