Prevalence of Occupational noise induced hearing loss (ONIHL) among industrial workers in Bhutan.

Abstract

Introduction: Exposure to any type of noise has a potential risk. Higher the level of noise and longer duration of exposure, the more the risk for the hearing sensitivity and health as a whole. The objective of the study is to determine the prevalence of Occupational Noise Induced Hearing Loss (ONIHL) 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 ONIHL among the various independent variables. Results: The study found that the prevalence of ONIHL stands at 27.9% among industrial workers in Bhutan. 42.45% of candidates who had ONIHL reported with tinnitus in either or both ears. This study found a significant association between the exposure duration and the severity of ONIHL 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 ONIHL and similarly, higher prevalence of ONIHL were found among occupations such as blaster, chipper, carpenters, dryer (knife grinder) and crusher operators. Conclusions: This study conduces that prevalence of ONIHL 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