Ozone Pollution

The State of the Air 2011 finds continued progress in cutting ozone pollution in 2007-2009, compared to the 2010 report. Thanks to reductions in emissions from coal-fired power plants and the transition to cleaner cars, the air has gotten much cleaner across the nation. However, millions still breathe too much ozone pollution.

Nearly half the people in the United States (48.2%) live in areas with unhealthful levels of ozone.
Counties that were graded F for ozone levels have a combined population of almost 148.1 million. These people live in the 338 counties where the monitored air quality places them at risk for premature death, coughing, wheezing, asthma attacks, decreased lung function, respiratory infection, lung inflammation and worsened lung diseases. The actual number who breathe unhealthy levels of ozone is likely much larger, since this number does not include people who live in adjacent counties in metropolitan areas where no monitors exist.

  • Each of the 25 cities with the most ozone pollution improved their air quality over the past year’s report. More than half of the country’s most smog-polluted cities experienced their best year yet—but people living there are still forced to breathe air that reaches dangerous levels.
  • Of the 25 metropolitan areas most polluted by ozone, fifteen reported their best ozone scores since the State of the Air reports began1: Los Angeles, CA; Bakersfield, CA; Fresno, CA; Sacramento, CA; Houston, TX; Dallas-Fort Worth, TX; El Centro, CA; Washington-Baltimore, DC-MD-VA; New York, NY; Knoxville, TN; Phoenix, AZ; Philadelphia, PA; Atlanta, GA; Pittsburgh, PA; and Las Vegas, NV.

What is ozone?

Ozone is a molecule of three oxygen atoms. Ozone attacks lung tissue by reacting chemically with it.

25 Most Ozone-Polluted Cities

  1. Full names for all these metropolitan areas can be found in the tables showing the most polluted and cleanest cities. The full metropolitan areas often include multiple counties, incorporated cities and counties in adjacent states.

FACT: When inhaled, ozone irritates the lungs, resulting in something like a bad sunburn within the lungs.

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SOTA 2011 Survey