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Isom Havs 23.03.07

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Isom Havs 23.03.07

  1. 1. Control of vibration at work Dr Peter Noone, Consultant Occupational Physician,
  2. 2. Vibration <ul><li>“ The men call the condition ‘dead fingers’and it is a good name, for the fingers do look like those of a corpse, a yellowish-greyish white and shrunken. There is a clear line of demarcation between the dead part and the normal part.” </li></ul><ul><li>“ they could not tell a dime from a nickel without looking at it” </li></ul>
  3. 3. Control <ul><li>There are few circumstances where control is not reasonably practicable, </li></ul><ul><li>Control often leads to better quality and increased productivity, </li></ul><ul><li>Investment for the future. </li></ul>
  4. 5. Hand-Arm Vibration Syndrome: History <ul><li>1862 - Primary Raynaud's phenomenon (Raynaud's Disease) identified by Dr Maurice Raynaud. </li></ul><ul><li>1911 - Secondary Raynaud's phenomenon first linked to use of pneumatic tools. </li></ul><ul><li>The use of power tools and machines became widespread with development of electrical power and internal combustion engine. </li></ul><ul><li>1975 - Taylor-Pelmear scale published allowing consistent assessment. </li></ul>
  5. 6. History <ul><li>1930’s & `1940’s: iron foundries (Seyring ); riveters (Hunt ); electrically powered high speed rotating hand tools ( Telford et al ); grinding wheels ( Agate and Druet ), </li></ul><ul><li>1960’s & 70’s; petrol-powered chain saws in forestry work (Finland, Scotland, Japan). </li></ul>
  6. 7. Alice Hamilton, the year she graduated from medical school, 1893 The Schlesinger Library, Radcliffe Institute, Harvard University
  7. 8. Bedford, Indiana, 1918: &quot;. . .the trouble seems to be caused by the vibrations of the tool, and cold. If these features can be eliminated the trouble can be decidedly lessened.&quot;. Alice Hamilton, MD . 1978 repeat of the Alice Hamilton study in Bedford, prevalence of HAVS=80%= same as 1918 result, nothing changed.
  8. 9. Alice Hamilton at her home, 1957, The Schlesinger Library, Radcliffe Institute, Harvard University, Scope Weekly
  9. 10. HAVS History <ul><li>1987 - the Stockholm workshop revised the Taylor-Pelmear scale that: </li></ul><ul><ul><li>divided the condition into two parts - vascular and neurological; </li></ul></ul><ul><ul><li>looked at each hand separately; </li></ul></ul><ul><ul><li>discounted seasonal variations in symptoms </li></ul></ul><ul><li>1992 - The Supply of Machinery (Safety) Regulations were introduced which required that risks resulting from vibration emissions should be reduced to the lowest level </li></ul><ul><li>1997 - England - Miners High Court compensation award £127,000 to 7 miners for HAVS </li></ul>
  10. 11. UK History <ul><li>Iron and steel trades insurers agreement- fixed payment, </li></ul><ul><li>IIAC –VWF prescribed first 1985 (PD A11), </li></ul><ul><li>1992 min of 14% disability before entitlement, </li></ul><ul><li>HAVS –prescribed 1995, </li></ul><ul><li>CTS assoc with HAVS 2004, </li></ul><ul><li>Compensation of Coal Miners by DTI. </li></ul><ul><li>Reports- FOM 1993, evidence based rev 2004. </li></ul><ul><li>HSE: Control of Vibration at Work Regs 2005, ACOP. </li></ul>
  11. 12. Epidemiology <ul><li>MRC survey- 288,000 prevalence of VWF cases (1997-8), 89% male, </li></ul><ul><li>4,800,000 exposed to HAV at work in UK, </li></ul><ul><li>HSE estimates over 2 million workers exposed above EAV in UK, </li></ul><ul><li>One million exposed above the ELV, </li></ul><ul><li>3000 IIB claimants per year in UK for VWF and vibration associated CTS. </li></ul>
