2006-05-02-世界卫生组织-Asbestos_-_hazards_and_safe_practice_for_clear-up_after_tsunami_4页_347kb

Asbestos Hazards and Safe Practices for Post-Tsunami Clear-Up

1. Asbestos Definition & Properties

• Naturally occurring minerals with strong tensile strength, poor heat conductivity, and chemical resistance.
• Fibers are non-biodegradable (IARC Group 1 human carcinogen).
• Principal types include chrysotile (most common now), crocidolite, amosite, and others (amphiboles).

2. Health Risks

• Long Latency: Diseases develop 10-50 years post-exposure.
• Key Conditions:
  • Asbestosis: Lungs scar, reducing elasticity and gas exchange.
  • Lung Cancer: Risk higher with smoking and occupational exposure.
  • Pleural Thickening: Scarring of lung lining (non-cancerous).
  • Mesothelioma: Malignant tumor of pleura/peritoneum.

3. Safe Exposure Levels

• No safe exposure threshold exists; risk increases with exposure.
• Occupational Limits: Vary by region (e.g., OSHA sets 0.1 fibers/ml 8-hour TWA).
• Indoor Actions: Wet methods recommended to minimize airborne fibers during manipulation.

4. Activities Releasing Asbestos Fibers

• Common sources: Friable insulation, asbestos cement, sawing/drilling/crushing friable materials.
• Fibers can remain airborne for long periods; small fibers travel far.

5. Post-Tsunami Risk & Mitigation

• Hazards: Volunteers/residents may disturb asbestos-containing debris.
• Minimization Strategies:
  • Identify materials and assess risk.
  • Protect workers (PPE, training, washing facilities).
  • Minimize disturbance: Wet debris, cover piles, limit access.
  • Avoid burning/disposal near future construction sites.

6. Emergency Response & Reference

• WHO/EPA guidance on asbestos health/exposure, disposal.
• Ensured presence in non-occupational settings, e.g., household exposure or proximity to emission sources.

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