Evaluation of the psychophysiological effects of the Cupressaceae family wood odor

The wood of the Cupressaceae conifer family is widely used for many purposes, such as the structural and interior elements of buildings. Several studies have reported the effects of the Cupressaceae wood odor on humans. However, only a few studies have investigated the effects of the volatile compounds on psychophysiological responses in an indoor environment. In this study, the psychophysiological effects following the inhalation of volatile essential oils from the Hinoki cypress (Chamaecyparis obtusa) and Sawara cypress (Chamaecyparis pisifera) woods were evaluated. Levels of salivary stress markers were used to determine the study participants’ endocrinological responses as well as the changes in their autonomic nervous systems during the experimental period. A questionnaire survey was also conducted to assess the perceptions of the odors in the experimental rooms and the participants’ psychological states. It was found that olfactory stimulation with volatile compounds from the essential oil of the Hinoki cypress wood increased salivary dehydroepiandrosterone sulfate levels in the rest period following stressful work. Sympathetic nervous activity levels were lower, and parasympathetic nervous activity levels were higher immediately following stressful work. A similar tendency was observed with exposure to the essential oil of the Sawara cypress wood. These observations suggest that an environment with the Hinoki or Sawara cypress wood odor may be useful in promoting physiological relaxation following stressful work.