As wildfires continue to intensify and spread across the Western United States, researchers from Colorado, Utah, and California are examining how wildfire smoke alters air quality and impacts human health.

A new study published in Atmospheric Environment reveals that massive wildfires in states such as Colorado, Oregon, and California generate significant amounts of ozone in the atmosphere. This worsens respiratory health risks and further contributes to climate warming.

Research Collaboration Across Universities

The project was a joint effort led by Derek Mallia, research assistant professor of Atmospheric Sciences at the University of Utah (UT). He worked alongside CU Denver mathematics professor emeritus Jan Mandel, and San Jose State University associate professor Adam Kochanski, both longtime collaborators in wildfire modeling.

The study concentrated on wildfires that burned across the West in 2020. Between August 15–26 of that year, more than 1 million acres burned across seven northern California counties, inflicting $12 billion in damage. Utah’s 90,000-acre East Fork fire and Oregon’s Lionshead and Beachie Creek fires, which together consumed 400,000 acres, added to the devastation. Colorado also faced smoke-filled skies and repeated air quality alerts during this period.

Modeling the Chemistry of Wildfire Smoke

Mandel developed much of the computer code used to simulate wildfire emissions and their chemical interactions in the atmosphere.

“Wildfires do not emit ozone directly,” Mandel explained. “Wildfire smoke contains chemical compounds that react with sunlight to produce ozone, often far from the fire itself. Modeling this requires sophisticated atmospheric chemistry and weather prediction software, which we integrated with our wildfire model.”

The findings show that wildfire smoke increases ozone concentrations by an average of 21 parts per billion (ppb). This is in addition to already elevated ozone levels in the West, frequently pushing concentrations above the 70-ppb health standard set by the U.S. Environmental Protection Agency.

Health Risks of Elevated Ozone

According to the Colorado Department of Public Health & Environment, ozone exposure can trigger coughing, aggravate lung and cardiovascular diseases, and even cause premature death in severe cases. The study highlights the growing public health burden as climate-driven wildfires increase in scale and frequency.

Contributions and Recognition of Jan Mandel

Mandel’s expertise spans applied mathematics, computational modeling, and high-performance computing. Over his career, he has published nearly 200 scientific articles, advised the National Science Foundation, and consulted for industries ranging from aerospace to nuclear energy.

His computational methods have been applied globally, including in the analysis of Japan’s Fukushima nuclear reactors. Recognized among the top 2% of highly cited scientists worldwide (Stanford University and Elsevier, 2025) and ranked by research.com among the top 1,000 mathematics scientists, Mandel retired in 2024 but continues his research as professor emeritus at CU Denver, contributing to NASA projects and supporting advanced computing infrastructure.

Research Team and Support

Other contributors to the study include Cambria White, an undergraduate student, and Angel Farguell, research scientist at San Jose State University’s Wildfire Interdisciplinary Research Center. Funding support came from the Utah Division of Air Quality, NASA’s FireSense Project, and the University of Utah’s Wilkes Center for Climate Science & Policy.

Summary of Key Points

• Wildfires generate chemicals that produce ozone when exposed to sunlight, far from the original fire zones.
• The study shows wildfire smoke increases ozone by an average of 21 ppb, exceeding safe health limits.
• Elevated ozone levels are linked to respiratory issues, cardiovascular disease, and premature death.
• Research involved collaborations between CU Denver, University of Utah, and San Jose State University.
• Professor emeritus Jan Mandel played a central role in computational modeling and continues advancing wildfire and atmospheric research.

Original Publication
Authors: Derek V. Mallia, Cambria White, Angel Farguell, Jan Mandel and Adam K. Kochanski.
Journal: Atmospheric Environment
DOI: 10.1016/j.atmosenv.2025.121404
Method of Research: Computational simulation/modeling
Subject of Research: Not applicable
Article Title: Simulating the impacts of regional wildfire smoke on ozone using a coupled fire-atmosphere-chemistry model
Article Publication Date: 25-Jul-2025
COI Statement: There is no conflict of interest.

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