Although in many cases symptoms may take several years to develop, they can appear after only a few months in susceptible people exposed to high levels of vibration. Many cases of VWF have been found in UK stonemasons' yards but masons themselves appear reluctant to report their symptoms, often thinking that they indicate arthritis. This feels much like using a powered lawnmower for four hours. Above this level a programme of preventive measures and health surveillance should be introduced. Powered hand tools are used in many yards but the amount of use varies widely from a few minutes per week to almost continuously.
Some masons use one type of powered hand-tool only, while others use a range of tools.
Powered hand-tools are used for tasks including cutting, carving, grinding, sanding, and polishing stone. Most tools are likely to be rotary but a few, particularly for carving, will be percussive. There is a wide range of work and hand-tools being used at different yards. Vibration levels of up to 40 ms -2 have been measured, so many masons are likely to be exposed above the HSE recommended limit. The table below indicates regular daily usage times for some tools after which a programme of preventive measures is required.