FILE - The Old Mill District in Bend, Ore., clouded in smoke Sept. 12, 2022. Bend, Medford and Grants Pass were among the smokiest cities in the U.S. identified in new research from the University of Washington Bothell.
Joni Auden Land / OPB
Over the past five years, more than 36 million acres of land have burned in wildfires across the United States. But the impacts of those wildfires reached far beyond the areas actually touched by fire: wildfire smoke carried hundreds and sometimes thousands of miles, affecting millions of people downwind.
Just ask residents of Medford, Grants Pass and Bend, the top three smokiest cities in the country from 2019 to 2023.
Researchers including Dan Jaffe and Haebum Lee at the University of Washington Bothell have developed a new way to quickly determine the number of days communities across the country experienced higher than normal levels of smoke. They combined particulate readings from air quality stations on the ground with satellite imagery.
In addition to Medford, Grants Pass and Bend, several other Oregon cities made their top 10 list: Klamath Falls (#5), Roseburg (#6) and Eugene/Springfield (#10). The smokiest city in Washington was Yakima (#15).
Particulate pollution comes from numerous sources: car and truck exhaust, power plants and other industry, wood stoves, and agriculture. In all of these Oregon and Washington cities, the particulate from wildfire smoke (PM 2.5) comprised at least 30% of the total particulate pollutants residents were exposed to each year.
The tiny particulates found in wildfire smoke are so small that they can be absorbed into the bloodstream through the lungs. They can cause minor and serious respiratory issues and increase the risk of heart attacks and strokes.
To try to determine the health impacts of wildfire smoke on communities, the researchers also looked at the number of emergency room visits caused by asthma in different communities. From 2019-23, they linked an estimated 42,500 ER visits to smoke exposure. The analysis showed that high-population metro areas in the Eastern U.S. ranked highest (in the number of individual cases) for these kinds of smoke-related health impacts.
In both Portland and Seattle metro areas, about 15% of all asthma-related ER visits could be attributed to wildfire smoke.
The new research was presented at the American Geophysical Union annual meeting in Washington, D.C.
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