Investigation on vehicular pollution level in various transport micro-environments in Beijing

The air pollution concentration features of vehicular pollution in Beijing were investigated. CO, NO, NO₂ and PM_2.5 were monitored in typical transport microenvironments, including bus stop, in-bus and in-car. The distribution of NO, PM_2.5 and CO concentration in microenvironments was similar. The concentrations in bus were highest, at bus stop were lowest. In bus, the CO was higher in the morning peak hours than in the afternoon peak hours. Meanwhile, CO, NO and NO₂ were lower in conventional buses than in air-conditioned ones, this revealed that ventilation could improve in-bus air quality significantly. The analysis on influence factors to concentrations in cars showed that traveling in level hours, good maintenance, and using inner-circulation mode in traffic jam areas could reduce in-vehicle pollution level effectively.