Vibration-induced white finger among selected underground rock drillers in British Columbia. by Brubaker RL, Mackenzie CJ, Hutton SG This article in PubMed: www.ncbi.nlm.nih.gov/pubmed/3490687

SO, SLAKOV J. Longitudinal study of vibration-induced white finger among coastal fallers in British Columbia. Scand J Work Environ Health 13 (1987) 305-308. Symptom-based vibration-induced white finger was determined longitudinally from a questionnaire administered to 71 full-time fallers exposed 2-4 h daily to generally heavy (> 11 kg), large displacement (> 95 cc) chain saws. The prevalence of Raynaud's phenomenon among 55 fallers (after 16 fallers were excluded because of possible confounders) was 51 010 in 1979-1980. This figure did not differ significantly from the prevalence in 1984-1985 (53 010). Among the 28 fallers reporting symptoms in 1979-1980, seven reported no symptoms in 1984-1985, while four indicated improvement in the severity of symptoms resulting in a decreased stage assessment. Evidence for actual recovery was weak because of discrepancies in the symptom reporting. Reported recovery and improvement in the group with symptoms in 1979-1980 was counterbalanced by a significant 30 010 onset of new symptoms among fallers who were asymptomatic in 1979-1980. Six of the eight fallers reporting new symptoms were exposed only to anti vibration saws, a finding suggesting that the type of saws used in the present investigation is not preventing the onset of new disease. Weighted 4-h equivalent acceleration levels from the handlebars of saws commonly used by the cohort group in 1984 ranged from 4.0 to 12.4 m/s-.

The vibration from chain saws can cause vibration-induced white finger disease (VWFD). Measurements of vibration levels on the front and rear handles of different chain saw-types, and on the operator's middle finger were collected at three logging camps on Vancouver Island. Factors effecting the vibration levels on the finger and handles were investigated. The acceleration at the firing frequency was found to be the dominant factor effecting handle and finger vibration. Other factors which were investigated were: grip force; the presence of handle covers; and chain sharpening procedure. Weighted acceleration levels are calculated and this information is used to assess the latency period for fallers to develop VWF disease.

No abstract

Based on a professionally administered medical questionnaire, 50% of 95, rock drillers using hand-held pneumatic drills from two large British Columbia underground mines reported symptoms of Vibration White Finger Disease (VWFD). Prevalence of this disease was 45% among a subgroup of 58 drillers without a medical or occupational history of possible predisposing factors other than drill vibration. Symptoms appeared to be dose-related with blanching attacks reported among 25% of subgroup drillers exposed for 1 −5 years, and in 80% of those exposed for 16 years or more. 9% of subgroup drillers had severe stage 3 symptoms (Taylor-Pelmear Classification). The median latent period for onset of blanching symptoms was 7.5 years. Prevalence of VWFD among 58 control miners from the two sites without a history of intense prolonged hand-arm vibration or other pre-disposing factors was 4%. There was objective evidence of vascular abnormality (based on delayed finger rewarming after combined digital cooling and ischemia) in 76% of subgroup drillers with blanching symptoms and in 18% of controls without symptoms. Comparison is made between the latent period for onset of blanching symptoms among drillers in this study and the predicted latent period based on suggested International Standards Organization guidelines for vibration exposure.