Asbestos
When is Asbestos a hazard?
- When it is "friable" (crumbles under finger pressure) --> When it is disturbed, when it is located in areas that may be disturbed by children, Prior to demolition/renovation projects
What is a "Pneumoconiosis"?
- a diffuse, interstitial, non-malignant scarring of the lungs
Lung cancer
- a neoplasm of the lungs, asbestos typically causes a BRONCHOGENIC CARCINOMA
How are we exposed to asbestos and associated diseases?
- air - water - soil - food - occupational
What to do with Asbestos?
- leave it alone - repair - encapsulate - enclose - remove
What are some examples of how asbestos is used?
- shingles - Thermal System Insulation - Brake/Clutch Lining - Water Pipes - Siding - Cement Filler - Wire Insulation - Spray-on Acoustical Material - Vinyl Flooring
What is CEMESTOS?
- used in the Manhattan Project - Strong asbestos material substance
What concerns do we have with Asbestos "unique hazard"?
- we have concerns about the FIBROUS nature and the ASPECT RATIO (length to width) that adds to the hazard
Why are Amphiboles the main concern with asbestos?
-Because their chemical structure and straight, needlelike fibers make them VERY DUSTY and highly BIOPERSISTENT
Types of asbestos: AMOSITE
-Brown asbestos - second most common - Fe Mg SiO3
Additional rare types of asbestos:
-Tremolite -Actinolite -Anthophyllite
The properties of asbestos made it an excellent material for uses ranging from...
-brake linings in cars and aircraft to pipes for water and sewer systems
What are the four characteristics that make up Asbestos?
-naturally occurring -fibrous -hydrated -mineral silicates
Asbestosis
-not cancer - a PNEUMOCONIOSIS (a diffuse, interstitial, non-malignant scarring of the lungs) - often goes unnoticed - typically diagnosed via x-rays -*typically occurs from very high exposures over many years
In a natural state, asbestos occurs where?
-occurs throughout much of the planet -It is found in 2/3rds of the rocks in the earth's crust
What are the TWO categories of Asbestos?
1) Fibrous SERPENTINE Chrysotile (white asbestos) 2) Fibrous AMPHIBOLES (make-up of five)
What are the 5 diseases associated with asbestos?
1. lung cancer 2. stomach cancer 3. Asbestosis 4. Mesothelioma 5. Colon-Rectal Cancer *Asbestosis is not a cancer, it is a disease
What is Asbestos?
Asbestos is a group of SIX (1 serpentine, 5 amphiboles) -naturally occurring -fibrous -hydrated -mineral silicates
Mesothelioma
*Mesothelioma is CANCER OF THE PLEURAL OR PERITONEAL LINING - most dangerous
Types of Asbestos: CROCIDOLITE:
- "Blue asbestos" -3rd most common, but RARE -Most dangerous, by far the most toxic - Na Fe [SiO3] 2H3O
Types of asbestos: CHRYSOTILE:
- "white asbestos" -by far, the most common - 3Mg O - Si O2 - 2H2O
Once Amphibole fibers enter the human body they....
- ... can remain indefinitely in the lung tissue
stomach cancer
- 2nd MOST COMMON CANCER --> 30,000 cases/yr. - 17,000 deaths
Up until the 1970's. how many products were made with asbestos fibers of ALL types?
- 3,000 products
Amphiboles: What amphibole fibers used commercially are extremely hazardous and why?
- Amosite - Crocidolite --> Because of their chemical structure and their straight, needlelike fibers, amphiboles very dusy as well as highly bio-persistent
Asbestos use in 2002: 99% of the world's current asbestos production is:
- Chrysotile -"today, asbestos means chrysotile"
Physical properties of asbestos:
- Fire resistance - Spinnability - Tensile strength
What are some of the desirable characteristics of Asbestos?
- Strong and durable: resists fungus growth, corrosion, heat, acids and vermin - Insulates against heat, vibration, electricity and sound. -Fibrous form helps bind fillers, rubber, asphalt, and cement. - fibers can be molded with plastics or glass, and dispersed in fluids, greases, adhesives, and sealing compounds
Asbestosis typically occurs from what?
very high exposures over many years
Today some______ countries still use asbestos, but_________
1) sixty 2)only the chrysotile variety are primarily in cement building materials such as roofing materials, cladding and pipe
What are the five groups of asbestos under FIBROUS AMPHIBOLES?
1. Amosite (brown asbestos) 2. Tremolite 3. Anthophyllite 4. Actinolite 5. Crocidolite (blue asbestos)
What are the symptoms of ASBESTOSIS?
1. Dyspnea (undue shortness of breath) 2. Rales - crackling sounds heard when heart is listened to vis stethoscope 3. Distinctive x-rays 4. finger clubbing 5. Long latency period (20-40 years)
What is the most dangerous cancer associated with asbestos?
Mesothelioma
What can cause "FINGER-CLUBBING"?
asbestos and other pneumoconiosis
