Sleep quality and health may be compromised in windowless office workers
Light has a powerful influence on the regulation of circadian rhythmicity and in particular the sleep-wake cycle. Research has shown that light levels during the working day are linked to productivity, mood and performance.
A recent study published in the Journal of Clinical Sleep Medicine, investigated daytime light exposure, sleep quality and health-related quality of life in 27 employees who worked in windowless environments compared with 22 employees who worked in workplaces where there was exposure to natural daylight. All participants worked normal day-shifts and were office-based university employees. Participants completed measures of sleep quality and health-related quality of life. In addition a subset from each group wore an actigraph watch to profile light exposure, activity and sleep-wake patterning.
The main results indicated that workers in windowless environments reported poorer overall sleep quality, greater day-to-day limitations due to physical problems and reduced vitality. Actigraph measurement in the sub-sample confirmed that windowless workers had reduced light exposure as well as less total sleep time (by approximately 45 minutes).
The authors conclude that architectural features of offices and places of employment should be considered a ripe target for intervention to improve sleep and health:
“Lower amounts of light exposure in the work place was associated with reduced sleep duration, poorer sleep quality, lower activity levels, and reduced quality of life in this sample of office workers. Light exposure in the work place may therefore have long lasting and compounding effects on the physical and mental health of the workers not only during but also beyond work hours. Enhanced indoor lighting for those with insufficient lighting in current offices as well as increased emphasis on light exposure in the architectural design of future office environments is recommended to improve office workers’ sleep quality and physical well-being.”
Boubekri, M., Cheung, I.N., Reid, K.J., Wang, C.H., Zee, P.C. (2014). Impact of windows and daylight exposure on overall health and sleep quality of office workers: a case-control pilot study. Journal of Clinical Sleep Medicine, doi:10.5664/jcsm.3780