Introduction: Occupational noise-induced hearing loss (ONIHL) describes an acquired hearing deficiency which is caused by excessive workplace noise exposure. But little is known in the developing world where many cases of SNHL are primarily due to excessive noise working areas.
Objectives: The study aims to assess the prevalence of noise induced hearing loss among workers in the metal and wood manufacturing sector of Gakiriro, Kigali.
Methods: This study was conducted on 200 workers including wood and metal industrial workers. It’s a cross-sectional and descriptive study. The age, the noise intensity levels per each category of occupation, duration of exposure, and category of occupation and measurement of hearing loss were correlated.
Results: The overall prevalence of HI was 36 % (72/200), and 35, 5 % (71/200) had NIHL. The mean age was 31.6 years and male workers were predominant. The age group between 30-39 years was more affected compared to other age groups. 99.5% of all participants were not protected during worktime, 47,7% had worked for 10 years and above with an average working time of 9 hours/day for five consecutive days. Noise levels average assessed were 99.4dB (range [97-105] in woodworkers and 105.4dB [99-115] in metalworkers on regular daily basis for five consecutive days .Metal workers were more affected than wood workers.
Conclusion: Working in excessive noise workplaces is a high risk for developing sensorineural hearing loss and more especially among the young adults workers who are the active group of workers in wood and metal manufacturing enterprises. Lack of ear protection during working time and longer durations of exposure increase the risk to develop ONIHL. Protective measures are needed for workers in these conditions and regular audiometric assessment.
Keywords: sensorineural hearing loss; Occupational noise induced hearing loss; Hearing impairement, decibel