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Tööga seotud kopsuhaigusedTartu, 8.-9. oktoober
2003

• ASBEST JA ASBESTOOS
• Panu Oksa
• Soome Töötervishoiu Instituut
• Tampere, Soome

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What is asbestos?

• asbestos is the name of a group of different
  naturally occurring minerals
• asbestos is fibrous silicate. Fibers are very
  strong and resistent to heat and chemicals
• serpentines chrysotile (white asbestos)
• amphiboles crocidolite (blue), amosite (brown),
  anthophyllite, tremolite, actinolite.

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Asbestos materials

• spray coating of steel work, concrete walls and
  ceiling for fire protection and insulation
• insulation lagging in buildings, on pipework, for
  boilers and ducts
• asbestos cement products walls, roofs, tiles
• asbestos used also in bitumen, paints, plastic,
  resin, rubber products

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ACM, serpetine and amphiboles

• any material containing more than 1 asbestos is
  called "asbestos-containing material" (ACM)
• all asbestos types are equally dangerous and
  confirmed human carcinogens
• in organism only chrysotile breaks into shorter
  fibers, all amphiboles split to thinner fibers

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Effects of asbestos exposure

• pleural plaques (pleura parietale)
• pleuritis
• fibrosis of visceral pleura
• asbestosis
• lung cancer and mesothelioma
• retroperitoneal fibrosis

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Pleural plaques

• benign hyaline plaques of parietal pleura
• latency time 20-40 years
• no effect on respiration
• already little exposure is enough, even purely
  environmental exposure
• high prevalence in Finland
• differential diagnosis subpleural fat, muscular
  insertions, technical fault and tumors

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Asbestosis

• diffuse fibrosis of lungs caused by asbestos
  dust. HRCT is most sensitive in showing it.
• moderate or heavy exposure is needed
• average latency period is 20-30 years
• symptoms shortness of breath and cough
• lung functions restriction and lowered diffusing
  capacity

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Fibrosis of visceral pleura

• not so specific to asbestos exposure
• acute pleuritis or pleural effusion precedes the
  pelural fibrosis, latency can be even under 10
  years
• typical complications are adhesions and rounded
  atelectasis
• differential diagnosis other pleurites

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WORK HISTORYMowe et al 1985, Tuomi et al 1991,
Zitting et al 1996,Wilkinson et al 1995, Pairon
et al 1994, Sakai et al 1994)

• Definite exposure Manufacture of asbestos
  products, asbestos spraying, insulation,
  demolition of old buildings
• Probable exposure Construction, shipbuilding,
  heating trades, pipefitting, sheet metal work
• Possible exposure Transport, railways, ship
  engine crew, firefighting, mining and quarrying,
  oil refining, chemical, paper and metal
  industries, car repair, general maintenance jobs
• Unlikely exposure Office work, agriculture and
  forestry, health care and education,
  telecommunication, textile industry

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Work history

• life long cumulative work history
• exposure to asebstos asked about for all work
  tasks
• quantification of cumulative asbestos exposure as
  none, slight, moderate, heavy
• fiber years exposure time (years) x exposure
  level (fibers/cm3)

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HELSINKI CRITERIA 1997ERS TASK FORCE 1998 1/2

• For clinical purposes, the following guidelines
  are recommended for identifying people who have
  highly probably been exposed to asbestos dust at
  work
• - over 0.1 million amphibole fibers (gt5 ?m)/g
  dry lung tissue or
• over 1 million asbestos fibers (gt1 ?m)/g dry
  lung tissue or
• over 1000 asbestos bodies/g dry tissue (100
  asbestos bodies/g wet tissue) or
• over 1 asbestos body/ml in bronchoalveolar
  lavage fluid

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HELSINKI CRITERIA 1997ERS TASK FORCE 1998 2/2

• An increased risk of mesothelioma and pleural
  plaques may occur below, at or above (1/2) the
  mentioned concentrations.
• A twofold risk of lung cancer is related to
  retained fiber levels of 2 million amphibole
  fibers (gt5 ?m)/g dry lung tissue or 5 million
  asbestos fibers (gt1 ?m)/g dry lung tissue.

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Diagnosing asbestos disease

• anamnesis (work history, smoking, resp. symptoms,
  lung diseases, thoracic traumas)
• status, auscultation of lungs
• thorax X-ray, high resolution computed
  tomography, HRCT
• spirometer, diffusion capacity
• differential dg (bronchoscopia, lavage, etc.)

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Guidance of patient

• STOP SMOKING!
• guidance of disease diagnosed (prognosis etc.)
• advisory opinion and statement of occupational
  disease, if needed
• follow-up

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Former asbestos workers in Finland (2003)

• 50 - 60 000 (moderate or heavy exposure)
• about 9 000 of them have an asbestos disease
• 7 000 plaques, 2 000 asbestosis
• average age about 70 years
• in 2001 the average age of new asbestos patients
  was 64 years

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EU legislation

• Directive 83/477/EEC on the protection of workers
  from the risk related to exposure to asbestos at
  work
• updated and amended by Directives 91/382/EEC and
  98/24/EC.
• The ban on the marketing and use of chrysotile
  asbestos introduced by Council Directive
  76/769/EEC, as amended in 1999 by Commission
  Directive 99/77/EC in effect on 1 January 2005,
  will lead to a substantial reduction in asbestos
  exposure among workers.
• SEE http//europa.eu.int/eur-lex