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Health hazards of Night and Shift Work

Shift work is any work done outside the normal daylight hours of 7 A.M. to 6 P.M. Shift work includes evening and night work, as well as overtime or extra-long workdays. Shift work also includes people in regular day jobs who bring their work home and work late at night on their computers on a regular basis. Shift work poses unique challenges to the body and increases the risk of many diseases. Shift work became popular during the Second World War when the war demanded rapid production of goods and arms. Following the war, there was also a great demand for industrialized goods to rebuild Europe. The march has been relentless since then, and now, all factories try to run 24 hours a day, 7 days a week (24◊7), lest they are out-produced by their competitors. This has given rise to this 24◊7 work culture which poses a significant hazard to personal and public health. Now, some may wonder why this is important; I only work the regular 9-5 shift. This is important to all, as facilities on which the public depends tend to run 24◊7. Thus, these facilities are also prone to accidents due to shift-work. Fatigue related to shift work and sleep deprivation have been attributed to industrial disasters like:

1. Nuclear accident at Three Mile Island, Pennsylvania in 1979
2. Chemical accident at the Union Carbide plant in Bhopal, India, in 1984
3. Nuclear accident at Chernobyl in Ukraine in 1986
4. Explosion of Challenger space shuttle in 1986
5. The Exxon Valdez Oil Spill in Alaska, USA in 1989

Most industries employ people in eight-hour shifts across the 24x7. These are the day shift (from 8 A.M. to 4 P.M.), the evening or swing shift (from 4 P.M. to 12 P.M.), and the night or graveyard shift (from 12 P.M. to 8 A.M.). It is estimated that 15-20% of workers in industrialized countries are employed in shift work. About 22 million Americans are involved in shift work across various sectors. Examples include health care, food service, retail, transportation, manufacturing, call centers, and public-safety industries like police officers, fire fighters, military, and security guards. Research suggests that shift workers (night workers) are more likely to sleep less, work more hours, and drive drowsy at least once a month and have poorer overall health when compared with non-shift workers.

Shift work is a major challenge among the Indian community which includes those living in India as well as the Non Resident Indians (NRI). Many Indians are employed in call centers at Bangalore, Mumbai, Hyderabad, Kolkata and other big cities. They provide customer care, technical support and other services to clients across the world, mainly in Europe and America. But they have to work irregular hours because of the time zone differences. Many Indians living in USA are employed in Information Technology. Many can work from home but have to travel frequently to different cities across time zones and other countries causing sleep disruptions. Other Indians employed in the medical sector, working as doctors, nurses, pharmacists, are engaged in shift work to provide round the clock service for patients. Then, there are those employed in gas stations and other stores working the night shift. Thus, a significant number of Indians are involved in shift work without being aware of the dangers it poses to their health and wellbeing.

How is shift work injurious to individual health?
Human physiology is the product of millions of years of evolution whereby the norm had humans staying awake during day and sleeping at night. The modern assault on this sleep-wake cycle (also called the circadian rhythm) may have dire health consequences. The hormone melatonin which is produced at night during sleep is also the most powerful antioxidant in nature. When we are awake and exposed to light, melatonin production is suppressed. Shift work-specially night work has been associated with increased risk of cancer, obesity, diabetes, heart disease, digestive problems and menstrual irregularities. Multiple studies have documented a link between night shift work and the increased incidence of breast cancer. In one such study, researchers in Denmark found that women who worked night shifts were up to four times more likely to develop breast cancer than women who didnít work nights. The World Health Organization has listed shiftwork disrupting sleep-cycle as a probable carcinogen. Working at night causes disruption with hormones that regulate our hunger and appetite. People staying up late at night will have cravings for sugar and more likely to binge on junk food. A high incidence of obesity and diabetes is thus seen in people who work more at nights. Additionally, shift work increases the risk of developing cluster headaches, heart attacks, sexual dysfunction, depression, dementia, and reproductive disorders. Shift work has also been associated with problems like increased smoking and use of recreational drugs.
As physicians, we regularly advise our patients about the importance of diet, exercise, and sleep for healthy living. But, when it comes to sleep, we do not always practice what we preach. Medical professionals are one of the most sleep deprived groups. The health care industry has to provide round the clock care to the critically sick. Health care services thus have to run 24x7 which poses double dangers. The doctors and nurses doing shift work, when fatigued and sleep deprived, make more mistakes, and these medical errors contribute to higher patient morbidity and mortality. A study published in New England Journal of medicine found that physicians in their first year of training made substantially more serious medical errors when they worked frequent shifts of 24 hours or more. Secondly, the shift workers are more likely to get into traffic accidents when they drive home after a full night of patient care. According to A study co-funded by the National Institute for Occupational Safety and Health (NIOSH) found that first-year doctors in training who work shifts of longer than 24 hours are more than twice as likely to have a car crash leaving the hospital and five times as likely to have a "near miss" incident on the road as medical interns who work shorter shifts.

Treatment Options: Maintaining healthy sleep hygiene can mitigate some of the dangers. If you are in a shift work, try to get as much sleep possible on your rest days. Try to have a nap before and after the shift work. Although caffeine can cause sleep problems in many, it can be beneficial for shift work to increase wakefulness and reduce errors. Research has shown that shift-workers who take prophylactic naps have reduced errors. There are also medications available which can promote sleep as well as wakefulness. Melatonin is safe and non-addictive choice, both for short- and long-term use. It helps to restore and increase sleep for night workers. Light inhibits melatonin. It has been seen that blue light causes maximum reduction in melatonin. Avoidance of bright light (especially blue) at night improves bodyís melatonin production. This can be done by keeping the room dark, use of dark glasses, as well as minimizing blue light found TV, computer, laptop, phone, and tablet screens.   Other medications like stimulants are used to promote wakefulness but not routinely recommended as side effects outweigh the benefits. Similarly, there are sedatives and hypnotics which can promote sleep and work wonders in the short-term for a sleep-deprived person, but their long-term use needs careful oversight by a doctor.

In summary, shift work is disruptive to our sleep and well-being. Unless one is careful and take steps to mitigate the sleep disruption caused by shift-work, one may endanger his well-being and the safety of others. The science of sleep and shift work has been translated into political action, and safety regulations have now been created for various industries in recognition of the dangers of shift work. The importance of sleep requires more public and personal awareness to increase safety. Laws and regulations can only go so far. Unless, everyone becomes aware on the life-giving property of sleep and makes it a priority, fatigue-related accidents will continue to occur. Additionally, we will continue to see a surge of cancer, obesity, heart disease, diabetes, depression, and other life-style illnesses whose incidence can be reduced with improved sleep. Fortunately, there are ways by which we can reduce the damage caused by shift-work. Use of timely scheduled naps, creating dark rooms during the day time, avoiding stimulants and other sleep disruptive chemicals, and using over the counter melatonin are some of the remedies. If you do shift work and your sleep and wellbeing remains compromised after all your efforts, consult a doctor. Also you can contact the national institute for occupational Safety and Health at the number 1-800-35-NIOSH for more information on your rights and options.


Dr. Panchajanya Paul, MD, ABIHM, ABPN, FAPA - is an American Board certified - Child, Adolescent, and Adult psychiatrist. He is a diplomat of the American Board of Integrative and Holistic Medicine, and a Fellow of the American Psychiatric Association. He holds adjunct faculty position at Emory University School of Medicine; University of Georgia, and University of Central Florida School of Medicine.