OBITUARY Louis Challis

There are limited epidemiologic data to allow reliable conclusions about industrial workers' exposure to hand-transmitted vibration and its disorders in developing countries. This study aimed to investigate the clinical features of hand-arm vibration syndrome (HAVS) and work disability caused by exposure to hand-transmitted vibration in stone cutting workers. The study population consisted of 40 stone cutting workers and 30 metal workers as a control group employed in the workshops located in Hamadan (western province of Iran). Measuring exposure to hand-transmitted vibration (HTV) was performed using a vibration meter (model 2260, B and K) and its analyzer (model 1700). By means of a clinically administered questionnaire, information on HAVS symptoms was obtained. The cold water provocation and touch sensory tests were performed for determining sensorineural and vascular functions. The grip strength and manual dexterity tests were also conducted for diagnosis of work disability. The daily vibration exposures of stone cutting workers were significantly higher than the national exposure limit. The prevalence of fingers' blanching and fingers' sensation disorders in stone cutting workers was 37.5 and 35%, respectively, but none of the controls had these symptoms. It is revealed that the work abilities of the stone cutting workers have been decreased from 18 to 35% compared with the control group. The findings confirmed that the vascular and sensorineural disorders have significantly reduced the work ability of the stone cutting workers during long-term exposure to HTV. This study covered the lack of information regarding the HAVS symptoms experienced by stone cutting workers and provided a local database for further research about dose-effect relationships.