Noise-induced hearing loss among manufacturing factory workers in Kuching, Sarawak: Prevalence and associated risk factors

INTRODUCTION: Noise-induced hearing loss (NIHL) is a common problem worldwide. Increased globalisation, as well as industrialisation, gives rise to an increase in the incidence of NIHL worldwide. Malaysia is not spared from this problem, either. The objectives were to determine the prevalence of NIHL and its associated factors among manufacturing factory workers.

MATERIAL AND METHODS: A cross-sectional study was done in Kuching, Sarawak, involving 173 randomly selected respondents among manufacturing factory workers. Data collected were respondents' workplace monitoring data and their audiometry records obtained from the factory record, and the otoscopy examinations performed. In addition, respondents were required to fill up an interviewer-guided questionnaire.

RESULTS: The prevalence of NIHL was high (49.7%). The factors which were found to have a significant association with NIHL in bivariate analysis were age (p < 0.05, 95% CI), male gender (p < 0.05; OR - 7.60; CI 3.34 -18.38), duration of employment (p <0.05), knowledge of noise level (p < 0.05; OR - 4.11; CI 1.10 - 15.28), working at polishing department (p < 0.05; OR - 4.23; CI 2.13 - 8.43), and smoking (p < 0.05; OR - 39.6; CI 16.5 - 94.8). Pack-years of smoking were also found to have a significant association with p < 0.05. However, only smoking was statistically significant in multivariate analysis, where the risk of developing NIHL was 27.55 (p < 0.005; CI 10.74 - 70.64) among smokers.

CONCLUSION: The high prevalence of NIHL despite the existing Hearing Conservation Program (HCP) may indicate that there may be some elements in HCP that require close monitoring by the factory management, and the importance of smoking cessation among the workers exposed to noise at the workplace should be highlighted.