Fatigue is common amongst the population, but particularly among those working abnormal hours, and can arise from excessive working time or poorly designed shift patterns. It is also related to workload, in that workers are more easily fatigued if their work is machine-paced, complex or monotonous.
Nowadays, employers have a duty to take all practicable steps to ensure that employees are safe at work, and fatigue is a workplace hazard that they must manage.
Fatigue is a general term used to describe a wide variety of conditions, but is generally accepted as feeling very tired, weary or sleepy as a result of insufficient sleep, prolonged mental or physical work, or extended periods of stress or anxiety. Fatigue can also be described as either acute (usually reversed by sleep and relaxation) or chronic (the constant, severe state of tiredness not relieved by rest).
Many negative health aspects are associated with shift work, including an increase in accidents while on the job, reduced duration and quality of sleep, fatigue, and being less alert when performing duties. The worker may experience decreased reaction times and poorer work performance. Most recently, shift work has also been implicated in breast cancer.
Fatigue at work has been identified as a contributory factor to some of the most significant disasters of our time: the Three Mile Island accident in Pennsylvania; the Chernobyl nuclear power plant accident in Russia and the grounding of the oil tanker Exxon Valdez off the coast of Alaska.
Workplaces can help by providing environments that have good lighting, comfortable temperatures and reasonable noise levels. Work tasks should provide a variety of interest and should change throughout the shift. If extended hours and overtime are common, remember to consider the time required for employees to commute from home, and workers should allow time for meal preparation, eating and socialising. Workplaces may also wish to consider providing:
•prepared meals for workers; and
•facilities where employees can take a nap before driving home.
Research into shift work and its effects on health have resulted in a set of ergonomic recommendations that should be taken into account, and include:
•minimise permanent night shifts;
•minimise sequence of night shifts, only two to four shifts in succession;
•consider shorter night shifts;
•avoid quick changeovers;
•plan rotas with some free weekends;
•avoid overlong work sequences;
•rotate forward (i.e. clockwise rotation morning/evenings/nights); and
•avoid early starts.