Regional joint PM-O control policy benefits further air quality improvement and human health protection in Beijing-Tianjin-Hebei and its surrounding areas.

Beijing-Tianjin-Hebei and its surrounding areas (hereinafter referred to as "2+26" cities) are one of the most severe air pollution areas in China. The fine particulate matter (PM) and surface ozone (O) pollution have aroused a significant concern on the national scale. In this study, we analyzed the pollution characteristics of PM and O in "2+26" cities, and then estimated the health burden and economic loss before and after the implementation of the joint PM-O control policy. During 2017-2019, PM concentration reduced by 19% while the maximum daily 8 hr average (MDA8) O stayed stable in "2+26" cities. Spatially, PM pollution in the south-central area and O pollution in the central region were more severe than anywhere else. With the reduction in PM concentration, premature deaths from PM decreased by 18% from 2017 to 2019. In contrast, premature deaths from O increased by 5%. Noticeably, the huge potential health benefits can be gained after the implementation of a joint PM-O control policy. The premature deaths attributed to PM and O would be reduced by 91.6% and 89.1%, and the avoidable economic loss would be 60.8 billion Chinese Yuan (CNY), and 68.4 billion CNY in 2035 compared with that in 2019, respectively. Therefore, it is of significance to implement the joint PM-O control policy for improving public health and economic development.