EPA Proposes Revisions to Particulate Matter NAAQS Under the Clean Air Act
In early January, the U.S. Environmental Protection Agency announced a proposal to revise and strengthen a key national ambient air quality standard (NAAQS) for fine particle pollution, also known as PM2.5. The Clean Air Act requires EPA to set two types of NAAQS: health-based standards, called primary standards, and standards to protect public welfare, called secondary standards. Based on …