Air pollution linked to poor quality sleep

Air pollution, a warm bedroom and high levels of carbon dioxide and ambient noise are all detrimental to our chance of getting a good night’s sleep, according to new research.

A team from the Perelman School of Medicine at the University of Pennsylvania and the University of Louisville’s Christina Lee Brown Envirome Institute examined a number of environmental variables in the bedroom and measured how they affected ‘sleep efficiency’ – the time spent sleeping relative to the time available for sleep.

For each of the environmental variables measured, the researchers compared sleep efficiency during exposures to the highest 20 percent of levels versus lowest 20 percent of levels.

Tracking a group of 62 participants over a period of two week, the researchers found that high noise was associated with a 4.7% decline in sleep efficiency compared to low noise, high CO2 levels with a 4.0% decline compared to low levels, high temperature with a 3.4% decline compared to low temperature, and high PM_2.5 with a 3.2% decline compared to low PM_2.5.

The effects of relative humidity and barometric pressure were also examined and found to have no significant impact on sleep efficiency.

The study was prompted by the fact that poor quality of sleep affects work productivity and quality of life and has also been linked to a higher risk of chronic diseases including heart disease, type 2 diabetes, depression and dementia.

Mathias Basner, professor and director of the division of Sleep and Chronobiology at Penn Medicine said: ‘These findings highlight the importance of the bedroom environment for high-quality sleep.

‘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.’

Aruni Bhatnagar, who lead the research said: ‘This could be as simple as leaving a bedroom door open to lower carbon dioxide levels, and using triple-pane windows to reduce noise. We also applied for (future) funding that will allow us to investigate whether planting trees can improve sleep and cardiovascular health through improving health behaviors and the bedroom environment.’