Author(s)

HIROKO NAKAOKA, NORIMICHI SUZUKI, YOSHITAKE NAKAYAMA, KAZUNARI TAKAYA, EMIKO TODAKA, SHINJI TANAKA, KAZUHIKO MATSUSHITA, CHISATO MORI

Abstract

The relationship between adverse health effects, including sensory irritation and decline in cognitive performance, and the exposure to indoor air pollutants has been considered inconclusive. This is possibly because the occurrence of relevant symptoms seems to largely depend on individual sensitivity and mental state. Therefore, further evaluation of the relationship between indoor environment and its related adverse health effects using subjective and objective data is required. In 2017, two new laboratory houses (LHs) were built on the campus of Chiba University (Japan) as part of a new project called the Chemiless Town Project, phase 3. This project aims to investigate the impact of the indoor environment on physical and mental health and to construct a healthy indoor environment. The interior and exterior appearances of the two LHs appear the same; however, the concentrations of chemicals inside them differ due to the differences in their construction and interior materials. The project commenced in November 2017 and will continue until 2021. In the project, approximately 400 participants will be recruited who will evaluate indoor air using sensory perception. The evaluation will be performed using objective methods, including monitoring brain waves and heart rate variability, and subjective methods, including completing self-reported questionnaires, while staying in each LH. Simultaneously, the indoor air samples of each laboratory will be collected and analysed. In 2017, 17 healthy female and 26 healthy male volunteers participated in the experiment. The median of sum concentrations of volatile organic compounds in the indoor air of each LH were 314 and 1674 μg/m³, respectively. No significant differences were found in terms of degrees of performance and relaxation of participants between the LHs. Additional research and analysis will be conducted with more participants to further examine the relationship between the indoor environment and related health effects.

Keywords

brain waves, Chemiless Town Project, healthy indoor environment, heart rate variability, indoor air quality, physical and mental health