Health Risks of Smoke and Ozone Rise in the West as Wildfires Worsen

High levels of two dangerous pollutants are occurring with increasing frequency, researchers say

A forest burns against a black silhouette of a fire fighter
Scientists identified a link between the severity of air pollution events and the amount of land that burned in nearby regions in the preceding week. Patrick T Fallon via Getty Images

The levels of two dangerous air pollutants are increasing alongside wildfires in parts of the western United States, according to new research published in Science Advances.

The study found worsening wildfires led to a surge in ozone and smoke particulates, which could pose a host of health issues for millions of Americans living in the region. The researchers say the spike in harmful pollutants is a result of wildfires and expect the issue to escalate with climate change.

“It’s this perfect storm of things which are all increasing to produce more air pollution and more population exposure to air pollution,” says study author Dmitri A. Kalashnikov, a doctoral student at Washington State University in Vancouver, to Kate Baggaley for Popular Science.

When wildfires rage, they release a hazardous cocktail of compounds that can trap heat and cause health issues for those living nearby. One pollutant the research team looked at was the sooty material in smoke, a fine particulate matter called “PM2.5” that is smaller than the width of a human hair. Because the tiny particulates are less than 2.5 micrometers in size, they can travel deep into lungs tissues and may even enter the bloodstream, leading to cardiovascular or respiratory damage.

The scientists also measured ozone, a significant component of smog, which can inflame airways and make lungs more susceptible to infection. When people are exposed to both pollutants at the same time, ozone and fine particulate matter are disproportionately harmful.

In their study, the team combed through two decades of daily records of fine particulate matter and ozone to find a worsening picture of the West. The researchers found individuals living in the western U.S. are exposed to higher levels of the two pollutants more frequently, and those exposure events cover larger areas and last longer than they did 20 years ago.

“These trends are congruent with what you would expect with a warming and drying climate,” Kalashnikov tells Henry Fountain of the New York Times. “We would expect to see more of these kinds of widespread co-occurring air pollution events in the Western U.S.”

The team also examined the connection between increased pollution and stagnant zones of high-pressure air, sometimes called heat domes. These pockets of hot air can create the perfect hot and dry conditions to spark wildfires. They can also cause dangerous heatwaves like the one that baked the Pacific Northwest in June 2021. These heat domes increased significantly since 2000, according to the research.

Additionally, the authors identified a link between the severity of air pollution events and the amount of land that burned in nearby regions in the preceding week. As wildfire severity continues to increase across much of the west, Kalashnikov is concerned for the health of residents.

“We are expecting these trends to continue given climate change, so the best we can do at this point is to increase awareness and take steps to protect ourselves from worsening air pollution,” Kalashnikov tells Popular Science.

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