Paper: Firefighters’ exposures to cardiovascular risk factors: Carbon monoxide, noise, physical exertion, and stress.

Author(s) and Affiliation(s):
Tracy Kirkham, School of Environmental Health, UBC
Barbara Karlen, School of Environmental Health, UBC
Mieke Koehoorn, School of Population and Public Health, UBC
Hugh Davies, School of Environmental Health, UBC
Paul Demers, School of Environmental Health & School of Population and Public Health, UBC
Day/Time: Friday at 13:30
Room: St. David Room, 3rd Floor

Firefighters are exposed to several cardiovascular risk factors while at work that may put them at risk; however, little is known about their exposure levels to these risk factors. We aim to characterize typical work exposures to carbon monoxide (CO), noise, physical exertion, and stress during typical fire fighting activities.


Firefighters were recruited from 15 halls based on their activity type, call volume, and presence of specialty units in three municipalities. Subjects were sampled for 4 consecutive shifts including 2 day shifts and 2 night shifts. Full-shift personal noise and CO samples were taken using datalogging devices, Bruel & Kjaer 4436 doimeters and Drager X-am 3000 confined space monitor respectively. At the end of each shift firefighters completed a questionnaire regarding their physical exertion and stress throughout their shift. Physical exertion was assessed using a standard Borg scale whereas stress was assessed using a five-point Likert scale. In addition, firefighters were observed during their shift and potential sources of exposure to the hazards were noted.


Noise levels (n=109) averaged 83.6 dBA (range: 67.7-126.2); 47.7% of samples exceeded noise limits. Noise exposures were greater on day-shifts compared to night-shifts (85.2 vs. 78.5 dBA, p<0.0001), and differed by job title. Significant noise sources were identified (ex. air-packs). No CO samples (n=166) exceeded occupational limits. Average physical exertion and maximum exertion levels did not differ (11.0 vs. 11.2). The most frequently reported stress level was 2 (i.e., a-bit-stressful), with the most stressful event reported as driving/barriers faced to reaching destination. Probationary firefighters reported a significant increase in stress to events compared to other job titles.


Firefighters experience elevated noise levels that may increase their risk of adverse cardiovascular events. Information regarding sources of exposure will be valuable for development of new workplace policies aimed at reducing occupational noise exposure among firefighters. Differences found in physical exertion events between job titles most likely reflect differences in job tasks. Interestingly, firefighters reported lower than expected stress levels. Stress levels to particular events varied widely, which may reflect personal differences on perceived stress. As anticipated probationary firefighters reported an increase in the stress they felt during events, which is most likely due to their lack of experience.