Level of noise-induced hearing loss and associated factors among workers in Bishoftu central air base of Ethiopia

Abstract

Background Excessive occupational exposure to noise results in occupational hearing loss was considered a major public health problem. Since the expansion of the aviation industry and its exposure to the intensity of noise level was simultaneously high. Objective This study aims to assess the level of noise-induced hearing loss and associated factors among workers in the Bishoftu central air base in Ethiopia. Methods Institutional-based cross-sectional study was conducted among 260 central air base workers through face-to-face interviews; an environment noise survey with an audiometric test had been conducted to collect data. Data were entered by Epidata version 3.1 and SPSS was used to analyze the data. Finally, a statistical analysis such as descriptive statistics and binary logistic regression analysis was applied. A P-value < 0.05 at 95%CI was considered statistically significant. Result The overall prevalence of noise-induced hearing loss and hearing impairments were 24.6 and 30.9%, respectively. From this, 16.9% bilateral and 7.7% unilateral noise-induced hearing loss. The highest prevalence noise level was recorded for workers who were exposed to noise levels greater than 90 dBA. Around 21.9% were males with an age category between 18 to 27 years were exposed to noise-induced hearing loss. Similarly, the lowest experience was between 1 to 10 years of exposure to noise-induced hearing loss by 16.9% with working department transport helicopter (4.7%), transport airplane (4.7%), and daily maintenance (3.5%). Those participants who were exposed to noise-induced levels at work place previously were five times (AOR = 5.0, 95% CI: 1.74–14.36) more likely exposed to the sound noise level at the workplace than those workers not exposed at work place previously. Those workers who were exposed to greater or equal to 90dBA noise level were 4.98 times (AOR = 4.98, 95% CI: 2.59–9.58) more likely exposed to noise-induced levels than those who were exposed to less than 90dBA noise level. Moreover, male air base workers were 3.5 times more likely exposed to hearing impairment than female workers (AOR = 3.5, 95%CI 1.01–12.0) and participants who have abnormal otologic examinations were 1.9 times more likely exposed to hearing impairment than those who have normal otologic examinations (AOR = 1.9, 95%CI 1.02–3.54). Conclusion Workers were exposed to high levels of occupational noise that could induce immediate hearing loss. The prevalence of hearing loss was significantly high.

Prevalence and associated factors of noise-induced hearing loss among workers in Bishoftu Central Air Base of Ethiopia

“…The sample size was determined using a single population proportion formula considering the p prevalence of NIHL 22% among Akaki basic metal industry workers 16 . A 95% confidence interval and a 5% margin of error were used to calculate the sample size.…”

“…Moreover, several studies have reported that the predictive factors related to NIHL were being male sex, higher age, duration of exposure or service year, noise intensity level, exposure to an explosion, vibration, smoking, ceruminous occlusion of the external auditory canal, and utilization of hearing protective devices as preventive factors [14][15][16] .…”

“…However, in Ethiopia, there is no study conducted in aviation industries. Still, there was a study conducted in the textile and metal industry with the prevalence rate for the NIHL was 34 and 22%, respectively 16,22 . Although aviation workers in Ethiopia are exposed to noise every day the level of noise exposure and its health effects are not known so understanding the noise level, prevalence, and factors related to noise-induced hearing loss is essential for effective noise prevention and control strategy.…”