Vibration Perception Threshold of Male Workers Exposed to Carbon Disulfide

Park, Seung Hoi; Lee, Eun Il; Chun, Byung Chul; Yum, Yong Tae; Chi, Jae Wook

Abstract

This study was conducted on 367 male workers to evaluate the change of vibration perception threshold (VPT) according to exposure degree to carbon disulfide. VPT was measured on both metacarpal bones of index and little fingers and on fibular malleoli by Vibrometer (Rion, on 125Hz). The exposure degree was classified by the name of department. Workers in department 1 had been exposed to high concentration of carbon disulfide, those in. department 2 had been exposed to carbon disulfide moderately or intermittently, and those in department 3 had been exposed to undetectable concentration of carbon disulfide. The results were as follows: 1. The mean values of VPT of metacarpal(MC) bones showed dose-response pattern, i.e., the mean values of VPT at department 1 were highest, and those of VPT at department 3 were lowest with similar work duration or age. But the mean values of VPT of fibular malleoli (FM) showed dose-response pattern only in workers having above 5 years of work duration or whose age were above 30. 2. The mean values of VPT of MC bone of workers increased by age. 3. There were statistically significant difference in mean values of VPT of MC bone only in workers having 5-10 year work duration. And there were statistically significant difference of mean values of VPT of left 2nd and 5th MC bone in workers whose age was 30's, of right 2nd MC bone in those whose age was 40's, and of left 2nd MC bone in those whose age was 50's. 4. The variables affecting VPT significantly were department and age (or age group) both in multiple regression and general linear model. The department showed to have more effect to VPT than age in multiple regression, but age group showed to have more effect to VPT than department in general linear model. 5. The variables were transformed to indicator variable to do logistic regression analysis. Department 1, 2, 3 were classified into high exposure (spinning department) and low exposure (other department), age was classified into old (above 30) and young, and work duration was classified into long(above 10 years) and short. The exposure and age were significant variables by logistic regression analysis. Odds ratios of department and VPT on metacarpal bones or malleoli were 2.7-3.2 and those of age and VPT were 2.6 or 2.7. Odds ratio of age and abnormality of VPT on'any point was 3.3(1.59-6.;8), and that of department and VPT was 2.8(1.5-5.5). We concluded that exposure of carbon disulfied was significantly associated with reduction of VPT regardless of age; and that the test of VPT would be useful tool for screening and early detection in neuropathy by carbon disulfide or other neurotoxic chemicals,even though it is simple and cheap.