A Comparison of Sources and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Urban Stormwater Runoff from Ground and Highway Roads in Shanghai, China

Abstract

Sixteen priority polycyclic aromatic hydrocarbon (PAH) concentrations in the runoffs of a ground road and elevated highway were monitored to analyze sources of PAH pollution between the two roads. The sources and potential toxicity effects of PAHs in the runoffs of the two kinds of road were evaluated. The arithmetic mean concentrations of a total of 16 PAHs in the runoffs of the ground road and elevated highway were respectively 1761 and 4153 ng/L. The individual PAH distributions had similar trends for the two kinds of road runoff, and BbF, FlA, Chy and BghiP were dominant PAHs. Coal/natural gas combustion, gasoline emission, diesel emission and oil leakage were identified as potential PAH sources for both road runoffs, but made different contributions. The potential toxicological effects of PAH sources in runoff were assessed by combining the total toxic BaP equivalent (TEQ) values with estimated source contributions. Results showed that (gasoline and diesel) vehicle emissions had the highest TEQ values, while coal/natural gas combustion and oil leakage had relatively low TEQ values. Reducing vehicle emissions is the most effective way to alleviate PAH toxic pollution in urban runoff, with road cleaning being another good choice.

Keywords:

• Polycyclic aromatic hydrocarbons
• risk assessment
• source apportionment
• urban runoff

Acknowledgments

This study was financially supported by funds from the Science and Technology Commission of Shanghai Municipality (14DZ1208200). We thank the anonymous reviewers for their kind constructive advice on the manuscript.

Additional information

Funding

Science and Technology Commission of Shanghai Municipality (14DZ1208200).