Relative Performance of Frequency Weighting W(h) and Candidates for Alternative Frequency Weightings for Predicting the Occurrence of Hand-transmitted Vibration-induced Injuries.

Exposure to hand-transmitted vibration is usually assessed according to International Standard ISO 5349-1:2001 using the frequency weighting W(h). This paper compares eight frequency weightings that might be used to supplement or replace W(h). The comparison is based on a data from two databases, one containing over 7200 measured hand-arm vibration (HAV) spectra from a wide range of industrial machines the other recording exposure history and injury for workers referred to the Health and Safety Laboratory. Acceleration spectra from the machinery database are analysed to give weighted values for the alternative frequency weightings. These weighted values are compared and then used to estimate a set of alternative lifetime vibration dose values for subjects in the referral database. Statistical comparison of these lifetime dose values against assessments of hand-arm vibration syndrome (HAVS) and sensorineural HAVS prevalence suggests that values based the two weightings W(h) and W(h50lp) (the W(h) weighing low-pass filtered at 50 Hz) provide the strongest indicators for developing these injuries. For vascular HAVS there was no clear evidence to advocate any individual frequency weighting. For all injury categories the strongest relationships were for the first power of acceleration magnitude.