An estimate of population exposure to automobile source PM 2.5 in Beijing using spatiotemporal analysis

Automobile source is a significant contributor to ambient particulate matter (PM), especially for PM2.5, which has become of growing public concern due to its urgency and sensitivity related to human health. A set of hourly PM2.5 data from 35 monitoring stations published by Beijing Environmental Protection Bureau (BJ-EPB), covering 2 months during autumn 2013 was collected. The association between PM2.5 concentrations at midnight and morning rush hours has been analyzed to estimate PM2.5 concentration from automobile source. Spatial interpolation method was conducted in order to form a PM2.5 distribution map of automobile source. Integrated with population data, we calculated the population exposure to automobile source PM2.5 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.