A new study reveals that Metro Phoenix’s air quality has deteriorated.

The American Lung Association ranks the city as seventh for dirtiest air among American cities for ozone in their 2018 State of the Air report.

“We were ranked eighth last year, so we did have more days where the air quality was bad,” said JoAnna Strother, the director of advocacy for the American Lung Association of Arizona.

From 2017 to 2018, Phoenix dropped from 20th to 13th for 24-hour pollution and from 50th to for year-round pollution. Strother said some blame should go to smoke and particles from last summer’s California wildfires.

“We have sunshine most of the year,” she said. “It gives us the perfect recipe to cook up ozone. That’s why we’re seeing some of those high levels.”

An increased amount of car emissions is also to blame.

“If everybody just committed to maybe commuting one day less, or using another form of transportation, that all adds and helps us to clean up our air,” she said.