Tulsa gets an F from the American Lung Association for ozone pollution and is ranked the 18th-most polluted metro area in the U.S.
The rankings, however, include 2012, the area’s second-worst ozone season ever. That year saw 21 alert days, more than 2013, 2014 and 2015 combined. The rankings also have a stricter standard than the Environmental Protection Agency.
Tulsa consistently has ozone levels just below the federal limit, though that presents its own problem when it comes to paying for projects to improve local air quality.