Prevalence of Onihl in Manufacturing Industry

Abstract

Objective: To find out the prevalence of occupational noise induced hearing loss (ONIHL) among the workers in a manufacturing engineering industry and to observe the effect of duration of noise exposure on hearing of workers. Study design:Observational case control study. Study sample: Of 236 subjects, 118 cases each in noise (>85dB) exposed (group A) and control (group B). All the subjects were subjected to audiometry and pure tone averages for frequencies 500Hz, 1kHz, 2kHz and 4kHz were calculated and compared. Results: Showed an overall prevalence of 41.5% hearing loss in the exposed study group A out of which 77.5% had mild while 22.5% had moderate hearing loss as compared to only 2.5% overall prevalence in unexposed group B, which was found to be statistically significant (p<0.005).The present study also compared the audiometry results with duration of exposure which revealed a hearing loss of 3.7% among workers exposed for duration of 5-9yrs, 51.6% for duration of 10- 14yrs and 100% for duration of ≥15yrs. Conclusion: ONIHL is prevalent in form of mild to moderate hearing loss within the manufacturing industry.