March 3 – 10 is National Sleep Awareness Week and it’s a reminder that fatigue on the job can be a health hazard, increasing the risk of accidents and elevating the chances of a disabling injury.
No one is more at risk than the estimated 25 to 30% cent of the working population who work nights, evenings, rotating and irregular hours.
A 2010 study by researchers at the University of British Columbia concluded that evening and night shift workers are almost twice as likely to be injured at work as those working regular day shifts.
The UBC study analyzed data on 30,000 working Canadians in Statistics Canada’s Survey of Labour and Income Dynamics. Researchers noted that while work injuries in Canada declined overall between 1996 and 2006, injury rates for night shift workers remained unchanged.
That comes as no surprise to Dr. Robert Whiting, a senior project manger with the Canadian Centre for Occupational Health and Safety, or to Dr. Cameron Mustard, head of the Institute for Work and Health.
“It is a real problem,” says Whiting, who recently convened a one-day symposium on the health hazards of shift work.
“Shift workers, particularly those who work at night, are vulnerable on three counts: fatigue, lower levels of supervision and less co-worker support. And more incidents are generally reported on the 4th successive night shift than on the first.”
Whiting says working at night, or on an irregular schedule, plays havoc with an individual’s natural circadian rhythms, creating internal confusion in the body.
“We are not a nocturnal species,” says Mustard, noting that human beings are biologically programmed to get sleepy at night, even after 6-8 hours of sleep.
As well, many night workers have problems with the quality of their daytime sleep, as they contend with families and surroundings that are busiest during the daytime.
“The third piece of the puzzle”, says Mustard, “is the way work changes in the evenings and overnight.” With less co-worker and supervisory support, the risk of injury increases at night.
Researchers have found the body responds better to staying up later than being forced to perform earlier in the cycle, says Whiting. With that in mind, shift schedules should consistently move workers from earlier to later shifts, rather than vice versa, to allow for easier transitions.
Whiting says research has also indicated shifts should be switched more often, with “no more than three days on a rotation, with at least a day off in between the next three-day cycle.”
When you regularly change your shift, it is easier to make the transition, he says, rather than working one shift for a very long time, then enduring a change. “The body makes the switch much easier if it changes regularly.”
Workers often express a preference for 12 hour shifts, notes Whiting, as it gives them lots of time off in the shoulder periods and allows them more flexibility in their personal lives.
“But there are more accidents on 12-hour shifts,” he argues, “especially when the job requires a high level of concentration.”
Establishing a strategy in the workplace for dealing with the health effects of shift work should be a team effort, with consultation all around.
There is increased recognition that organizations scheduling staff for evening and overnight work benefit from what is called ‘self-rostering.’
Says Mustard: “There will always be people who prefer to work at night, and with computers, this is easy to organize. Airlines have been doing this for years.”
Whiting agrees: “You need to involve the workers who are doing the shifts. There are always compromises to be made. It is also important in scheduling to ensure workers don’t get isolated on a shift rotation, and that there are managers and senior staff on site working.”
What is NOT a good idea, says Mustard is the use of stimulants – caffeine being the #1 choice – to get through the night. Higher octane stimulants, such as amphetamines, are even worse. Similarly during the day, night shift workers who take sleeping pills, sedatives or even ‘natural’ remedies such as melatonin to help them sleep are making a poor choice.
Finally, Whiting argues that shift work is not strictly a younger worker’s game.
“Older workers have established routines and are probably better candidates for the physical discipline of shift work,” says Whiting.
As well, using shift work as a reward system or symbolic of the workplace pecking order “is not good for social cohesion in the workplace. If there is some element of social prestige awarded to working days, night workers will feel punished and less satisfied on the job.”