Features of Particle-Phase Pahs from Traffic Emissions Using Tunnel Measurement and Urban Roadside Observation in China

Particle-phase polycyclic aromatic hydrocarbon (PAHs) accounts for a large proportion of hazardous compounds in PM2.5 derived from vehicle emission. This study aimed at determining the profiles of PAHs based on tunnel measurement and urban roadside observation. The real-world vehicle emission factors from mixed fleets were quantified in the tunnel. The emission factors for total PAHs, total carbon (TC), organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) are 8.15 μg·veh -1·km-1, 8.91, 1.63, 1.34 and 0.64 mg·veh -1·km-1, higher PAH emission factors are found in high-rings PAHs. Moreover, the concentrations of 15 PAHs in the roadside were quantified, with an average of 23.81 ng·m-3. Besides, the 4-rings, 5-rings, and 6-rings PAHs account for 80% on the roadside and 87% in the tunnel. Diesel vehicles emission is the primary emission source in the tunnel, and emissions of non-tailpipe pollutants cannot be ignored. While gasoline vehicles emission dominated in the roadside. Catering and domestic cooking are also potential sources of PAHs. In addition, asphalt from road surfaces may also be the producer. Moreover, the total Benzo[a]pyrene (BaP) toxicity equivalent concentration is significantly higher than the limit of 1 ng·m-3 set by the World Health Organization (WHO). It is concluded that PAHs potential risk for the health of citizens living in big cities was great