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ountless cube dwellers have dreamed of alternative careers that transport them into the great outdoors, the open road, or simply beyond the confines of an office building. But few realize the high price that many who actually work in these careers must pay to enjoy their freedom. Three professions recently studied by Harvard School of Public Health researchers in the Education and Research Center (ERC) for Occupational Health and Safety--bicycle messenger, family farmer, and commercial truck driver--can come with unwelcome "perks" that include everything from bone fractures to terminal cancers.

Picture yourself as a bicycle messenger, speeding past a city of suited worker drones with the wind in your hair. But before you apply to become a two-wheeled, urban road warrior, make sure you plan to watch out for all those cars, trucks, and pedestrians. On-the-job injuries for bicycle couriers can add up, says Assistant Professor of Ergonomics and Safety Jack Dennerlein, a self-proclaimed "bicycle nerd," who routinely bikes to work. "I feel the crunch of Boston traffic," he observes, "and there’s not much sharing of the road between cars and bikes." Dennerlein's experiences on the road led him to investigate the rate of occupational injuries among bicycle messengers in downtown Boston.

In the first study of its kind, Dennerlein surveyed 113 bicycle messengers, asking them to indicate the number and severity of on-the-job injuries and to describe in detail their most severe or most recent injury. Funded by the Harvard Injury Control Research Center, the study found that collision or the avoidance of collision with motor vehicles and pedestrians accounted for 66 percent of the reported injuries, which included bone fractures, dislocations, sprains, and strains. Dennerlein's survey also revealed that this cohort on average experienced an injury every 19 work hours and an injury requiring time off the job every 42 work hours.

The latter figure is more than 15 times the national average for occupational health injuries, and three times that of the notoriously risky meat packing industry. "We need to create a system where bicyclists and cars can be separated from each other in a safe manner," concludes Dennerlein. He argues that these results indicate that courier services, downtown businesses, and city planners need to pay more attention to the health and safety of bicycle messengers. At the same time, he says, the messengers need to be more vigilant about their safety; only 24 percent of the surveyed messengers regularly wear helmets.

If the pace of a bicycle messenger seems too frenetic, you might go the pastoral route and run a small, family farm in the rural hinterlands. But don't forget to protect yourself from those pesky pesticides. During the early 1990s, studies indicated that American farmers suffered from certain cancers, including non-Hodgkin's lymphoma, leukemia, and Hodgkin's disease, far more frequently than the general population. At the time, Melissa Perry, a specialist in behavioral epidemiology and preventive intervention, began talking to farmers in her home state of Vermont to collect anecdotal information about their safety practices. "They were using pesticides regularly with little understanding of how to use them safely," recalls Perry, now an assistant professor of occupational epidemiology with the ERC. "I was surprised that the farmers weren't informed about the health risks at all."

In 1995, Perry and colleagues began a series of National Cancer Institute-funded studies to assess pesticide-related safety practices of independent dairy farmers in Wisconsin and to identify preventions to reduce their exposures. The first study surveyed a small focus group of farmers on their perceptions of health risks and their use of protective gear such as gloves, goggles, and chemical-resistant aprons. The second investigation measured compliance with pesticide-specific protective gear requirements among 220 randomly selected dairy farmers. "We found that farmers were very aware of being exposed," says Perry, "but less than 10 percent of the farmers fully complied with the protective gear requirements the last time they applied pesticides to their crops."

In search of an educational solution, Perry and her colleagues launched a third study in which they collected data on the exposures and safety practices of 400 farmers, and provided 100 randomly selected participants with a three-hour pesticide safety educational workshop. While those in the intervention group reported an increase of protective gear use and a decrease in number of pesticides used after six months, they reported no significant reduction in exposures or increase in full compliance with gear requirements. Perry concludes that more intensive educational programs will be necessary to achieve these goals.

For those who long for the thrill of the open road, a career in commercial trucking might appeal. What comes out of the tailpipe, however, may not. Past research suggests a clear increased risk of lung cancer for workers exposed to diesel emissions, but more quantitative data is needed to relate the degree of risk to the exposure level. In a five-year study funded by the National Cancer Institute, Professor of Industrial Hygiene Thomas Smith aims to quantify the risk that diesel engine emissions pose to truckers'health. To that end, he is employing a modeling approach he developed to help evaluate exposures in epidemiologic studies.

Smith's study addresses two questions: Does exposure to diesel emissions in the trucking industry lead to increases in lung cancer risk? How much exposure causes how much of an increase in that risk? To get the answers, he and Dr. Eric Garshick of Harvard Medical School are obtaining job titles, work locations, and mortality data for 65,000 drivers associated with four major trucking companies since 1985, and specifications about all the truck terminals run by these companies in the past 50 years. Using state-of-the-art techniques to distinguish diesel from other ambient particles, the investigators will also collect about 4,000 exposure samples from 36 major terminals across the country.

When the study concludes in 2006, Smith hopes to pinpoint health risks for individual drivers. "If your job title was this and you worked in that truck terminal, the study should be able to say that you'd have this level exposure to diesel and these health risks," Smith predicts. He expects the results of the study to be used by the Environmental Protection Agency and other regulatory agencies to determine diesel engine emissions exposure standards for truckers and for the general public.

Highlighting and finding ways to reduce unrecognized workplace health hazards both outside and inside the office is nothing new for the Education and Research Center for Occupational Health and Safety. Since its inception in 1977, the ERC has trained a wide range of public health researchers and practitioners to identify and prevent workplace illness and injury through the control or elimination of harmful occupational exposures. Professional disciplines include industrial hygiene, and occupational health-oriented nursing, medicine, epidemiology, and injury prevention and control.

One of a small number of regional ERCs established by the National Institute for Occupational Safety and Health, the School-based Center strongly emphasizes its mission to "train the trainers." Says ERC Director and Professor of Occupational Medicine and Epidemiology David Christiani, "The basis of good preventive medicine and public health is good public health practice and policy, and the basis for good public health practice is good research and education."

The ultimate goal of ERC projects is to improve the health and productivity of the more than 100 million active workers in the U.S. In some cases, studies carried out at the Center have led to more effective regulations and standards. But Christiani cautions that legislative improvements can only go so far. "It's impossible for U.S. regulators to keep tabs on all 4.5 million workplaces with a handful of inspectors," he says. "A regulatory approach is very hard to implement without a cultural change in how worker health and safety is viewed by management and employees. Our research and training aim to inform both policy and practice."

Mark Dwortzan


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