2014 年 29 巻 S1 号 p. s55-s65
This study utilized an inertial filter (INF) sampler to evaluate gas adsorption and chemical components in ultrafine particles (Dp < 0.1 μm; PM0.1). They were measured at suburban roadside and background sites under low conditions of PM vaporization and gas adsorption and compared with the components of fine particles (Dp < 2.5 μm; PM2.5). Atmospheric samplings of PM0.1 and PM2.5 were performed in summer and winter with 11.5 h sampling durations to observe the variation of chemical components between daytime and nighttime and to clarify the emission sources and the growth behavior of PM0.1to PM2.5. It was shown that the main components in PM0.1 and PM2.5 were different. Carbonaceous components at both sites accounted for 70 % in PM0.1 and for 40 % in PM2.5 respectively, because ionic components were dominant in PM2.5. The carbonaceous and ionic components near the roadside in PM0.1 had a tendency to be transported to background sites as they expanded via heterogeneous nucleation, especially in winter. Ultrafine particles with a diameter of 20-30 nm and OC1 fraction in OC components were confirmed only in winter, and OC1 fraction indicated higher correlation with soot EC components at both sites. Therefore, it was thought that OC1 fraction was emitted from the diesel exhaust and played an important role in the growth of PM0.1 to PM2.5.
