Trends and characteristics of ozone and nitrogen dioxide related health impacts in Chinese cities

Abstract

Ambient ozone pollution has been becoming severe and attributed to considerable health impacts in China. Nitrogen dioxide (NO2) is involved in atmospheric ozone production while also affecting public health directly. Joint control ozone and NO2 pollution would be of significance. This study quantitatively assessed the health impact attributed to ambient ozone and NO2 pollution in 338 Chinese cities from 2015 to 2020. The results reveal the generally opposite trends of ozone- and NO2-related health impacts in China. From 2015–2020, respiratory and chronic obstructive pulmonary disease (COPD) health impacts attributed to ozone in 338 cities increased by 65.30% and 63.98%. The NO2-attributed health impacts decreased by 24.80% and 24.62%. In 2020, the ozone- and NO2-related respiratory health impacts were 3.96 million DALYs (disability-adjusted life years) and 1.47 million DALYs. High health impacts are concentrated in big cities and city clusters. In 2020, the sum of ozone- and NO2-related respiratory health impacts in the top 20 cities was 0.98 million DALYs and 0.44 million DALYs, accounting for 24.70% and 30.24% of the 338 cities. The population attribution fraction analysis identified the increasing distributional consistency of ozone and NO2-related health impacts, emphasizing the necessity and possible efficiency of ozone-NO2 joint control. Emission source analysis based on gridded data provided a reference for understanding health impacts and developing targeted strategies.