VOCs emitted from Japanese cedar (Cryptomeria japonica) interior walls induce physiological relaxation

Wood has been used since ancient times as a building material around the world. One of the characteristics of wood is volatile organic compounds (VOCs), which indicates the relaxant effects on human body. In this study, we attempt to evaluate the psychophysiological responses to VOCs emitted from interior walls containing Japanese cedar (Cryptomeria japonica). Japanese cedar is the most commonly planted in forests and the timber has often been used as an interior material in Japan. The evaluation indices of the participants are arithmetic performance, subjective assessments of VOC, salivary stress markers, and temporal changes in heart rate and autonomic nerve activity. We found that the inhalation of air containing VOCs emitted from Japanese cedar interior walls suppresses the increase in salivary α-amylase activity and chromogranin A secretion. And it causes participants to feel that the odor is pleasant. The present study thus indicated that VOCs emitted from Japanese cedar walls affect the autonomic nervous system and emotion. Therefore, we suggested that an interior containing Japanese cedar can help people maintain an optimum living environment.