Size distributions and characteristics of atmospheric inorganic particles by regional comparative study in Urban Osaka, Japan

Size distributions and characteristics of atmospheric inorganic particles at two different monitoring sites were statistically compared in order to survey site-specific original sources of the particulate constituents. The average concentration difference of fine and coarse particles between the sites was, respectively, 1.4 and 4.7 μg/m3, and coarse particulate Fe, Mn, Zn and Pb were significantly high at the heavy traffic-flow site. Coarse particulate Zn and Pb form a closely related cluster group but Mn belongs to another independent group together with Fe. Comparative study for the Zn/Pb ratio possibly suggested that the regional differences of Zn and Pb were derived from road dust components and this might be caused essentially by tire wears and previous lead additives, respectively. On the contrary, the differences of coarse particulate Fe and Mn might be commonly and directly affected by industrial sources such as iron–steel factories close to the heavy traffic-flow site.