The following is my Literature Review on Shiftwork and Health.
Our 24-hour society means that shift work is becoming more common and a higher number people are now working outside the ‘normal’ hours of nine to five. In addition to the 24-hour emergency services available to us, we now experience round-the-clock services such as banking, transport and shopping. Many people benefit from this, but there have been suggestions that the people who provide these services are putting their health and well-being at risk.
Parkes (nd:3) found that shift work had been linked to a variety of diseases and her research revealed that disruption of circadian rhythms (24-hour body clock) led to disturbed sleep, which could further lead to family problems and stress and that increased smoking, poor diet and irregular meals could also be a contributing factor to poor health. Additionally, Finn's (1981:31) findings indicated that shift work could create health problems in workers', as well as problems in family life, social life and safety in the workplace. Similarly, Saskatchewan Labor (1998:3) state that shift workers' irregular patterns of eating, sleeping, working and socialising could lead to health and social problems.
Finn’s (198:32) research found that fatigue was the most commonly encountered and upsetting reaction shift workers experience from sleep deprivation. Saskatchewan Labor (1998:4) explain that our bodies have a 24 hour ‘biological clock’ (the circadian rhythm) which tells it when to sleep and when to wake up. Sunlight and darkness regulate this clock. They add that darkness triggers changes in the body that lead to sleep and when falling asleep, the body’s blood pressure, heart rate, breathing rate and temperature drop and digestion slows down. So, when working during normal ‘sleep hours’, Saskatchewan Labor (1998:4) state that the body’s ability to digest food, rest, restore and repair itself will be disturbed and may affect a person’s sense of well-being.
Parkes (nd:4) discovered that disturbed sleep is an outcome of the disruption to normal circadian rhythms and her studies concluded that problems were caused by a mismatch between the need to be awake during night hours and sleeping during the day. Likewise, Finn (1981:32) states that the disturbance of these circadian rhythms contributes to physical and emotional problems. Parkes’ (nd:4) and Finn’s (1981:32) research revealed that shift worker’s sleep is often disturbed by domestic and traffic noise and unavoidable light and heat, which occur during the day.
Parkes (nd:5) states that gastrointestinal complaints, such as indigestion, heartburn, constipation, loss of appetite and nausea, are frequent among shift workers and are more common among night shift workers than those working during the day. What is more, Saskatchewan Labor’s (1998:5) research showed similar findings and they suggested reasons for this, such as over- or under-eating, relying on high-fat snack foods and drinking more coffee to stay alert at night, increasing the risk of developing ulcers. Finn’s (1981:32) research also revealed that loss of appetite and irregular eating habits are a common occurrence among shift workers which could lead to weight loss and nutritional deficiency. However, Finn (1981:32) also discovered that there was conflicting evidence regarding matter.
Parkes (nd:6) discovered that shift workers are more at risk of cardiovascular disease and Saskatchewan Labor's (1998:6) findings suggested the same, but that the way in which shift work affected the heart was not made clear. Saskatchewan Labor (1998:6) do, however, suggest that these cardiovascular problems may, in some way, be caused by the altered eating habits and disrupted sleep patterns, reduced physical activity and smoking.
Parkes (nd:7) research revealed that there is a connection between working nights and developing breast cancer and her report suggests the reason for this is because of the reduced production of melatonin during the night which is thought to lead to an increase in reproductive hormones which increase the hormone-sensitive cells in the breast.
Saskatchewan Labor (1998:7) reported that asthma, diabetes, epilepsy and depression could be made worse by shift work and Parkes’ (nd:7-8) research revealed that there was evidence linking shift work to premature births, miscarriages, low birth weight and irregular menstruation. Saskatchewan Labor’s (1998:7) research concurs with Parkes’ findings.
Working shifts also affects work performance. Saskatchewan Labor’s (1998:7) stated that most night workers complained of sleepiness and sometimes fell asleep at work. They explain that working extended shifts could cause poor performance and decreased alertness. This reduced alertness, can also cause accidents at work. Parkes’ (nd:8) evidence suggested that work-related fatalities were more than twice as likely at night as during the day. However her research found no evidence of elevated rates of minor accidents during night work. Finn’s (1981:33) research also showed that workers on night shifts made more mistakes than day shift employees and Saskatchewan Labor’s (1998:3) add that these higher accident and injury rates have not been clearly linked to shift work because shift work is only one of many factors contributing to accidents and injuries. Interestingly, as a result of her research, Parkes (nd:8) discovered that the disasters of Three Mile Island, Chernobyl, and the Challenger space shuttle all occurred during the night.
Another risk to employees working at night is that of violence, which Saskatchewan Labor’s (1998:8) research bears out. They state that some night workers work alone at night and they may be more vulnerable to violence from customers, residents and inmates.
Working nights often means that shift workers cannot participate in family and social activities. Finn’s (1981:32) research indicates that shift workers experience more family-related problems than daytime employees as the time they spend with their families are severely curtailed by their hours of work. Parkes’ (nd:5) findings revealed chronic fatigue and the disruption of family life might contribute to anxiety and depression.
There are, however, strategies that can be implemented to improve working conditions for shift workers. Parkes’ (10) research suggests that if employers pay attention to rest breaks, workload and aspects of the physical environment, and that if shift workers adapted a regular sleep routine, avoiding caffeine and alcohol prior to sleep, adopting a healthy diet, for example, they may lessen the negative effects of shift work. Saskatchewan Labor’s (1998:8) report suggested that employers ensure that workloads could work together to identify and control shift work hazards, including adjusting workloads to prevent boredom, limiting shift work to essential jobs and allowing adequate meal and rest breaks. Additionally, Saskatchewan Labor (1998:13) recommend workers be told how to control and minimise the effects of shift work themselves by eating nutritious meals regularly and maintaining physical fitness.
This research has revealed the possible connection between working shifts and developing health and social problems. The effects of shift work will differ from individual to individual, but the evidence is logical and persuasive. Taken as a whole, it appears that although 24-hour working is advantageous for industry and society, shift workers can suffer serious problems through working at night, and that employers and employees can work together to improve conditions at work to help to reduce these problems.
Sources
- Finn, P (1981) Effects of Shiftwork on Lives of Employees. Monthly Labor Review, 31-35
- Parkes, K (undated) Shiftwork and Health, University of Oxford, 1-15
Saskatchewan Labor (1998), Managing Shiftwork, Occupational Health and Safety, 3-16
