The Characteristics of Ozone Concentration Variation and Associated Health and Agricultural Effects during Heatwaves in China

The frequency of heatwave and ozone pollution events in China has increased significantly, posing dual threats to human health and agricultural production. This study systematically analyzed the spatiotemporal evolution of ozone pollution during heatwaves and its compound impacts on health and crops using national ozone monitoring data from 2015 to 2024 and the ERA5 reanalysis dataset. Results demonstrate substantial ozone concentration increases in the Fenwei Plain (FP), Beijing–Tianjin–Hebei (BTH) region, Sichuan Basin (SB), Yangtze River Middle Reaches Urban Agglomerations (YRMRU), and Yangtze River Delta (YRD) (with a slight decrease in the Pearl River Delta (PRD)). In the SB, YRD, YRMRU, BTH, and PRD, the average annual growth rate of nighttime average ozone concentration (NTAvg) exceeds that of daytime average ozone concentration (DTAvg), while the opposite pattern is observed in the FP. Nationwide ozone exposure caused total yield losses of 5.84 million tons for wheat, rice, and maize, with associated economic losses approximating USD 2.98 billion. During concurrent heatwave and ozone exceedance events, the highest population-attributable fractions (PAFs) for three major disease categories were observed in BTH, Shanxi, and Shandong (PAF > 2%). Therefore, there is an urgent need to develop coordinated air quality improvement strategies that address both heatwaves and ozone pollution.