Fatigue suffered by seafarer poses a massive threat to life, property and environment.
Fatigue was identified as a significant contributing factor to the marine disasters of Exxon Valdez (oil spill), Chernobyl (the nuclear accident) and Three Mile Island fatigue was identified as a significant contributing factor.Japanese research has revealed that fatigue and lack of alertness is responsible for over 50 % of ship grounding and 38 % of collision.The research made by the university of Wale, Cardiff, showed that fatigue are mainly caused by the excessive pressure of work, the poor quality of sleep and the shift work systems.
What is fatigue?
Fatigue is the state of feeling very tired, weary or sleepy resulting from insufficient sleep, prolonged mental or physical work, or extended periods of stress or anxiety.Boring or repetitive tasks can intensify feelings of fatigue. Fatigue can be described as either acute or chronic.Acute fatigue results from short-term sleep loss or from short periods of heavy physical or mental work. The effects of acute fatigue are of short duration and usually can be reversed by sleep and relaxation.
What are some causes of fatigue?
There are many, many causes of fatigue.Work-related factors may include long work hours, long hours of physical or mental activity, insufficient break time between shifts, inadequate rest, excessive stress or a combination of these factors.Sometimes, a sleep disorder may cause fatigue.It is typically the result of working, mental stress, jet lag or active reaction, but also from boredom or disease or simply lack of steep.
What are the signs of fatigue?
Signs and symptoms of fatigue include:
sleepiness, including falling asleep against your will (micro” sleeps),
loss of appetite,
digestive problems, and increased susceptibility to illness
What are the effects of fatigue and their relationship to work?
Again, fatigue and sleepiness cannot be easily “measured” so it is difficult to pinpoint their effect on accident rates or incidents in the workplace. However, studies report the effects of fatigue as:
reduced decision making ability,
reduced ability to do complex planning,
reduced communication skills,
reduced attention and vigilance,
reduced ability to handle stress on the job,
reduced reaction time – both in speed and thought (a few studies have shown this effect as similar to being legally drunk),
loss of memory or the ability to recall details,
failure to respond to changes in surroundings or information provided,
unable to stay awake (eg, falling asleep while operating machinery or driving a vehicle),
increased tendency for risk-taking,
increased errors in judgement,
increased sick time, absenteeism, rate of turnover,
increased medical costs, and
increased accident rates.
Workplace related causes
Common workplace issues that can cause fatigue include:
Shift work – the human body is designed to sleep during the night. This pattern is set by a small part of the brain known as the circadian clock. A shift worker confuses their circadian clock by working when their body is programmed to be asleep. Sleeping during the day is usually difficult, because the person’s brain chemicals (neurotransmitters) are naturally set to ‘wakefulness’ mode.
Sleep is as basic to survival as food and water. Losing as little as two hours of sleep can negatively affect alertness and performance. Sleep deprivation affects a person’s carefulness and ability to respond to an emergency. Symptoms can include: decreased judgement, decision-making and memory; slower reaction time; lack of concentration; fixation; and worsened mood.
Studies monitoring brain activity show that one shift worker in five dozes off during the shift. Often, they do not realize afterwards that they have done so. Drowsy drivers, according to sleep researchers, may cause as many crashes as impaired drivers. Regardless of motivation, professionalism, training or pay, an individual who is very sleepy can lapse into sleep at any time, despite the potential consequences of inattention.
People often nod off or fall asleep when not intending to – while sitting on the couch watching TV, during a long meeting, or reading a book or newspaper. No great harm is done if this happens.But if it happens while you are driving a high speed craft – even for a couple of seconds – the ship is moving blindly. At high speed, a crash is likely with a high risk of death or severe injury. Fatigue is a significant factor contributing to human error, but for some reason someone is trying to avoid it. However we have to face it.