Impulsive vibration and exposure limit.

Several cases of exposure to hand-transmitted shocks in two different factories were studied with an intention to improve our knowledge about the influence of the impulsive components of vibration on human being. Two types of shocks affecting the workers could be distinguished, i.e., shocks having small amount of energy at frequencies higher than 100 Hz and shocks having relatively high frequency components up to 1000 Hz. An exposure to the hand-arm shocks of both types was measured and assessed in accordance with the international standard ISO 5349. Health condition of workers was examined. Carpal tunnel syndrome was found among the workers of the workshop in wood industry, who work with staple gun. The investigation of the health condition of about 60 forge workers up to now did not confirm the severity of hand-arm shocks as it had been assessed according to the Annex A of the ISO 5349. The exposure to hand-arm shocks in the forge leads to the incidence of occupational diseases and disorders, which however, differ from the diseases normally reported as a consequence of the hand-arm vibration and shocks. It seems obvious that for the assessment of shock exposure, the ISO 5349 is not quite suitable in its present form.