POLYCYCLIC AROMATIC-HYDROCARBONS IN AIR, SOIL AND VEGETATION IN THE VICINITY OF AN URBAN ROADWAY

The polycyclic aromatic hydrocarbon (PAH) content of air particulate matter, surface soil and grass in the vicinity of an urban roadway was measured using gas chromatography. All fourteen PAHs analyzed for were found in soil and, except for dibenz[a,h]anthracene, were also detected in air particulate matter. Only phenanthrene, anthracene, fluoranthene and pyrene were detected in grass. Motor vehicle exhaust was the dominant source of PAHs in air particulate matter and soil. The soil concentrations of PAHs decrease with increasing distance from the road, although significant concentrations were present at a distance of 15 m. PAHs with three or four rings existed in both particulate and vapour forms in the atmosphere, which probably contributed to their relatively wide distribution. On the other hand, the PAHs with more than four rings were deposited close to the roadway due to their predominant particulate form.