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Characterization of noise and carbon monoxide exposures among professional firefighters in British Columbia.

OBJECTIVES
To characterize exposures to noise and carbon monoxide (CO) among firefighters in British Columbia, Canada.


METHODS
Subjects were recruited from 13 fire halls across three municipalities in Metro Vancouver. Personal full-shift noise and CO samples were collected using datalogging noise dosimeters and CO monitors on both day and night shifts. Determinants of exposure (DoE) information were recorded by trained research staff and hygienists through direct observation during the measurement period.


RESULTS
In total, 113 noise and 156 CO samples were collected from 45 male firefighters, aged 41.0 ± 7.2 years with 14.2 ± 9.0 years of experience. Mean L(eq) and peak noise levels were 81.1 ± 4.8 dBA and 137.1 ± 5.2 dB, respectively; 45% of samples exceeded occupational limits. Noise levels were significantly greater on day shifts, among firefighters in non-supervisory jobs, for those working on engine and rescue trucks, by number of emergency calls they attended and in particular for motor vehicle accident (MVA) and building alarms calls, if subjects worked near or used fire equipment, or if they participated in active firefighting training activities. Full-shift and peak CO levels were 1.0 ppm [geometric mean (GM) = 0.7, geometric standard deviation (GSD) = 1.8] and 42.9 ppm (GM = 9.95, GSD = 5.6), respectively; 1% of CO samples exceeded occupational limits. Both full-shift and peak CO levels were significantly correlated by number of MVAs and building alarms calls.


CONCLUSIONS
Our results show that firefighters may be at an increased risk of exposure to high noise levels, but CO exposures were lower than anticipated. Additional exposure studies are needed to confirm our results and to better understand the DoE to noise and CO among this occupational group.