Characteristics and sources of polycyclic aromatic hydrocarbons in impervious surface run-off in an urban area in Shanghai, China

Abstract

Rainwater and run-off from three kinds of impervious surface in the Shanghai urban area, China were sampled. Polycyclic aromatic hydrocarbons (PAHs) were measured in the samples, and their sources were assessed. The mean sum of the 16 PAH concentrations measured in rainwater and run-offs from ceramic tiles, asphalt roofs, and asphalt roads were 873, 1404, 1743, and 4023 ng/L, respectively. The PAH concentrations found in this study were moderate compared to PAH concentrations found in run-offs in other studies. The main PAH components in the rainwater, roof run-off, and asphalt road run-off samples were 3-ring PAHs, 3–4-ring PAHs, and 4–6-ring PAHs, respectively. Source apportionment results indicated that combustion (47.4%–55.5%) and vehicular emissions (30.5%–33.0%) were the major contributors to PAHs in roof run-off. Vehicular emissions were the most significant contributors to asphalt road run-off (47.2%), followed by combustion (23.5%), and petroleum (16.3%). Vehicular emissions and coal and natural gas combustion are therefore the most significant sources of PAHs in run-off from impervious surfaces in the Shanghai urban area.