'State of the Air' Report Finds Continued Improvement in Air Quality, Yet Increase in Life-threatening Spikes of Particle Pollution

American Lung Association report finds 4 in 10 Americans live in counties with unhealthful levels of air pollution

The American Lung Association's 2017 "State of the Air" report found continued improvement in air quality, but a continued increase in dangerous spikes in particle pollution is putting Americans' health at risk. The annual, national air quality "report card" found that 125 million Americans—nearly four in ten (38.9%)—lived in counties with unhealthful levels of either ozone or particle pollution in 2013-2015, placing them at risk for premature death and other serious health effects such as lung cancer, asthma attacks, cardiovascular damage, and developmental and reproductive harm.

"This year's 'State of the Air' report is a testament to the success of the Clean Air Act, which has reduced air pollution in much of the nation," said Harold P. Wimmer, National President and CEO of the American Lung Association. "As a result, Americans' lung health is far better protected today than it was before the Clean Air Act health protections began nearly five decades ago. However, this report adds to the evidence that the ongoing changes in our climate make it harder to protect human health. As we move into an ever warmer climate, cleaning up these pollutants will become ever more challenging, highlighting the critical importance of protecting the Clean Air Act."

Each year the "State of the Air" reports on the two most widespread outdoor air pollutants, ozone pollution and particle pollution. The report analyzes particle pollution in two ways: through average annual particle pollution levels and short-term spikes in particle pollution. Both ozone and particle pollution are dangerous to public health and can be lethal. But the trends reported in this year's report, which covers data collected by states, cities, counties, tribes and federal agencies in 2013-2015, are strikingly different for these pollutants.

The largest improvements in air quality tracked in the 18th annual report result from the ongoing reduction in high ozone days and in levels of year-round particle pollution. Steps to clean up emissions that produce these widespread pollutants have allowed many cities to reach the lowest concentrations of these pollutants since the "State of the Air" report first reported them. By contrast, despite these improvements, many cities hit their highest average number of days when particle levels spiked. 

"Even with the ongoing improvements, too many people in the United States live where the air is unhealthy for them to breathe. This is simply unacceptable," Wimmer said. "Everyone has a fundamental right to breathe healthy air. Our nation's leaders must do more to protect the health of all Americans."


Particle Pollution
Unhealthy particles in the air emanate from wildfires, wood-burning devices, coal-fired power plants and diesel engines. Technically known as PM2.5, these microscopic particles lodge deep in the lungs and trigger asthma attacks, heart attacks and strokes, cause lung cancer and shorten life. The report grades both daily spikes, called "short-term" particle pollution, and annual average or "year-round" level that represents the concentration of particles day-in and day-out by location.

Short-term Particle Pollution
Looking at short-term spikes in particle pollution in this year's report, spikes increased in eight of the ten most polluted cities in 2013-2015, including in the city ranked once again as having the worst short-term particle pollution problem, Bakersfield, California. Many cities experienced their highest number of spikes since the monitoring for this pollutant began in 2000-2002, with 43 million people living in counties that experienced too many days when particle pollution peaked at unhealthy levels. Increased heat, changes in climate patterns, drought and wildfires - all related to climate change - contributed to the extraordinarily high number of days with unhealthy particulate matter.


Top 10 U.S. Cities Most Polluted by Short-Term Particle Pollution (24-hour PM2.5):

  • Bakersfield, Calif.
  • Visalia-Porterville-Hanford, Calif.
  • Fresno-Madera, Calif.
  • Modesto-Merced, Calif.
  • Fairbanks, Alaska
  • San Jose-San Francisco-Oakland, Calif.
  • Salt Lake City-Provo-Orem, Utah
  • Logan, Utah-Idaho
  • Los Angeles-Long Beach, Calif.
  • Reno-Carson City-Fernley, Nev.



Year-round Particle Pollution
By contrast, year-round particle pollution levels have dropped across much of the nation, including in half of the ten cities most polluted by year-round particle pollution. While fewer people suffered from unhealthy year-round levels of particle pollution, 19.9 million people were still living with unhealthy levels in 2013-2015. Several cities, including four among the ten most polluted, reached their lowest levels ever. This continued progress comes thanks to the cleanup of coal-fired power plants and the retirement of old, dirty diesel engines, steps taken because of the Clean Air Act. Visalia-Porterville-Hanford, California was an area where levels worsened, and it ranked as the city with the worst year-round level in 2013-2015. 


Top 10 U.S. Cities Most Polluted by Year-Round Particle Pollution (Annual PM2.5):

  • Visalia-Porterville-Hanford, Calif.
  • Bakersfield, Calif.
  • Fresno-Madera, Calif.
  • San Jose-San Francisco-Oakland, Calif.
  • Los Angeles-Long Beach, Calif.
  • Modesto-Merced, Calif.
  • El Centro, Calif.
  • Pittsburgh-New Castle-Weirton, Pa.-Ohio-W.Va.
  • Cleveland-Akron-Canton, Ohio
  • San Luis Obispo-Paso Robles-Arroyo Grande, Calif.



Ozone Pollution
The 2017 report found that far fewer people suffered from unhealthy ozone pollution than in the 2016 report, although 116.5 million people lived in counties that earned an F for too much pollution. Los Angeles remains the most polluted city for ozone, yet it's one of the six of the ten most ozone-polluted cities list that have reached their best levels yet. This progress is due to steps taken under the Clean Air Act to clean up the emissions nationwide that create ozone, including emissions from power plants, cars and trucks. Inhaling ozone pollution acts like a sunburn of the lung, and can trigger coughing and asthma attacks, and may even shorten life.

Top 10 Most Ozone-Polluted Cities:

  • Los Angeles-Long Beach, Calif.
  • Bakersfield, Calif.
  • Fresno-Madera, Calif.
  • Visalia-Porterville-Hanford, Calif.
  • Phoenix-Mesa-Scottsdale, Ariz.
  • Modesto-Merced, Calif.
  • San Diego-Carlsbad, Calif.
  • Sacramento-Roseville, Calif.
  • New York-Newark, N.Y.–N.J.-Conn.-Pa.
  • Las Vegas-Henderson, Nev.-Ariz.


Cleanest Cities
The report also identified the cities with the least air pollution in 2013-2015, and found that only six cities had no days when ozone or particle pollution reached unhealthy levels and had the lowest year-round levels of particle pollution as well. 

Top Cleanest U.S. Cities (listed in alphabetical order)

  • Burlington-South Burlington, Vt.
  • Cape Coral-Fort Myers-Naples, Fla.
  • Elmira-Corning, N.Y.
  • Honolulu, Hawaii
  • Palm Bay-Melbourne-Titusville, Fla.
  • Wilmington, N.C.

"The Clean Air Act is the most important tool in the fight for healthy air; it has successfully saved lives and improved health by driving emission reductions for more than 47 years, as 'State of the Air' continues to document," Wimmer said. "We urge President Trump, EPA Administrator Scott Pruitt and members of Congress to fully fund, implement and enforce the Clean Air Act for all pollutants – including those that drive climate change and make it harder to achieve healthy air for all."

Learn more about the 2017 "State of the Air" report at Lung.org/sota. For media interested in speaking with an expert about lung health and healthy air, contact the American Lung Association at [email protected] or 312-801-7628.

For more information, contact:

Allison MacMunn
[email protected]

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