The Fifth Ward Elementary School and residential neighborhoods sit near the Denka Performance Elastomer Plant, back, in Reserve, La., Sept. 23, 2022. In what could prove a significant move for communities facing air pollution, the Environmental Protection Agency proposed on Thursday, April 6, 2023, that chemical plants nationwide measure certain hazardous compounds that cross beyond their property lines and reduce them when they are too high. (AP Photo/Gerald Herbert, File)