Lecture on Asbestos

Introduction

• Trace from DNews conducting the lecture.
• Discussion on asbestos, a hazardous material in old homes/buildings.
• Commercial use in North America for over a century.
• In 2016, the EPA evaluated it as a high priority risk, potentially banning it.

What is Asbestos?

• Originally identified in ancient Greece, 300 BCE.
• Looks like rotten wood, resistant to fire.
• Not man-made or chemical; it's a group of six naturally occurring silicate minerals.
• Found in rock and soil, in 900 regions across the US.
• Properties:
  • Stronger than steel and fire-resistant.
  • Does not biodegrade, decompose, dissolve in water, or evaporate.

Types of Asbestos

• Amesite: Brown asbestos.
• Chrysitilite: Blue asbestos.
• Chrysatil: White asbestos.
• Other types: Actinolite, Anthropolite, Tremolite.
• White asbestos is softer, more flexible, used in 95% of asbestos products.

Uses of Asbestos

• Heat-resistant fabrics, paints, plastics, paper products.
• Car brakes and clutches.
• Building materials such as roofing, siding, flooring, and insulation.

Health Risks

• Airborne Asbestos: When crumbled, asbestos becomes thin threads.
• Risks of inhaling/swallowing these threads, especially for construction workers.
• No immediate symptoms like coughing or sneezing.
• Invisible, odorless, tasteless.
• Protective Equipment: Essential for those working with asbestos.

Health Effects

• According to OSHA:
  • Hazard for 1.3 million US construction workers.
• EPA: Asbestos is a known carcinogen.
• Health issues include:
  • Lung cancer.
  • Mesothelioma: Cancer in lung lining.
  • Asbestosis: Long-term lung disease.
• Statistics:
  • 200,000 asbestosis cases annually in the US.
  • Over 6,000 deaths from related diseases.

Regulation and Bans

• Regulated since the 1970s in the US.
  • Checks in drinking water, schools, consumer products, workplace air.
• Some uses banned: Certain paper and spray-on materials.
• Potential for a complete ban by the EPA.

Conclusion

• Asbestos: A naturally occurring material used throughout history, with fatal consequences.
• Importance of regulation and awareness to manage the risks.
• Highlights misconception of natural = safe.
• Encouragement for further scientific inquiries and understanding.