1 / 20

Occupational vibration syndrome

Occupational vibration syndrome. Department of Occupational Medicine Finnish Institute of Occupational Health. Markku Sainio Markku Vanhanen. Definitions. Vibration Hand-arm vibration (HAV) Whole-body vibration (WBV) Vibration white finger (VWF) Hand-arm vibration syndrome (HAVS)

dunne
Download Presentation

Occupational vibration syndrome

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Occupational vibration syndrome Department of Occupational Medicine Finnish Institute of Occupational Health Markku Sainio Markku Vanhanen

  2. Definitions • Vibration • Hand-arm vibration (HAV) • Whole-body vibration (WBV) • Vibration white finger (VWF) • Hand-arm vibration syndrome (HAVS) • Raynaud's phenomenon • Electroneuromyograpy (ENMG)

  3. Vibration • Periodic motion of a body in alternate opposite directions from a position of rest • Mathematical "vector quantity"= described by both a direction and a magnitude • directions of vibration • acceleration • Present in most work settings where mechanical equipment is used

  4. Measurements and standards • ACGIH TLVs 1984 • 4 m/s2 < 8 hours a day • 6 m/s2 < 6 hours a day • 8 m/s2 < 2 hours a day • 12 m/s2 < 1 hour a day • ISO 5349 (1986) • Standard for measurements over frequencies from 5 to 1500 Hz • Mitä laatua käytetään, millaiset tasot aih tautia, impact vibration (high impulsiveness) important!

  5. Dose-response curves and threshold limits • are not applicable to all tools • are derived from chain-saw data • do not take into account impulsiveness and high frequency of many tools

  6. Directive 2002/44/EC… .. on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents (vibration)... • daily (8 h) exp. limit value 5 m/s2 • daily exp. action limit value 2,5 m/s2

  7. HAV as occupational disease in Finland 1990-2001 RODFIOH • 2001-4/2002 10 • 1999-2000 32 16 • 1997-98 38 17 • 1995-96 37 7 • 1993-94 44 18 • 1990-92 (3 yrs) 92 37

  8. Chain saw work 22 Construction worker 15 Miners+ drillers 15 Machine work,-repair, tool makers 9 Welders 5 Pipework 4 Railroad or road work 3 Stonework 3 1-2 : dental technician, teacher, painter, manufacture of diff. devices, plastics worker etc. Occupations (FIOH 1990-2001)

  9. Exposure • Vibration level, acceleration, frequency, angles, impulses • Duration, continuity, radiation of the vibration (tool weight, grip strength, hand position, exposure area) • Smoking increases VWF prevalence, if > 20 cigarettes/d > 20 years • Temperature

  10. Hand-arm vibration syndrome (HAVS) • Disease entity with separate components, all of which may not be recognized at the same time: • Circulatory disturbances • secondary Raynaud: vasospasm with local finger blanching • Sensory and secondary motor disturbances • local polyneuropathy: numbness, clumsiness • Musculoskeletal disturbances (?) • HAVS may lead to severe disease causing permanent working disability

  11. Hand-arm vibration syndrome (HAVS) • White finger symptoms are essential • however, not always present • Dose-related (quantity and quality of exposure) • May be reversible, but usually irreversible and progressive if exposure continues • Smoking and cold exposure predisposing risk factors • Individual differences in susceptibility (other causes of Raynaud???)

  12. Symptoms • Cold/damp (sometimes vibration) induced white fingers • However, also peripheral sensory reduction and slight clumsiness without white fingers • More proximal bone and joint symptoms occur occasionally (may be due to ergonomic factors) • Carpal tunnel syndrome and epicondylitis coexist often

  13. PATOPHYSIOLOGY • Local oedema in nerve and perineural tissue • Local damage in non-myelinated nerve fibers  changes in blood vessels vasoconstriction in cold • mechanism: adrenergic reseptor damage in vessel wallsalfa-2-reseptor predominance

  14. Objective findings • Vibration detection levels increase (damaged thick myelin fibers) • Temperature detection levels increase (damaged thin myelin fibers) • Two-point differentiation ability reduced • Grip strength reduced • Finger pletysmography: blood pressure of the affected finger drops in cold exposure • ENMG: sensory conduction velocities reduced before motor velocities

  15. Diagnosis I • Exposure sufficient • Exp. in Occupational med+neurology+fysiatry • Clinical status: Sensory testing, grip strength, fine motor testing • Finger pletysmography (sensitive, not all mild cases detected, replicability ok) • Lab: La, CRP, PVK, tromb, CDT, GT, TSH, kryoglobulins, RF, nucleus-ab, B-gluc, Pt-Gluc-R1, S-B12-vit, fE-folaat

  16. Diagnosis II • ENMG, possible carpal tunnel syndrome and excludes other PNS disease • Vibration and cold/hot perception threshold • Neurologist: PNP exclusion • Fysiatrist: exclusion of TOS or over extremity/cervical disease • Angiography not rutinely used

  17. VWF ”clinical problems" • No white finger findings, only sensory findings • White finger findings, but also • generalized polyneuropathy • cervical radiculopathy • blood vessel changes mimicing vasculitis • Primary Raynaud´s disease in the history or symptoms/findings suggesting it (prevalence 5-6% in males) • Occupational rehabilitation is often difficult (progressed HAVS or wide accompanied musculoskeletal symptoms)

  18. Whole body vibration • May increase the rsik of low back pain, disc protrusion and joint arthritis • May increase the risk of spontaneous abortions and premature births • Difficult to diagnose at indivudual level • Directive 2002/44/EC • 8 hour limit 1,15 m/s2 • 8 hour action limit 0,5 m/s2

  19. Treatment and prevention • Calcium antagonists may help • Carpal tunnel operation may help, but may also worsen symptoms • Stop smoking, reduce risk factors of polyneuropathy • Stop or decrease exposure to minimum • technical improvements of tools • minimum exposure time • gloves etc. • Increase temperature • Periodic health examinations

  20. Literature • Hannu Vironkannas: ”Peripheral vascular and nerve disorders in workers exposed to hand-arm vibration with special reference to snowmobile drivers”, 1992. (Thesis) • Pelmear PL, Leong D. Review of occupational standards and guidelines for hand-arm (segmental) vibration syndrome (HAVS). Applied Occupational and Environmental Hygiene. Vol 15(3):291-302, 2000.

More Related