DENVER — A new study from a collaboration of researchers in Colorado, Utah, and California is shedding light on a hidden danger of Western wildfires: the creation of harmful ozone, even far from the flames. The research, published in the journal Atmospheric Environment, reveals that smoke from large blazes not only directly impacts air quality but also triggers a chemical reaction that can harm human health and contribute to climate change.
As wildfires become more frequent and larger in scale across the West, a team of researchers is delving into how the smoke from these fires affects the air and our well-being. The study’s findings demonstrate that significant wildfires, like those that have ravaged parts of Colorado, Oregon, and California in recent years, release large amounts of ozone into the atmosphere.
“Wildfires do not emit ozone directly,” said Jan Mandel, a professor emeritus of mathematics at the University of Colorado Denver and a member of the research team. “Wildfire smoke contains chemical compounds that react with sunlight to produce ozone, often far from the fire itself.”
The research, led by Derek Mallia, a research assistant professor of Atmospheric Sciences at the University of Utah, focused on the large-scale wildfires of 2020. This period saw catastrophic fires across the Western U.S., including blazes that burned over one million acres in California, the 90,000-acre East Fork fire in Utah, and the Lionshead and Beachie Creek fires in Oregon, which together consumed 400,000 acres. During this time, multiple air quality and pollutant alerts were issued in Colorado as residents contended with smoke-filled skies.
Mandel, who has a long-standing collaboration with Mallia, developed most of the computer code used to model the wildfire chemical emissions. This sophisticated software integrates atmospheric chemistry and weather prediction to track the path and impact of these emissions.
The study concludes that, on average, the presence of wildfire smoke increases ozone concentrations by 21 parts per billion (ppb). This addition pushes existing ozone levels in the West closer to the 70-ppb health standard established by the U.S. Environmental Protection Agency.
Ozone is a recognized health hazard. According to the Colorado Department of Public Health & Environment, exposure can lead to a range of symptoms, from coughing and shortness of breath to more severe conditions like lung and cardiovascular disease, and in some cases, premature death.
The study’s findings underscore the far-reaching and complex health consequences of Western wildfires, demonstrating that their impact is not limited to the immediate vicinity of the fire but can affect communities and individuals hundreds of miles away.