Hearing Problems Among the Members of the Defence Forces in Relation to Personal and Occupational Risk Factors.

INTRODUCTION: The Defence Forces' members are exposed to high-level noise that increases their risk of hearing loss (HL). Besides military noise, the other risk factors include age and gender, ototoxic chemicals, vibration, and chronic stress. The current study was designed to study the effects of personal, work conditions-related risk factors, and other health-related traits on the presence of hearing problems. MATERIALS AND METHODS: A cross-sectional study among active military service members was carried out. Altogether, 807 respondents completed a questionnaire about their health and personal and work-related risk factors in indoor and outdoor environments. The statistical analysis was performed using statistical package of social sciences (descriptive statistics) and R (correlation and regression analysis) software. RESULTS: Almost half of the active service members reported HL during their service period. The most important risk factors predicting HL in the military appeared to be age, gender, and service duration. Also, working in a noisy environment with exposure to technological, vehicle, and impulse noise shows a statistically significant effect on hearing health. Moreover, we could identify the effect of stress on tinnitus and HL during the service period. Most importantly, active service members not using hearing protectors, tend to have more tinnitus than those who use it. CONCLUSIONS: The members of the Defence Forces experience noise from various sources, most of it resulting from outdoor activities. Personal and work conditions-related risk factors as well as stress increase the risk of hearing problems.

Hearing loss among military personnel in relation to occupational and leisure noise exposure and usage of personal protective equipment.

CONTEXT: Hearing loss (HL) is a major health concern among military personnel due to noise from shooting, blasts, military vehicles, and noisy training environments. Nevertheless, one's exposure can be partially reduced by using personal protective equipment (PPE). The aim of this study is to estimate the prevalence of HL among military personnel, to analyse associations between HL and self-reported occupational and leisure noise exposure, and use of PPEs. MATERIALS AND METHODS: A cross-sectional study was conducted among 150 military personnel during their routine medical examinations. First, all participants filled in a questionnaire about their exposure to noise and later the respondents went through an audiometric test. The diagnostic criteria for slight, moderate, and severe HL was HL of 25-40, 41-60, and >60 dB at 4 and 6 kHz, respectively. The associations between noise exposure and HL were studied with multinomial logistic regression analysis. RESULTS: The prevalence of slight to severe HL in high frequencies (4 and 6 kHz) among study participants was 62.7%. Nevertheless, the majority of it was slight, as the prevalence of severe HL was 9.3%. The prevalence of any kind of HL was highest in the Navy and the prevalence of severe HL was highest in the Central Command Units. The relative risk ratios (RRRs) for HL were higher among those who had been working for a long time in a noisy environment, working with noise-producing equipment, driving in a PASI or a Bandvagn or had been shooting with blanks at least once per week. It also appeared that military personnel who had HL, reported tinnitus more often. Respondents' previous health problems, music-listening habits, and amount of exposure to loud noise in non-military environments were not independently associated with HL, but in several cases it increased the RRRs together with military exposure. We also found significantly more frequent HL among those never using PPEs. CONCLUSION: HL loss was more prevalent among personnel who are more often exposed to military noise, especially among those who never use PPEs. The effect was enhanced by leisure time noise, but it was not independently associated to HL.

In-vehicle noise exposure among military personnel depending on type of vehicle, riding compartment and road surface.

INTRODUCTION: Noise-induced hearing loss is one of the most common health problems among military service personnel. Exposure to noise in military vehicles constitutes a large proportion of total noise exposure. This pilot study aimed to evaluate in-vehicle noise levels depending on the type of vehicle, riding compartment and road surface. METHOD: Noise levels were measured in armoured personnel carriers and heavy all-terrain trucks, in the cab and rear passenger compartment, while driving on paved or off-road surfaces. The results were compared with national LLV and allowed noise exposure times were calculated per vehicle and surface. RESULTS: The equivalent noise levels in the cab of SISU XA-188 (p=0.001) and peak noise levels in MAN 4620 (p=0.0001) and DAF 4440 (p=0.0047) were higher on paved road, compared with off-road. The equivalent noise levels in the canvas covered rear compartment of MAN 4620 were significantly higher than in the cab on both paved (p=0.004) and off-road (p=0.0003). Peak noise levels in the cab of DAF 4440 exceeded the parameters measured in the canvas covered rear compartment on both paved (p=0.002) and off-road (p=0.0002). In most cases, peak noise levels were below the LLV (p=0.02-0.0001). The maximum noise exposure to passengers in the canvas covered rear compartment of MAN 4620 despite road surface was calculated 0.6 hours per working day. CONCLUSION: A high risk of noise-induced hearing loss among military personnel occurs during long distance transportation with vehicles showing noise levels higher than allowed LLV.