Combined effect of noise and other occupational hazards on hearing impairment and electrocardiograph / 中国职业医学

ABSTRACT

OBJECTIVE: To explore the combined effect of noise and other occupational hazards on hearing impairment and electrocardiograph(ECG) of workers in automobile manufacturing enterprises. METHODS: A judgment sampling method was used to select 3 434 workers as study subjects from an automobile manufacture enterprise. According to the exposure to different types of occupational hazardous factors, they were divided into noise series group, noise dust group, noise welding dust group, noise benzene series group, noise nitrogen oxide group and control group, with 716, 693, 1 540, 45, 195 and 245 cases in each group, respectively. The subjects were examined with pure-tone hearing test and ECG. RESULTS: The total rate of high frequency hearing loss was 11.2%(385/3 434), and high frequency hearing loss was the main type of hearing loss among workers in each group. The simple high-frequency hearing loss rates of noise group, noise dust group, noise welding dust group, noise benzene series group, noise nitrogen oxide group and the control group were 10.3%, 11.5%, 12.3%, 26.7%, 10.3% and 4.1% respectively, and the rate of total hearing loss were 13.7%, 14.6%, 14.6%, 31.1%, 16.9% and 6.5% respectively. Compared with the control group, the rate of simple high-frequency hearing loss and total hearing loss were higher in the other 5 groups(P<0.005). The rate of high-frequency hearing loss in noise group was lower than that in noise benzene series group(P<0.005). The rate of arrhythmia was 20.9%(717/3 434). Arrhythmia was the main type of ECG abnormality in all groups. The rates of arrhythmia in noise group, noise dust group, noise welding dust group, noise benzene series group, noise nitrogen oxide group and control group were 16.9%, 16.6%, 27.9%, 17.8%, 13.8% and 6.9%, respectively. The rate of arrhythmia in noise welding dust group was higher than that in noise group(P<0.005). CONCLUSION: The combined effect of noise and benzene series increases the risk of high-frequency hearing loss in workers. The combined effect of noise and welding dust increases the risk of arrhythmia in workers.