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

PurposeTo provide an updated epidemiological validation for a supplementary method for assessing the risk of vascular disorders from hand-transmitted vibration.MethodsThe 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-h defined in international standard ISO 5349-1:2001 [A(h)(8) in ms(-2)] or the hand-arm vascular frequency weighting W-p proposed in the ISO technical report (TR) 18570:2017 [A(p)(8) in ms(-2)]. To estimate a threshold value for vascular hand-arm vibration risk, the W-p-weighted vibration exposure value E-p,E-d (in ms(-1.5)) 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-h or W-p was investigated by means of logistic modelling.ResultsMeasures of daily vibration exposure constructed with the frequency weighting W-p [A(p)(8) and E-p,E-d], 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-h [A(h)(8)]. There was some epidemiological evidence for a threshold value of E-p,E-d for the onset of VWF in the vibration-exposed workers.ConclusionsMeasures of daily vibration exposure evaluated with the vascular weighting W-p performed better for the predictions of VWF than those obtained with the frequency weighting W-h recommended in ISO 5349-1.