New research has revealed which areas in the United States face the worst air quality as a result of wildfire smoke, with regions in the West seeing the most severe impacts.
The study, led by Dan Jaffe, an atmospheric chemist at the University of Washington, utilized a novel algorithm to analyze five years of wildfire smoke data using satellite imagery and PM2.5 (fine particulate matter) levels. This approach identified the hardest-hit cities and shed light on the broader health implications of wildfire smoke.
The findings were presented on Tuesday at the American Geophysical Union’s 2024 annual meeting.
“While wildfire smoke happens every year and impacts some communities, our research tells us which communities are consistently most impacted and therefore which communities should be doing the most to plan ahead for smoke,” Jaffe told Newsweek.
Traditionally, cities in the West have borne the brunt of wildfire smoke. Medford, Grants Pass and Bend in Oregon topped the list as the smokiest cities, on average, between 2019 and 2023, with Medford reporting daily PM2.5 levels averaging 4.2 µg/m³ annually.
Other hotspots are Gardnerville Ranchos, Nevada (3.4 µg/m³), and Yakima, Washington (2.5 µg/m³).
But 2023 disrupted this pattern. Smoke from Canadian wildfires engulfed the Midwest and East Coast, driving emergency room visits for respiratory conditions to unprecedented levels.
Cities like Detroit attributed up to a third of PM2.5-related emergency room (ER) visits to wildfire smoke, and Baltimore saw its annual PM2.5 average rise from 0.7 µg/m³ to 2.0 µg/m³.
Stuart Westmorland/Getty
Jaffe’s algorithm, which cross-references satellite smoke imagery with ground-level PM2.5 readings, offers a rapid method for identifying smoke-affected areas and quantifying their impact.
He said the team plans to have analysis of 2024 data completed by February 2025. “This is much faster than any other approaches,” he added.
Health data integrated into the study underscored the urgency of the problem. In Bend, normally a city with clean air, 60 percent of asthma-related ER visits in 2023 were linked to wildfire smoke.
Nationwide, the total number of smoke-related ER visits spiked by 16,000, compared with previous years.
As climate change drives larger and more frequent wildfires, the population exposed to hazardous smoke is growing.
Areas near major wildfire zones, such as Northern California and parts of Oregon and Nevada, remain most vulnerable. However, 2023’s unusual wildfire patterns suggest that no region is immune.
“All predictions are for more smoke from both the Western U.S. and Canada as we continue to warm,” Jaffe said. “Every community in the West and, well, everywhere needs to take more steps like those mentioned above.”
He said regions need to increase preparedness for smoke by increasing awareness of health impacts, providing smoke shelters and increasing access to air purifiers in low-income communities.
“We need to let people know that breathing smoke is bad for your health. Even low levels of smoke inhaled for a long time are bad, and the evidence is accumulating that smoke is worse than other forms of air pollution,” Jaffe said.
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Reference
Jaffe, D. A., Lee, H., Goldberg, D. L., & O’Dell, K. (2024, December 10). The Smokiest Cities in America. AGU24. https://agu.confex.com/agu/agu24/meetingapp.cgi/Paper/1603711
