Working beyond the standard 8 hours day may raise the risk of job-related injuries, regardless of a person's occupation. Previous research has shown that people who work long hours tend to sustain more injuries and health problems than workers with standard 40-hour weeks. But these studies have often been limited by shortcomings in their methodology. The following study found that longer work hours appeared to raise injury risk even when job type and other factors - such as a worker's age and gender - were weighed. This strengthens the argument that something about long work hours themselves makes people more vulnerable to injury. That something could be stress and fatigue, which can make workers more prone to mistakes and mishaps. Researchers from the University of Massachusetts Medical School, Shrewsbury, analysed data collected from 10,793 participants between 1987 and 2000, starting when the men and women were between the ages of 22 and 30. Workers were considered to have logged long hours if their jobs included overtime - beyond the usual 40-hours per week occasionally - or if they regularly worked 12-hours per days or 60-hours per week. Overall, there were more than 5,100 work-related injuries or health problems during the study period, with more than half occurring in jobs with long hours. People who normally worked long shifts were 37 percent more likely to sustain an injury than their peers who worked shorter hours. Those who worked overtime were at 61 percent greater risk than workers whose jobs included no overtime. The fact that overtime seemed to be a greater injury risk than regularly extended shifts is one of the most interesting findings from the study. Mandatory overtime may create tension and stress for some workers. But whether that's the case is unclear, as the study data didn't separate mandatory from voluntary overtime. Muscle and joint problems were the most common complaint, followed by cuts and bruises. If long work hours are a risk factor for injury, a potential preventive measure could be to ensure employees get adequate rest breaks. These could take the form of both short breaks during the day, as well as days off with limits on how many days in a row an employee can work extended hours.
Occupational and Environmental Medicine,
September 2005