Firefighters may have their own medical emergencies to worry about when the alarm sounds, according to a Harvard study published today in the New England Journal of Medicine.

The study showed an up to 100-fold increase in the risk of coronary heart disease (CHD) events—such as heart attacks—for firefighters while engaged in emergency activities, a finding that focuses attention on the prevalence and efficacy of preventative health measures for emergency responders.

According to data collected in the study, CHD events are the leading cause of death of firefighters on the job, accounting for 39 percent of on-duty fatalities.

“We hope that our study will reinforce efforts in the firefighting community to improve their health and wellness programs,” said Stefanos N. Kales, the study’s lead author and an assistant professor at the Harvard School of Public Health and Harvard Medical School, in a statement. “We also hope that these striking results will make physicians who care for firefighters, such as internists and cardiologists, more cognizant of the demanding nature of this occupation and get them to be more aggressive with regard to cardiovascular risk reduction.”

The researchers found that 32 percent of CHD deaths among firefighters occur during the one to five percent of on-duty time that is spent on fire suppression, and disproportionately high rates were seen for other emergency activities, such as alarm response.

“The recent Harvard study clearly demonstrates the further need for expanding medical evaluations for firefighters,” said Richard Duffy, assistant to the General President of the International Association of Firefighters, a major national union. “Probably less than 20 percent of the career fire departments have full-blown health and fitness programs.”

The Cambridge Health Alliance (CHA) runs a health and wellness program for Cambridge firefighters that was co-designed by the Cambridge firefighters’ Local 30 and the City of Cambridge Fire Department, and formed in the wake of the September 11 attacks.

The program, known as the First Responder Wellness Program, offers firefighters guidance on “nutrition, fitness, and stress reduction,” according to the program’s coordinator, Lynda L. Bolduc-Hicks.

CHA also employs Kales as its director of employee health and industrial medicine.

“I think the program’s been taken seriously—we’ve always been known to eat big meals, but I think the trend may be getting away from that,” said Captain Stephen G. Persson of the City of Cambridge Fire Department. “Now we’re trying to eat more healthy and exercise and do the things we’re supposed to be doing.”

But according to Bolduc-Hicks, the program’s funding is set to run out this August, which could leave Cambridge firefighters without a wellness program.

“As far as I know, we’re the only program that’s currently doing what we’re doing in the area,” Bolduc-Hicks said. “It’s taken four years to develop what we offer at this point.”

The program is now supported by a grant from the American Red Cross, according to CHA’s website.

The study analyzed data on all firefighter deaths in the United States between 1999 and 2004, excluding those connected with the September 11 terrorist attacks.

—Staff writer Clifford M. Marks can be reached at cmarks@fas.harvard.edu.