Metropolitan areas were ranked by the highest weighted average among the counties within a given Metropolitan Statistical Area as of 2013 as defined by the White House Office of Management and Budget (OMB). MSA and CSA are terms used by the U.S. Office of Management and Budget for statistical purposes. MSA stands for Metropolitan Statistical Area and includes one or more counties. CSA stands for Combined Statistical Area and may include multiple MSAs and individual counties.
Metropolitan Statistical Areas
Did You Know?
- More than one in three Americans live where the air they breathe earned an F in “State of the Air” 2023.
- Nearly 120 million people live in counties that received an F for either ozone or particle pollution in “State of the Air” 2023.
- More than 18 million people live in counties that got an F for all three air pollution measures in “State of the Air” 2023.
- Breathing ozone irritates the lungs, resulting in inflammation—as if there were a bad sunburn in the lungs.
- Breathing in particle pollution can increase the risk of lung cancer.
- Particle pollution can cause early death and heart attacks, strokes and emergency room visits.
- Particles in air pollution can be 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.
- If you live or work near a busy highway, traffic pollution 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 children, older adults and people with lung diseases such as asthma.
- People of color and those with lower incomes are disproportionately affected by air pollution that puts them at higher risk for illness.
- Air pollution is a serious health threat. It can trigger asthma attacks, harm lung development in children, and even be deadly.
- You can protect yourself by checking the air quality forecast in your community and avoiding exercising or working outdoors when unhealthy air is expected.
- Climate change enhances conditions for ozone pollution to form and makes it harder clean up communities where ozone levels are high.
- Climate change increases the risk of wildfires whose smoke spreads dangerous particle pollution.
- Policymakers at every level of government must take steps to clean the air their residents breathe.
- The nation has the Clean Air Act to thank for decades of improvements in air quality. This landmark law has driven pollution reduction for over 50 years.
- EPA estimated that cutting air pollution through the Clean Air Act was projected to prevent over 230,000 deaths and save nearly $2 trillion in 2020 alone.