We have developed a portable gas chromatograph with an adsorption/combustion type micro gas sensor for the simple and on-site measurements of volatile organic compounds in indoor air. The detection characteristics of the device were examined for toluene, o-xylene, styrene and butyl acetate at the concentration levels of the indoor guideline values set by the Ministry of Health, Labour and Welfare, Japan, or above. Finally, field tests were conducted in a furniture factory and a ceramic art studio. As a comparison to evaluate the measurement results of the device, active samplings were simultaneously conducted and the concentrations calculated from GC/MS measurements as the conventional method. As a result, toluene was mainly detected and the measurement values by the device were in good agreement with that by the conventional one in the concentration range of 0.02ppm to 2ppm..

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The atmospheric aerosols were investigated from April 2003 to March 2006 at Maebashi and Mt. Akagi, both of which are located on the inland Kanto plain. Fine (< 2.1 μm) and coarse (2.1 - 11 μm) particles were collected using an Andersen low-volume air sampler, and the organic carbon (OC), elemental carbon (EC), and ionic components were measured. The mean mass concentrations of the fine particles were 21.7 and 9.4 μg/m³ at Maebashi and Akagi, respectively. The highest concentration of fine particles was observed in spring; nitrate and sulfate were the major components. Sulfate and OC were dominant in summer and fall. Nitrate and sulfate were present in the form of ammonium nitrate and ammonium sulfate, respectively. We compared the concentrations of the ionic components in the fine particles collected at Maebashi and Akagi and found that the distribution of ammonium sulfate was widespread, while that of ammonium nitrate was localized to Maebashi. The localized distribution of ammonium nitrate at Maebashi was attributed to the high concentration of gaseous ammonia in this region and transport of gaseous nitric acid from the southern Kanto area. The mass concentration of fine particles was estimated by a chemical mass closure model. The ammonium nitrate, ammonium sulfate, and organic aerosols accounted for a large fraction of the total mass of the fine particles in the inland Kanto area.

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The measurements of OH reactivity of exhaust gases determined by the laser-induced pump and probe technique were carried out. The tested gasoline vehicles have adopted the regulation standard for 2005 emissions. The concentrations of trace species in the exhaust gases from these gasoline vehicles were found to depend on the condition of the driving cycles, temperature of the catalysts or the load on the engines. For all driving cycles, there were 4 to 60 % differences between the measured and calculated OH reactivities in the vehicles that have adopted the regulation standard for 2005 emissions. These results suggested that unknown trace species exist in the exhaust gases. (Especially, during the JC08C driving mode, the OH reactivity was much higher than that of the other driving modes).Therefore, for improvement of the ambient air quality, it is very important to enhance the performance of the purification system for the exhaust gases (during JC08C driving mode) and to study the relationship between the unknown trace species and OH reactivity. Moreover, we also measured the exhaust gases of vehicles that have adopted the regulation standard for 2000 emissions. These results showed that the OH reactivity was about 30 to 98 times higher than the vehicles that have adopted the regulation standard for 2005 emissions. Since the current use of vehicles adopting the regulation standard for emissions earlier than 2005 are predominant, it is important to take countermeasures against the exhaust gases of these vehicles.

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Satoyama, the hometown mountain, was studied from the viewpoint of its biological diversity and ecosystem maintenance. The effects of air pollution on the Satoyama near urban areas have not been clarified although it could be strongly affected by air pollutants. In this study, we investigated the effects of air pollution on Satoyama in the suburban area (small-scale forest ecosystem) and evaluated the environmental cleanup ability of Satoyama in this area, especially with a focus on the acid buffering capacity and the decontamination ability of inorganic nitrogen. The bulk precipitation, throughfall of Sugi, Japanese cedar (Cryptomeria japonica) and Konara oak (Quercus serrata) and soil water from five depths (10, 20, 40, 80, and 100 cm) near Konara trees were collected from the FM Tama Hills (12 ha), located in the western part of Tokyo from June 2007 to June 2008. The mean pH of the bulk precipitation and throughfall of Sugi and Konara was 4.64, 5.35, and 5.57, respectively, indicating the high acid buffering capacity in the Sugi and Konara canopies. The canopy exchange model using Na⁺ as a tracer of atmospheric deposition indicates no seasonal change in the contribution of the dry deposition to the throughfall fluxes of K⁺, Mg²⁺, and, Ca²⁺ was observed in both canopies and the contribution of the dry deposition was higher in the Sugi canopy than in the Konara canopy during the studied period probably reflecting the leaf area index. The pH of the soil solution increased from the surface (5.93 at 10 cm) to the deeper layer (6.32 at 100 cm). Higher concentrations of Ca²⁺ and Mg²⁺ in the soil solution than those in the throughfall indicated that the cation exchange reaction is the main acid buffering mechanism. A simple soil infiltration model using Cl^- as a tracer of the throughfall deposition showed that the ratio of the input and output of inorganic nitrogen flux was nearby 1, suggesting that nitrogen saturation was occurring.

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Seven particle-bound polycyclic aromatic hydrocarbons (PAHs) were measured over one year, from September 2005 to August 2006, in the ambient air at ground level outside and inside a small forest (12 ha) at the Field Museum (FM) Tama Hills, an experimental forest of the Tokyo University of Agriculture and Technology, located 20 km west of central Tokyo. The concentrations of PAHs found in the suspended particulate matter (SPM) in the ambient air inside the forest (C_in) were lower than those in the ambient air outside the forest (C_out), indicating the capture of particle-bound PAHs by the forest canopy. High correlation coefficients between C_out and (C_out - C_in) were observed for five of the PAHs (r > 0.83), but not for benzo[a]pyrene or perylene. The capture efficiencies of the PAHs by the forest filter effect (FFE), which are defined as the slopes of the regression lines estimated by a least-square method, ranged from 0.22 (pyrene) to 0.29 (indeno[1,2,3-cd]pyrene) and increased with the increasing octanol-water partition coefficients, K_ow. The results indicated that more hydrophobic PAHs could be efficiently captured by the forest canopy and the capture efficiencies of the particle-bound PAHs reached about 30 %

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