A new analysis of 20 years of satellite observations links wildfire smoke to higher ground-level ozone across the United States. Researchers report that pollutants formed from wildfire emissions raise ozone levels at the surface, creating an additional health risk beyond direct smoke exposure. The study, led by Minghao Qiu of Stony Brook University and published in Science Advances, finds that wildfire-derived ozone is associated with about 2,045 excess deaths per year on average nationwide. The estimate reflects health impacts attributed to elevated ozone levels over the study period. Both outlets describe the work as identifying a “hidden” pathway in which wildfire smoke alters atmospheric chemistry and leads to increased ozone concentrations near the ground, rather than only affecting air quality temporarily during active fires. The results are based on satellite data and a modeling approach that evaluates how changes in ozone related to wildfire activity correspond to mortality. The study therefore concludes that wildfire events can contribute to additional year-to-year health burdens through ozone pollution, even when considering broader temporal patterns captured over two decades.