Fatigue and Worker Safety

The National Safety Council has launched an initiative about fatigue, gathering data with the aim of identifying solutions and releasing a policy toolkit and other resources.

The estimated annual injury incidence rate per 100 workers is 7.89 for U.S. workers who usually sleep less than five hours per day, compared with 2.27 per 100 workers among those who tend to sleep between seven and eight hours, according to research from Lombardi and others, using data from the National Health Interview Survey.

A 2012 guidance statement from the American College of Occupational and Environmental Medicine defines fatigue as the body’s response to sleep deprivation or lengthy physical or mental hard work. Risk factors related to occupational fatigue include long work hours, a heavy workload, lack of sleep, environmental factors and medical conditions.

The most significant consequences of fatigue were short-term degradation in cognitive (thinking) and physical functioning. Illnesses, human error, and injuries also occurred to a lesser extent. Evidence suggested that some consequences of fatigue can make other outcomes worse, reinforcing fatigue and leading to a “downward cycle.”

Effects of fatigue can include slower reaction time, more errors and decreased cognitive ability. Fatigue can occur in all industries, but numerous studies have focused on its effects on shift workers, health care workers, and drivers.

Recent research published by Université Paris Descartes shows that worker-related injuries are 31 percent higher among night shift workers than morning shift workers; by the fourth consecutive night shift, risk was 36 percent higher than on the first night, and risk nearly doubled by the 12th hour of work. However, injury risk decreased by nearly 50 percent after any length of rest break.

In addition, many people work multiple jobs, leaving them vulnerable to fatigue. People who work several jobs get 40 minutes less sleep per day than those who work one job, according to David Lombardi, principal research scientist at the Center for Injury Epidemiology at the Liberty Mutual Research Institute for Safety in Hopkinton, MA. Lombardi presented this data during the Dec. 13 “Fatigue Blue Ribbon Panel” in Chicago, hosted by the National Safety Council.

Environmental conditions can include things like noise or vibration, really heavy mental task loads for long periods of time.