OSH Briefing Document on Stress and Fatigue OSH has taken the trouble to research available sources and relate it to NZ.
Let's have a look and see what they found.

Table of Contents

The OSH briefing document was produced in January 1998 and is a digest of available literature, which attempts to put this into a New Zealand context.


Definition of Stress:

  • The awareness of not being able to cope with the demands of one's environment, when
  • This realisation is of concern to the person, in that both are associated with a negative emotional response.
  • Stressors: Events or circumstances which may lead to the perception that physical or psychological demands are about to be exceeded.

Definition of Fatigue:

  • The temporary inability, or decrease in ability, or strong disinclination to respond to a situation, because of previous over-activity, either mental, emotional or physical.

There is a model used, which depicts fatigue in terms of factors that drain a bucket and those that restore, or refill the bucket. (See below)

People recover from the demands of life and work through sleeping, exercising, relaxing, enjoying friendships, achieving goals and finding fulfilment at work, through sporting activities, hobbies and social events.

The following diagram is used by OSH to summarise these factors:

  • Fatigue can be considered as local or general, acute or chronic.
  • Acute fatigue is the result of sudden and/or severe exposure or onset.
  • Chronic fatigue usually develops after longer exposures, often of a significantly smaller intensity than for acute fatigue.

Symptoms:

  • Forgetfulness
  • Poor communication
  • Poor decision making
  • A state of apathy
  • Slowed reaction time
  • Lethargy
  • Reduced vigilance
  • Bad mood

Restorative Factors:

Work-related restorative processes occur as well, and may include:

  • The completion of tasks
  • The resolution of problems
  • Supportive relationships
  • Progress towards worthwhile goals
  • The opportunity to do high-quality work
  • The prospect of advancement and training

These can restore reserves of capacity, stamina, enthusiasm and endurance. Wellbeing requires a balance in the tension between the opposing draining and recuperative forces.

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Causes of stress and fatigue:

1. The intensity and duration of physical and mental effort

  • A long, physically demanding job will tire people more quickly than a sedentary job. Extended work days of 12 hours or more increases fatigue and sustained working over several days with sleep loss causes a decrease in performance.
  • Sustained mental effort is more fatiguing than work which is not mentally demanding. The intensity and duration of the physical and mental effort required by the job are major factors.
  • Jobs with low mental (and physical) activity can act as stressors.

2. The environment: climate, light, noise, workstation design

  • Environmental factors can place demands on people. For example, being in very cold or very hot work environments, being exposed to draughts, or handling vibrating tools can all lead to health problems.
  • Poor lighting can also cause problems that increase mental and physical effort.
  • Noise, when very loud or when it has a particular quality (high-pitched or throbbing, for example), can be damaging or distressing. There is considerable evidence that acute noise exposure produces physiological responses which, if prolonged, may have harmful effects on health.
  • Workstation design is an important factor in physical comfort. When the designs are inappropriate, the effort required may become excessive, leading to musculoskeletal problems. Static muscle effort can rapidly lead to "static" muscle fatigue, or occupational overuse syndrome.

3. Mental and emotional well-being, responsibilities, worries, conflict, social interactions

  • Sometimes the pressure of non-work events can be a cause of distress, for example the loss of a loved one.
  • The perception of distress may be more real than the events.
  • Good social relationships are important for health. People who experience supportive relationships cope better.

4. A lack of physical wellbeing: illness, pain, disrupted circadian rhythm, sleep loss, inadequate nutrition and exercise

  • A sick employee will have more difficulty coping with stressors, compared others
  • People who have a balanced diet and take adequate and regular exercise suffer less illness, and people who take moderate physical activity have better mental health and mood.

5. The organisational characteristics of work

  • The psychological stressors in getting the work done
  • The individual's control over his/her own conduct during the day; and
  • Support for the individual in the organisation.

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Shift Work:

  • Shift-workers, particularly on rotating shifts, have a higher incidence of sick leave, visits to clinics at the work site, and poorer scores on a variety of health measures.
  • Difficulty with shift-work is often experienced as people approach 50 years of age.
  • The ILO has recommended that shift-workers should have the possibility of transferring to day work at age 50.
  • It has been recognised that most occupational fatigue symptoms now result from disturbances of sleep and the circadian biological clock.

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Indicators:

  • The presence of stress can be inferred or measured in terms of health problems,  emotional reactions and organisational characteristics such as absenteeism or presenteeism (where employees may be described as being physically present at work, but "mentally absent").
  • It may be useful to think of the "goodness of fit" between each employee and the work. If the fit between the employee and their work is poor, then problems are more likely.
  • Life events such as getting married, changing or losing a job, or the death of a spouse. Seemingly "pleasant" experiences can be stressful. Getting married and the death of a spouse are given similar rankings.

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Personal factors:

  • No one is immune to stress. People may react in different ways.
  • The employee's personality, age, educational level, degree of training, health status and social status in the organisation are factors.

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Managing stress and fatigue:

  • The methods are already available through the hierarchy of controls outlined in the Health and Safety in Employment Act 1992 - elimination, isolation or minimisation.
  • If "stress management" is the only strategy used, the onus of coping lies only with the individual, whereas the power to alter the situation usually lies with the organisation.
  • Primary prevention should include strategies which involve adaptation by the organisation as well as the individual. There is, therefore a shared responsibility for controlling stress.

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Assessing an employee's stress or fatigue:
This is not a science, however, below is the OSH offering on fatigue. For stress, you can try our own questionnaire but use it with caution.

Stress Questionnaire

Fatigue assessment:

Try OHS Occupational Health & Safety Software Program, SafetyBase NZ

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