Indoor Environmental Quality and its Effects on Human Sleep Quality

Sleep is essential for multiple aspects of a person’s well-being and can be affected by a person’s physical and mental state in addition to the environment they sleep in. To date, the majority of research analyzing the relationship between a person’s sleep quality and indoor environment has focused on environmental parameters such as temperature, relative humidity, light, and noise. However, in recent years, a few key studies have identified indoor air quality (IAQ) as a potential contributor to sleep quality. The recent interest in IAQ’s effect on sleep quality has been sparked by the introduction of multiple affordable sensing technologies in both the IAQ and sleep quality fields. In this study, we combine five, commercially available IAQ sensors into one device that we provided to participants to measure their IAQ in addition to temperature, relative humidity, and light. Participants were provided with wearable sleep monitoring devices and were also asked to fill out four-question surveys in the morning to get a sense of two types of sleep quality: device-monitored and self reported.
We found that certain pollutants such as NO2, CO, and PM2.5 altered device-monitored sleep metrics like sleep efficiency when comparing nights with low versus high pollutant concentrations. When considering self-reported sleep metrics, we found that participants rated their sleep as more restful when CO2 concentrations were low, but we did not see this relationship with any other measured pollutant. Results from our study indicate that there is merit in measuring both device-monitored and self-report sleep quality as a function of exposure to multiple indoor air pollutants in the sleeping environment.