Key Findings for 2009-2011

"State of the Air 2013 shows that cleaning up air pollution produces healthier air across the nation. Thank the Clean Air Act for that progress."

Thanks to the Clean Air Act, the United States continues to make progress providing healthier air. The "State of the Air 2013" shows that the nation’s air quality is overall much cleaner, especially compared to just a decade ago. Still, over 131.8 million people—42 percent of the nation—live where pollution levels are too often dangerous to breathe. Despite that risk, some seek to weaken the Clean Air Act, the public health law that has driven the cuts in pollution since 1970.

Still, 131.8 million people live in counties that had unhealthy levels of either ozone or particle pollution. That's 4 in 10 of us."

The "State of the Air 2013" report looks at levels of ozone and particle pollution in 2009, 2010, and 2011 across the United States. The report uses the most current quality-assured data available nationwide for these analyses—data collected by states, tribes and federal agencies from local monitors. Click on the links below to learn more about what the Lung Association found.

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For ozone pollution, the report looks at levels averaged over an 8-hour period each day. The report examines particle pollution (PM2.5) in two different ways: averaged year-round (annual average) and over short-term levels (24-hour). For both ozone and short-term particle pollution, the analysis uses a weighted average number of days that allows recognition of places with higher levels of pollution. For the year-round particle pollution rankings, the report uses averages calculated and reported by the U.S. Environmental Protection Agency (EPA). For comparison, the "State of the Air 2012" report covered data from 2008, 2009 and 2010. More details about this process is in Methodology.

Overall Trends

Sources of Pollution
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Thanks to stronger standards for pollutants and for the sources of pollution, the United States has seen continued reduction in ozone and particle pollution as well as other pollutants for decades. This chart from the EPA shows that, since 1970, the air has gotten cleaner while the population, the economy, energy use and miles driven increased greatly. Even as the economy continues to recover after the recession, overall air emissions that create the six most widespread pollutants continue to drop.

Air emissions have dropped steadily since 1970 thanks to the Clean Air Act. Even as the economy continues to recover from the recession, emissions that contribute to the most widespread pollutants continue to drop. (Source: U.S. EPA, Air Trends, 2012)
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Air emissions have dropped steadily since 1970 thanks to the Clean Air Act. Even as the economy continues to recover from the recession, emissions that contribute to the most widespread pollutants continue to drop. (Source: U.S. EPA, Air Trends, 2012)

  • Ozone Pollution — Nearly 4 in 10 people lived in areas with unhealthful levels of ozone in 2009-2011. See which cities with the worst ozone had their cleanest years yet, and which had even more unhealthy air days.
  • Year-round Particle Pollution — More than 44.3 million people live in an area burdened year-round by unhealthful levels of deadly particle pollution. See which cities saw continued progress in cleaning up sources and which suffered even more pollution.
  • Short-term Particle Pollution — Many cities endured more days where particle pollution spiked during this period. Fifteen percent (15%) of people in the United States live where they suffered too many days with unhealthful levels of particle pollution.
  • Cleanest Cities — Only four cities made the cleanest list in all three categories, but several were among the cleanest in two.
  • People at Risk —More than 4 in 10 people live in counties that have unhealthful levels of either ozone or particle pollution. Learn more about people who face the greatest risk—probably someone you know is one of them.
  • What Needs to be Done to Get Healthy Air —What do we need to do as a nation? How can you help clean up the air?