The Trump administration has exempted 200 industrial facilities from nine Biden-era Clean Air Act rules meant to curb mercury, toxic metals, and cancer-linked chemicals like ethylene oxide. Among them is Missouri’s largest coal plant, the fifth-largest mercury emitter among U.S. power plants as of 2024. The EPA first delayed its deadline to 2029, then repealed the mercury rule outright. Seventy petrochemical plants got a two-year pass, half of them along the Gulf Coast, including Louisiana’s Cancer Alley. The Biden EPA estimated that the petrochemical rule would have cut the number of people facing elevated cancer risk near those plants by 96%. Texas leads the country with 28 exempted sites, most of them in coastal cities like Houston. Nearby residents and environmental groups are now suing.