초록
Objectives: Firefighters are exposed to various harmful factors. Prominent among them is noise, which can lead to hearing loss. Once hearing is damaged, its recovery is nearly impossible. Firefighters are reported to be exposed to brief but high levels of noise from sirens, horns, and rescue equipment, but research in this area in South Korea is limited. The objective of this study was to evaluate the noise levels of sirens, horns, and radios in fire vehicles based on whether the windows are open or closed, and to investigate the noise sources of rescue equipment primarily used by rescue personnel. Methods: Nine types of fire vehicles were examined in this study: ambulance, rescue vehicle, pump truck, mountain rescue vehicle, safety support vehicle, equipment transport vehicle, command vehicle, water tanker, and fire investigation vehicle. A total of 31 samples of rescue equipment were analyzed, including 36 samples when including the breathing apparatus charging stations. The equipment used for noise source evaluation was a 1/3 octave band frequency analyzer. The measured values included LAeq, LCpeak, and LAFmax, and the LAeq and LCpeak values were assessed for each frequency. The noise levels inside the fire vehicles were evaluated based on the window status (whether open or closed) with noise sources including sirens, horns, radios, and simultaneous noise. For the rescue equipment, the evaluation was conducted from the position of a rescuer's ear during operation. Results: There was a statistically significant difference (p<0.05) in all noise sources based on the window status, with noise levels increasing when the windows were open. The 1/3 octave band analysis of the motor-driven siren and electric siren in the rescue vehicle showed that the motor-driven siren produced higher noise levels at high frequencies. In the worst-case scenario (simultaneous noise, windows open), the highest noise levels were observed in the command vehicle, with a noise level of 103.1 dBA (123.1 dBC), followed by the mountain rescue vehicle at 99.9 dBA (111.1 dBC). When comparing the noise levels of rescue equipment based on the drive method, pneumatic equipment showed a statistically significant difference (p<0.05), with battery-powered equipment producing lower noise levels than engine-driven equipment. The noise levels of cutters and chainsaws were lower in the battery-powered versions compared to engine-driven models, but the difference was not statistically significant. While cutting metal with a cutter, an increase in noise levels was observed in the high-frequency range (4-8 kHz). Conclusion: The noise levels generated by fire vehicles and rescue equipment are high, and exposure to such noise could lead to hearing loss in firefighters. Therefore, engineering measures should be implemented to reduce noise in fire vehicles, and battery-powered equipment is recommended over engine-driven models for rescue operations. Additionally, the implementation of appropriate hearing conservation programs, including the use of hearing protection by firefighters, is necessary.
