Impacts of the differences in PM2.5 air quality improvement on regional transport and health risk in Beijing–Tianjin–Hebei region during 2013–2017

Abstract

Due to the implementation of different air pollution control measures in the Beijing–Tianjin–Hebei (BTH) region during 2013–2017, the air quality exhibited varied improvements in each province, indicating substantial changes in the interprovincial regional transport of PM2.5. In this study, we investigated these changes by using the Community Multiscale Air Quality (CMAQ) model coupled with the integrated source apportionment method (ISAM) during this period. The results showed that the concentrations of primary particles, SO42−, and NO3− decreased by 41.5, 40.8, and 1.8%, respectively due to the air pollutants emission reduction. Local air pollutant emissions were the predominant contributors of PM2.5 for each region in BTH, accounting for 41.3–47.6, 38.1–40.6, 50.6–53.6, and 54.0–57.1% of PM2.5 in Beijing, Tianjin, and northern and southern Hebei, respectively. Total PM2.5 has been mitigated by 7.1–12.3 and 5.1–11.7 μg/m3 from local and regional emission reduction, respectively in the BTH. Moreover, diverse local meteorological conditions variation increased the PM2.5 concentration by 5.3 μg/m3 in Tianjin and decreased it by 7.6, 2.0, and 4.9 μg/m3 in Beijing, and northern and southern Hebei, respectively. Estimation by integrated exposure-response function revealed that the number of premature deaths attributable to PM2.5 exposure decreased by approximately 3000 in the BTH region during 2013–2017. Additional policies that focus on PM2.5-O3 coordinated control and stringent regional joint air pollution regulation are required to substantially reduce the health impacts, especially in southern Hebei.