Abstract No:
1215
Abstract Type:
Professional Poster
Authors:
S Kim1
Institutions:
1Korea Occupational Safety and Health Agency, Republic of Korea
Presenter:
Sung Ho Kim
Korea Occupational Safety and Health Agency
Description:
Firefighters face unpredictable, high-intensity noise from sirens, horns, rescue tools, and emergency vehicles. Unlike industrial workers exposed to steady noise, they experience sudden bursts that increase the risk of noise-induced hearing loss (NIHL). While NIHL among firefighters has been reported internationally, only limited cases have been documented in Korea, and scientific data remain limited. This study assessed noise exposure in 115 Korean firefighters across fire suppression, rescue, and emergency medical service (EMS) roles. Personal dosimeters were set to Korean MOEL and ISO standards, and fire station records were used to classify tasks. Time-weighted average (TWA) and peak exposures were analyzed by role and activity. Although average TWAs did not exceed regulatory limits, some tasks-such as equipment checks, training, and rescue operations-exceeded 100 dBA. Rescue personnel had the highest exposures, while EMS onboard staff faced greater noise than drivers. Elevated levels were also observed during in-station training activities. Currently, Korean firefighters are not required to undergo noise exposure assessments, and most stations lack structured hearing conservation programs. Hearing tests are limited to general medical exams, making occupational NIHL difficult to establish. These findings highlight the need for firefighter-specific hearing conservation programs and preventive strategies, including communication-friendly hearing protection.
Situation / Problem:
Hearing is essential for firefighters, as effective communication with firefighters is critical in life-threatening emergencies such as fire suppression. Once impaired, hearing cannot be restored, making hearing loss an irreversible and serious occupational disease. Worldwide, cases of noise-induced hearing loss (NIHL) caused by intermittent but intense noise from sirens, horns, and rescue tools have been reported. In Korea, however, only limited cases and supporting scientific evidence are available. Currently, Korean firefighters are not required to undergo mandatory noise exposure assessments, and most fire stations have not established hearing conservation programs. Hearing tests are performed only as part of general medical examinations, which makes it difficult to prove whether NIHL is work-related. Even when exposure assessments are conducted, the Korean Ministry of Employment and Labor (MOEL) applies a 5 dB exchange rate (criterion 90 dBA). This method has limitations in evaluating intermittent, high-intensity noise typical of firefighting duties. Awareness of hearing protection is also low. Firefighters often fail to use protective devices during tasks with obvious noise risks, such as equipment checks, training, and rescue activities. Due to the insufficient nationwide statistics on NIHL among firefighters, it is challenging for Korea to create effective occupational health policies and preventive measures aimed at protecting their hearing.
Methods:
This study evaluated task-specific personal noise exposure among 115 firefighters from three fire stations in Korea. Participants included personnel assigned to firefighting, rescue, and emergency medical services (EMS), while administrative staff served as a control group. The aim was to characterize exposure patterns according to job type, task, and vehicle, providing a comprehensive assessment of occupational noise risks among Korean firefighters. Personal noise dosimeters were worn near the ear to measure exposure during work shifts. Instruments were calibrated before and after measurements using a 1 kHz, 114 dB calibrator to ensure accuracy. Noise measurements were analyzed according to both the Ministry of Employment and Labor (MOEL) standard-criterion level 90 dBA, exchange rate 5 dB, threshold limit value 80 dBA-and the ISO standard-criterion level 85 dBA, exchange rate 3 dB, threshold limit value 80 dBA. This dual-standard approach enabled comparison of exposure estimates under different regulatory criteria. Firefighter activity logs were integrated with fire station dispatch records to classify tasks. The tasks included active firefighting, rescue operations, EMS responses, equipment inspections, shift duties, training, education, and standby periods. Vehicle types were categorized as command vehicles, pump trucks, rescue vehicles, and ambulances, with measurements collected for both drivers and passengers. This detailed task and vehicle classification provided insights into specific sources of noise exposure within daily operations. Due to the 24-hour shift schedule of Korean firefighters, measured noise levels were converted into 8-hour time-weighted averages (TWA) to facilitate comparison with occupational exposure limits. Differences in noise exposure across job types, vehicles, and tasks were analyzed using ANOVA with Tukey post-hoc tests implemented in SPSS 29.0. Distributions and exposure patterns were visualized using SigmaPlot 14.0, allowing clear representation of task-specific and vehicle-specific noise levels. This study provides a systematic and detailed evaluation of occupational noise exposure among Korean firefighters. By combining personal measurements with operational records and analyzing them under two regulatory frameworks, the study offers a robust approach to understanding occupational noise risk in emergency services settings.
