The U.S. Court of Appeals for the District of Columbia Circuit has paused litigation brought by states and industry against the agency’s disapproval of many states’ plans to curb interstate ozone pollution, pending a decision by the Supreme Court on whether to hear challenges to a regional court’s decision to transfer litigation to the D.C. court.

The American Lung Association (ALA) in its annual “state of the air” report identifies a worsening trend of wildfire-driven fine particulate matter (PM2.5) across western states, increasing a disparity between poor air quality in the western part of the country and elsewhere, even as overall progress toward reducing ozone levels continues.