  12. 13. Who’s at risk
  13. 14. Mechanisms contributing to Raynaud’s phenomenon
  14. 15. Wigley F. Raynaud’s Phenomenon. N Engl J Med 2002;347(13):1001-8
  15. 16. Secondary Raynaud’s <ul><li>atherosclerosis </li></ul><ul><li>cervical rib </li></ul><ul><li>CREST syndrome </li></ul><ul><li>dermatomyositis </li></ul><ul><li>hyperfibrinogenaemia </li></ul><ul><li>hypothyroidism </li></ul><ul><li>leukaemia </li></ul><ul><li>polyarteritis nodosa </li></ul><ul><li>polycythaemia rubra vera </li></ul><ul><li>rheumatoid arthritis </li></ul><ul><li>scleroderma </li></ul><ul><li>systemic lupus erythematosus </li></ul><ul><li>the presence of cold haemagglutinins </li></ul><ul><li>thoracic outlet syndrome </li></ul><ul><li>thrombo-embolic disease </li></ul><ul><li>vasculitis </li></ul><ul><li>vasculopathy in diabetes </li></ul>
  16. 17. Secondary Raynaud’s <ul><li>Connective Tissue Disease: </li></ul><ul><ul><li>Scleroderma </li></ul></ul><ul><ul><li>Mixed connective tissue disease </li></ul></ul><ul><ul><li>Systemic lupus erythematosus </li></ul></ul><ul><ul><li>Sjögren's syndrome </li></ul></ul><ul><ul><li>Dermatomyositis </li></ul></ul><ul><ul><li>Polymyositis </li></ul></ul>
  17. 18. A few drug treatments and toxins are associated with symptoms of secondary Raynaud’s phenomenon: <ul><ul><li>beta blockers </li></ul></ul><ul><ul><li>bleomycin </li></ul></ul><ul><ul><li>ergot </li></ul></ul><ul><ul><li>methysergide </li></ul></ul><ul><ul><li>vinblastine </li></ul></ul><ul><ul><li>vinyl chloride </li></ul></ul>
  18. 19. Secondary Raynaud’s <ul><li>Drugs and Toxins </li></ul><ul><ul><li>β -Blockers </li></ul></ul><ul><ul><li>Ergotamines </li></ul></ul><ul><ul><li>Clonidine </li></ul></ul><ul><ul><li>Chemotherapeutic agents </li></ul></ul><ul><ul><li>Polyvinyl chloride </li></ul></ul><ul><ul><li>Cyclosporin </li></ul></ul><ul><ul><li>Interferon </li></ul></ul><ul><ul><li>Oestrogen </li></ul></ul><ul><ul><li>Narcotics </li></ul></ul><ul><ul><li>Cocaine </li></ul></ul><ul><ul><li>Nicotine </li></ul></ul><ul><ul><li>Vinblastine, </li></ul></ul><ul><ul><li>methysergide </li></ul></ul>
  19. 20. Secondary Raynaud’s <ul><li>Large-artery disease: </li></ul><ul><ul><li>Vasculitis </li></ul></ul><ul><ul><li>Atherosclerosis </li></ul></ul><ul><ul><li>Thromboangiitis obliterans </li></ul></ul><ul><ul><li>Embolic disease </li></ul></ul><ul><li>Paraproteinemia </li></ul><ul><li>Hyperviscosity state (e.g., Polycythemia vera) </li></ul><ul><li>Cryoglobulinemias </li></ul>
  20. 21. Secondary Raynaud’s <ul><li>Neuropathy </li></ul><ul><ul><li>Carpal tunnel syndrome </li></ul></ul><ul><ul><li>Thoracic outlet syndrome </li></ul></ul><ul><li>Environmental agents and injury </li></ul><ul><ul><li>Cold Stress (Frostbite) </li></ul></ul><ul><ul><li>Repetitive occupational stress (hand–arm vibration syndrome) </li></ul></ul><ul><ul><li>Hypothenar hammer syndrome </li></ul></ul>
  21. 22. Secondary Raynaud’s <ul><li>Wrong Diagnosis: </li></ul><ul><ul><li>Acrocyanosis </li></ul></ul><ul><ul><li>Central Cyanosis </li></ul></ul><ul><ul><li>Chilblains/Pernio </li></ul></ul>
  22. 23. The symptoms attributed to the neurological component of HAVS may arise from some medical conditions. <ul><li>These include: </li></ul><ul><ul><li>alcoholic peripheral neuropathy </li></ul></ul><ul><ul><li>carpal tunnel syndrome (see Hand symptoms ) </li></ul></ul><ul><ul><li>cervical spondylosis (where one root is affected on one side) </li></ul></ul><ul><ul><li>diabetic peripheral neuropathy </li></ul></ul><ul><ul><li>hemiplegia </li></ul></ul><ul><ul><li>multiple sclerosis </li></ul></ul><ul><ul><li>neurofibromatosis </li></ul></ul><ul><ul><li>poliomyelitis </li></ul></ul><ul><ul><li>spinal cord compression </li></ul></ul><ul><ul><li>syringomyelia </li></ul></ul>
