A study on bedroom environment and sleep quality in Korea

The purpose of this study was to investigate both the sleep environment and sleep quality in bedrooms. It was also to reveal the relationship between sleep environment and sleep quality, and to study its seasonal changes in winter, spring, and summer. The subjects for this study were 24 women who lived in apartments in Seoul and its environs. We conducted two groups of measurements. One group considered elements of the sleep environment: mean radiant temperature, air temperature, relative humidity, carbon dioxide (CO₂) concentration, illumination, and equivalent noise level. The other looked at elements of sleep quality: the apnea hypopnea index, and inspiratory flow limitation (as %FL), which were measured simultaneously while subjects were asleep. Results showed first, that people were exposed to a variety of problems when asleep, related to their sleep environment such as too low or high air temperatures, or relative humidity and high CO₂ concentrations. Second, these were seasonally dependant and people slept best during spring, then winter, and then summer. Third, the effect of the sleep environment on sleep quality varied with age.