Short-term Particle Pollution

What Are "Short-term Levels" of Particle Pollution?

Particle pollution can be harmful even if it is inhaled over just a few hours or days, even if the year-round averages are low. "Short-term levels" refers to just such spikes. These represent levels averaged over a 24-hour period. Those days or weeks of high levels can be dangerous, even deadly. Learn more about short-term particle pollution.

Bakersfield, CA retains its ranking as the most polluted city for spikes in particle pollution in this report as it had in the 2016 report and in four other reports since 2010. Unfortunately, Bakersfield suffered more unhealthy days on average in this year’s report.

Fifteen of the 25 most-polluted cities had more days with higher episodes of particle pollution, including eight that suffered their most days since the report started and one that maintained its worst report ever.

Cities recording their worst short-term particle episodes in 2013-2015 concentrated in the western states: Visalia-Porterville-Hanford, CA; Fairbanks, AK; San Jose-San Francisco.; Reno, NV; El Centro, CA; Lancaster, PA; Anchorage, AK; and Bend-Redmond-Prineville, OR, marking that city’s first time on this list.

Seven other western cities recorded more unhealthy days than in the previous report. : Bakersfield, CA; Salt Lake City, UT; Logan, UT-ID; Los Angeles; Sacramento, CA; Seattle-Tacoma, WA; and Medford-Grants Pass, OR.

Fortunately, eight cities improved with fewer days of spikes in particle levels in 2013-2015 than in 2012-2014. Six of these are western cities: Fresno-Madera, CA; Modesto-Merced, CA; Missoula, Mont.; Yakima, WA; Eugene, OR; and Phoenix, AZ Two cities in Pennsylvania also improved: Harrisburg-York-Lebanon; and notably, Pittsburgh. Pittsburgh, which had been ranked the most polluted city in the same category in the 2008 report, experienced its fewest unhealthy days ever in 2013-2015.

Eight cities suffered their highest number of spikes in particle pollution since the reporting began.

Philadelphia and South Bend, Ind., recorded the same number of days in this year’s report as in last year’s report. However, as noted above, that kept South Bend stuck at its worst average number of unhealthy particle pollution days.

Regional differences. Locations with many days of spikes shows the burden of concentrated smoke from wildfires, brushfires and wood-burning devices. For example, Reno, NV, suffered wildfires, and Logan, UT-ID; Eugene, OR, and Fairbanks and Anchorage, AK, rely heavily on wood burning devices for heat. Wildfires have increased, in part, from drought and heat enhanced by climate change. Inversions trap particles in place behind mountains and ridgelines. For example, inversions in the San Joaquin Valley in California and in the Wasatch Ridge in Utah contributed to high pollution days in both states.

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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