  23. 24. Drug treatment can sometimes cause neuropathy <ul><li>For example: </li></ul><ul><ul><li>chloramphenicol </li></ul></ul><ul><ul><li>cyclosporine </li></ul></ul><ul><ul><li>ethambutol </li></ul></ul><ul><ul><li>gold </li></ul></ul><ul><ul><li>indomethacin </li></ul></ul><ul><ul><li>isoniazid </li></ul></ul><ul><ul><li>metronidazole </li></ul></ul><ul><ul><li>nitrofurantoin </li></ul></ul><ul><ul><li>perhexiline </li></ul></ul><ul><ul><li>phenytoin </li></ul></ul><ul><ul><li>polymyxin </li></ul></ul><ul><ul><li>streptomycin </li></ul></ul><ul><ul><li>vincristine </li></ul></ul>
  24. 25. HAVS: Pathophysiology <ul><li>Neural Dysfunction </li></ul><ul><li>Local Acral vaso-dysregulation </li></ul><ul><li>Shear stresses </li></ul><ul><li>Blood Viscosity and cell activation </li></ul>
  25. 26. HAVS: Pathophysiology <ul><li>Neural Dysfunction </li></ul><ul><ul><li>Autonomic dysfunction </li></ul></ul><ul><ul><li>Receptor dysfunction </li></ul></ul><ul><ul><li>Nerve ending dysfunction. </li></ul></ul><ul><li>Local Acral vaso dysregulation </li></ul><ul><ul><li>Endothelial damage </li></ul></ul><ul><ul><li>Endothelial dysregulation </li></ul></ul>
  26. 27. HAVS: Pathophysiology <ul><li>Shear stresses </li></ul><ul><ul><li>cause of endothelial damage </li></ul></ul><ul><li>Blood Viscosity and cell activation </li></ul><ul><ul><li>Erythrocyte activation </li></ul></ul><ul><ul><li>Platelet activation </li></ul></ul><ul><ul><li>Leukocyte activation </li></ul></ul>
  27. 28. Hand-Arm Vibration Syndrome: Pathophysiology Stoyneva et al. Current pathophysiological views on vibration-induced Raynaud’s phenomenon. Cardiovascular Research. 2003. 57, 615-624
  28. 29. HAVS Diagnosis <ul><li>Physical exam: </li></ul><ul><ul><li>Grip strength, Phalen’s, Tinel’s, Allen’s (compression radial, ulnar arteries at wrist), Roo’s tests, Lewis-Prusik (nailbed compression), Adson’s (neck rotation & deep inspiration). </li></ul></ul><ul><li>Objective tests: </li></ul><ul><ul><li>cold provocation testing (thermometry), Doppler examination of the upper extremities, electromyography, digital plethysmography and current perception threshold studies (CPT). Semmes-Weinstein monofilaments. </li></ul></ul><ul><li>Bloods: </li></ul><ul><ul><li>CBC, serum electrolytes, creatinine, urea, urinalysis, glucose, ESR, TSH, uric acid, rheumatoid factor, antinuclear antibody, cryoglobulins, serum protein electrophoresis. </li></ul></ul>
  29. 31. Test TOS
  30. 32. Other tests
  31. 34. Hypothenar Hammer Syndrome: <ul><li>Results from repetitive blunt trauma to the palm of the hand, </li></ul><ul><li>Repeated trauma over the hypothenar eminence may result from gripping a piece of equipment that is intrinsically associated with vibration, </li></ul><ul><li>The position of the ulnar artery in the hypothenar eminence crossing the hamate bone makes it vulnerable to repetitive trauma, </li></ul><ul><li>May result in aneurysm formation or ulnar artery thrombosis, </li></ul><ul><li>The aneurysm occasionally serves as a source for digital emboli. </li></ul>
  32. 35. Cook RA. Hypothenar Hammer syndrome: a discrete syndrome to be distinguished from hand-arm vibration syndrome. Occupational Medicine 2003;53:320-324
  33. 37. Control of Vibration at Work Regulations 2005 <ul><li>Employers have a duties to: </li></ul><ul><li>Assess </li></ul><ul><li>Control </li></ul><ul><li>Information, Instruction and training </li></ul><ul><li>Check (including health surveillance) </li></ul>
  34. 38. ISO 5349-1:2001 for HAV and ISO 2631-1:1997 for WBV.
