Prevalence of Occupational noise induced hearing loss (ONIHL) among industrial workers in Bhutan.
Introduction: Exposure to any type of noise has a potential risk. Higher the level of noise and longer duration of exposure, more the risk for hearing sensitivity and health as a whole. The objective of the study is to determine the prevalence of Occupational Noise Induced Hearing Loss among the industrial workers in Bhutan and to ascertain high risk establishment and vulnerable occupations. Methods: The hearing assessment was conducted among 1638 workers considering different types of industries and occupations to ascertain the prevalence of occupational noise induced hearing loss and vulnerable group among different industries
and occupations. Descriptive statistics and binary logistic regression were performed to test the significance of Occupational Noise Induced Hearing Loss among the various independent variables. Results: The study found that the prevalence of Occupational Noise Induced Hearing Loss stands at 27.9% among industrial workers in Bhutan. 42.45% of candidates who had Occupational Noise Induced Hearing Loss reported with tinnitus in either or both ears. This study found a significant association between the exposure duration and the severity of Occupational Noise Induced Hearing Loss among the industrial workers. Considering the type of industry, wood based industry, hydro services, cement and polymer were found to have a higher prevalence of
Occupational Noise Induced Hearing Loss and similarly, higher prevalence of Occupational Noise Induced Hearing Loss were found among occupations such as blaster, chipper, carpenters, dryer (knife grinder) and crusher operators. Conclusion: This study conduces that prevalence of Occupational Noise Induced Hearing Loss among industrial workers is found to be at the higher side and some of the occupations and industries impose higher risk. The study suggests that there is need for intervention such as strict enforcement of the permissible exposure limit, monitor and evaluate hearing conservation programs, and providing advice and
recommendation to address such issues by the relevant agencies and industries.