1. Asbestos: health effects and risk Peter Franklin Senior Scientific Officer Environmental Health Directorate

2. What is asbestos  Naturally occurring mineral that has crystallised to form long thin fibres and fibre bundles (silicate fibres) Two main types (6 specific materials) Amphibole – crocidolite (blue asbestos) amosite (brown) (tremolite, actinolite, anthophylite) Serpentine – chrysotile (white)  Used extensively because of its flexibility, tensile strength, insulation from heat and electricity, and chemical inertness

3. Why does it cause disease? Disease is caused by the inhalation of asbestos fibres  Fibre shape and size  Thin fibres that can penetration deep into the lung  Persistence in the lungs  Cant be broken down  Difficult to clear from the lungs

4. Asbestos-related Diseases (ARD) Diseases caused by asbestos exposure  Malignant (cancers)  Mesothelioma  Lung cancer  Other cancers (laryngeal, colo-rectal, ovarian)  Non-malignant  Asbestosis  Diffuse pleural thickening  Pleural plaques

5. Disease risk  Most ARD have been due to occupational exposure BUT is now as much a public as occupational health concern  Risk of disease increases with level of exposure  For mesothelioma (and other cancers?) there is no known ‘safe’ threshold  For other ARD (eg asbestosis) high levels of exposure are required (but a lot of uncertainty) Mesothelioma rate (per 100,000) Cumulative exposure (f/ml-yrs) Dose-response for asbestos exposure and disease

6. Non-occupational exposure scenarios  Around the home  Weathered/Broken asbestos containing material (ACM)  DIY Renovations  Pressure Cleaning  In the community (built environment)  Dumping  Contaminated Land  Fire damage buildings  Dodgy Demolitions  Other concerns  C&D Recycling  Mining Activities

7. Mesothelioma and non-occupational exposure Mesothelioma is a specific outcome of asbestos exposure There is no other known cause of mesothelioma WA Mesothelioma Registry Includes all mesotheliomas in WA (1960 – present) Assigns a primary route of exposure based on occupational and non-occupational history

8. Mesothelioma cases in WA: 1960 - 2014 * Still ~ 100 new cases per year

9. DIY and Mesothelioma 153 cases since 1981, BUT 152 cases were exposed before asbestos was banned Most recent exposure was in 1991 More renovations (↑ risk) Greater precaution (↓ risk) Occupational DIY

10. Non-occupational fibre levels  Background levels  <0.0001 f/mL (workplace standard 0.1 f/mL over 8hrs)  Near weathering ACM  0.0004 – 0.006 f/mL (decreases with distance from ACM)  In buildings  0.00059 (ACM in good condition)  0.00073 (with damaged ACM)  Renovation activities Hand sawing ACM sheet 1 – 4 f/mL Jigsaw 2 – 10 Circular saw10 – 20 Sanding vinyl tiles ~1 Removing pipe insulation 2 – 6 ACM removal ~1.5

11. Risk of developing Mesothelioma  Very rare cancer  Background rate: 1-2/1,000,000/yr  Background rate possibly due to either background or unknown exposures  Risk from (unprotected?) home renovation  Hard to determine - no idea of number of people exposed  (Very crude) estimate: 5-10X above background  Still very low (Witt miners ~2000/1,000,000pyr)  DIY exposures likely to be much > than other non-occupational exposures (  risk from other exposures is much lower)

12. Concluding remarks  Risk of ARD from non-occupational exposures is very low  Just because you are exposed to asbestos DOES NOT mean you will get an ARD BUT  there is no known safe threshold level of exposure  the consequences are very high  there is no way of determining who will develop an ARD Asbestos needs to be managed with extreme caution