Vascular and nerve damage in workers exposed to vibrating tools. The importance of objective measurements of exposure time

The subjective estimation of the mean daily exposure-time to vibrating tools was 192 min (range 18-480 min) among the workers. The estimated mean exposure time calculated from the consumption of grinding wheels was 42 min (range 18-60 min), approximately a four-fold overestimation (Wilcoxon's signed ranks test, p<0.001). Thus, objective measurements of the exposure time, related to the standard ISO 5349, which in this case were based on the consumption of grinding wheels, will in most cases give a better basis for adequate risk assessment than self-exposure assessment.