05:19pm Friday 22 November 2019

Shedding light on shift worker drowsiness


The collaborative research project between Monash University, the Woolcock Institute for Medical Research and the University of South Australia is testing the idea that certain types of light can provide an alerting stimulus that will assist to keep shift workers alert and safe.

The primary investigator is Associate Professor Shantha Rajaratnam, an internationally renowned sleep expert and the leader of the Sleep and Chronobiology Research Group at Monash University.

Associate Professor Rajaratnam said with 1.4 million Australians reporting they usually worked non-standard hours and 64 per cent of employees reporting working some of their weekly hours between 7pm and 7am according to the 2006 census, the research is essential in gaining a greater understanding of how negative health consequences related to shiftwork could be reduced.

“Night work requires an individual to work when the body is programmed for sleep and to sleep when the body is programmed to be awake. Conflict between the sleep/wake cycle and the internal body clock creates a mismatch between the internal body clock and the sleep/wake cycle, which can negatively impact upon the sleep, social life and overall health of the shift worker.” Associate Professor Rajaratnam said.

“Excessive sleepiness is now considered a major cause of accidents in shift working industries. Shift workers often report excessive sleepiness and performance deficits during night shift, resulting in reduced productivity. Compared to day shift, working night shift is associated with increased risk of injuries, errors and motor vehicle crashes,”

“Directly targeting sleepiness across night shift appears to provide the greatest potential for management of alertness and performance deficits in shift workers,”

Associate Professor Rajaratnam said that while wake-promoting drugs are available to counteract sleepiness, such drugs have problems of side effects, interactions and, in some cases, dependence. A non-pharmacological, non-invasive, low-cost and safe intervention to enhance alertness during the night shift will have safety and health benefits for many industries that engage in 24 hour operations.

“Light exposure has a direct, arousing effect in humans, improving alertness and performance. Recent research has shown that light input to the internal body clock uses different cells in the eye to those used for normal vision.” Associate Professor Rajaratnam said.

The study will recruit healthy men and women who regularly work night shifts. Volunteers will be asked to monitor their own sleep patterns for one to three weeks and then visit the sleep laboratory in their home city for an overnight, simulated night shift. The simulated night shift will occur under one of two conditions of overhead lighting enriched with different wavelengths of light. During the simulated night shift, performance, sleepiness and mood will be recorded from each volunteer.

“Given the rapid growth in our understanding of how the internal body clock receives light information, and technological advances in the way lighting can be produced, the proposed study will provide valuable scientific evidence to inform the design, implementation and testing of light interventions in field settings to ultimately increase the safety outcomes associated with night shift work,” Associate Professor Rajaratnam said.

For more information contact Megan Gidley, Media and Communications + 61 3 9903 4843 or 0448 574 148. To volunteer for the research or to find out more information, please visit the Faculty of Medicine, Nursing and Health Sciences website, email sleepstudy@monash.edu or telephone +61 03 9905 3952.

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