Overview
- A University of Iowa–led study published June 4, 2026 used a 1‑km, daily ozone dataset to show national ozone trends flipped after 2015 with wildfire emissions as the main driver.
- Researchers combined about 1,000 ground monitors, satellite observations, atmospheric models, weather data and deep learning to produce the first 2003–2024 daily ozone map at kilometer scale.
- The study estimates wildfire-driven ozone has added about 318 premature U.S. deaths per year since 2013 and erased roughly 5.3 years of ozone-control progress since 2015.
- During the extreme 2022–2024 fire seasons, including record 2023 Canadian fires, wildfires exposed an estimated 43 million additional Americans to ozone above federal standards and sent smoke hundreds to thousands of miles downwind.
- Authors and NASA say the findings complicate state and federal air-quality enforcement and standard-setting but note new tools such as TEMPO satellite data and the FireAQ decision-support system can improve monitoring and public health responses.