The American Lung Association "State of the Air 2018" report ranks the metropolitan areas based on ozone and particle pollution during 2014, 2015 and 2016. For particle pollution, we rank separately the areas with high year-round (annual average) levels and high short-term levels (24-hour) found in monitoring sites across the United States. We take official data from the U.S. Environmental Protection Agency (EPA) to compile the rankings. For more information about how we grade and rank cities, go to Methodology.
The cities on the cleanest cities lists for ozone and for short-term levels of particle pollution had no days with unhealthy levels of ozone or particle pollution. These lists are not ranked because all the cities earned the same scores. The cities on the list of the cleanest for year-round particle pollution levels are ranked by their average levels of particles, as calculated by the EPA. Note that some cities are clean for one category, but not for others.Learn more
Most Polluted Cities
The cities are ranked by the air quality in the most polluted county in the metropolitan area. Select your city name to open links to a chart of the trends for ozone and year-round particle levels, as well as more information about air pollution and the local Lung Association. Note that some cities rank high on one list and don’t show up on other lists because of the differences in their pollution problems. Each city includes all the counties that form the economic and transportation network that makes up the metropolitan area as defined by the federal government.Learn More
Compare Your Air
Find out how your city measures up when it comes to air pollution.Learn more
Get the report card for your state's air quality, including high ozone days, particle pollution and groups at risk.Learn more
Did You Know?
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Help us fight for air
- More than 5 out of 10 people live where the air they breathe earned an F in State of the Air 2016.
- Nearly 166 million people live in counties that received an F for either ozone or particle pollution in State of the Air 2016.
- Nearly 20 million people live in counties that got an F for all three air pollution measures in State of the Air 2016.
- Breathing ozone irritates the lungs, resulting in something like a bad sunburn within the lungs.
- Breathing in particle pollution can increase the risk of lung cancer, according to the World Health Organization.
- Particle pollution can also cause early death and heart attacks, strokes and emergency room visits for people with asthma, cardiovascular disease and diabetes.
- Particles are smaller than 1/30th the diameter of a human hair. When you inhale them, they are small enough to get past the body's natural defenses.
- Ozone and particle pollution are both linked to increased risk of lower birth weight in newborns.
- Do you live near, or work on or near a busy highway? Pollution from the traffic may put you at greater risk of harm.
- People who work or exercise outside face increased risk from the effects of air pollution.
- Millions of people are especially vulnerable to the effects of air pollution, including infants, older adults and people with lung diseases like asthma.
- People of color and those earning lower incomes are often disproportionately affected by air pollution which put them at higher risk for illnesses.
- Air pollution is a serious health threat. It can trigger asthma attacks, harm lung development in children, and can even be deadly.
- You can protect your family by checking the air quality forecasts in your community and avoiding exercising or working outdoors when the unhealthy air is expected.
- Big polluters and some members of Congress are trying to change the Clean Air Act and dismantle 45 years' of progress. The Lung Association is fighting to keep the law strong to continue to protect public health.
- Cutting air pollution through the Clean Air Act will prevent at least 230,000 deaths and save $2 trillion annually by 2020.