Paul Atkinson/KJZZ

Phoenix, Arizona.

The American Lung Association issued its 2018 "State of the Air" report — and Phoenix stinks. Of the 10 most ozone-polluted cities, Phoenix is ranked eight.

Stacey Mortenson , with Arizona chapter of the Lung Association, said the report also grades each county based on ozone and particle pollution. Maricopa County received an F.

"There were four counties in Arizona that received an F for ozone pollution Gila, Maricopa, Pinal and Yuma. We will say Maricopa County actually had the lowest amount in unhealthy zones than it has ever had in 19 years of doing the report," said Mortenson.

With the exception of Phoenix and New York, the remaining ozone-polluted cities were in California. Ozone, said Mortenson, is the result of certain gasses coming into contact with heat and sunlight.