Risk assessment of vascular disorders by a supplementary hand-arm vascular weighting of hand-transmitted vibration.

PURPOSE

To provide an updated epidemiological validation for a supplementary method for assessing the risk of vascular disorders from hand-transmitted vibration.

METHODS

The occurrence of vibration-induced white finger (VWF) in the vibration-exposed workers of the Italian cohort of the EU VIBRISKS study was related to measures of daily vibration exposure expressed in terms of r.m.s. acceleration magnitude normalised to an 8-h day, frequency weighted according to either the frequency weighting W defined in international standard ISO 5349-1:2001 [A(8) in ms] or the hand-arm vascular frequency weighting W proposed in the ISO technical report (TR) 18570:2017 [A(8) in ms]. To estimate a threshold value for vascular hand-arm vibration risk, the W-weighted vibration exposure value E (in ms) was calculated according to the ISO/TR document. The difference in the predictions of VWF between the exposure measures calculated with the frequency weightings W or W was investigated by means of logistic modelling.

RESULTS

Measures of daily vibration exposure constructed with the frequency weighting W [A(8) and E], which gives more importance to intermediate- and high-frequency vibration, were better predictors of the occurrence of VWF in the vibration-exposed workers than the metric derived from the conventional ISO frequency weighting W [A(8)]. There was some epidemiological evidence for a threshold value of E for the onset of VWF in the vibration-exposed workers.

CONCLUSIONS

Measures of daily vibration exposure evaluated with the vascular weighting W performed better for the predictions of VWF than those obtained with the frequency weighting W recommended in ISO 5349-1.