Operating vibrating tools and prevalence of subjective complaints in vibration syndrome

The aim of this paper is to evaluate the prevalence of subjective symptoms and signs related to vibration syndrome in various groups of subjects exposed to hand-arm vibration (HAV). In 9 groups of subjects occupationally exposed to HAV, one group of subjects previously exposed to HAV, one control group, and 2 groups of general population (males and females), the prevalence of finger blanching, numbness in the hands, stiffness in the hands, and pain in the hands were investigated. The age of subjects ranged from 25 to 59 years. In subjects exposed to HAV, hand-transmitted vibration levels (HTVLs) were measured by means of vibration dosimeters, and the frequency-weighted acceleration levels [(Lh,w)eq,t] were determined as the vibration levels. The prevalence of vibration-induced white finger (VWF) in the exposed subjects was in the range of 0.0-9.6%, and that in subjects who were previously exposed to HAV was 4.1%. The prevalence rates of finger blanching in males and females of the general population were 2.7 and 3.4%, respectively. The highest prevalence rate of VWF was observed among subjects exposed to HTVLs of 2.7-5.1 m/s2. The prevalence of numbness of the hands fluctuated among the groups; i.e., in the exposed groups: in the range of 6.5-30.4%; in those previously exposed to HAV: 16.4%; and was 13.4% in males and 29.5% in females of the general population. The prevalence rates of stiffness in the hands were in the range of 7.6-65.2% in the exposed workers, 13.7% in those previously exposed to HAV, and was 5.5% in males and 20.9% in females of the general population. The prevalence of pain in the hands was between 7.4 and 17.4% in the exposed groups, 1.4% in those who stopped exposure to vibration, and 1.2% in subjects without segmental vibration exposure. Among the subjective symptoms, only VWF showed a significant positive correlation with the measured vibration acceleration; Y = -0.9 + 1.9 X, r = 0.8, P = 0.01. It was concluded that VWF is the most appropriate signs in decisions concerning quantitative recommendations for segmental vibration exposure.