  35. 39. RISK ASSESSMENT <ul><li>The purpose of assessment is to enable management of risk, </li></ul><ul><li>An assessment is adequate if it provides enough information to enable you to take the most appropriate action. </li></ul><ul><li>Helps to target the highest exposure processes (biggest gain) </li></ul>
  36. 40. Do you have a problem? <ul><li>Do employees: </li></ul><ul><ul><li>complain of tingling and numbness in hands or fingers after using vibrating tools? </li></ul></ul><ul><ul><li>Hold work pieces, which vibrate while processed by powered machinery such as pedestal grinders? </li></ul></ul><ul><ul><li>Regularly use hand-held or guided power tools and machines such as: </li></ul></ul><ul><ul><ul><li>Concrete breakers, concrete pokers; </li></ul></ul></ul><ul><ul><ul><li>Sanders, grinders, disc cutters; </li></ul></ul></ul><ul><ul><ul><li>Hammer drills; </li></ul></ul></ul><ul><ul><ul><li>Chipping hammers; </li></ul></ul></ul><ul><ul><ul><li>Chainsaws, brush cutters, hedge trimmers, </li></ul></ul></ul><ul><ul><ul><li>Powered mowers; </li></ul></ul></ul><ul><ul><ul><li>Scabblers or needle guns. </li></ul></ul></ul><ul><ul><ul><li>Hammer action tools for more than about 15 minutes per day; or </li></ul></ul></ul><ul><ul><ul><li>Rotary and other action tools for more than about one hour per day. </li></ul></ul></ul><ul><ul><li>Do you work in an industry where exposures to vibration are particularly high, such as construction, foundries, or heavy steel fabrication/shipyards? </li></ul></ul>
  37. 41. Which jobs and industries are most likely to involve hand-arm vibration? <ul><li>Jobs with regular, frequent use of vibrating tools/ equipment, handling of vibrating materials found widely in industries: </li></ul><ul><li>Building and maintenance of roads and railways; </li></ul><ul><li>Construction; </li></ul><ul><li>Estate management (eg maintenance of grounds, parks, water courses, road and rail side verges); </li></ul><ul><li>Forestry; </li></ul><ul><li>Foundries; </li></ul><ul><li>Heavy engineering; </li></ul><ul><li>Manufacturing concrete products; </li></ul><ul><li>Mines and quarries; </li></ul><ul><li>Motor vehicle manufacture and repair; </li></ul><ul><li>Public utilities (eg water, gas, electricity, telecommunications); </li></ul><ul><li>Shipbuilding and repair. </li></ul>
  38. 42. What kinds of tools and equipment can cause ill health from vibration? <ul><li>Chainsaws; </li></ul><ul><li>Concrete breakers/road breakers; </li></ul><ul><li>Cut-off saws (for stone etc); </li></ul><ul><li>Hammer drills; </li></ul><ul><li>Hand-held grinders; </li></ul><ul><li>Impact wrenches; </li></ul><ul><li>Jigsaws; </li></ul><ul><li>Needle scalers; </li></ul><ul><li>Pedestal grinders; </li></ul><ul><li>Polishers; </li></ul><ul><li>Power hammers and chisels; </li></ul><ul><li>Powered lawn mowers; </li></ul><ul><li>Powered sanders; </li></ul><ul><li>Scabblers; </li></ul><ul><li>Strimmers/brush cutters. </li></ul>
  39. 43. Exposure Levels <ul><li>For hand-arm vibration— </li></ul><ul><ul><ul><li>the daily exposure limit value is 5 m/s² A(8); </li></ul></ul></ul><ul><ul><ul><li>the daily exposure action value is 2.5 m/s² A(8), </li></ul></ul></ul><ul><li>For whole body vibration— </li></ul><ul><ul><ul><li>the daily exposure limit value is 1.15 m/s² A(8); </li></ul></ul></ul><ul><ul><ul><li>the daily exposure action value is 0.5 m/s² A(8), </li></ul></ul></ul>
  40. 46. How do I estimate vibration exposure? <ul><li>Need vibration emission from the tool(s) </li></ul><ul><li>Also time of exposure </li></ul><ul><li>Combine to obtain daily exposure A(8) in m/s 2 </li></ul>
  41. 49. Vibration magnitude <ul><li>The vibration magnitude, a hv , is ascertained using the formula: </li></ul><ul><li>a hwx , a hwy and a hwz are the rms acceleration magnitudes, in m/s2, measured in three orthogonal directions, x, y and z, at the vibrating surface in contact with the hand, and frequency-weighted using the weighting Wh. </li></ul><ul><li>The definition for the frequency weighting Wh is given in British Standard BS EN ISO 5349-1:2001. </li></ul><ul><li>Where both hands are exposed to vibration, the greater of the two magnitudes a hv is used to ascertain the daily exposure. </li></ul>
