Assessing the evolution of PM2.5 and related health impacts resulting from air quality policies in China

Air pollution represents one of the world's largest environmental health risks. Following China's promulgation of a series of harsh clean air policies, the long-term evolution of its air pollution and the effects of policies implemented were assessed. The 3D spatio-temporal dynamic evolution characteristics of PM2.5 concentrations in China were analyzed based on pixel and urban-scale PM2.5 annual mean concentration datasets from 2000 to 2019 and using emerging spatial and temporal hot spots. The reduction of premature deaths affected by environmental policies at the city scale was estimated using improved health effect assessment methods. The results show that: 1) The evolution trend of the average PM2.5 concentration in China from 2000 to 2019 follows an "M" shape; the year 2013 was an important turning point marking a significant decline in PM2.5 concentrations. 2) PM2.5 concentrations east of Hu's line showed a decreasing trend during the period 2013-2019. Although urban agglomerations are areas of severe air pollution, in recent years they showed the best control effects. 3) The proportion of population, land, and cities exposed to PM2.5 > 35 mu g/m(3) decreased by 27.98%, 13.50%, and 29.15%, respectively, during 2013-2019. 4) As a result of air quality policies, annual deaths attributable to PM2.5 pollution in 2019 decreased by 177 thousand (14.75%). This study contributes to the formulation of China's policies and action plans for pollution abatement and also provides insights and methods that could be applied to other countries.