Mike Harnett, the vice-president of human factors at Six Safety Systems, was the presenter for a session entitled I’ll sleep when I’m dead at the Vancouver Regional Construction Association’s Construction Leadership Forum held earlier this month in Whistler, B.C.
Harnett defined fatigue as a decreased capacity to perform mentally or physically as a result of a lack of restorative sleep. It is influenced by the time of day and how long you’ve been awake and has a direct long-term effect on physical and mental health.
In the construction industry long hours, irregular shift times, timeline pressures, physical demands, mental demands and a lack of break facilities can all contribute to fatigue. But coffee or a splash of cold water is not a fix.
“Only sleep cures fatigue,” Harnett said, adding it is not the same as drowsiness, which fluctuates naturally during the day.
Circadian rhythms are our built-in body clock, she said, built around a 24-hour cycle and responding to light and dark. These rhythms affect alertness, behaviour, co-ordination and emotions.
The body temperature curve, controlled by light entering our eyes, dictates how alert we feel. The “post lunch dip” is a natural part of our rhythm and is the reason we get drowsy after lunch.
She explained that the more fatigue that’s built up, the more drowsiness you’ll have.
But the circadian cycle has been disrupted. In the last 100 years, society has reduced sleep from an average of nine hours to less than seven hours, and 36 per cent get less than six hours. The difference is the invention of electricity. Previously, we got up and went to bed with the sun, and now we pack more “daylight” into our day.
Harnett said that how much sleep is enough is genetically pre-determined, but most require a minimum of seven to nine hours. When you miss out on sleep one can see it the next day, daylight savings time being the best example.
And not getting that sleep can impact one far beyond the workplace. Short sleeping accelerates the aging process of every cell at the DNA level, she said, and there is also a connection to Alzheimer’s and dementia to lack of sleep. Obesity and diabetes are also tied to a lack of sleep.
“We can put on more weight simply from not having enough sleep,” Harnett added.
Chronic sleep loss is also tied to a number of different disease risk factors, including stroke, digestive disorders, depression and cancers. Medications also don’t metabolize at night in the same way.
Sleep disorders affect 40 per cent of Canadians, including sleep walking, sleep talking, periodic limb movement disorder and circadian rhythm sleep disorders. There is also a substantial increase in Obstructive Sleep Apnea (OSA) where breathing stops while you sleep. Equipment operators are at the highest risk of OSA, Harnett said.
Fatigue is dangerous, she said, because it can induce automatic behaviour syndrome, which is taking actions but not engaging in cognition.
None of the tricks like rolling down the window or turning up the radio do anything but provide a short term solution. There is no substitute for a good night’s sleep.
Harnett offered some tips to make sure one gets a good night’s rest, including buying a good bed, which stops the transfer of movement.
While having a pre-bedtime activity like reading helps, it’s a good idea to ditch the devices for a darker environment. All sources of light should be removed, including televisions. TV is a flashing source of light and the sound aspect also damages sleep patterns.
While it’s better to read a book before bed than a Kindle or iPad, Apple has a “night shift” setting and Android has a filter, which will change the colour temperature of the phone’s light to something appropriate to nighttime reading. One can also buy AM/PM bulbs or tunable LEDs that will change with the time of day.
According to Harnett, from an organizational perspective, sleep is controllable by workers and is often equated with laziness, when in fact it is a sign of a healthy lifestyle. The supervisor’s role, if someone suffers from fatigue, is to ensure the problem is addressed because if it isn’t errors will crop up and cause problems in the workplace.
“It’s about safety and performance,” Harnett said, about the physical and mental ability as well as emotional stability and alertness.
She suggested employers analyze work schedules and the true cost of overtime and educate the workforce on fatigue-related risks and personal management strategies.