And the most polluted city is ...
Los Angeles: Home of creative cuisine, warm beaches year-round and, apparently, terrible air.
The report suggests nearly 150 million Americans live in areas with unhealthy air -- that's almost half of the country.
And despite California making progress in improving the environment, it still takes the top five spots in the nation's dirtiest cities.
But the odds might be against the state -- climate change potentially makes progress on air quality more difficult and the state has seen an increased number of hot, sunny days ... which causes ozone levels to increase to dangerous levels.
Ozone irritates respiratory illnesses, cancer, heart and lung disease and other health problems.
The report comes on the heels of the U.S. Supreme Court's ruling that the federal government can police particle pollution that floats across state lines to protect public health.
Visalia, Porterville and Hanford, California all took the #2 spot for America's most polluted cities, followed by Bakersfield.