Vibration white finger
Encyclopedia
Vibration white 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 Use of the term Vibration White Finger has generally been superseded by Hand-Arm Vibration Syndrome or HAVS. The symptoms of VWF are the vascular component of HAVS.
HAVS is a widespread recognized industrial disease affecting tens of thousands of workers. It is a disorder which affects the blood vessels, nerves, muscles, and joints, of the hand, wrist and arm. Its best known effect is vibration-induced white finger (VWF), a name coined by the Industrial Injury Advisory Council in 1970. Injury can occur at frequencies between 5 and 2000 Hz but the greatest risk is between 5 and 150 Hz.
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:
In extreme cases, the sufferer may lose fingers. The effect is 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.
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 introduced in 1987. In 1997 the Miners 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.
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.
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 (EAV, the time which a tool can be used before action needs to be taken to reduce vibration exposure) and an Exposure Limit Value (ELV, the time after which a tool may not be used).
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 on worker vibration limits is intended to drive employers to provide better-designed, better-maintained tools, and to train workers appropriately. It also drives tool designers to innovate to reduce vibration. Some examples are the EMMA (Easily Manipulated Mechanical Arm) and the suspension mechanism designed into chainsaws.
Raynaud's phenomenon
In medicine, Raynaud's phenomenon is a vasospastic disorder causing discoloration of the fingers, toes, and occasionally other areas. This condition can also cause nails to become brittle with longitudinal ridges. Named for French physician Maurice Raynaud , the phenomenon is believed to be the...
, an industrial injury
Industrial injury
An occupational injury is bodily damage resulting from working.In the United States in 2007, 5,488 workers died from job injuries, 92% of which were men, and 49,000 died from work-related injuries. NIOSH estimates that 4 million workers in the U.S...
triggered by continuous use of vibrating hand-held machinery. Use of the term Vibration White Finger has generally been superseded by Hand-Arm Vibration Syndrome or HAVS. The symptoms of VWF are the vascular component of HAVS.
HAVS is a widespread recognized industrial disease affecting tens of thousands of workers. It is a disorder which affects the blood vessels, nerves, muscles, and joints, of the hand, wrist and arm. Its best known effect is vibration-induced white finger (VWF), a name coined by the Industrial Injury Advisory Council in 1970. Injury can occur at frequencies between 5 and 2000 Hz but the greatest risk is between 5 and 150 Hz.
Effects
Excessive exposure to hand arm vibrationsHand arm vibrations
In terms of occupational safety and health HAV stands for Hand Arm Vibrations and is directly responsible for Hand Arm Vibrations Syndrome.- Description :Exposure to hand arm vibrations is a respectively newer occupational hazard in the work place...
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 (blood vessels and nerves affected): 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 (blood vessels affected): 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 (sometimes preceded by a dusky bluish phase) signalling the return of blood circulation to the fingers and is usually accompanied by uncomfortable throbbing.
- Loss of manual dexterity (nerves and muscles affected): 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 effect is 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 ItalyItaly
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
in 1911, although the link was not made between the symptoms and vibrating hand tools until a study undertaken by Alice Hamilton
Alice Hamilton
Alice Hamilton was the first woman appointed to the faculty of Harvard University and was a leading expert in the field of occupational health...
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
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
until 1985, and the Stockholm scale introduced in 1987. In 1997 the Miners 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 is the legislation that governs exposure to vibration and assists with preventing HAVS occurring.Good practice in industrial health and safety management
Occupational safety and health
Occupational safety and health is a cross-disciplinary area concerned with protecting the safety, health and welfare of people engaged in work or employment. The goal of all occupational safety and health programs is to foster a safe work environment...
requires that worker vibration exposure is assessed in terms of acceleration amplitude
Amplitude
Amplitude is the magnitude of change in the oscillating variable with each oscillation within an oscillating system. For example, sound waves in air are oscillations in atmospheric pressure and their amplitudes are proportional to the change in pressure during one oscillation...
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
Accelerometer
An accelerometer is a device that measures proper acceleration, also called the four-acceleration. This is not necessarily the same as the coordinate acceleration , but is rather the type of acceleration associated with the phenomenon of weight experienced by a test mass that resides in the frame...
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.
The UK Health and Safety Executive
Health and Safety Executive
The Health and Safety Executive is a non-departmental public body in the United Kingdom. It is the body responsible for the encouragement, regulation and enforcement of workplace health, safety and welfare, and for research into occupational risks in England and Wales and Scotland...
gives the example of a hammer drill
Hammer drill
A hammer drill, also known as a "Hammer drill", "roto-drill" or "hammering drill", is a rotary drill with a hammering action. The hammering action provides a short, rapid hammer thrust to pulverize relatively brittle material and provide quicker drilling with less effort...
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 (EAV, the time which a tool can be used before action needs to be taken to reduce vibration exposure) and an Exposure Limit Value (ELV, the time after which a tool may not be used).
The National Institute for Occupational Safety and Health
National Institute for Occupational Safety and Health
The National Institute for Occupational Safety and Health is the United States’ federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the Centers for Disease Control and Prevention within the U.S...
published a similar database
NIOSH Power Tools Database
The NIOSH Power Tools Database contains sound power levels, sound pressure levels, and vibrations data for a variety of common power tools that have been tested by researchers. Data are collected for both the unloaded and loaded use of power tools...
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 on worker vibration limits is intended to drive employers to provide better-designed, better-maintained tools, and to train workers appropriately. It also drives tool designers to innovate to reduce vibration. Some examples are the EMMA (Easily Manipulated Mechanical Arm) and the suspension mechanism designed into chainsaws.
External links
- BBC News article on coal miners claims
- Trades Union Congress information sheet
- UK Health and Safety Executive
- NIOSH Power Tools Sound Power and Vibrations Database
- Hand Arm Vibration Syndrome
- Low-Vibration.com Hitachi Power Tools information on Hand-Arm Vibration Syndrome
- http://www.thehavi.com The HAVi Hand-Arm Vibration Monitoring Equipment and independent audit service
- http://www.hae.org.uk/pages/index.cfm?page_id=44 Hire Association Europe, HAVS advice and info - part 1
- http://www.hae.org.uk/pages/index.cfm?page_id=70 Hire Association Europe, HAVS advice and info - part 2