| Budget Amount *help |
¥3,810,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥210,000)
Fiscal Year 2007: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2006: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2005: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
Airborne Paticulate Matter (APM) was collected and trace elements existing in the particles were monitored since May 1995. APM sample was collected separately by size (d<2μm, 2-11 μm and>11μm) in the campus of Chuo University. The collected sample was digested and major elements (Na, Mg, Al, K, Ca and Fe) were measured by ICP-AES, and trace elements (Li, Be, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, Ba and Pb) were measured by ICP-MS. Toxic pollutant elements (Sb, Se, Cd, Pb and As) were found in small particles with d of<2μm in concentrated levels. Antimony (Sb) had the highest enrichment factor (EF), and the results suggested that Sb level in APM was extremely high. The origins of Sb were sought, and brake pad wears of automobiles and incineration waste of plastic and chemical fiber were suspected.
In all sizes of APM, proportions of Al, Fe, and Ti (>80% of the total element concentration) were high in the insoluble fraction. The proportions of Na, Mg and K were rather high (40-90%) in the water-soluble fraction. Zn and Cd in fine particles (d<2un) have large EF values, indicating an anthropogenic origin, and their proportions in the water-soluble fraction were high (up to 90%).When anthropogenic fine APM is deposited in the lungs, leached toxic elements such as Cd may adversely affect human health.
Water-soluble Sb in APM (d<2 Inn) was about 30%. Speciation analysis was performed by measuring the extracted water with HPLC-ICPMS. Water-soluble Sb was in the form of inorganic Sb(V) and organic trimethyl Sb^+-OH (TMSb^+). The concentration of Sb(V)and TMSb^+ was 48.3μg g^<-1>and 2.37 μg g^<-1>, respectively.
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