Epidemiological study of vibration syndrome in response to total hand-tool operating time.

Abstract

The correlation between the severity of vibration syndrome and hand-tool operating time in chain saw workers has been studied. The total chain saw operating time was calculated by using the equation: chain saw operating hours/day x days/year x years, and 266 chain saw operators were classified into four groups (0-2000 h, 2000-5000 h, 5000-8000 h, over 8000 h). Forty-six forestry workers not using chain saws were used as controls. The prevalence rates of symptoms were checked and statistically compared in each group.In the group with under 2000 hours' experience, symptoms were generally confined to tingling, numbness, or pain; with 2000-5000 hours peripheral nerve and circulatory disturbances, including Raynaud's phenomenon, and muscle and general body conditions were influenced to some degree; with 5000-8000 hours' functional changes were noted; while with over 8000 hours about half the operators suffered severely from functional or organic changes due to vibration.Since Lorigal first reported the occurrence of occupational hazards due to the use of vibrating tools, many cases of workers affected by the use of vibrating tools in a wide range of industrial tasks (riveting, drilling, or jobs requiring chain saws and pneumatic hammers) have been reported. Many researchers first paid attention to vibration-induced white finger (Raynaud's phenomenon) and this syndrome is now well described. Recently, however, the concept of a "vibration syndrome" has been introduced to encompass the complex of symptoms associated with vibrating tools, such as vibration-induced white finger (Raynaud's phenomenon), hypesthesia of the hand and arm, weakness of grip strength, restriction of joints in hands, and so on.2-4 Several papers investigating the frequency and severity of vibration syndrome have been published,57 and criteria for the diagnosis of vibration syndrome have been established and used to describe the progress of this syndrome.6 These papers have detailed the progress of the syndrome but they do not show the correlation between the time for which vibrating tools have been used and each symptom, except Raynaud's phenomenon.In this paper we have introduced "total operating time (TOT)' as a new index of vibration dose and have tried to show the correlation between the sev-92 erity of vibration syndrome and total hand tool operating time by using the medical records of over 2000 chain saw workers. The field study was carried out from 1975 to 1979. SubjectsOver 2000 forestry workers in the mountain area near Osaka in Japan were surveyed and examined for vibration syndrome. From these, 266 subjects professionally exposed to chain saw hand-arm vibration were selected; 46 controls, forestry workers never exposed to vibration, were also selected. We used these subjects who were all men and aged from 40 to 59 to eliminate the effects of sex and age.To determine the vibration exposure dose for an individual, TOT was calculated from the full occupational history using the following equation: chain saw operating hours/day x days/year ...

White fingers, cold environment, and vibration – exposure among Swedish construction workers

“…It is a well-known fact that WF episodes are manifested or occur when the temperature is low, because low temperature significantly influences peripheral blood Burström et al circulation (10,11). One reason for our finding could be that the symptoms are more easily provoked in cold climate (ie, if the HAV-exposed workers living in the south had lived in the north they should have reported WF to the same extent).…”

Prevention of the hand-arm vibration syndrome.

“…M iya shita et al (12) ha ve reported on the relationship be tween the progress o f th e vibra tion syndro me and the tota l chain-saw operating t im e among forestry wor kers. They show ed th at a group wit h 2 000 to 5 000 h of cha in-saw operation had peripheral ne rve a nd circulatory d isturba nces, including Ra ynaud' s ph enomenon, while even the group with less than 2 000 h of expe rience complain ed of ti ng ling, numbness, o r pain and that the group with over 5 000 h of exposure su ffered severe functional , o r o rganic changes owing to vibration.…”

Impaired Manual Dexterity and Neuromuscular Dysfunction in Patients with Hand-Arm Vibration Syndrome

“…It is known that long-term exposure to hand-transmitted vibration causes reduced grip strength and intrinsic muscular dysfunction [16][17][18] . Biopsies from the abductor pollicis brevis muscle in vibration-exposed workers have shown malalignment of myofibrils 19) .…”