America's 10 Best and 10 Worst Cities for Air Pollution

Where are people choking on smog, and where can they stay healthy? The American Lung Association has answers.

RTR1ILPRedit.jpg

The sun reflects on downtown skyscrapers as it sets through the Los Angeles smog and haze. Lucy Nicholson/Reuters


Since the passage of the Clean Air Act in 1970, American air quality has steadily improved. Emissions of air pollutants have decreased by around 1 to 3 percent each year, which may not seem like much, but over a 40-year period it has led to a decrease in harmful emissions of more than 50 percent.

To track progress, each year the the American Lung Association monitors the country's air pollution with its State of the Air report. This year's report, released yesterday, shows improvements nationwide, but as you can see, some areas (many of them in California) could still use some help. Here, we've ranked the 10 most polluted and 10 cleanest cities in the U.S. on the basis of long-term particle pollution (such as smog).

Story continues below galleries




Specifically, the report tracks levels of ozone and particle pollution found across the country using the following methodology:

For particle pollution, the report examines fine particulate matter (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. For comparison, the State of the Air 2010 report covered data from 2006, 2007 and 2008.

Here are some other interesting findings—some uplifting, others worrisome—from the 2011 report:

  • Roughly half the people in the United States (50.3 percent) live in counties that have unhealthy levels of either ozone or particle pollution.
  • Roughly one in 17 people—more than 18.5 million in the United States—live in 10 counties with unhealthful levels of all three measures covered in the report.
  • More than half of the country's most-smog-polluted cities experienced their best year yet.
  • All metro areas in the 25 cities most-polluted by ozone showed improvement over last year's report.
  • All but two of the 25 cities most polluted by year-round levels of particle pollution (sometimes called soot) improved over last year's report.
  • Nineteen of those cities reported their best-ever particle pollution levels.
Presented by

Rebecca Greenfield is a former staff writer at The Wire.

Saving the Bees

Honeybees contribute more than $15 billion to the U.S. economy. A short documentary considers how desperate beekeepers are trying to keep their hives alive.

Join the Discussion

After you comment, click Post. If you’re not already logged in you will be asked to log in or register.

blog comments powered by Disqus

Video

How to Cook Spaghetti Squash (and Why)

Cooking for yourself is one of the surest ways to eat well.

Video

Before Tinder, a Tree

Looking for your soulmate? Write a letter to the "Bridegroom's Oak" in Germany.

Video

The Health Benefits of Going Outside

People spend too much time indoors. One solution: ecotherapy.

Video

Where High Tech Meets the 1950s

Why did Green Bank, West Virginia, ban wireless signals? For science.

Video

Yes, Quidditch Is Real

How J.K. Rowling's magical sport spread from Hogwarts to college campuses

Video

Would You Live in a Treehouse?

A treehouse can be an ideal office space, vacation rental, and way of reconnecting with your youth.

More in Health

Just In