Distribution of polycyclic aromatic hydrocarbons (PAHs) in an urban roadway system.

The distribution of PAHs in soil, leaf litter, vegetation, soil fauna, and litter fauna in a roadside environment in Brisbane, Australia, was measured using gas chromatography and gas chromatography coupled with mass spectrometry. Sixteen common environmental PAHs were found to be widely distributed with leaf litter exhibiting the highest concentrations (1254 ng/g total wet wt). The carcinogenic PAHs benzo(a)anthracene, chrysene, benzo(a)pyrene, benzo(e)pyrene, benzo(k)fluoranthene, and indeno(1,2,3-c, d)pyrene constituted about half the total. Lipid content was positively correlated with total PAH content in the soil and leaf litter as was organic carbon content with leaf litter alone. The PAH content of leaf litter, soil, and vegetation declined exponentially with distance from the roadway, soil depth, and vegetation height, respectively. This decline was not related to the physicochemical characteristics of the compounds, suggesting that dispersal occurred as particulates with sorbed PAHs.