Abstract
The hand-arm vibration exposure level of workers who occupationally use hand-held power tools was measured in four operating processes of aluminum-die-cast manufacturing. Also the workers orally answered questions regarding the daily exposure time to hand-arm vibration caused by the use of hand-held power tools, subjective symptoms in the hand-arm during / after daily tool operation, and countermeasures used to reduce vibrations on the to the hand-arm system. According to vibration dose evaluation based on the daily equivalent vibration exposure, the exposure limit durations were a little more than 1 hour for polishing operation in the finishing process and less than 1 hour for final polishing in the inspection section. Actually the workers in these sections are engaged in polishing, using the tools for 5 hours in a day. Almost all of the tool operators complained of temporary fatigue and numbness of the hand during / after the daily tool operation. However no use of anti-vibration gloves was observed in these workplaces. The results suggest the current workplaces require the systematic control of hand-arm vibration exposure based on the concept of energy-equivalent daily vibration exposure, which includes educational orientation on the use of anti-vibration gloves.
