Influence of traffic conditions on polycyclic aromatic hydrocarbon abundance in street dust

Abstract

Polycyclic aromatic hydrocarbon (PAH) concentrations were quantified in sieved street dusts from eight sampling sites with different traffic conditions in Beijing. The parent diagnostic ratio test and multi-regression analysis were used to identify the different PAH pollution sources. Results showed that more than 93% of the cumulative 16 priority pollutant PAHs (∑ 16EPA-PAH) load was present in street dust with a diameter less than 300 μ m across all the sampling sites. The concentration of ∑ 4–6 ring PAHs was 93 to 284% higher than that of ∑ 2–3 ring PAHs for most of the sites except the cycle lane site, indicating the dominance of pyrogenic inputs in street dusts at these sites. Cooking oil is an important PAH source in street dusts for all the sampling sites. Tire debris and vehicle emissions were also identified as significant contributors to the PAH loading in the heavy traffic zone, vehicle parking areas, the frequent brake usage zone, and the construction area.

Keywords:

• PAH
• multivariate regression analysis
• sieving
• source diagnostic
• street dust

Acknowledgments

This research was supported by the National Natural Science Foundation of China for Young Scholars (grant 50809006), the National Basic Research Program (973 Program, grant 2006CB403303) and the National Science Foundation for Distinguished Young Scholars (grant 50625926). The authors are grateful for their support.

Notes

*Average daily traffic (ADT)

** Not available.