| Budget Amount *help |
¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 2006: ¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 2005: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2004: ¥7,300,000 (Direct Cost: ¥7,300,000)
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| Research Abstract |
Daily concentrations of trace metals in aerosols collected at Tsinghua University, Beijing, China from March 2001 to March 2006 were measured by using Laser Ablation/ICP-MS analysis. The source identification and long-term trend of aerosol in Beijing, China were investigated by using these data. All metal concentrations in aerosols in Beijing were higher than those in Tokyo in Japan. Especially, the concentration of As originated from coal combustion was over 25 times higher than that of Tokyo. The long-term trend of metal concentration was examined by using regression analysis. The concentrations of heavy metals as Cu, Zn, As, Cd, Pb were increasing by 4.9%〜19.8% per year from March 2001 to February 2006.
The concentrations of PAHs in aerosol samples collected from September 2003 to April 2006 in Beijing, China were determined by the developed method in this study. SPAHs, which is the sum of the concentrations of all detected PAHs, was 188.4ア317.9 ng/m^3 (n=114), and this was about 100 times higher than that in Tokyo, Japan. The El3AHs concentration in the heating season was 10.7 times higher than that in the non-heating season. The strong seasonal variation in atmospheric PAHs concentration is possibly due to coal combustion for residential heating in winter. Positive Matrix Factorization (PMF) method was applied to source identification of PAHs in aerosols. Coal combustion, waste incineration, wood burning and motor vehicles were identified as major sources of PAHs in aerosols. In the heating season, the sum of contributions of coal combustion, waste incineration, wood burning were about 70%. Therefore, it was considered that these sources released large amount of PAHs. The contributions of these three sources in the heating season were more than 10 times higher than in the non-heating season.
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