  42. 50. Daily exposure to vibration <ul><li>where: </li></ul><ul><li>a hv is the vibration magnitude, in m/s 2 ; </li></ul><ul><li>T is the duration of exposure to the vibration magnitude a hv ; and </li></ul><ul><li>T 0 is the reference duration of 8 hours (28,800 seconds). </li></ul>
  43. 51. Combined operations <ul><li>total daily exposure consists of two or more operations with different vibration magnitudes, the daily exposure ( A (8)) for the combination of operations, </li></ul><ul><li>where: </li></ul><ul><li>     n is the number of individual operations within the working day;      a hvi is the vibration magnitude for operation i ; and      T i is the duration of operation i . </li></ul>
  44. 54. Dose-response curves and threshold limits <ul><ul><li>are not applicable to all tools </li></ul></ul><ul><ul><li>are derived from chain-saw data </li></ul></ul><ul><ul><li>do not take into account impulsiveness and high frequency of many tools, </li></ul></ul><ul><ul><li>All use the same Wh (freq weighting), derived Japan in 1960’s, predicts discomfort rather than pathological change. </li></ul></ul>
  45. 55. Getting realistic vibration data <ul><li>Ask tool supplier </li></ul><ul><li>Databases </li></ul><ul><ul><ul><li>http:// umetech.niwl.se/eng/default.lasso </li></ul></ul></ul><ul><ul><ul><li>http://www.las-bb.de/karla/index_.htm </li></ul></ul></ul><ul><li>Trade associations, consultancies, government, </li></ul><ul><li>Measurements (ISO 5349 parts 1 and 2) </li></ul>
  46. 56. www.hse.gov.uk/vibration
  47. 57. Points 100 points Action value- 400 points -Limit value-
  48. 58. Limit and action values <ul><li>If A(8) is greater than 5.0 m/s² (ELV) </li></ul><ul><li>Take immediate action to reduce exposure below ELV, </li></ul><ul><li>Identify why ELV is exceeded, </li></ul><ul><li>Amend protection and prevention measures. </li></ul><ul><li>(2007 or 2010) </li></ul><ul><li>If A(8) greater than 2.5 m/s² (EAV) </li></ul><ul><li>Establish a programme of risk control measures, </li></ul><ul><li>Introduce a programme of health surveillance for those who remain above the EAV, </li></ul><ul><li>Info & training. </li></ul><ul><ul><li>(July 2005) </li></ul></ul>
  49. 59. Simple ‘exposure points’ system to estimate the daily exposure.
  50. 61. Average latent periods for vibration-induced diseases in different occupations Vibration effects on the hand and arm in industry. Edited by A.J. Brammer et al. New York : John Wiley and Sons, 1982. 13.7 Blanching Grinder 4 Numbness Chain saw operator 9.1 12.0 16.8 Tingling Numbness Blanching Shipyard worker 1.8 2.2 2.0. Tingling Numbness Blanching Foundry worker Latency (years) Stage of VWF Occupation
  51. 62. What we do not know <ul><li>We do not know that the Wh in current standards reflects the relative importance of different frequencies and axes of vibration in producing any specific disorder. </li></ul><ul><li>whether the energy-based daily time-dependency inherent in A (8) reflects the relative importance of vibration magnitude and daily exposure duration. </li></ul><ul><li>Relation between A (8) and the years of exposure to develop finger blanching, as in appendix to ISO 5349-1 (2001), is not well-founded. </li></ul><ul><li>No consensus on, extent of the disorders caused by HTV (e.g. vascular, neurological, muscular, articular, central), or the pathogenesis of any specific disorder caused by HTV, or the roles of other factors (e.g. ergonomic factors, environmental factors, or individual factors). </li></ul><ul><li>Acute exposures to HTV cause both vascular and neurological changes analogous to the changes seen in those occupationally exposed to HTV, but we do not yet know how acute changes relate to the chronic disorders. </li></ul>
  52. 63. Hierarchy of control <ul><li>Elimination, </li></ul><ul><li>Substitution, </li></ul><ul><li>Engineering control, </li></ul><ul><li>Exposure management </li></ul><ul><li>Information, instruction and training </li></ul>
  53. 64. Demolition without vibration Use hydraulic crushers instead of demolition hammers
  54. 65. Elimination by design Eliminating the need for fettling Pile cropping C(DM)
  55. 66. Piling operations
