Cuyahoga County's air quality report card isn't pretty

The big picture: Roughly 44% of Americans live in places that receive failing grades for unhealthy levels of ozone or particle pollution, per the report.

How it works: Researchers use local air quality data to grade and rank locations based on high-ozone days, daily particle pollution and annual particle pollution.

• Ground-level ozone, the main component of smog, forms when emissions from cars, power plants and other sources react in sunlight.
• The report notes that ozone pollution has worsened across much of the U.S. over the past two years as climate change drives extreme heat and wildfires.
• Particle pollution involves tiny airborne particles from car exhaust, wildfires, fossil fuel burning and more.

Zoom in: The Cleveland-Akron-Canton metro area ranked No. 12 nationally for worst annual particle pollution among more than 200 U.S. metros.

• It also ranked No. 51 for the most high ozone days and No. 39 for the worst 24-hour particle pollution.

Yes, but: Cuyahoga County's air has dramatically improved over the past two decades, per American Lung Association measures.

What we're watching: You can check daily pollution forecasts at Airnow.gov.

Go deeper: Key findings