increasing awareness: asbestos ancient history, characteristics, types, uses, health effects
TRANSCRIPT
Increasing Awareness: Asbestos Ancient History, Characteristics, Types, Uses, Health Effects
Asbestos Definition
The word asbestos derives from a Greek word meaning “inextinguishable”
Asbestos definition
Either of two incombustible, chemical-resistant, fibrous mineral forms of impure magnesium silicate, used for fireproofing, electrical insulation, building materials, brake linings, and chemical filters.
What is Asbestos?
Natural Mineral (Rock)
Brief History
First known use: 2,500 B.C. pottery and hut insulation Greeks spun and used in cloth Used for wicks in sacred lamps Pottery
Diseases in the 1950s-1960s 1971 Asbestos listed as a hazardous air
pollutant
Characteristics
Aerodynamic
Aerodynamic
Characteristics
Aerodynamic Chemically Resistant Hydrophobic Heat resistive (1250-2000 deg. F) Flexible with High Tensile Strength
Aerodynamic Chemically Resistant Hydrophobic Heat resistive (1250-2000 deg. F) Flexible with High Tensile Strength
Characteristics continued
Size Fibers (1-5 microns, human hair is 80) Fibers>Fibrils>microfibrils
Asbestos Types
Chrysotile (white) >95% of all asbestos (white) Hair-like
Asbestos Types
Amosite (Brown) 5 % of all asbestos Needle Like
Asbestos Types
Crocidolite (blue) <1 %
Asbestos Types
Chrysotile >95% of all asbestos (white)
Amosite <5% of all asbestos (brown)
Crocidolite (blue) <1 Tremolite Anthophyllite Actinolite
Asbestos Types
Tremolite, Anthophyllite, Actinolite Little commercial value Usually a contaminant of other
asbestos or material type
Vermiculite?
Why Use Asbestos?
Heat resistive (1250-2000 deg. F) Chemically resistive Great acoustical reduction
properties Good elastic/tensile strength
properties Poor conductor of electricity Great binder
Asbestos Containing Materials
Acoustical Materials Fire proofing Heat resistive materials Ceiling and floor tile Sheet rock mud Plaster Insulation
Materials cont.
Decorative spray for texture Roof shingles, siding shingles,
sheets, etc. Mastics, glues Welding booth panels and soffits Window glazing Some paints
Health Effects
Caused by Inhalation (most likely) Ingestion Injection
Asbestos Diseases
Asbestosis (lung scarring) Lung cancer Mesothelioma (cancer of membrane
lining lungs) Pleural plaques, pleural thickening Colon, stomach, esophagus,
pancreas cancers
Respiratory Systems Defense Mechanisms
Nose, Mouth, Trachea, Bronchus, Bronchioles
Turbulent airflow Smaller pathways
Mucous Sticky layer, catches some particles
Respiratory Systems Defense Mechanisms (Continued)
Cilia Hair-like Coated with mucous and move
particles back up through bronchus Alveoli (air sacs)
O2/CO2 exchange Macrophage Cells
Macrophage Cell
Smoking/Asbestos Relationship
Asbestos-Smoking-Lung Cancer
Asbestos exposure=5X greater chance lung cancer
Smoking no asbestos exposure=10X greater chance lung cancer
Asbestos exposure of Smoker=50X greater chance of lung cancer. Newest figures now say 88X greater chance
“King of Cool” - Steve McQueen
Died of Mesothelioma in 1980 at the Age of 50
Exposed to Asbestos from Work/Hobbies Brake Pads on Cars Construction Work Ship Work
What Level of Exposure is Safe or Permissible????????
0.1 fibers per cc of air 5 f/cc, 1 f/cc, 0.1 f/cc in last 10
years
Asbestos Health Benefits
Crowds gather at Market and Laguna streets to flee the Great Fire. Building at lower center right still survives along Laguna. Almost all others pictured here burned.
Crowds gather at Market and Laguna streets to flee the Great Fire. Building at lower center right still survives along Laguna. Almost all others pictured here burned.
The 1906 San Francisco Great Fire as seen from a ferry boat in the Bay.
Closing Thought. Keep Health Effects in Perspective
Expected deaths per 100,000 Motor vehicle 1,600 Coal mining 441 Diagnostic X rays 75 Lightning 3 Hurricanes 3 Asbestos in buildings 1
Acknowledgement
Created by Larry Hagel, Industrial Hygienist, Kyron Environmental Consulting and Training
Formerly with Spokane Public Schools and a member of AASA’s Urban Healthy Schools Coalition
Email [email protected] AASA is dedicated to healthy school
environments, visit http://www.aasa.org/focus/