Air pollution, heat, high levels of carbon dioxide linked to lower sleep quality

Air pollution, heat, high levels of carbon dioxide and ambient noise may all adversely affect our ability to get a good night’s sleep. Published in the journal Sleep Health, the research is one of the first to measure multiple environmental variables in the bedroom and analyse their associations with sleep efficiency.
The researchers found that in a group of 63 participants tracked for two weeks with activity monitors and sleep logs, higher bedroom levels of air pollution, carbon dioxide, noise, and temperature were all linked independently to lower sleep efficiency. Study lead author Mathias Basner, a University of Pennsylvania, US professor, said, “These findings highlight the importance of the bedroom environment for high-quality sleep.”
The researchers said in addition to work and family obligations that compete with sleep for a time, a quickly changing environment due to growing urbanisation and climate change seems to have made it harder to get a good night’s sleep. Sleep of inadequate duration or efficiency due to frequent disruption affects work productivity and quality of life. It also has been linked to a higher risk of chronic diseases, including heart disease, type 2 diabetes, depression, and dementia.
The team, including researchers from the University of Louisville, US, recruited participants from the National Institutes of Health Green Heart Project, which investigates the effects of planting 8,000 mature trees on the cardiovascular health of Louisville residents. For each environmental variable measured, the researchers compared sleep efficiency during exposures to the highest 20 per cent of levels versus the lowest 20 per cent of levels. They found that high noise was associated with a 4.7 per cent decline in sleep efficiency, high carbon dioxide with a 4 per cent reduction, high temperature with a 3.4 per cent decline, and high PM2.5 with a 3.2 per cent reduction. “We seem to habituate subjectively to our bedroom environment and feel there is no need to improve it, when in fact our sleep may be disturbed night after night as evidenced by the objective measures of sleep we used in our study,” Basner added.