  56. 67. Old: Pneumatic pick Slow process with exposure to noise, vibration, dust, heat
  57. 68. Substitution <ul><li>Is it the best tool for the job? (suitability and efficiency) </li></ul><ul><li>Ask the tool users if it’s low vibration? </li></ul><ul><li>Use manufacturers’ data </li></ul><ul><li>Implement purchasing / hiring policy </li></ul>Choose the right powered hand-tool
  58. 69. Engineering control <ul><li>JIGS </li></ul><ul><li>Vibration reduction </li></ul><ul><li>Better ergonomics </li></ul><ul><li>Increased productivity </li></ul>
  59. 70. Example – vibration reduced breaker: <ul><li>Keep the moil point sharp </li></ul><ul><li>Break a little at a time, </li></ul><ul><li>Don’t get jammed </li></ul><ul><li>Don’t force anti-vibration handles </li></ul><ul><li>Stop breaker before pulling out </li></ul>
  60. 71. Exposure management <ul><li>Specify maximum exposure times </li></ul><ul><li>May need job rotation </li></ul><ul><li>Need to take account of </li></ul><ul><ul><li>Productivity – what are you asking workers to do? </li></ul></ul><ul><ul><li>Communication </li></ul></ul><ul><ul><li>Supervision </li></ul></ul><ul><ul><li>Bonus! </li></ul></ul>
  61. 72. Always <ul><li>Keep warm and dry </li></ul><ul><ul><li>(assume anti-vibration gloves offer no protection) </li></ul></ul><ul><li>Avoid Smoking </li></ul><ul><li>Provide training </li></ul><ul><ul><li>Risks/symptoms </li></ul></ul><ul><ul><li>Control measures </li></ul></ul><ul><ul><li>Correct tool use (grip/feed force) </li></ul></ul><ul><li>Keep equipment well maintained </li></ul><ul><ul><li>Tools </li></ul></ul><ul><ul><li>Attachments </li></ul></ul>
  62. 73. Reduce Personal Risks <ul><li>M aintenance - keep tools well maintained </li></ul><ul><li>E xercise hands during work periods </li></ul><ul><li>A lways report any Hand-Arm symptoms </li></ul><ul><li>S moking - don't smoke, especially before using tools </li></ul><ul><li>U se the right tool for the job in the right way (ergonomics) </li></ul><ul><li>R eport faulty, ineffective or poorly maintained tools </li></ul><ul><li>E nsure you keep your hands as warm as possible </li></ul><ul><li>S hort breaks - multiple short breaks better than long ones </li></ul>
  63. 74. How do I protect myself? <ul><li>Use suitable low-vibration tools. </li></ul><ul><li>Right tool for each job (to do the job more quickly and less exposure to HAV). </li></ul><ul><li>Check tools before use to make sure they're properly maintained and repaired to avoid increased vibration caused by faults or general wear. </li></ul><ul><li>Make sure cutting tools are kept sharp so they remain efficient. </li></ul><ul><li>Reduce the amount of time you use a tool in one go, by doing other jobs in between. </li></ul><ul><li>Avoid gripping or forcing a tool or work piece more than necessary. </li></ul><ul><li>Store tools so that they do not have very cold handles when next used. </li></ul><ul><li>Encourage good blood circulation by: </li></ul><ul><ul><li>Keeping warm and dry (wear gloves, a hat, waterproofs and use heating pads if available); </li></ul></ul><ul><ul><li>Giving up or cutting out smoking because it reduces blood flow; and </li></ul></ul><ul><ul><li>Massaging and exercising your fingers during work breaks . </li></ul></ul>
  64. 75. HEALTH SURVEILLANCE-when <ul><li>Regular exposure above EAV of 2.5 m/s 2 A(8) , </li></ul><ul><li>(or cases of HAVS occurring below EAV), </li></ul><ul><li>Baseline ( pre-employment, pre-placement ), </li></ul><ul><li>First six months, </li></ul><ul><li>Annually thereafter. </li></ul><ul><li>(unless accelerated change) </li></ul>
  65. 76. Provide employees with information on: <ul><li>the health effects of HTV; </li></ul><ul><li>sources of HTV; </li></ul><ul><li>whether they are at risk, and if so whether the risk is high (above the ELV), medium (above the EAV) or low; </li></ul><ul><li>the risk factors (eg the levels of vibration, daily exposure duration, regularity of exposure over weeks, months and years); </li></ul><ul><li>how to recognise and report symptoms; </li></ul><ul><li>the need for health surveillance, how it can help them remain fit for work, how you plan to provide it, how you plan to use the results and the confidentiality of the