Aerosol, acid fog, acid rain, ammonia and trans-boundary air pollution research conducted were reviewed. Sulfate and nitrate concentrations over Tokyo Metropolitan area are obtained with 5 min sampling time of air upon introduction of tape air sampler and ion-chromatography. Acid fog survey was started in Mt. Akagi which is located the downstream of Tokyo metropolitan area. The development of low pH and high concentration of nitrate fog was clarified. Collaboration of air pollutant observation, long range transport model and emission inventory is essential to tackle the trans-boundary air pollution issue. We conducted collaborative research work on trans-boundary air pollution. Extremely low pH acid rain produced by the big eruption of Miyake-jima island was observed by the automatic acid rain collection and ion-chromatographic analysis system. Gridded emission inventory of ammonia for Japan and the Republic of Korea was compiled. Wide area distribution of ammonia in the air is in advance.

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Seasonal VOCs concentrations were characterized and the chemical mass balance (CMB) receptor model was applied to the source apportionment of VOCs measured at Kanto area in Japan. Analyzed data set was obtained from five canister samples every season in field campaign that was carried out at five sites in 2004 and 2005. Sum of the VOCs concentrations in fall and winter were higher than that in spring and summer. The contribution of C4 - C5 aliphatic hydrocarbons to Total-VOC (sum of the analyzed VOC concentrations) increased in summer, while the < C3 hydrocarbons were major contributor in winter. The CMB analysis indicates that gasoline vehicle exhaust was major contributor to VOCs in warm seasons. The contribution of gasoline vapor increased in summer at several sites, while LP gas contribution increased in winter. The contribution of painting solvent and LP gas in Kanto area was larger than that in Kansai area in Japan. The reasons for these remarkable features were explained by the differences of LP gas supply and estimation of VOC emissions from paint solvent use in both areas. Comparison of source apportionment of VOCs in this study with that in previous studies using CMB indicated that the contribution of paint solvent use in Tokyo was lager than that in another cites.

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We developed new plume rise and diffusion models for gas dispersion from a mechanical-draft cooling tower. Wind tunnel experiments were conducted to investigate effects of fan location and cooling tower configuration on gas dispersion from the cooling towers. The results show that cooling tower configuration does not affect the plume rise and diffusion, but the fan location and numbers strongly affect them. The plume rise increases with the fun number in case of the fans located in downwind direction, but it is comparable level to the single fan in case of orthogonally-aligned fans to the wind direction. In addition, the vertical and horizontal diffusion becomes large as the fan number increases. These effects are not considered by the previous Gaussian type model (FOG model), generating the large difference of the plume rise and dispersion between the model and the wind tunnel experiment. On the other hand, the developed models considering the fan location and number can accurately estimate the plume rise and diffusion from the mechanical-draft cooling towers.

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Aerosol particles and gases were measured every 24 hours by filer pack method for one year from January to December 2006 at Toyama. When kosa was observed in April at Toyama with high concentration of SPM, non-seasalt Ca concentration was found to be increased. Furthermore, flying particle with non-sphere shape was observed by rider. An ammonium sulfate particle was observed to be a causative agent for haze based on chemical compornent in aerosol on haze day of June. On haze day, flying particle with sphere shape was observed by rider. The back trajectory analysis of haze day represents that some air masses were derived from China and Korea, although there were exceptional air masses passing over the interior of Japan. Kosa and haze phenomenons were also observed in days by extinction other than the kosa day or the haze day announced by the Toyama meteorological observatory.

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Volatile organic compounds (VOC), aldehydes, ketones, phenol, sulfuric compounds, polyaromatic hydrocarbons (PAH) and dioxins were analyzed to investigate the concentrations in the sand mold foundry and also to consider the influence of each working process on the production of odor and harmful compounds. As a result, the concentrations of VOC, aldehydes, ketones, phenol, sulfuric compounds, PAH were 120-270 ppb, 18-84 ppb, 9.5-25 ppb, 0.59-0.91 ppb, 11-35 ppb, and 0.017-0.022 ppb, respectively. The obvious production of dioxins was not recognized. It was suggested that the molding process caused the changing of chemical composition in the air and also increased the dilution ratio required until single component threshold. The odor was composed of a simple odor contributed by a few specific compounds such as sulfuric acid and acetoaldehyde while the complex odor was caused by numerous compounds.

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