Vascular and nerve disorders at exposure to hand-held vibrating tools related to ISO 5349

The authors present the results of the investigation of peripheral nerves of the hand in a group of 30 glass cutters, 21 metal grinders, 10 blacksmiths and 24 workers who worked with nailers. The measurements of vibrotactile sensitivity were carried out by Vibrometry System Brüel & Kjaer Type 9627. The vibrotactile perception thresholds (VPT) were measured in frequency range from 8 to 500 Hz. The same investigations were carried out in 103 healthy subjects with no previous work-exposure to vibration or shocks. Further electromyographic examination was carried out in all members of exposed groups. The results of measurements VPT have proved reliability and high sensitivity of this method for the early detection of light disorders of peripheral nerves of the hand due to vibration. All the workers also passed investigation of vascular system of fingers. Simultaneously the measurement of vibration and shocks of single types of hand-held tools used by workers was done. The results of measurement have been worked up according to ISO 5349 (1) that enables to determine the beginning of the incidence of disorders of the hands and arms on the base of measured values of vibration and shocks. The results of the vascular system investigation have been compared with the results of the assessment of exposure according to ISO 5349. The conformity has been proved in the case of hand-transmitted vibrations not in the case of shocks.