Removal efficiencies of environmental tobacco smoke (ETS) and its odor with newly developed ETS removal equipment were evaluated. The developed equipment consists of two units: Particulate and VOC Removal Unit (PVRU) and Odor Removal Unit (ORU) connected in series. The 1^st unit is PVRU for removing suspended particulate matter (SPM) and volatile organic compounds (VOC) composed of two air filters (HEPA: High Efficiency Particulate Air filter and activate charcoal filter). The 2^nd unit is ORU for removing acetaldehyde and ETS odor composed of a wet element using chemical absorbent containing amino acids mixture. First, removal experiment of acetaldehyde in air was carried out. In the experiment, we measured acetaldehyde concentration at inlet of PVRU, and outlet of ORU. Removal efficiency of acetaldehyde by the developed equipment was higher than 90%. Next, removal experiment of ETS and its odor was carried out during tobacco smoke generating. We found that SPM and most of VOC except oxygenated compounds were almost completely removed by PVRU. The removal efficiencies of acetaldehyde and odor by PVRU were 80%, 90% respectively, and the removal efficiency of acetaldehyde was decreased with time. But the removal efficiencies of these components after ORU were 95%, 99% respectively. Acetaldehyde is considered to be chemically absorbed by amino acids in the chemical absorbent, and its absorption capacity of acetaldehyde was at least 70 mg L^-1. The removal efficiency was confirmed to be maintained after treatment of tobacco smoke of 400 cigarettes.

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We evaluated air quality of a quasi-office (194.4 m³) in which a smoking booth (24.3 m³) was installed with developed ETS removal equipment (Developed Equipment). The ventilation rate of the office was set 1440 m³ h^-1 and the tobacco smoke continuously emitted from 8 cigarettes was processed by the developed equipment with circulation air flow at 1200 m³ h^-1 to be exhausted into the office. Increase in the concentrations of tobacco smoke ingredients in the office room was prevented by operating the developed equipment even when 8 cigarettes were burned. Concentrations of carbon monoxide (CO), which was included in tobacco smoke but not be removed by the developed equipment, were increased. However, the concentrations were in range of 0 to 2.7 ppm, which are below the indoor standard value at 10 ppm. This is due to the high ventilation rate. The moisture content, which was emitted by the developed equipment were decreased by the ventilation system. Observed distribution of concentrations of the ingredients of ETS in the office room was not affected by the position of the ventilation exhaust, back of the office room or above developed equipment's outlet. Thus, if we can set the ventilation rate high enough for the volume of the office room, the office air quality can be kept clean. Observed concentrations were well agreed with the CFD simulation results. We can estimate the performance of the smoking booth before actual installation.

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An air purifier is often introduced in home to remove pollens. However, not many reports are found about pollen behaviors in airflow generated by the air purifier. Recently we developed the Computational fluid dynamics and Aerosol Motion Property Analysis Suite, CAMPAS. The CAMPAS implements 4 features, such as CFD simulation, particle motion simulation, data analysis, and visualization tools. The LES model is employed in CAMPAS, and the Coherent Structure Model as a SubGrid-Scale model is used. We simulate the pollen motion and study the removal performance of the air purifier that is installed in the center of a square room with each side of 5 meters and height of 2.5 meters. The air purifier has the exhaust outlet on its top surface and the inlet on its front surface. It is found that the model air purifier can remove about 40% pollens and about 50% pollens eventually fall on the floor by the gravity force. From pollen motion observation using the visualization tool, it appears that the fallen pollens are carried by the airflow and, however, collide with the back and side surface of the air purifier or the room wall without being inhaled from the inlet. Imaginably, floating pollens near the front inlet can be easily removed. It is also found that suspended pollens in the upper back region of the air purifier can be also removed after being carried by the outlet flow. The pollen existing within the boundaries of elevation angle φ and azimuth angle θ from the intake surface of the air purifier is easily removed. The value of the elevation or azimuth angle probably depends on the air purifier model. By improving the inlet and outlet structure, it is possible to enhance the pollen removal efficiency of the air purifier.

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Stimulatibility, mutagenicity and carcinogenicity have been indicated the formaldehyde which exist for the indoor environment. Therefore, the guideline has been instituted on the formaldehyde in the indoor air in WHO and Japan. HPLC and GC method using the DNPH cartridge are widely used for the measuring method of the formaldehyde in indoor air. However, mutagenicity and carcinogenicity have been indicated the DNPH method in reagent itself, and they grope for the new method for replacing it. In this study, the 2,4-pentanedione solution (ammonium acetate, acetic acid, 2,4-pentanedione) without the harmfulness was made to be the collecting solution, and it examined the method for using Miniature Diffusion Scrubber (MDS) for the sampling. The form formaldehyde reacts under the existence of ammonium acetate with 2,4-pentanedione, and the measurement principle of this method forms derivative (3,5-diacetyl-1, 4-dihydrolutidine). The derivative is measured by the HPLC with ultraviolet detector (413 nm). The determination limit of this method is 0.012 ppm in the case of 1 L sampling. In this method, the effect of SO₂, NO₂ and O₃ of indoor level is not received. Significant correlation was observed between this method and JIS method (active sampling method). From the above mention result, the practicability of this method was confirmed.

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In 1994, Society of Indoor Environment, Japan (SIEJ) was established as an indoor environment workshop in order to offer opportunities to exchange knowledge and opinions among researchers. This study aimed to present fundamental data for further considerations of the indoor environmental studies by showing current and past concerns of researches. In this paper, a research trend on the indoor environment was investigated using Proceedings of the annual meeting of SIEJ based on a bibliometric analysis. The trend analysis was conducted about number of annual presentations, fields of indoor environment, target substances and affiliations of presenters. As a result, the number of presentations increased especially in 2003, which was approximately three times as many as that in 1998, and marked about 100 in the last 4 years. Until 2004 most of presentations were focused on Sick Building Syndrome/ Sick House Syndrome with discussions on formaldehyde and/or volatile organic compounds (VOCs). However, the interests of recent researches became diverse in both fields and target substances. About a half of presentations were conducted by corroborative works among academia, industry and/or public sectors. This suggests researchers attending the annual meetings of SIEJ tend to develop a practical science in the field of indoor environment.

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