Assessment of the short-term mortality effect of the national action plan on air pollution in Beijing, China

The Air Pollution Prevention and Control Action Plan (referred to as the Action Plan henceforth) provides a golden opportunity for China to evaluate whether the remarkable air quality improvements as a result of the plan have brought about health benefits to residents. Based on the ground-level particulate matter with an aerodynamic diameter of less than 2.5 mu m (PM2.5) concentrations and the daily respiratory-cardiovascular mortality, we aimed to assess changes in the mortality effect associated with short-term exposure to PM2.5 due to the implementation of the Action Plan in Beijing. We analyzed the changes in PM2.5 concentrations and air quality during the pre- and post-emission reduction periods. We then used the generalized additive model to estimate the changes in mortality risk associated with PM2.5 exposure during both periods. We found that following the introduction of the Action Plan, the annual average PM2.5 concentrations declined from 101.7 mu g m(-3) in 2013 to 58.6 mu g m(-3) in 2017, attaining the target of the plan (60 mu g m(-3)). The remarkable reduction in PM2.5 concentrations has led to a marked decrease in mortality risk. Compared with the pre-emission reduction level, total respiratory mortality decreased from 0.56% (95% CI: 0.40%-0.73%) to 0.43% (95% CI: 0.23%-0.63%), while the total cardiovascular mortality decreased from 0.44% (95% CI: 0.37%-0.52%) to 0.29% (95% CI: 0.19%-0.39%). Significant decreases were also observed in sex-specific subgroups. Our study implied that the significant efforts of the nation to clean China's air has yielded positive results of air quality improvement and human health protection in Beijing. However, the ambient air pollution in Beijing remains severe. The PM2.5 concentrations still exceed the level (annual average of 10 mu g m(-3)) recommended by the World Health Organization. Thus, consistent efforts are required to implement the emission abatement measures to continuously curb air pollution and protect public health.