Quantifying the interactive effects of meteorological, socioeconomic, and pollutant factors on summertime ozone pollution in China during the implementation of two important policies

Abstract

In recent years, ground-level ozone (O3) pollution has increasingly impacted both climate and human health in China. This study used the Bayesian space-time hierarchy model to reveal the spatial heterogeneity of the summertime O3 concentrations based on the monitoring data of 331 cities in China from 2015 to 2020. The GeoDetector model was then used to quantify the associations of meteorological, socioeconomic, pollutant factors, and their interactive effects with summertime O3 concentrations in six representative regions of China during the implementation of two policies: the Air Pollution Prevention and Control Action Plan (2015–2017) and the Blue Sky Defense Action policy (2018–2020). The results showed that O3 concentrations increased by 11.33% from 2015 to 2017 and slightly decreased by 4.2% from 2018 to 2020. Spatially, hot spots (high-risk areas) of O3 pollution are mainly clustered in North China (Beijing-Tianjin-Hebei, Shandong, Henan, and Shanxi) and the Yangtze River Delta (Shanghai, Anhui, and Jiangsu), while cold spots (low-risk areas) are mainly distributed in Northeast China (Heilongjiang, and Jilin) and Southwest China (Tibet, Sichuan, Guangxi, and Yunnan). Furthermore, regional differences exist among the examined meteorological, socioeconomic, and pollutant factors in terms of impacting the spatiotemporal heterogeneity of O3 concentration: exactly, the dominant meteorological factors impacting O3 concentration were average temperature and air pressure; population density and industrial output were the most important socioeconomic factor, which have impact on O3 concentration; and the dominant pollutant factors impacting O3 concentration were PM2.5 and PM10 in six representative regions of China during 2015–2017 and 2018–2020. These findings increase our understanding of the spatiotemporal characteristics of O3 pollution in China and can assist in urban policy-making.