Prevalence of occupational noise induced hearing loss among wood and metal workers of Gakiriro, Kigali city

Introduction: Occupational noise-induced hearing loss (ONIHL) is describeed as an acquired hearing deficiency caused by excessive workplace noise exposure. Little is known about cases of SNHL in our developing country where excessive noise working areas are more prominent.

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 was a cross-sectional and descriptive study conducted on 200 workers including wood and metal industrial workers. It’s a 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 hearing induced was 36 % (72/200), and 35, 5 % (71/200) had NIHL. The mean age was 31.6 years with predominance of male workers. 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 level 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 could be a high risk for developing sensorineural hearing loss among young adults active in the wood and metal manufacturing enterprises. Lack of ear protection during working time and longer durations of exposure may increase the risk to develop ONIHL. Protective measures are needed for workers in these conditions and regular audiometric assessments should be conducted.