都市地表面上における多環芳香族炭化水素類の光変換性

抄録

PAHs (Polycyclic aromatic hydrocarbons) are the one of the major environmental toxic substances thatdeposit on ground surface of urban site and are discharged with precipitation runoff. To obtain more accurate knowledgeof the behavior of PAHs, phototransformation on ground surface of urban site was investigated. Transformationcoefficients, kmed (m edian of all kinds of PAHs at one measurement) were around 0.05 to 0.1 d_-1, on the surface coverd with concrete, and correlated with sunlight intensity and ambient temperature. The main transformation processes were however supposed to be due to ambient chemical components generated with sunlight, not to be due to direct sunlightexposure of PAHs. Tranformation rate on the surface coverd with grass was estimated to be rather smaller than that withconcrete. This difference was supposed to be due to the differences of the properties of deposited particles.