Year Round Particle Pollution

The State of the Air 2012 finds continued progress in cutting year-round particle pollution in 2008-2010, compared to the 2011 report. Thanks to reductions in emissions from coal-fired power plants and the transition to cleaner diesel fuels and engines, cleaner air shows up repeatedly in the monitoring data, especially in the eastern U.S.

  • Nearly 6.4 million people (2.1%) in the United States live in an area with unhealthful year-round levels of particle pollution. These people live in areas where chronic levels are regularly a threat to their health. Even when levels are fairly low, exposure to particles over time can increase risk of hospitalization for asthma, damage to the lungs and, significantly, increase the risk of premature death.
  • All but three cities with the most year-round particle pollution improved over the previous report1, 2: Philadelphia, PA; Fairbanks, AK; and Columbus, GA each had worse average year-round levels in 2008-2010 than in 2007-2009. Bakersfield, CA, remained the city with the highest year-round average levels. Improving over the previous report were these 25 metropolitan areas: Bakersfield, CA; Hanford, CA; Los Angeles, CA; Visalia, CA; Fresno, CA; Pittsburgh, PA; Phoenix, AZ; Cincinnati, OH; Louisville, KY; St. Louis, MO; Birmingham, AL; Weirton-Steubenville, WV-OH; Indianapolis, IN; Cleveland, OH; Dayton, OH; Charleston, WV; Huntington, WV; Parkersburg, WV; Wheeling, WV; Houston, TX; Atlanta, GA; Davenport, IA; Fairmont, WV; and Hagerstown, MD.
  • Four cities moved on to the list of the most polluted cities this year despite having improved annual particle average levels because other cities made greater improvements. Those cities included Wheeling, WV; Atlanta, GA; Fairmont, WV; and Davenport, IA.
  • Six cities that had previously been ranked among the most polluted improved enough to fall off of the list: Detroit, MI; New York, NY; Lancaster, PA; Modesto, CA; York, PA; and Knoxville, TN. This report marks the first time Detroit and York have been off this list entirely.
  • Only seven cities averaged levels showing more pollution than the official national standard allows: Bakersfield, CA; Hanford, CA; Los Angeles, CA; Visalia, CA; Fresno, CA; Pittsburgh, PA; and Phoenix, AZ. Twenty of these cities actually had average year-round particle pollution below the official “safe” level, the EPA-adopted national air quality standard. However, that standard is out of date. The American Lung Association and other public health and medical groups have long supported a much more protective national air quality standard for particle pollution. The Lung Association has taken legal action to require EPA to update the particle pollution standards.

What is year-round particle pollution?

Particle pollution is a mix of very tiny solid and liquid particles in the air. “Year-round” refers to an annual average level that represents the concentration of particles day-in-and-day-out. To learn more, go to Health Risks.

» 25 Cities Most Polluted by Year-round Particle Pollution
» 25 Cleanest Cities for Year-round Particle Pollution

  1. The usual list of 25 cities with the most year-round particle pollution actually includes 27 cities because of ties in the rankings values among many cities.
  2. 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: The American Lung Association’s State of the Air 2012 report shows continued strong progress in improved air quality, but unhealthy levels of air pollution still exist across the nation.

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