Identifying and controlling “a hazard” is the main process in controlling occupational risk. Ideally, the elimination of this hazard is preferable; however where this is not possible, minimizing the hazard should be enforced.
One of the most riskful hazards in relation to sleep disorders is fatigue. Fatigue can be classed as a hazard and is 4 times more likely to impair workplace performance than alcohol or drug use.
Fatigue is a state of mental or physical exhaustion that impairs a person’s ability to function normally. It is more than just feeling tired or drowsy. Most people are well aware of becoming tired after physical or mental effort, but fatigue is worse than simple tiredness or sleepiness. It is brought on by an inability for the body to achieve sufficient amounts of restorative rest (eg. sleep) for whatever reason.
Fatigue can be best described by having either physical weakness in the muscles and lack of physical stamina, or having an inability to concentrate, remember or problem solve efficiently or effectively.
The signs and symptoms of fatigue include:
Microsleeps are short periods of time (from less than a second to up to 5 seconds) where the brain simply goes to sleep without the person actually being aware of it. Microsleeps happen when someone is particularly sleep deprived, fatigued, or have sustained wakefulness for over 17 hours.
Microsleeps do not necessarilly induce muscle relaxation and can occur even when the eyes are open. Thus, people can often continue performing a mundane, ordinary task (like driving) while they are in a microsleep. The difference is their ability to react to change is completely disabled during this time.
An interesting study in the USA showed that if chronically sleep deprived the study patients slept for up to 13 seconds per minute from microsleeps. That’s over 20% of total driving time spent asleep!
It is first important to distinguish between fatigue (exhaustion from an imbalance of activity and rest) and chronic fatigue syndrome (a multi-system medical condition, with a symptom being fatigue). Fatigue can be caused by a varied number of things listed below, however the most influential factor for managing fatigue is the amount and quality of sleep a person achieves.
Workplace fatigue however, often results from a few common causes.
Fatigue can also become evident through working shifts. Even though a shift worker may achieve 8 hours of sleep a day, a person’s type of sleep is altered during the day. Sleep during the day does not allow the person to go into a deep, restorative sleep as much as they would at night. Thus it is important that if shift workers allow themselves time off to sleep during the night also.
Shift work can also have a significant effect on circadian rhythms. This can lead to insomnia and cause fatigue.
Good quality sleep is the only effective long-term counter-measure to fatigue. Maintaining sufficient levels of sleep will prevent fatigue.
An American study decided to initiate a sleep apnoea diagnostic and treatment program within a large transportation company. It was found that the company made two to three times more profit for every dollar invested in the sleep apnoea treatment program. Further to this, employee retention was doubled during the course of the program. Drivers treated for sleep apnea had a 73% reduction in accidents, a 91% reduction in hospital admissions, and overall a 57% reduction in healthcare expenses.
This is not an isolated finding. Almost unanimously, studies find productivity is significantly increased once a successful fatigue management plan is initiated. The elimination of sleep disorders like sleep apnoea contributed to higher profits based off less sick leave time for employers, higher retention rates, higher productivity, and less expense on other health management programs.
With chronic sleep disorders there are daytime neurobehavioral performance impairments which are more likely when the duration of average sleep is less than 5 hours/night plus those with severe obstructive sleep apnea.
Strategies that should be employed by in Australia to reduce sleepiness, and potentially crash risk, in commercial drivers include plans to –
These strategies are in development in Europe and USA, and are our standard service of care with The Thoracic and Sleep Group (QLD).
You have a responsibility to yourself, your workmates, and your employer to ensure you are safe, healthy and informed.
Accidents are more likely to occur at night, particularly during the period when the core body temperature is at its lowest point (midnight to dawn) when a person would normally be sleeping. As body temperature drops the general level of alertness drops which impairs concentration and judgment. The risk of a work accident is therefore doubled.
It is strongly recommended that the following be implemented by anyone working shifts.
The mining industry is an extremely high risk industry. In Queensland, the Health and Safety Regulations for the mining industry is enforced under a specific legislation. To read more on mining health and safety see:
In New South Wales, the state government has issues a public action plan geared toward promoting Workplace Health and Safety in the Mining Industry:
The combination of long working hours, physically intense labour, heavy machinery, potential shift work, and working in dark spaces makes this occupation very susceptible to workplace accidents.
Working in places without sunlight (even in offices sheltered from sunlight), impact on levels of alertness. Natural light has the ability to stimulate an area of the brain (the hypothalamus) which helps control our wake-sleep cycle. Halogen, tungsten and fluorescent lights do not have the same effect on the brain as sunlight and therefore, prolonged hours away from daylight can have a dulling affect on mental performance.
The most dangerous times to drive are between the hours of 2pm-5pm and 3am-5am. This is due to the core body temperature dropping at these times, causing noticeable increases in sleepiness. The risk of a crash is particularly increased in the early hours of the morning – the sun is not up, the roads are empty (which contrary to common belief increases the risk of a single vehicle accident), and most people are used to being asleep at this time.
In 2007, the National Transport Commission developed and successfully implemented a Fatigue Management Program Reform for Heavy Vehicle Drivers. Details of the Reform can be found at:
*Excerpt from the American Academy of Sleep Medicine Drowsy driving Factsheet.
Be aware of some of the no-no’s…
While caffeine and other stimulants can improve some symptoms caused by sleep loss or poor quality sleep. They can complicate others, by giving a false sense of security or by making things worse (ie. Motor control and concentration are made worse by caffeine).
For more information on Governmental Legislation relating to fatigue:
16 hours of prolonged wakefulness can impair functioning as much as a blood alcohol level of .05%.
21 hours of prolonged wakefulness can impair functioning as much as a blood alcohol level of .10%.
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