In order to respond to various factors affecting health, Tokyo Metropolitan Government formulates various guidelines on indoor environmental health measures, and gives advice based on knowledge dissemination and the precautionary principle. “Guidelines for healthy and comfortable living environment” showing cautions / problems and improvement methods for living healthy, and showing the main points of efforts to reduce chemical substances in indoor air Under the “Health consideration guidelines of house”, “Children’s Guidelines for Chemical Substances-Indoor Air-” which showed measures against chemical substances that were only from the perspective of children, and “Rules for ventilation in facilities” to create opportunities for considering the timing and method of ventilation that were in facilities etc, we are working on the spread and enlightenment of chemical substance measures in indoor air.

In recent years, there have been very few cases of severe sick house disease caused by improvement of construction materials and construction materials. However, indoor odor complaints that are not caused by sick house substances are not without exception. In this report, we will describe the current situation and survey cases of senior condominiums and hotels where there is concern that odor problems will occur as the demand increases, and the actual situation of odor generation.

This paper reported the indoor air quality for airborne gaseous contaminants. First, the results of previous studies were discussed to demonstrate changes in indoor pollutants from the past to the future. Since the 1950s, levels of certain indoor pollutants, such as formaldehyde and aromatic solvents have increased and then decreased. Levels of other indoor pollutants such as phthalate esters and brominated flame-retardants have increased and remain high. It is also reported that the molds and allergen contaminations in damp buildings will become a serious problem in the future. Second, 2-ethyl-1-hexanol (2E1H) emitted from a raw materials contained with a raw compound or secondary emitted from plasticizers was introduced as indoor air contaminants, emission mechanisms and countermeasure of 2E1H.

2-Ethyl-1-hexanol (hereafter referred to as “2-EH”) is a higher alcohol with an unpleasant odor. 2-EH is generated by carpet tiles that are installed directly onto concrete slabs and is known to be a cause of odor-related complaints. With efforts currently underway to determine guideline exposure limits for 2-EH to protect building occupants from sick building syndrome, this substance must be re-examined while considering its effects on human health. To acquire knowledge regarding 2-EH, we performed the long-term monitoring of 2-EH in an actual building and investigated the effects of temperature and humidity on its concentration. Furthermore, the relationship between 2-EH concentrations and odor were examined. In this paper, we report an example application of a 2-EH-proof installation method that can be used to install carpet tiles on concrete slabs with high moisture content.

One of the problems from drinking alcohol is that it can cause bad breath, and the present methods to reduce the unpleasant odor do not have a direct effect on the components that cause it. Therefore, a novel more effective method for reducing bad breath is required. We investigated the effect of acetic acid bacterial enzymes on bad breath, as they are known to convert alcohols and aldehydes into carboxylic acids. Therefore, we determined that the odor concentration of expiration depended on ethanol by examining the influence of the ratio of ethanol and other odor components on the odor concentration. Furthermore, it was suggested that the diffusion of bad breath could be suppressed by reducing the ethanol concentration in expiration. These results indicate that acetic acid bacterial enzymes can reduce both the strength and diffusion of bad breath. Therefore, acetic acid bacterial enzymes could potentially be developed into new products that can effectively reduce unpleasant bad breath after drinking alcohol.

This study investigated how did participants perceived the intensity of the odor when the odor was presented 40 times along with their inhale. The pleasant / unpleasant odor which were suggested by previous study were used and the effect of pleasantness for perceived odor intensity was investigated too. As results, there were no differences of perceived intensity between pleasant and unpleasant odor were presented. Furthermore, based on subjective report, many participants could perceive the odor till the end of presentation.