Many people view sleep as a luxury rather than a necessity. Indeed, people are cutting sleep out of their lives at an alarming rate. Nearly 30 percent of Americans sleep less than six hours per night. Research indicates similarly low levels of sleep in Korea, Sweden, Finland, and England. In one large scale study, 29 percent of participants reported extreme sleepiness or falling asleep at work in the past month. This may occasionally provide amusing stories, such as a bank employee falling asleep on a keyboard and mistakenly transferring hundreds of millions of dollars. However, a growing body of research indicates that a lack of sleep can have more sobering consequences: the jeopardization of workplace safety, leading to work injuries and even death.
A recent summary of the effects of even short term sleep deprivation on cognition reveals that a lack of sleep hinders most of our thought processes. When we are short on sleep, we have a hard time focusing our attention, we think slower, forget things, and make more mistakes. In many contexts, such mental errors can make workplaces more dangerous. A lapse of attention when operating dangerous equipment, even for a brief moment, can lead to disastrous consequences. Losing focus while reaching on a ladder can result in a terrible fall. Even missing a sign indicating that a recently mopped floor is slippery can result in an injurious fall.
High profile incidents provide examples of how a lack of sleep can create unsafe work environments. In the US Air Force, Class A Mishaps are accidents involving permanent disability, fatality, or property damage of $2 million or more. A 2003 study conducted by Luna indicates that fatigue played a role in 8 percent of all such incidents. Nuclear disasters such as Chernobyl, Three Mile Island, Davis-Besse, and Rancho Seco all occurred in the early morning (2:00 a.m. to 4:00 a.m.), a time of day that naturally produces sleepy employees.
However, even outside of such high profile events, a lack of sleep can create dangerous workplaces. A recent study of almost 2,000 full time employees of small and medium businesses in Japan found that short sleep duration and poor sleep quality were both related to an individual's risk of workplace injury. A study of over 48,000 Finnish public sector employees found that disturbed sleep was associated with higher risk for occupational injury in men. A study of almost 70,000 Canadians found that trouble sleeping as associated with increased risk of work injury.
Even small amounts of lost sleep matter. In my own research, I found that the change to Daylight Saving Time in the Spring is associated with a loss of about 40 minutes of sleep that Sunday night. This 40 minutes of lost sleep is associated with a spike in American mining injuries of 5.6 percent on that Monday, and a spike in the severity of those injuries (measured by the number of lost work days) of 67.6 percent.
Organizations spend a lot of time and resources on training, equipment, and procedures that are intended to increase workplace safety. These have helped increase the safety of many employees. However, regardless of training, equipment, or procedures, if employees work while short on sleep, their odds of making dangerous mistakes will increase. Thus, if we want safe workplaces, we all need to get more sleep.
Fortunately, there are strategies that people can use to increase their sleep, including good sleep hygiene. Creating work schedules that cooperate with circadian rhythms rather than conflict with them can also help people sleep better. Re-evaluating time allocation to sleep, work, and other activities is also necessary; sleep should be a higher priority. Anything less creates unnecessary danger in the workplace, resulting in injuries ranging from minor blunders to dismemberment and death.
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