results; </li></ul><ul><li>ways to minimise risk including: </li></ul><ul><ul><ul><li>changes to working practices to reduce vibration exposure; </li></ul></ul></ul><ul><ul><ul><li>correct selection, use and maintenance of equipment; </li></ul></ul></ul><ul><ul><ul><li>correct techniques for equipment use, how to reduce grip force etc; </li></ul></ul></ul><ul><ul><ul><li>maintenance of good blood circulation at work by keeping warm and massaging fingers and, if possible, cutting down on smoking. </li></ul></ul></ul><ul><li>You should consult your safety or employee representative on your proposals for training and information. </li></ul>
  66. 77. Why do health surveillance for HAVS? <ul><li>Detection of adverse health effects at an early stage, </li></ul><ul><li>Identifying and protecting individuals at increased risk, </li></ul><ul><li>Feedback on risk assessment, check effectiveness of control measures, </li></ul><ul><li>Prevent progression to disability. </li></ul>
  67. 78. Tiered Process <ul><li>Qualified person ( tiers 1,2 & 3), </li></ul><ul><li>Responsible person ( tier 2), </li></ul><ul><li>Doctor; usually OP ( tier 4), </li></ul><ul><li>Competency- FOM approved training course ( www.facoccmed.ac.uk) </li></ul>
  68. 79. Health surveillance (Tiered approach) <ul><li>Level 1 – Pre-placement Questionnaire/leaflet </li></ul><ul><li>Level 2 – Routine Annual Health Surveillance (Responsible person) </li></ul><ul><li>Level 3 – Assessment by Qualified Person </li></ul><ul><ul><li>(Grip strength, Purdue Pegboard, Monofilament) </li></ul></ul><ul><li>Level 4 – Diagnosis by Doctor (Fitness to work, RIDDOR, IIDB) </li></ul><ul><li>Level 5 – Standardised Testing </li></ul><ul><ul><li>Vascular: CPT, FSBP, </li></ul></ul><ul><ul><li>Neurological: Vibrotactile Threshold, Thermal Perception Threshold </li></ul></ul>
  69. 80. HAVS Components <ul><li>HAVS SN COMPONENT; numbness, tingling, loss of sensation, </li></ul><ul><li>VASCULAR; Vibration white finger, </li></ul><ul><li>MUSCULOSKELETAL;Pain,stiffness,arthritis,bone cysts, reduced grip strength. </li></ul>
  70. 81. Impairment due to HAVS <ul><li>White finger, numbness, tingling </li></ul><ul><li>Pain </li></ul><ul><li>Loss of tactile sensation in hands (clumsy) </li></ul><ul><li>Reduced manual dexterity </li></ul><ul><li>Reduced grip strength/cramps </li></ul><ul><li>Interference with function (ADL & ability to perform simple tasks) </li></ul>
  71. 85. Staging for Hand-arm Vibration Syndrome (Taylor-Pelmear System)
  72. 86. Stockholm (Revised) Hand-arm Vibration Syndrome Classification
  73. 88. Adapted Stockholm Scale (Lawson 2005) <ul><li>Splitting of Stage 2 </li></ul><ul><li>Vascular </li></ul><ul><ul><li>Early: </li></ul></ul><ul><ul><ul><li>Frequency of blanching< 3/week </li></ul></ul></ul><ul><ul><ul><li>Griffin score (5 – 9) </li></ul></ul></ul><ul><ul><li>Late: Frequency of blanching> 3/week </li></ul></ul><ul><li>Neurological </li></ul><ul><ul><ul><li>Early: Intermittent symptoms </li></ul></ul></ul><ul><ul><ul><li>Late : Persistent symptoms > 2 hours </li></ul></ul></ul><ul><ul><ul><li>Abnormal VTT, TPT, Abnormal Purdue </li></ul></ul></ul>
  74. 89. SWS Sensorineural modification Persistent = > 2 hours, Constant= all the time >6<9+ Intermittent numbness and/or tingling 2SN early >9<16+ late persistent numbness and/or tingling reduced sensory perception 2SN >19+ Constant numbness and/or tingling reduced sensory perception+ manipulative dexterity reduced in warmth 3SN >3<6 Intermittent numbness and/or tingling 1SN >3<6 Nil 0SN Sn Scores Symptoms Stage
  75. 90. SWS Vascular modification 18+ Frequent attacks all fingers most, digits all year 3 Occasional 3 or < /wk, Frequent > 3/wk Trophic changes 4 10-16 Frequent distal and, middle phalanges 2 V late 5-92 Occasional distal and, middle phalanges 2 V early 1-4 Fingertips only 1V 0 None 0 Griffin Score Vasospastic attacks Stage
  76. 91. Standardised Tests <ul><li>Used to assess degree of dysfunction </li></ul><ul><li>Sensorineural Tests: </li></ul><ul><ul><ul><li>Vibrotactile Threshold </li></ul></ul></ul><ul><ul><ul><li>Thermal Perception Threshold </li></ul></ul></ul><ul><ul><ul><li>(aesthesiometry), </li></ul></ul></ul><ul><li>Vascular Test: </li></ul><ul><ul><ul><li>FSBP – following cooling of the digits ( measures interruption of blood flow in response to cold) </li></ul></ul></ul><ul><ul><ul><li>Cold Provocation Test – provides visual evidence of blanching </li></ul></ul></ul>
