Emissions of particle-phase polycyclic aromatic hydrocarbons (PAHs) in the Fu Gui-shan Tunnel of Nanjing, China

Real-world vehicle emission factors for PM10 (particulate matter with aerodynamic diameter smaller than 10 μm) and particle-phase polycyclic aromatic hydrocarbons (PAHs) from mixed vehicles were quantified in the Fu Gui-shan Tunnel of Nanjing during summer and winter of 2010. Concentrations of PM10 and sixteen particle phase polycyclic aromatic hydrocarbons (PAHs) in the entrance and exit of the tunnel were studied. The results showed that the four most abundant particular phase polycyclic aromatic hydrocarbons (PAHs) of motor vehicle were benzo[ghi]perylene, benzo[k]fluoranthene, benz[a]anthracene and benzo[a]pyrene. The emission factors for PM10 and particle-phase PAHs were 687 mg veh− 1 km− 1 and 18.853 mg veh− 1 km− 1 in summer, 714 mg veh− 1 km− 1 and 20.374 mg veh− 1 km− 1 in winter. Higher particle-phase PAH emission factors were found to be associated with a high proportion of diesel-fueled vehicles (DV). The estimated PM10 emission factor of gasoline-fueled vehicles (GV) was 513 mg veh− 1 km− 1 and the value for DV was 914 mg veh− 1 km− 1, while EFDV of particulate PAH (31.290 mg veh− 1 km− 1) was nearly 4 times higher than EFGV (9.310 mg veh− 1 km− 1). The five highest emission factors of diesel-fueled vehicles (DV) were benzo[ghi]perylene, benzo[k]fluoranthene, Indeno[1,2,3-cd]pyrene, benz[a]anthracene and benzo[a]pyrene, which was similarly found in the gasoline-fueled vehicles (GV). The sum of these five emission factors accounted for ~ 69% of the total particle-phase PAH of DV and ~ 67% of GV.

► We conduct the study including all vehicles both in summer and in winter.
► We find the most four abundant PAHs in maxed vehicles which is consistent with other studies.
► The emission factors of PAHs for diesel-fueled vehicles is nearly 4 times higher than those for gasoline-fueled vehicles.
► We examine the largest five emission factors of PAHs for diesel-fueled vehicles, which accounted for ~ 69% of DV.