The patterning and duration of the hours a person works are a very important aspect of his or her experience of the work situation. Most workers feel that they are paid for their time rather than explicitly for their efforts, and thus the transaction between the worker and the employer is one of exchanging time for money. Thus, the quality of the time being exchanged is a very important part of the equation. Time that has high value because of its importance to the worker in terms of allowing sleep, interaction with family and friends and participation in community events may be more highly prized, and thus require extra financial compensation, as compared to normal “day work” time when many of the worker’s friends and family members are themselves at work or at school. The balance of the transaction can also be changed by making the time spent at work more congenial to the worker, for example, by improving working conditions. The commute to and from work is unavailable to the worker for recreation, so this time too must be considered as “grey time” (Knauth et al. 1983) and therefore a “cost” to the worker. Thus, measures such as compressed workweeks, which reduce the number of commuting trips taken per week, or flexitime, which reduces the commute time by allowing the worker to avoid the rush hour, are again likely to change the balance.
As Kogi (1991) has remarked, there is a general trend in both manufacturing and service industries towards greater flexibility in the temporal programming of work. There are a number of reasons for this trend, including the high cost of capital equipment, consumer demand for around-the-clock service, legislative pressure to reduce the length of the workweek and (in some societies such as the United States and Australia) taxation pressure on the employer to have as few different employees as possible. For many employees, the conventional “9 to 5” or “8 to 4”, Monday through Friday workweek is a thing of the past, either because of new work systems or because of the large amounts of excessive overtime required.
Kogi notes that while the benefits to the employer of such flexibility are quite clear in allowing extended business hours, accommodation of market demand and greater management flexibility, the benefits to the worker may be less certain. Unless the flexible schedule involves elements of choice for workers with respect to their particular hours of work, flexibility can often mean disruptions in their biological clocks and domestic situations. Extended work shifts may also lead to fatigue, compromising safety and productivity, as well as to increased exposure to chemical hazards.
Biological Disruptions due to Abnormal Work Hours
Human biology is specifically oriented towards wakefulness during daylight and sleep at night. Any work schedule which requires late evening or all-night wakefulness as a result of compressed workweeks, mandatory overtime or shiftwork will lead, therefore, to disruptions of the biological clock (Monk and Folkard 1992). These disruptions can be assessed by measuring workers’ “circadian rhythms”, which comprise regular fluctuations over the 24 hours in vital signs, blood and urine composition, mood and performance efficiency over the 24-hour period (Aschoff 1981). The measure used most often in shiftwork studies has been body temperature, which, under normal conditions, shows a clear rhythm with a peak at about 2000 hours, a trough at about 0500 hours and a difference of about 0.7°C. between the two. After an abrupt change in routine, the amplitude (size) of the rhythm diminishes and the phase (timing) of the rhythm is slow to adjust to the new schedule. Until the adjustment process is complete, sleep is disrupted and daytime mood and performance efficiency are impaired. These symptoms can be regarded as the shiftwork equivalent of jet-lag and can be extremely long lasting (Knauth and Rutenfranz 1976).
Abnormal work hours can also lead to poor health. Although it has proved difficult to precisely quantify the exact size of the effect, it appears that, in addition to sleep disorders, gastrointestinal disorders (including peptic ulcers) and cardiovascular disease can be more frequently found in shift workers (and former shift workers) than in day workers (Scott and LaDou 1990). There is also some preliminary evidence for increased incidence of psychiatric symptoms (Cole, Loving and Kripke 1990).
Social Disruptions due to Abnormal Work Hours
Not only human biology, but also human society, opposes those who work abnormal hours. Unlike the nocturnal sleep of the majority, which is carefully protected by strict taboos against loud noise and telephone use at night, the late wakening, day-sleeping and napping that are required by those working abnormal work hours is only grudgingly tolerated by society. Evening and weekend community events can also be denied to these people, leading to feelings of alienation.
It is with the family, however, that the social disruptions of abnormal work hours may be the most devastating. For the worker, the family roles of parent, caregiver, social companion and sexual partner can all be severely compromised by abnormal work hours, leading to marital disharmony and problems with children (Colligan and Rosa 1990). Moreover, the worker’s attempts to rectify, or to avoid, such social problems may result in a decrease in sleep time, thus leading to poor alertness and compromised safety and productivity.
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 and education of the worker
- selection of the most appropriate work schedule or roster
- 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 (e.g., older workers and those with high sleep needs, extensive domestic workloads or long commutes). Education in circadian and sleep hygiene principles and family counselling should also be made available (Monk and Folkard 1992). Education is an extremely powerful tool in helping those with abnormal work hours to cope, and in reassuring them about why they may be experiencing problems. Selection of the most appropriate schedule should begin with a decision as to whether abnormal work hours are actually needed at all. For example, night work may in many cases be done better at a different time of day (Knauth and Rutenfranz 1982). Consideration should be 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 raising illumination levels and providing adequate canteen facilities at night.
The particular pattern of work hours chosen for an employee can represent a significant challenge to his or her biology, domestic situation and role in the community. Informed decisions should be made, incorporating a study of the demands of the work situation and the demographics of the workforce. Any changes in hours of work should be preceded by detailed investigation and consultation with the employees and followed by evaluation studies.