The health effects of asbestos exposure.


Published on

The health effects of asbestos exposure.

Published in: Health & Medicine, Technology
1 Like
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide
  • Greek for indestructible
  • Chrysotile most commonly used
  • The above three photographs are examples of friable asbestos. Friable asbestos is was more widely used in industrial and commercial buildings.
  • Fibres are most likely to be released if the asbestos is mishandled. Example during home renovations or repairs where the material is drilled, cut or sawn and large amounts of dust is produced and then inhaled.
  • People who have suffered health effects from E to asbestos have generally worked in either the asbestos mining or milling industry, worked in industries involved in making or installing asbestos products or are from the immediate families of these people. In all of these situations there was E to high levels of airborne dust, either from the processes involved or from the clothes of the workers.
  • Miners at Wittenoom (crocidolite)
  • Asbestosis causes breathlessness, tightness in the chest, persistent coughing and skin may have a bluish tinge from lack of oxygen. Breathing becomes more difficult. It usually worsens overtime. May lead to respiratory failure and death.
  • South African miner
  • It is usually diagnosed when someone develops a persistent cough, weight loss and coughs up blood. If diagnosed early can be treated with surgery +/_ chemo, radiotherapy
  • 1945- 2000 0ver 6,000 cases in Australia. By 2020, expected to be 18,000 cases in total
  • Spreads to lung and chest wall May have pleural effusion
  • Rapid progression MM on x-ray
  • Unlikely that a brief asbestos exposure necessarily causes a substantial risk of mesothelioma. Use of crocidolite ceased in the late 1960's.  Later cement sheet products contained only chrysotile until its use ceased in the early to mid 1980's.
  • Asbestos-related disease causes 100,000 deaths each year in the world The greatest risks have been from past industry over long periods of time
  • The health effects of asbestos exposure.

