Relationship between Smoking and Hearing Impairment of Automotive Industry Workers Exposed to Noise

Working in noisy environments may cause hearing loss. Studies have shown that some factors along with noise are independently involved in hearing loss, one of which is cigarette smoking. The aim of this study was to evaluate the effects of smoking on hearing loss in workers exposed to occupational noise. The workers’ hearing loss was measured through a tonal hearing test (air-conduction). Their demographic information was also recorded and evaluated using some checklists. A total of 250 people were enrolled in this study, of whom 133 were smokers and 117 were non-smokers. The mean age of the participants was 36.07 ± 3.66 years, and there was no significant difference between the two groups in terms of age. The mean sound pressure level in the work environment was 86 dB based on the ISO standard. There was a significant difference between the hearing loss levels in the right ears and the left ears of the two groups of smokers and non-smokers (P value <0.001). In general, smoking plays a significant role in hearing loss along with other factors, such as noise in the workplace, and conducting periodic audiometry tests to identify smokers with hearing impairment can be effective in primary or secondary prevention of occupational hearing impairment.