Detroit meets clean air goals by calling bad air 'exceptional'

The US environmental regulators propose to declare that Detroit met its clean air targets for ozone pollution. This happened because the state convinced the agency to discount certain days with high pollution, labeling them 'exceptional events' not caused by local sources.

Detroit will avoid stricter pollution controls and other penalties that apply to areas failing to meet federal clean air standards. This decision sets a precedent for how other cities and states might use the 'exceptional events' rule to meet their own air quality deadlines, even if local air quality remains poor on certain days.