An estimate of population exposure to automobile source PM2.5 in Beijing using spatiotemporal analysis

Automobile source is a significant contributor to ambient particulate matter (PM), especially for PM_2.5, which has become of growing public concern due to its urgency and sensitivity related to human health. A set of hourly PM_2.5 data from 35 monitoring stations published by Beijing Environmental Protection Bureau (BJ-EPB), covering 2 months during autumn 2013 was collected. The association between PM_2.5 concentrations at midnight and morning rush hours has been analyzed to estimate PM_2.5 concentration from automobile source. Spatial interpolation method was conducted in order to form a PM_2.5 distribution map of automobile source. Integrated with population data, we calculated the population exposure to automobile source PM_2.5 in each geographic census unit. Computational and analytical results show that the hot spots are mainly concentrated in the south and northwest of Beijing, especially near the main ring roads.