The Trump administration is enacting legal interpretations that significantly limit the Environmental Protection Agency's (EPA) authority to regulate air pollution under the Clean Air Act. One major change includes the rescinding of the 2009 endangerment finding, which determined that carbon dioxide and other greenhouse gases endanger public health. This move could facilitate the elimination of existing greenhouse gas regulations and hinder future efforts to address climate change. Additionally, the administration's reinterpretation of the Clean Air Act could restrict the EPA's ability to assess health risks from toxic air pollutants, such as ethylene oxide, a known carcinogen used in medical sterilization. By arguing that the EPA can only assess residual risks once, the administration is effectively withholding critical health protections from the public. If these legal interpretations are upheld by the U.S. Supreme Court, they could have lasting implications for environmental regulation and public health in the United States.