Study on the spatial and temporal evolutionary characteristics of ozone concentration and the impact of human activities in China in 2019

Ozone (O₃) pollution has a profound impact on human health, vegetation development, and the ecological environment, making it a critical focus of global academic research. In recent years, O₃ pollution in China has been on a steady rise, with ozone emerging as the sole conventional pollutant to consistently increase in concentration without any decline. This study conducted a quantitative analysis of O₃ concentrations across 367 Chinese cities in 2019, examining spatial autocorrelation and local clustering of O₃ levels, and investigated the diverse relationships between human activity factors and O₃ concentration. The seasonal fluctuation of O₃ exhibited the “M-type” pattern, with peak concentrations in winter and the lowest levels in summer. The center of O₃ pollution migrated southeastward, with the area of highest concentration progressively shifting south along the eastern coast. Moreover, O₃ concentration showed a strong positive correlation with population density, road freight volume, and industrial emissions, suggesting that human activities, vehicle emissions, and industrial operations are significant contributors to O₃ production. The results provide comprehensive information on the characteristics, causes, and occurrence mechanism of O₃ in Chinese cities that can be utilized by global government departments to formulate strategies to prevent and control O₃ pollution.