Immature individuals under the development are considered to have high sensitivity and vulnerability to chemical exposure. The brain is sexually differentiated under the influence of testosterone secreted from the testes during developing period. Inhalation exposure to toluene reduces blood testosterone levels in men and male rats in adulthood. We reported that developmental exposure to toluene via maternal inhalation decreases blood testosterone levels and the expression of 3β-HSD, a steroidogenic enzyme involved in testosterone synthesis, in fetal male rats. Our findings suggest that decreased expression of 3β-HSD in the fetal testes is responsible for the reduction of blood testosterone level. The brain has nuclei exhibiting the morphological sex differences, sexually dimorphic nuclei. The SDN-POA, a sexually dimorphic nucleus of the rat brain, is larger and has more neurons in males than in females. We recently found that the volume of the SDN-POA became smaller in male rats exposed to toluene during the perinatal period. We here discuss the effects of developmental exposure to toluene on the sexual differentiation of the brain in rats.

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This review is described about the flow of TVOC as the indoor air quality indicator, the definition, the measuring method, the biological influence, the standard value, the defect and effect, the significance of existence, and how to use it.
TVOC was proposed assuming that the possibility of the pollution influence was shown as the overall, simple notation of VOC that many kinds exist in the indoor air. And, it has been used in a lot of surveillances and studies. However, TVOC cannot become an essential, toxic academic indicator. Moreover, the defect as the that shows the pollution level is pointed out in a present VOC•TVOC measuring method so that the missed small amount stimulatory component may exist. On the other hand, because a lot of VOC to which the standard value is not set coexists, TVOC has the meaning as an rough environmental management indicator to achieve the decrease of the VOC risk through both monitoring of VOC from the source in buildings and evaluation of VOC from construction materials.

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The antibacterial activity of sulfur-doped titanium dioxide (TiO₂) thin film was investigated under visible-light illumination. Sulfur-doped TiO₂ revealed visible-light-induced antibacterial activity against Escherichia coli that was higher than that of TiO₂. The bactericidal activity increased further when various metals (e.g., copper, silver or nickel) were added to the sulfur-doped TiO₂ as supplements. Most notably, the antibacterial activity of the sulfur-doped TiO₂ was highest when supplemented with 4-7% copper. The antibacterial activity of the copper-supplemented sulfur-doped TiO₂ was strong even under daily-used light conditions. Thus, following only 5 min exposure to visible light (1,700 lx), no viable cells were detected on the copper-supplemented sulfur-doped TiO₂ coated surface that initially contained 10⁶ CFU/mL E. coli. The utility of the copper-supplemented sulfur-doped TiO₂ coating as an antibacterial agent was further confirmed by testing its effectiveness on the restroom floors of a nursing home. This antibacterial feature of the copper-supplemented sulfur-doped TiO₂ makes it a suitable agent for applications in environmental decontamination.

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The use of room air cleaners is becoming increasingly popular to improve the quality of the indoor air environment and provide a healthier, more comfortable living space. However, the performance of the room air cleaners commonly deteriorates when used for a long time. Thus, it is necessary to determine the relationship between time of use and deterioration characteristics. Up to now, no quantitative study has been reported on the deterioration characteristics in the performance of room air cleaners. In present study, a new method was proposed to determine the performance degradation of air cleaner for removal of gaseous pollutants by combining a large scale chamber method for measuring precise equivalent clean air rates and exposure device for degradation of a room air cleaner under ambient air concentration levels. The method was practically applied to test one sorption type air cleaner over four months for removing formaldehyde, which is known as a major causative agent of "Sick House Syndrome". As a result, the formaldehyde removal performance of the room air cleaner greatly deteriorated with increased time of use. Specifically, the air cleaner performance at initial startup was 99.6 m³/h. After one, two, three, and four months of continuous use, the performance declined to 40.7 m³/h (rate of decrease: about 59 %), 29.1 m³/h (about 71 %), 29.2 m³/h (about 71 %), and 25.5 m³/h (about 74 %), respectively. In particular, there was a remarkable decline in removal performance between startup and one month of use. This method can be applied to inspect various kinds of room air cleaners. In addition, future studies are necessary to clarify the actual situation of performance deterioration in developed and distributed room air cleaners.

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Patients with so-called "sick house syndrome" were observed in a newly built elementary school in Hokkaido, the northern part of Japan, and we have surveyed its indoor air chemicals. Indoor air was found to be markedly polluted with 1-methyl-2-pyrrolidone (maximum concentration: 1000μg/m³) and 2,2,4-Trimethyl-1,3-pentanediol monoisobutyrate (Texanol) (maximum concentration: 510μg/m³), and these compounds were suspected as plausible compounds that had induced harmful effects on human health. We have searched the emission sources and identified these two compounds were constituents of water-based paints, which are thought to be relatively safer than oil paints. We have measured the amount of these two compounds emitted from the water-based paints by small chamber test method under the simulated condition of the elementary school. We have discussed the concentrations of these two compounds when school children and staffs had begun to use the school facilities.

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The measurement of volatile organic compounds (VOCs) and aldehydes in indoor air in a newly built wooden house showed that the concentrations of acetaldehyde, hexanal, nonanal, acetic acid, acetone, terpenes and p-dichlorobenzene were higher than those of other VOCs such as toluene and formaldehyde. An investigation of the emission sources of these compounds revealed that the under flooring space was a common source for all compounds except p-dichlorobenzene. An analysis of the flooring adhesive polymer revealed that water-based polyvinyl acetate (PVA) adhesive had been used during floor construction; therefore, the compounds emitted from a cured PVA adhesive prepared in a laboratory and their degrees of variation with humidity were investigated. It was determined that the cured PVA adhesive predominantly emitted acetic acid, acetaldehyde, acetone and vinyl acetate, and the emission levels increased with humidity. Because the under flooring space has poor ventilation, the emitted compounds from the cured PVA adhesive were collected in a sampling bag made from polyvinyl fluoride film and the concentration change in the compounds was monitored for 7 days. The measurement results on the seventh day showed that the concentrations of both acetaldehyde and acetone were 2.5 times those at the start of the measurement. Considering that coniferous material emits acetaldehyde, acetone, terpenes, hexanal and nonanal, the compounds detected in higher concentrations in the newly built house were believed to be emitted mostly from the PVA adhesive and wood-related construction materials. It was considered that the emitted compounds first stagnated in the under flooring space before gradually leaking into the indoor area through the narrow gaps between the floor materials.

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Environmental education takes an important role for progress and development of awareness of environment. However, few practical examples were presented on the indoor environmental education. Presenters, including both High School teachers and University researchers, offered special science course about indoor environment for high school students as a part of Science Partnership Project supported by Ministry of Education, Culture, Sports, Science and Technology. The purpose of this course was learning about prevention and improvement of the Sick House Syndrome. In the lessons, fundamental experiments were conducted about colorimetric detector and catalytic decomposition of formaldehyde. These techniques have been developed in Tokai University. At the end of lessons, a questionnaire was carried out for students to examine degrees of their understanding and satisfaction. The results showed this course promoted students' interests for science by helping their understanding on the contents.

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