Effect of bedroom environment on sleep quality in Beijing during heating season

In order to investigate the bedroom environment, sleep quality of residents and the association with bedroom environment and sleep quality, this study randomly investigates 48 households in the urban area of Beijing during the heating season. Bedroom environment parameters, including temperature, relative humidity and CO2 concentration, are recorded during the whole measured night. Objective sleep quality is measured by an actigraphy sensor. Subjective assessments on sleep quality and environmental perceptions are collected by paper-based questionnaires before and after sleep. The results indicate that the thermal and humid conditions of bedrooms during the measured night are in good condition. Nearly 80% of surveyed bedrooms have an average CO2 concentration above 1 000×10-6. There is a significant correlation between objective sleep quality measured by actigraphy sensor and subjective sleep quality collected by questionnaires. Indoor CO2 concentration is significantly and positively correlated with sleep onset latency. When bedroom air quality perception is higher, subjects have a higher deep sleep ratio and lower sleep onset latency, and they report feeling easier to fall asleep, easier to get up, and more satisfied with sleep. This study indicates that reducing indoor CO2 concentration and improving indoor air quality evaluation are beneficial to improve sleep quality.