In order to reveal compositional differences between airborne road dust and airborne soil particles and to evaluate their local emissions in the early wintertime, the determination of geological profiles becomes a crucial and essential work. In this study, road dust and soil particles collected at the 7 sites of southern Kanto plain were prepared for the chemical analyses of apparent elemental carbon (Cae), apparent organic carbon (Cao), carbonate (CO
32-), elements and water soluble ions. Though the main components, Al, Fe, Mg, Na, Ti and K, were at the same levels of road dust with these of soil particles,the concentrations of Cae, Cao, Ca and CO
32- in the road dust samples were observed about one order higher than those in the soil samples. Cae, Cao, Ca and CO
32- can be the better indicators used for separating the contribution of road dust from soil particles with the Chemical Mass Balance (CMB) method. As the equivalent ratios of [Ca
2+] / [CO
32-] for road dust samples were near 1.0, but ones for soil samples were about 10. Thus, the most of Ca
2+ and CO
32- in road dust are probably existing as a form of CaCO
3 particle which has neutralizing effect on ambient aerosol acidity as a major alkaline component. A satisfied explanation for spatial differences and diurnal variations of ambient aerosol acidity (H
+) was given using the CMB results in this study.
抄録全体を表示