Results / Conclusions:
In the results, This study assessed personal noise exposure among 115 Korean firefighters across three stations, classifying exposure by job role, vehicle, and task. Rescue personnel experienced the highest mean 8-h time-weighted averages (TWAs)-71.4 dBA under MOEL settings and 81.2 dBA under ISO-while fire suppression (66.5/74.2 dBA) and EMS (68.6/73.0 dBA) did not differ significantly from each other. Peak exceedances above 140 dBC were most frequent in rescue (33.3%), followed by fire suppression (30.2%) and EMS (27.2%). By vehicle, occupants of rescue trucks showed the highest exposure; within ambulances, on-board EMS personnel had significantly higher averages than drivers (70.6 vs 65.8 dBA, MOEL; p<0.05). Under ISO criteria, exceedance counts were meaningfully larger than under MOEL: 25 samples exceeded 80 dBA, 11 exceeded 85 dBA, and 4 exceeded 90 dBA. Task analysis revealed that several station-based routines produced significant noise exposure. Using MOEL settings, maximum levels reached 94.3 dBA during firefighter training, 93.8 dBA during equipment checks, and 92.2 dBA at shift handover. Under ISO, maxima exceeded 100 dBA during shift handovers (100.5 dBA) and equipment checks (107.6 dBA), and exceeded 90 dBA during training (96.5 dBA) and emergency responses (94.2 dBA). Notably, "standby at the station" occupied the largest share of the day (66.1%) and accounted for 46.4% of all >140 dBC instances; overall, 66.1% of peak exceedances occurred during in-station tasks. In the conclusions, average daily exposure levels were modest, but intermittent, short-duration high peaks-many occurring during routine in-station activities-underscore a persistent risk of NIHL for firefighters. Hearing protection use was rare, particularly during routine tasks, despite recurrent peak exceedances; this highlights the need for stronger hearing conservation programs that mandate HPD use for high-noise tasks (e.g., equipment checks, training) and emphasize education and monitoring. Because communication demands can hinder HPD uptake, the adoption of communication-friendly solutions (e.g., intercom-enabled or noise-canceling HPDs) is recommended, alongside engineering and administrative controls targeting vehicle and siren noise and task-specific sources. Considering the intermittent high-intensity pattern of exposure, applying a 3 dB exchange rate can reduce underestimation and better align protection with actual risk. Future work should evaluate long-term auditory outcomes and the effectiveness of control measures in real operations.
Core Competencies:
Noise and Hearing Loss Prevention
Secondary Core Competencies:
Exposure Assessment
Noise and Hearing Loss Prevention
Choose at least one (1), and up to five, (5) keywords from the following list. These selections will optimize your presentation's search results for attendees.
Consulting
Exposure Assessment
Hearing conservation and noise reduction
Legal and expert witness
Personal protective equipment
Based on the selected primary competency area of your proposal, select one group below that would be best suited to serve as a subject matter expert for peer review:
(Select one)
Noise Committee
Based on the information that will be presented during your proposed session, please indicate the targeted audience practice level: (select one)
Practitioner: Practitioner is a job title given to persons in various occupational fields who are trained to assist professionals but are not themselves licensed or certified at a professional level by a certification body recognized by the National Accreditation Recognition (NAR) Committee of IOHA. The IH/OH practitioner performs tasks requiring significant knowledge and skill in the IH/OH field, such as conducting worker exposure monitoring and, in some cases, may even function independently of a professional IH/OH but may not be involved in the breadth of IH/OH practice nor have the level of responsibility of a professional IH/OH certified by examination.
The IH/OH practitioner requires a certain level of education that can be obtained from an accredited university or equivalent. Additional training in specific skill sets that provide additional career paths to the IH/OH practitioner can also be obtained. IH/OH practitioners may also serve as team leaders or project managers.
Was this session organized by an AIHA Technical Committee, Special Interest Group, Working Group, Advisory Group or other AIHA project Team?
No
Are worker exposure data and/or results of worker exposure data analysis presented?
Yes
If yes, i.e., If worker exposure data and/or results of worker exposure data analysis are to be presented please describe the statistical methods and tools (e.g. IHSTAT, Expostats, IHSTAT_Bayes, IHDA-AIHA, or other statistical tool, please specify) used for analysis of the data.
SPSS 29.0, SigmaPlot 14.0
How will this help advance the science of IH/OH?
Firefighting entails repeated exposure to intermittent, high-intensity noise from sirens, tools, and vehicles, which can cause noise-induced hearing loss (NIHL). Current exposure criteria largely rely on time-weighted averages, a metric that inadequately captures short, high-level bursts. In Korea, routine assessments commonly apply a 5-dB exchange rate (criterion level 90 dB), which tends to underestimate risk relative to a 3-dB exchange rate (criterion 85 dB). Accordingly, IH/OH practice for firefighters should prioritize identifying peak-intensity tasks and implementing engineering and administrative controls, alongside communication-friendly hearing protection, to preserve hearing. Firefighters often underrecognize the occupational origin of NIHL; as a result, hearing protection devices are frequently not worn during tasks where protection is feasible (e.g., equipment checks and station training). Because NIHL is typically progressive rather than sudden, measurable deficits may not be evident until late in a career, and many personnel misattribute these changes to age-related presbycusis. Therefore IH/OH should conduct systematic noise measurements, analyze and archive task- and location-specific patterns, and maintain longitudinal records that support causal attribution, guide targeted controls, and document the effectiveness of hearing-conservation efforts.
What level would you consider your presentation content geared towards?
Intermediate: Specific topics within a subject. The participant would have two (2) to ten (10) years experience in industrial hygiene or OEHS and a good understanding of the subject area, but not of the specific topic presented. Prerequisites required: another course, skill, or working knowledge of the general subject.
Have you presented this information before?
No
I have read and agree to these guidelines.
Yes