  77. 92. Prognosis <ul><li>HAVS with solely sensory symptoms = 20%, Often more disabling. </li></ul><ul><li>Vascular symptoms may be reversible following removal from vibrating tools (n=113, 78% improved) </li></ul>
  78. 93. Whole Body Vibration
  79. 95. WBV- Who is at risk? <ul><li>Very little need for concern about WBV in road vehicles </li></ul><ul><li>Some concern for industrial trucks </li></ul><ul><ul><li>particularly if used on inappropriate surfaces </li></ul></ul><ul><li>Main concern in off-road machinery: </li></ul><ul><ul><li>agriculture, construction, quarrying, mining, forestry, small fast boats, etc. </li></ul></ul>
  80. 96. WBV <ul><li>9,000,000 exposed to WBV </li></ul><ul><ul><ul><li>Mostly road transport </li></ul></ul></ul><ul><ul><ul><li>Low risk, simple management measures </li></ul></ul></ul><ul><li>>1,300,000 above the EAV </li></ul><ul><ul><ul><li>Many still at low risk </li></ul></ul></ul><ul><li>>370,000 above 15 m/s VDV </li></ul><ul><ul><ul><li>see pie chart </li></ul></ul></ul><ul><li><1% exposed above the ELV </li></ul><ul><ul><ul><li>>20,000–Some activities in agriculture, mining, quarrying, construction, etc. </li></ul></ul></ul>
  81. 97. What we do not know <ul><li>We are not able to predict the probability of any disorder from the severity of an exposure to WBV. </li></ul><ul><li>We do not know whether there is any disorder specific to WBV, or what disorders are aggravated by exposure to WBV </li></ul><ul><li>We do not know the relative importance of vibration and other risk factors in the development of back disorders. </li></ul>
  82. 98. Control <ul><li>Driver </li></ul><ul><ul><li>Drive slowly and avoid rough ground </li></ul></ul><ul><ul><li>Provide training (seat and cab adjustment) </li></ul></ul><ul><li>Vehicle </li></ul><ul><ul><li>Right vehicle for the right job </li></ul></ul><ul><ul><li>Maintenance (tyre pressures, seats) </li></ul></ul><ul><li>Site </li></ul><ul><ul><li>Traffic management </li></ul></ul><ul><ul><li>Maintain surfaces </li></ul></ul>
  83. 99. Holistic approach to lower back pain <ul><li>Many issues with the nature of low back pain: </li></ul><ul><ul><li>High prevalence in the general population </li></ul></ul><ul><ul><li>Many causative and influencing factors </li></ul></ul><ul><ul><ul><li>Ergonomics </li></ul></ul></ul><ul><ul><ul><li>Manual handling </li></ul></ul></ul><ul><ul><ul><li>etc </li></ul></ul></ul><ul><ul><li>Symptoms not always synonymous with damage </li></ul></ul><ul><ul><li>No dose-response relationship </li></ul></ul>
  84. 100. Summary <ul><li>Start with a fit for purpose assessment of the risk. </li></ul><ul><ul><li>Simple risk assessment </li></ul></ul><ul><ul><li>Target high risk processes for control </li></ul></ul><ul><li>Refine risk assessment </li></ul><ul><li>Update and maintain control </li></ul><ul><li>Information, instruction and training </li></ul><ul><li>Health surveillance </li></ul><ul><li>HAVS is a preventable disease </li></ul>
  85. 101. Standards <ul><li>ISO 5349-1 (2001): Mechanical vibration – Measurement and evaluation of human exposure to HTV, Part 1 General requirements. </li></ul><ul><li>ISO 5349-2 (2001): Mechanical vibration – Measurement and evaluation of human exposure to HTV, Part 2 Practical guidance for measurement at the workplace. </li></ul><ul><li>ISO 8662-1 (1988): Hand-held portable power tools – Measurement of vibrations at the handle, Part 1 General, </li></ul><ul><li>ISO 8662-3 (1992): Hand-held portable power tools – Measurement of vibrations at the handle, Part 3 Rock drills and rotary hammers, </li></ul><ul><li>ISO 8662-4 (1994): Hand-held portable power tools – Measurement of vibrations at the handle, Part 4 Grinders, </li></ul><ul><li>ISO 8041 (1990): Human response to vibration – Measuring instrumentation. </li></ul><ul><li>ISO 8041 (1993): Technical Corrigendum, Human response to vibration – Measuring instrumentation. </li></ul>

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