Comparative Analysis of PM2.5- and O3-Attributable Impacts in China: Changing Trends and Driving Factors

China’s divergent fine particulate matter (PM2.5) and surface ozone (O3) pollution trends pose critical threats to sustainable development. This study quantifies the spatiotemporal evolution of health burdens (premature deaths) and economic costs across 333 cities during 2015–2023, integrating the Global Exposure Mortality Model (for PM2.5) and Log-linear Exposure-Response Model (for O3) with income- and age-adjusted Value of Statistical Life. The results revealed an 11% decrease in PM2.5-attributable premature deaths, but this benefit was partially offset (60%) by an 87% increase in O3-related deaths. Furthermore, the per capita economic loss from O3 exposure increased by 154%, far exceeding China’s 79% growth in per capita disposable income. Decomposition analysis revealed that while diverging exposure levels primarily drove differential PM2.5- and O3-related impacts, this disparity was significantly amplified by population aging. These findings underscore the need for air quality strategies to both sustain PM2.5 reduction achievements and implement rigorous O3 controls, while integrating pollution considerations into public health frameworks with special emphasis on protecting vulnerable populations.