Reports indicate a persistent shortage of truck drivers in the United States and that drivers are leaving the occupation for a variety of reasons, some connected to lifestyle.

Now comes an academic study that concludes that truckers’ very work conditions may put them in danger by increasing the likelihood of crashes.

Truck drivers who are frequently fatigued after work, use cell phones while driving, or have an elevated pulse pressure—a potential predictor of cardiovascular disease—may be at increased risk for getting into truck accidents, according to a study from the University of Utah.

Long-haul truck driving is one of the deadliest professions, according to the Bureau of Labor Statistics. Truck drivers are involved in an estimated 250,000 crashes each year, with one to two percent resulting in fatalities. The Utah study sought to identify health and occupational factors that may contribute to crash risk.

“Conditions that are characteristic to a truck drivers’ job may be putting them in danger,” said Matthew Thiese, Ph.D., assistant professor of family and preventative medicine at Utah’s Rocky Mountain Center for Occupational and Environmental Health (RMCOEH). “Being able to understand associations with crash risk, and bringing attention to them, will hopefully one day lead to fewer people getting hurt.”

The researchers surveyed 797 truckers at truck shows and truck stops in six states, Illinois, Iowa, Kentucky, Nevada, Texas, and Utah. Participants underwent a basic physical exam and completed a self-reported questionnaire tracking crash history, indicators of health and mental status, working conditions, and lifestyle choices. After adjusting for multiples variables, statistical analyses identified factors that were significantly linked to crash histories.

Two indicators of poor health management—high pulse pressure and fatigue—were highly associated with crash risk. High pulse pressure, a blood pressure measurement, may signal heart problems. Thiese added that any number of characteristics common to the profession—including stress, long hours, heavy lifting, and lack of sleep and exercise—could contribute to these conditions.

As has been observed among the general population, cell phone use while driving was also highly associated with crash risk.

“We’ve founds personal and occupational factors that we think are meaningfully related to being involved in a crash,” said Kurt Hegmann, M.D., director of RMCOEH. “Some of these risk factors could arise from unhealthy working conditions.”

The research also revealed signs that truck driver health is not well managed. Nearly 24 percent of truck drivers in whom they had detected high blood pressure had not previously been diagnosed, and their condition was not being treated medically. The study also found that 62 percent of participants were obese, much higher than the 35 percent reported for the general adult population by the Centers for Disease Control and Prevention.

“The high incidence of uncontrolled hypertension was a surprise, particularly given that truckers must undergo medical certification every two years,” said Thiese. “It’s another indication that truck drivers’ health needs are not adequately being met and could be endangering them in ways that we may not anticipate.”