Vibration-induced white finger among selected underground rock drillers in British Columbia

Abstract

Ninety-five rock drillers who used pneumatic hand-held drills were interviewed and tested. Thirty-seven were excluded because of factors predisposing to the appearance of white fingers other than exposure to industrial hand-drill vibration. Forty-five percent of the remaining 58 drillers suffered from periodic attacks of Raynaud's phenomenon. Symptoms were present in 25 % of the drillers exposed for 1 - 5 years and in 80 % of those exposed for ≥ 16 years. Nine percent of the cases were classified as severe. The median latency for the onset of the blanching symptoms was 7.5 years. The prevalence of Raynaud's phenomenon was 4 % among a reference group of 56 miners not exposed to hand vibration and corrected for possible predisposing factors. Objective evidence indicated delayed finger rewarming after a combination of digital ischemia and cooling in 75 % of the drillers with blanching symptoms and 18 % of the referents without symptoms. There was evidence of an increased frequency of vibration-induced white finger among current cigarette smokers. Weighted 4-h equivalent acceleration levels measured from the handles of 26 jack-leg and 13 stoper drills from the same mines as the miners ranged from 15 to 32 m/s2. These levels exceed recommended guidelines of the International Organization for Standardization.