Shift work, particularly where long evening shifts are involved, is a generally underestimated risk factor when it comes to accidents at the workplace and work related health conditions. It is known to have adverse physical, social and biological effects on a worker’s health.
The biological make-up of human beings is orientated towards wakefulness during the day time and sleep at night.
Working abnormal hours at times when people should normally be asleep, particularly if it requires all night wakefulness, tends to upset an individual’s biological clock or circadian rhythm, resulting in fatigue and stress, leading sometimes to heart disease and gastro-intestinal trouble.Various factors need to be taken into account, therefore, when it comes to shift work, including whether working at night time is really necessary and the suitability or unsuitability of particular individuals for shift work, as well as how long and how regular shifts should be.
Improving the working environment to make it more congenial and balancing the need for work to be done and for workers to have some rest can help reduce the safety and health risks inherent in night work.There are various reasons why people end up doing shift work. One of the main reasons is technology advancement, which is resulting in a 24 hours-a-day society. Other reasons include the high cost of capital equipment, consumer demand for around the clock service, pressures in some countries to reduce the length of the working week, taxation pressure in some countries to have as few different workers as possible and employee needs.
Some services, such as nursing and police work, have to be provided round the clock.
Shift work is common among those working in the health, police, defence, security, transport and fire service sectors, as well as among factory and restaurant workers.There are a variety of accidents and health problems that shift work can give rise to.
Poorly designed shift working arrangements and long working hours that do not balance working requirements with the need for time to rest and recover can result in fatigue, accidents, injuries and ill health.
Tiredness can result in workers falling asleep on duty, thereby increasing the risk of industrial accidents. This risk is increased when those who do night work do not sleep for long enough during the day.
Fatigue results in slower reaction time, reduced ability to process information, memory losses, absent-mindendess, decreased awareness, lack of attention, reduced co-ordination and underestimation of risks. It can lead to errors and accidents, ill health, injury and reduced productivity.
Employers have a responsibility to manage risks from fatigue, even if an employee is willing to work extra hours or prefers certain shifts. Apart from fatigue, shift work can give rise to sleep disorders and stress.
Ergonomic-related injuries, often called musculoskeletal disorders, affecting the muscles, tendons, nerves, ligaments, joints and blood vessels, which tend to be related to posture at work, are also common as a result of people dozing off at their workstations when doing night shifts. Shift work is even believed to be a cause of low birth weight and pre-term babies. This finding makes it critical for employers to take into consideration the gender-dimensions when planning shift work for employees.
Working anti-social hours means loss of time for family and social functions, which can itself be a source of stress.
Illnesses and injuries stemming from fatigue and other causes related to shift work result in sick leave and reduced production, which in turn diminishes economic gain.
Just as the problems of abnormal work hours are multifaceted, so too must be the solutions to those problems. The primary areas to be addressed should include: selection of workers for shift work and their education about the risks involved and how to minimise them; selection of the most appropriate work schedule or roster; and improvement of the work environment.
Selection and education of the worker should involve identification and counselling of those persons likely to experience difficulties with abnormal or extended work hours, such as older workers and those with high sleep needs, extensive domestic workloads or long commutes.
Education and family counselling about the impact that the body’s biological rhythms and sleep have on health should be made available.
Selection of the most appropriate shift schedule should begin with consideration of whether abnormal work hours are actually needed at all. Night work may in many cases be done better at a different time of day.
Consideration should also be given to the schedule best suited to the work situation, bearing in mind the nature of the work and the demographics of the workforce.
Improvement of the work environment may involve improving lighting and providing adequate canteen facilities at night.
In drawing up the work schedule, a permanent night shift should be avoided. Consecutive night shifts should be kept to a minimum. Quick shift changes should also be avoided.
Plan at least some free weekends. Keep long shifts and overtime to a minimum. The schedule should be kept regular and predictable.
Although more research is still required on the risks to safety and health involved in shift work, particularly in respect of such risks in a local setting, it is clear from research done internationally that shift work is a risk factor where accidents and health is concerned and that it is a risk factor that tends to be underestimated by many employers and employees.It is a risk factor that should be considered in all occupational safety and health programmes.