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Safeguard OSH Solutions - Thomson Reuters

Safeguard OSH Solutions - Thomson Reuters

Alert24 - Safeguard Update

Sleep as a safety issue

Sleep as a safety issue
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New Zealand

Safety-critical workplaces cannot afford to ignore employees' sleeping habits, a team of sleep researchers told the Royal Australasian College of Physicians Congress in Auckland last month.

Sleep deprivation, whether the result of shiftwork, obstructive sleep apnoea (OSA) or lifestyle factors, is a hazard to both health and safety, and must be monitored and managed, they said.

Dr Philippa Gander, director of Massey University's Sleep/Wake Research Centre, explained how improvements in sleep science had seen the UN's aviation regulatory body, the International Civil Aviation Organisation (ICAO), completely revise its fatigue management protocols. Previously it had relied on prescriptive flight duty limits, but now airlines are being encouraged to support these limits with fatigue risk management systems.

"High-risk industries have had complex management systems for other kinds of hazard for a long time, but fatigue is the first human factors hazard to be dealt with in this way."

There were a number of reasons for the change, she said. "The science behind fatigue management has advanced to the point where we can actually apply it in a practical way in the workplace, and we now have aircraft that can fly for 24 hours non-stop. But there is another reason too - there is real doubt, around the world, as to whether prescriptive limits actually work."

Despite the US having well established work limits for commercial drivers, the National Transportation Safety Board has identified fatigue as the second most critical risk factor in road safety. "Clearly the old solution of prescriptive limits is not delivering a level of safety that this organisation is happy with."

While roster design is widely recognised as a means of managing fatigue, it is only one of the factors to be considered. "You also need to look at workload, breaks and skill levels, to monitor workforce health, and provide education about fatigue. And you need a safety culture where people are comfortable to report that they're feeling fatigued."

Shiftworkers must come in for special consideration, in light of mounting evidence that it is linked to a variety of adverse health effects. While researchers continue to argue about the exact definition of shiftwork, Gander said that from a physiological perspective it was any work that required you to be awake when you would normally be asleep.

"We've known for a long time that shift workers are at increased risk of developing gastrointestinal problems and cardiovascular disease, and in 2007 the International Agency for Research on Cancer concluded that it was probably carcinogenic."

In Denmark in 2008, 37 breast cancer patients were granted workers' compensation on the grounds that their illnesses were linked to shiftwork. "It was controversial, but these were women who had typically worked at least one night a week for 20 or 30 years, and where there were no other significant risk factors."

A large number of population-based studies have found evidence that less than seven hours sleep a night increases the risks of obesity, impaired glucose tolerance, type two diabetes, cardiovascular disease, poor general health, and premature death.

"It's become apparent over recent years that when get desynchrony between the central circadian pacemaker and peripheral oscillations in the liver, kidney and pancreas that are synchronised by food intake, you can very quickly get metabolic changes at cellular level, so the health consequences of shift work are likely to be much broader than is currently believed."

Chronotoxicity - the way the body's response to toxins is influenced by the circadian cycle - is another issue employers must consider, Gander said.

"You are much more sensitive [to toxins] when you should be asleep, so maybe you should think about changing the exposure thresholds for night workers? And from a safety perspective, think about what you're asking them to do. What are the particular issues on the shift in terms of work demands and high risk times?"

"And," she added, "getting them home safely is an employer's responsibility too."


People Mentioned:
Philippa Gander
Organisations Mentioned:
Massey University
Reference No:

From Alert24 - Safeguard Update

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