Vibration white finger, also known as hand-arm vibration syndrome or dead
finger,) is a secondary form of Raynaud's syndrome, an industrial injury
triggered by continuous use of vibrating hand-held machinery. Use of the term
"vibration white finger" has generally been superseded in professional usage by
broader concept of HAVS, although it is still used by the general public. The
symptoms of vibrating white finger are the vascular component of HAVS.
HAVS is a widespread recognized industrial disease affecting tens of
thousands of workers. It is a disorder that affects the blood vessels, nerves,
muscles, and joints, of the hand, wrist, and arm. Its best known effect is
vibration-induced white finger, a term introduced by the Industrial Injury
Advisory Council in 1970. Injury can occur at frequencies between 5 and 2000
Hz but the greatest risk is between 50 and 150 Hz.
Effects Excessive exposure to hand arm
vibrations can result in various patterns of diseases casually known as
HAVS or VWF. This can affect nerves, joints, muscles, blood vessels or
connective tissues of the hand and forearm:
Tingling 'whiteness' or numbness in the fingers: This may not be noticeable at
the end of a working day, and in mild cases may affect only the tips of the
fingers. As the condition becomes more severe, the whole finger down to the
knuckles may become white. Feeling may also be lost.
Fingers change colour: With continued exposure the person may suffer periodic
attacks in which the fingers change colour when exposed to the cold.
Initially the fingers rapidly become pale and feeling is lost. This phase is
followed by an intense red flush signalling the return of blood
circulation to the fingers and is usually accompanied by uncomfortable
throbbing. Loss of manual dexterity: In more severe
forms, attacks may occur frequently in cold weather, not only at work, but
during leisure activities, such as gardening, car washing or even watching
outdoor sports and may last up to an hour causing considerable pain and loss
of manual dexterity and reduced grip strength.
In extreme cases, the sufferer may lose fingers. The effects are cumulative.
When symptoms first appear, they may disappear after a short time. If
exposure to vibration continues over months or years, the symptoms can worsen
and become permanent. History
The symptoms were first described by Professor Giovanni Loriga in Italy in
1911, although the link was not made between the symptoms and vibrating hand
tools until a study undertaken by Alice Hamilton MD in 1918. She formed her
theory through following the symptoms reported by quarry cutters and carvers
in Bedford, Indiana. She also discovered the link between an increase in HAV
symptoms and cold weather as 1918 was a particularly harsh winter.
The first scale for assessing the condition, the Taylor-Pelmear scale, was
published in 1975, but it was not listed as a prescribed disease in the United
Kingdom until 1985, and the Stockholm scale was introduced in 1987. In 1997,
the UK High Court awarded £127,000 in compensation to seven coal miners for
vibration white finger. A UK government fund set up to cover subsequent claims
by ex-coalminers had exceeded £100 million in payments by 2004.
Prevention The Control of Vibration at Work
Regulations 2005, created under the Health and Safety at Work etc. Act 1974.
is the legislation in the UK that governs exposure to vibration and
assists with preventing HAVS occurring. Good practice in industrial health and
safety management requires that worker vibration exposure is assessed in terms
of acceleration amplitude and duration. Using a tool that vibrates slightly for
a long time can be as damaging as using a heavily vibrating tool for a short
time. The duration of use of the tool is measured as trigger time, the period
when the worker actually has their finger on the trigger to make the tool
run, and is typically quoted in hours per day. Vibration amplitude is quoted
in metres per second squared, and is measured by an accelerometer on the tool
or given by the manufacturer. Amplitudes can vary significantly with tool design,
condition and style of use, even for the same type of tool.
In the UK, Health and Safety Executive gives the example of a hammer drill
which can vary from 6 m/s² to 25 m/s². HSE publishes a list of typically
observed vibration levels for various tools, and graphs of how long each day a
worker can be exposed to particular vibration levels. This makes managing
the risk relatively straightforward. Tools are given an Exposure Action Value
and an Exposure Limit Value. In the United States, the National
Institute for Occupational Safety and Health published a similar database
where values for sound power and vibrations for commonly found tools from
large commercial vendors in the United States were surveyed. Further testing is
underway for more and newer tools. The effect of legislation in various
countries on worker vibration limits has been to oblige equipment providers to
develop better-designed, better-maintained tools, and for
employers to train workers appropriately. It also drives tool
designers to innovate to reduce vibration. Some examples are the easily
manipulated mechanical arm and the suspension mechanism designed into
chainsaws. Reactive monitoring
A simpler system, known as re-active monitoring, may be used by, for example,
monitoring rates of usage of consumable items. Such a system was introduced by
Carl West at a fabrication workshop in Rotherham, England. In this system, the
vibration levels of the angle grinding tools in use was measured, as was the
average life of a grinding disk. Thus by recording numbers of grinding disks
used, vibration exposure may be calculated.
See also List of cutaneous conditions
References External links
BBC News article on coal miners claims Trades Union Congress - basic facts
UK Health and Safety Executive NIOSH Power Tools Sound Power and
Vibrations Database HSE webpage HAV case studies