Year Round Particle Pollution

The State of the Air 2011 finds continued progress in cutting year-round particle pollution in 2007-2009, compared to the 2010 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.

  • Over 18.5 million people (6%) 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 two cities with the most year-round particle pollution improved over the previous report.1
    Bakersfield, CA, and Hanford, CA, each had worse average year-round levels in 2007-2009 than in 2006-2008. Bakersfield, CA, moved into the most polluted city rank. Improving over the previous report were these 25 metropolitan areas2: Los Angeles, CA; Phoenix, AZ; Visalia, CA; Pittsburgh, PA; Fresno, CA; Birmingham, AL; Cincinnati, OH; Modesto, CA; Louisville, KY; Cleveland, OH; Weirton-Steubenville, WV-OH; Charleston, WV; Huntington, WV; Indianapolis, IN; St. Louis, MO; Detroit, MI; Houston, TX; Hagerstown, MD; New York, NY; Dayton, OH; Lancaster, PA; York, PA; Philadelphia, PA; Knoxville, TN; and Parkersburg, WV.
  • Only eight cities averaged levels showing more pollution than the official national standard allows:
    Bakersfield, CA; Los Angeles, CA; Phoenix, AZ; Visalia, CA; Hanford, CA; Fresno, CA; Pittsburgh, PA; and Birmingham, AL. Nineteen of these cities actually had levels of year-round particle pollution that were lower than the official national air quality standard. However, that standard is currently under review. 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.

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.

25 Cities Most Polluted by 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: Steps you can take to improve air quality will also help fight climate change. Drive less. Don’t burn wood or trash. Use less electricity. Make sure your school system requires clean buses.

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SOTA 2011 Survey