Year-round 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. Learn more about year-round particle pollution.

Fifteen of the 25 cities with the highest year-round particle pollution reduced their levels, including 12 that reached or matched their lowest levels ever in 2013-2015. The 10 most polluted remain the only metropolitan areas in the nation that fail to meet the official national limits on annual fine particle pollution.

Eight of the 25 cities suffered higher annual particle pollution levels, including Visalia-Porterville-Hanford, CA, the city that ranked as the most polluted for year-round levels. In addition to Visalia, 3 other California cities –Bakersfield; San Jose-San Francisco; and San Luis Obispo – and 2 other cities in the western states-- Medford-Grants Pass, OR, and Fairbanks, AK had worse year-round levels. The two remaining cities with higher year-round average levels were in the east: Johnstown-Somerset, PA and New York City metro area. San Luis Obispo reached its worst level ever.

Two cities in the list of the 25 most polluted maintained the same level as in the 2016 report: Cleveland and Houston.

Twelve cities improved to their lowest levels of year-round particle pollution.

Regional differences. Much of the eastern and middle parts of the country have improved significantly since the report first started to track these fine particles. Much of that improvement came from reducing emissions from coal-fired power plants, as well as benefiting from nationwide cleanup of diesel engines. However, the western states’ burden of so much wildfire smoke and high inversions seems to have moved from just being a short-term problem to adding to the burden year-round. Cities in California’s San Joaquin valley were hit hard, as were other locations where particle pollution is usually limited to the short spikes, including Fairbanks, AK, and Medford-Grants Pass, OR.

Data remain missing in all of Illinois, most of Tennessee and parts of Maine. That means that millions of people, including in large cities Chicago, Memphis and St. Louis (which is missing suburban counties in Illinois), cannot know how much particulate matter they are breathing.

Did You Know?

  1. More than 4 out of 10 people live where the air they breathe earned an F in State of the Air 2017.
  2. More than 125 million people live in counties that received an F for either ozone or particle pollution in State of the Air 2017.
  3. More than 18 million people live in counties that got an F for all three air pollution measures in State of the Air 2017.
  4. Breathing ozone irritates the lungs, resulting in something like a bad sunburn within the lungs.
  5. Breathing in particle pollution can increase the risk of lung cancer, according to the World Health Organization.
  6. Particle pollution can also cause early death and heart attacks, strokes and emergency room visits for people with asthma, cardiovascular disease and diabetes.
  7. Particles are smaller than 1/30th the diameter of a human hair. When you inhale them, they are small enough to get past the body's natural defenses.
  8. Ozone and particle pollution are both linked to increased risk of lower birth weight in newborns.
  9. Do you live near, or work on or near a busy highway? Pollution from the traffic may put you at greater risk of harm.
  10. People who work or exercise outside face increased risk from the effects of air pollution.
  11. Millions of people are especially vulnerable to the effects of air pollution, including infants, older adults and people with lung diseases like asthma.
  12. People of color and those earning lower incomes are often disproportionately affected by air pollution that put them at higher risk for illnesses.
  13. Air pollution is a serious health threat. It can trigger asthma attacks, harm lung development in children, and can even be deadly.
  14. You can protect your family by checking the air quality forecasts in your community and avoiding exercising or working outdoors when the unhealthy air is expected.
  15. Big polluters and some members of Congress are trying to change the Clean Air Act and dismantle 47 years of progress. The Lung Association is fighting to keep the law strong to continue to protect public health.
  16. Cutting air pollution through the Clean Air Act will prevent at least 230,000 deaths and save $2 trillion annually by 2020.
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