In the new, large-scale study, researchers from the Harvard School of Public Health (HSPH) examined the link between coronary heart disease (CHD) deaths and firefighting and looked at specific job duties to see which might increase the risk of dying from a coronary event. "We found conclusive evidence that the risk of CHD death is significantly higher during fire suppression, responding to alarms, returning from alarms and during certain physical training activities," said Stefanos Kales, lead author and assistant professor in the Department of Environmental Health at HSPH.

The results showed that, of the 1,144 firefighter on-duty deaths during the study period, 449 (39%) were attributed to CHD. Of those, 144 took place during fire suppression. Estimates showed that firefighters spent just 1% to 5% of their time on fire suppression, yet that job responsibility accounted for 32% of deaths from coronary events. Therefore, the relative risk of death from CHD while putting out fires was on the order of ten to 100 times as high as the risk associated with non-emergency duties.

An increased risk was also observed for other emergency duties, such as alarm response, as compared to non-emergency duties. "The present study confirms our previous results from a smaller study of deaths and an investigation of non-fatal events leading to retirement from firefighting. It provides the strongest evidence to date that firefighters' work activities can trigger CHD events," said Kales.

The authors hypothesize that the risk of dying from heart disease may increase during fire suppression because of the effects of strenuous exertion on firefighters who have underlying CHD. Also, many firefighters are overweight and lack adequate physical fitness, which may be contributing risk factors, the scientists concluded.

MEDICA.de; Source: Harvard School of Public Health