Shift work and health
Construction workers working night shift. © Colourbox
Definitions and occupations who work shifts
Many workers have their working hours at night when other persons sleep. This is necessary, as the workers here cannot close the hospital in the afternoon, and go home. The patients are still sick and need care, even though a “normal” working day is over. However, to work at other times than other persons, can give negative effects on the health. However, work schedules can be influenced, and we can give advice on how to reduce the problems related to work at odd hours. This way we can prevent negative health effects from shift work. Before we go into the theoretical issues regarding shift work, we will let the midwife Clare from Ethiopia tell you some issues from her working life:
A healthy, newborn baby is a great result of the midwife’s work.
“My life as a midwife is very rewarding. I deliver babies, and to see the new babies arrive in our world gives me fantastic moments of life. However, very often I also become worried during my work. The births often take place during the night. When the morning comes and my night shift is over, I very often cannot go home. If a mother is about to deliver, being in the middle of the birth, I have to stay until the birth has taken place. Sometimes only midwife trainees are present in the morning, and I cannot give them all responsibility alone. So, I continue my work until the baby is born. Sometimes this can take hours, and I might not be able to leave the ward before it is rather late in the day. I sometimes have no time for going home at all, before the next work shift starts. This happens almost every week and makes me very tired and sleepy. I am afraid of doing mistakes as I am tired and maybe not concentrated enough at work. This worries me a lot.”
Similar stories can be told by many employees. Some countries have minor focus on the side effects of long working hours, and this kind of situations may occur. It is no doubt that the consequences can become serious. We know that shift workers, like midwifes, who do not get enough sleep and rest between their shifts can become very tired – and errors at work can be one of the consequences. But to be able to discuss this topic properly, we need to start with some theoretical definitions. Let us first tell you what shift work is.
What is shift work?
Shift work can in general be defined as working, either permanent or periodical, in periods outside normal working hours. The literature uses the term shift work in several ways. You should be aware of this if you want to find information on the subject. You can easily become confused, as shift work definitions differ in different texts and books. Shift work can be defined in a large number of ways, depending on the number of hours you work, what time of day you work and frequency of change between different types of shifts. It may also vary between companies and countries what kind of definitions they use. Night shift work is often defined as work in the time 2100-0600, while shift work can be defined as work in the time from 1800 to 0600. The International Labor Organization (ILO) defines night work as all work performed from midnight to 5 a.m. (ILO Night Work Convention, no 171, 1990) The different definitions can be set in relation to salaries, and be the results from discussions between authorities and trade unions; that is why the definitions might differ from country to county. We also describe the shifts by using the words day shift, afternoon shift and night shift. Shift work can also be classified as follows:
A. Permanent shift
Permanent shifts means that the employee only works a type of shift, for example only night shifts or only afternoon shifts. Some also calls these types of shifts “regular” shifts.
B. Rotating shifts
This expression means that one and the same worker varies between different types of shifts, i.e. can work afternoon shifts one day, night shift another day and so on. Some call these “irregular” shifts. However, sometimes there is a system in the change of shifts. Some nurses in hospitals can work in a system of day shift, afternoon shift, night shift, day off, day shift, and so on.
C. Continuous shift
This expression means that shift work takes place from Monday to Sunday. This definition means that shift work also includes the weekend, meaning that the work does not stop at the workplace. Many use the term continuous about such work. Others use the term “continuous” about shifts that are the same type throughout the week, for example if you work the night shift every night for a week, then changes to day shifts for a week, then changes to afternoon shifts for a week and so on.
D. Discontinuous shift
This expression means that the employee work shifts from Monday through Friday, or Monday through Saturday. The whole weekend is not included.
E. Swing shift
Swing shift is an expression that means that switching between the types of shift takes place during a working period. This can be the work system for instance at offshore installations, at construction work sites or in mines where the workers stay for several weeks. They can work night shifts for a period of days and then change (swing) to day shift for a period before they go home, or vice versa.
How many persons work shifts?
How many employees who work shifts, is hard to say for sure, but we know it is a large number. In the European Union it is estimated that only 25% of workers have a working day within the period we call “normal”; between 8 and 16, meaning that 75% of the employees work some kind of shift. Outside the European Union, data on shift work is limited. However, a figure of 25.2% of the workers in Japan work night shifts. A much higher figure of night shift workers – 44 % - has been reported from the Republic of Korea (2002). At present no figures exist regarding the number of night shift workers or other types of shift workers in developing countries. Shift work is common where work must be done at night because the process that takes place in the enterprise that cannot be stopped (e.g. in smelting industry and hospitals), or because the work is related to the night as such (e.g. a night watchman). Also, the number of night shift workers seems to increase in large cities, due to night open petrol stations, cafeterias and shops.
© University of Bergen/Author: B.E. Moen