Introduction to Health and Safety at Work

Introduction to Health and Safety at Work
252
The risk factors, which can lead to the onset of 
WRULDs, are repetitive actions of lengthy duration, the 
application of signifi cant force and unnatural postures, 
possibly involving twisting and over-reaching and the 
use of vibrating tools. Cold working environments, work 
organization and worker perception of the work organiza-
tion have all been shown in studies to be risk factors, as is 
the involvement of vulnerable workers such as those with 
pre-existing ill-health conditions and pregnant women.
Ill-health due to vibrations
Hand-held vibrating machinery (such as pneumatic 
drills, sanders and grinders, powered lawn mowers and 
strimmers and chainsaws) can produce health risks from 
hand–arm or whole body vibrations.
Hand–arm vibration syndrome (HAVS)
HAVS describes a group of diseases caused by the expos-
ure of the hand and arm to external vibration. Some of 
these have been described under WRULDs, such as car-
pal tunnel syndrome.
However, the best known disease is 
vibration white 
fi nger (VWF)
in which the circulation of the blood, particu-
larly in the hands, is adversely affected by the vibration. 
The early symptoms are tingling and numbness felt in the 
fi ngers, usually some time after the end of the working 
shift. As exposure continues, the tips of the fi ngers go 
white and then the whole hand may become affected. 
This results in a loss of grip strength and manual dexter-
ity. Attacks can be triggered by damp and/or cold 
conditions and, on warming, ‘pins and needles’ are 
experienced. If the condition is allowed to persist, more 
serious symptoms become apparent including discolor-
ation and enlargement of the fi ngers. In very advanced 
cases, gangrene can develop leading to the amputation 
of the affected hand or fi nger. VWF was fi rst detailed as 
an industrial disease in 1911.
The risk of developing HAVS depends on the 
frequency of vibration, the length of exposure and the 
tightness of the grip on the machine or tool. Some typical 
values of vibration measurements for common items of 
equipment used in industry are given in Table 15.1.