Internal Mixing of Pollutants for Submicron Particles Observed during Springtime in Japan

Abstract

Internally mixed states of submicron particles during transport from the Asian continent to the Pacific Ocean were analyzed using a single-particle time-offlight mass spectrometer. The observation was conducted at Tsukuba in Japan in the spring of 2005 in order to investigate springtime transport of particles from the continent. The sum of ion intensities of sulfate (HSO 4 -) detected in particles originating from the continental air masses counted for 75% of that in all particles during the observation. By analyzing correlations among compounds, origins and internally mixed states of compounds were estimated. It was found that nitrate was mixed with sulfate-rich particles as the air mass approached Japan. It was confirmed that Asian mineral dust particles played significant roles for transport of continental sulfate to Japan. As a result of analysis on internal mixing of chlorine and nitrate, it was implied that the chlorine loss in fine sea salt particles had already proceeded at Tsukuba. It was characteristic that fluoride ions were significantly detected, coal combustion in the Asian Continent can be an important source of fluorides detected in Japan through the westward transportation of fine particles including fluorides.

Partitioning of dioxins (PCDDs/Fs) in ambient air at urban residential locations

“…Because the world's largest consumption of coal occurs in the northeast of Asia, an understanding of the atmospheric presence of these compounds in this region is particularly important (Bao and Sakamoto 2009;Huang et al 2009;Matsumoto et al 2009;Tang et al 2009) .…”