Eight northeastern states appealed the Environmental Protection Agency's denial of their petition to add nine states, mostly in the Midwest, to a region where additional air pollution controls are imposed to reduce interstate transport of ground-level ozone, or smog. The petition for review was filed by New York, Connecticut, Delaware, Maryland, Massachusetts, Pennsylvania, Rhode Island and Vermont. In its decision last November, EPA said it was "unnecessary" to add Illinois, Indiana, Kentucky, Michigan, North Carolina, Ohio, Tennessee, West Virginia and portions of Virginia to the Ozone Transport Region.