일 작업장 근로자의 청력변동에 관한 조사 연구

Abstract

Noise-induced hearing loss ranks among one of the most important occupational health problems due to its high prevalence, the disability and potential costs it creates and the potential for preventing it. Not all individuals with a given noise level develop the same degree of hearing loss. There is a great individual variation such as, presbycusis, disease, non-occupational agents and susceptibility. The purpose of the study was to estimate host and environmental factors which influence of the change in the hearing threshold level(CHTL) in one company using a nested cohort study. The author investigated 435 workers who were surveyed with a questionnaire and whose initial hearing threshold level all within normal range. The obtained results were as follows : 1. The mean workplace noise level was 79.2 dB(A). The mean durarion of observed CHTL was 62.9 months(5.2 years). And mean CHTL of right and left ear was 1.2 dB(A) and 0.3 dB(A) respectively. 2. CHTL was significantly increased in the workers, who had a past history of ear disease in left ear(p=0.05) and those who worked in environment with back noise with respect to both ear(Rt p=0.02, Ltp=0.03). 3. CHTL in the left ear was positively correlated with diastolic blood pressure(r=0.109, p=0.05). The duration of observed CHTL in the right ear(r=0.093, p=0.05) and age for both ears(r=0.129, p=0.00). 4. Analyzing of the effect of influential factors to CHTL by stepwise multiple regression after established significant factors in univariate analysis, revealed that noise level(back noise) was the mosts significant variable for the left ear(p=0.02). These findings suggest that ; Occupational health nurses in the company should be more active in dealing with activities to promote hearing conservation necessary especially in workers whose noise level. was back noise.