    1. 1. The health effects of asbestos exposure   Dr Marion Carey Senior Medical Adviser Social and Environmental Health Dept of Human Services
    2. 2. What is asbestos?   <ul><li>A group of naturally occurring minerals whose characteristic feature is that they occur as fibres </li></ul><ul><li>Masses of tiny fibres form dust if disturbed </li></ul>
    3. 3. Most common types of asbestos used in Australia   <ul><li>Serpentine </li></ul><ul><ul><ul><li>Chrysotile (white asbestos) </li></ul></ul></ul><ul><li>Amphibole </li></ul><ul><ul><li>Amosite (brown asbestos) </li></ul></ul><ul><ul><li>Crocidolite (blue asbestos) </li></ul></ul>
    4. 4. Blue asbestos White asbestos Brown asbestos Photographs provided by Kilpatrick & Associates
    5. 5. Why was it used?   <ul><li>Asbestos was commonly used 1940-1980s for </li></ul><ul><ul><ul><ul><li>Durability </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Fire resistance </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Excellent insulating properties </li></ul></ul></ul></ul>
    6. 6. Where do you find it?   <ul><li>Over 3,000 uses of asbestos known </li></ul><ul><li>in majority of homes built before 1990 </li></ul><ul><li>asbestos-cement products </li></ul><ul><li>electrical, thermal & acoustic insulation </li></ul><ul><li>fire resistant insulation </li></ul>
    7. 7. Different forms of asbestos material have different levels of risk   <ul><li>Friable (nonbound) vs bound asbestos </li></ul><ul><li>Where asbestos fibres are stable and bonded in good condition, little risk </li></ul><ul><li>However when broken, damaged or mishandled, fibres become loose and airborne, creating hazard </li></ul>
    8. 8. Friable asbestos material unlikely to be found in homes in Victoria   <ul><li>a dry material which can be reduced to powder by hand pressure. </li></ul><ul><li>a health risk as it becomes airborne and more likely to be inhaled. </li></ul><ul><li>eg: insulation inside stoves & heaters </li></ul><ul><ul><li>industrial grade insulation in commercial buildings </li></ul></ul>
    9. 9. Non friable (bound) asbestos   <ul><li>AC sheeting (fibro) </li></ul><ul><li>flexible building boards </li></ul><ul><li>flue & water pipes </li></ul><ul><li>Vinyl floor tiles </li></ul><ul><li>Ceiling insulation </li></ul>
    10. 11. What are the health effects of exposure to asbestos?   <ul><li>Asbestos becomes a health hazard when fibres become airborne and are inhaled. </li></ul><ul><li>Effects depend on length, diameter and composition of fibre </li></ul><ul><li>Disease is usually associated with long-term exposure in occupational or para-occupational setting (immediate family or live near asbestos mine or factory) </li></ul><ul><li>Risk depends on how much and how long </li></ul>
    11. 14. Asbestos related diseases   <ul><li>All forms of asbestos can potentially cause: </li></ul><ul><li>Non cancer </li></ul><ul><ul><li>pleural plaques </li></ul></ul><ul><ul><li>asbestosis </li></ul></ul><ul><li>Cancer </li></ul><ul><ul><li>lung cancer </li></ul></ul><ul><ul><li>malignant mesothelioma </li></ul></ul>
    12. 17. Pleural plaques   <ul><li>Pleura: 2 layers of membrane line the chest wall & cover the lungs </li></ul><ul><li>asbestos may produce thickened patches </li></ul><ul><li>is not cancerous but can affect lung function </li></ul><ul><li>generally no symptoms </li></ul><ul><li>indicates significant previous exposure </li></ul><ul><li>Common in occupational E & sometimes where high environmental levels </li></ul>
    13. 19. Asbestosis   <ul><li>A chronic and progressive lung disease caused by inhaling asbestos fibres over a long period of time. </li></ul><ul><li>5- 20 years to develop </li></ul><ul><li>inflammation from fibres causes scarring (fibrosis) and stiffening of the lung. This causes less oxygen exchange </li></ul><ul><li>Symptoms – short of breath, cough, chest tightness </li></ul>
    14. 20. Asbestos
    15. 21. Lung cancer   <ul><li>usually takes 10 to 20 years to develop after asbestos exposure. </li></ul><ul><li>asbestos in non-smokers: 5x background rate </li></ul><ul><li>asbestos in smokers: 50x background rate </li></ul><ul><li>Symptoms: persistent cough, weight loss, cough up blood </li></ul>
    16. 23. Lung Cancer
    17. 24. Malignant mesothelioma   <ul><li>a cancer of the lining of the lung and chest cavity (pleural mesothelioma) (2/3) </li></ul><ul><li>or the lining of abdominal cavity (peritoneal mesothelioma) </li></ul><ul><li>can take 30 to 50 years to develop </li></ul><ul><li>particularly associated with crocidolite </li></ul><ul><li>Australia has world’s highest incidence </li></ul>
    18. 25. Malignant mesothelioma   <ul><li>Rapidly fatal : 75% dead 1 year after diagnosis </li></ul><ul><li>Smoking has no apparent effect on risk </li></ul><ul><li>Symptoms: short of breath, chest pain, weight loss </li></ul><ul><li>Has occurred in people without direct occupational exposure but exposed to large quantities of dust </li></ul>
    19. 28. Exposure to asbestos fibres in air   <ul><li>Small quantities are present in air breathed by most people without developing asbestos-related disease </li></ul><ul><li>People who have developed disease from asbestos were exposed to workplace air levels around 5 fibres/ml </li></ul><ul><li>Measured E in public buildings, schools </li></ul><ul><li>0.0001- 0.0005 fibres/ml. </li></ul><ul><li>Life-time E at this level < 1 in 100,000 life-time cancer risk. </li></ul>
    20. 29. What is the risk from a one off exposure?   The risk has not been quantified, but except for intense exposures, the risk caused by brief exposure is likely to be undetectably low. .
    21. 30. What is a safe level of exposure to asbestos?   <ul><li>The level of exposure that may cause health effects is not known. </li></ul><ul><li>It is therefore important to keep exposure to asbestos fibres as low as possible and precautions must always be taken. </li></ul>
    22. 31. Conclusion   <ul><li>The major route of exposure to asbestos is inhalation </li></ul><ul><li>There is no known “safe” level of exposure </li></ul><ul><li>Tightly bound asbestos poses no immediate hazard </li></ul><ul><li>Asbestos becomes a health hazard when fibres become airborne </li></ul><ul><li>Exposure should be minimised by sensible precautions </li></ul>