Workers traveling more than one hour make up the fastest growing category of commuters, but little is known about the effects of long-distance commuting on workers' health. A study in May's Health Psychology (Vol. 25, No. 3) is shedding light on the experience, however, finding that the longer commuters spend on the train, the more likely they are to be stressed at the end of their commute. "When we think about occupational health and stress, we focus understandably on the work environment, but that ignores the fact that for a lot of people, one of the most stressful parts of work is commuting," says Gary W. Evans, PhD, the Elizabeth Lee Vincent Professor of Human Ecology at Cornell University, who conducted the study with Richard E. Wener, PhD, a psychology professor at Polytechnic University in Brooklyn, New York.
For their study, Wener and Evans recruited 208 commuters, ages 25 to 60, taking the train from New Jersey to Manhattan at least three times per week. Their commutes ranged from 45 to 180 minutes. On an appointed weekday morning, the participants undertook their usual train ride, during which they filled out questionnaires about their commute. They also indicated how stressful they found the commuting experience by evaluating statements such as "It takes a lot of effort to commute to work" on five-point Likert scales. For about the last 10 minutes of their trip, they completed a proofreading task, evaluating how many errors they failed to detect. When the participants arrived at their destination, the researchers collected a saliva sample to measure the participants' levels of the stress hormone cortisol. That weekend, the researchers collected another sample of cortisol at the same time of morning to compare workday and weekend stress levels. The participants' partners also assessed their interactions with participants over the past week.
Longer commutes were significantly associated with elevated cortisol, poorer proofreading performance and higher levels of perceived commuting stress--even after controlling for participants' sociodemographic characteristics and the conditions of the train, including passenger density and whether commuters had their own seat. However, commuting time wasn't associated with partner ratings of the commuters' stress.
"I'm not ready to conclude there is no spillover; it's just that we didn't find it," says Evans.
What the data do suggest, he notes, is that the duration of stress may be just as important an environmental health factor as intensity. Indeed, while environmental studies often examine levels of toxins, pollutants, noise and crowding, they may also need to take into account how long people contend with such conditions, he notes.
For example, a 2003 study in Transportation (Vol. 30, No. 2, pages 203-220) by Wener, Evans and their colleagues found that improvements to New Jersey Transit service--such as eliminating the need for some passengers to switch trains--significantly lowered those commuters' stress levels.
--D. SMITH BAILEY