Asbestos has been used in lamp wicks and candles since 4000 BC. It's amazing fact that it was also used in the shrouds of Egyptian mummies. Perhaps this is the real origin of "The Curse of The Mummy" stories. Asbestos clothing was extremely expensive in ancient times to wrap the bodies of Kings, in order to keep their ashes pure during cremation, and it is said the Romans merely threw their asbestos napkins into a fire to cleanse and purify them.
Large natural deposits of asbestos discovered in Canada, Australia and Africa. The fibers, from which this mineral consists of, can be 700 times thinner than human's hair. Their small size lets them stay suspended in the air for quite long time. Asbestos is very staunch material: resistant to chemicals, flame-retardant, insoluble, it does not evaporate into air and does not break down over time. Due to these properties asbestos has been widely used in construction and in production of insulation materials. Greeks called asbestos the miracle mineral', the word 'asbestos' comes from the Greek word meaning 'indestructible'.
This mineral is called 'Fibre of Death' due to its carcinogenic properties. Its threat to health was recognized in 1898, and first laws were adopted in England in 1931.
The term "Asbestos" is common for a fibrous variety of six naturally occurring minerals that have been recently used extensively in numerous branches of industry. Actually, "asbestos" is a commercial name given to a group of minerals with special features, such as flexibility, high tensile strength, electrical resistance and resistance to chemical and thermal degradation. These minerals have been used in producing of different products, among them building materials, fire- and bulletproof materials, brake pads and shoes, textile products and many more.
One of asbestos's features is to divide into tiny size particles that could get in the lungs of a person with the air. There are some professions concerned with long-term use of asbestos. They can cause dangerous diseases, including lung cancer. In spite of recent recession in use of asbestos products, they are still being used in many residential and commercial projects and pose threat to health of all people around.
Tremolite, Anthophyllite and Actinolite are asbestos containing formations, which still being used in production of building materials, such as talcum powders and vermiculite.
White asbestos - Chrysotile, CAS No. 12001-29-5, Mg3(Si2O5)(OH)4, is referred to serpentine group of minerals. This type of minerals was widely adopted in United States industry. Inhalation of chrysotile has been shown to be less harmful than inhalation of other forms of asbestos. According to UK Health & Safety Commission report (Asbestos: Effects on health of exposure to asbestos, 1985) it's the least dangerous type of all asbestos types.
Brown asbestos - a mineral, named Amosite (acronym from "Asbestos Mines of South Africa"), CAS No. 12172-73-5, Fe7Si8O22(OH)2. This is amphibole, scientifically is known as Grunerite.
Blue asbestos - Riebeckite, CAS No. 12001-28-4, Na2Fe2+3Fe3+2Si8O22(OH)2, is the mineral of the amphibole group, it is found in Africa and Australia. Crocodolite is asbestiform type of this mineral, it is supposed to be the most dangerous type of asbestos.
There are some more asbestos minerals, which industrial use is not significant. Among them actinolite asbestos (or smaragdite), CAS No. 77536-66-4, Ca2(Mg, Fe)5Si8O22(OH)2, anthophyllite asbestos, CAS No. 77536-67-5, (Mg, Fe)7Si8O22(OH)2, tremolite asbestos, CAS No. 77536-68-6, Ca2Mg5Si8O22(OH)2 can be named. They still used in producing of building and insulation materials. The types of consumer products that can hold small quantities of asbestos are named in Asbestos Ban and Phase Out Rule, which was adopted in 1989 by Environmental Protection Agency (EPA), United States, and was overturned two years later.
Industrial exploitation of asbestos deposits started in the late 1800s in North America along with commercial use of the mineral, and rose significantly during World War II. Since then an application for it have been found in many industries, such as automotive industry, building and construction. Asbestos is used or has been used in more than 5,000 products:
- Asbestos cement sheet and pipe products used for water supply and sewage piping, roofing and siding, casings for electrical wires, fire protection material, electrical switchboards and components, and residential and industrial building materials;
- Friction products, such as clutch facings, brake linings for automobiles, gaskets, and industrial friction materials;
- Products containing asbestos paper, such as table pads and heat-protective mats, heat and electrical wire insulation, industrial filters for beverages, and underlying material for sheet flooring;
- Asbestos textile products, such as packing components, roofing materials, and heat- and fire-resistant fabrics (including blankets and curtains);
- Other products, including ceiling and floor tile; gaskets and packings; paints, coatings, and adhesives; caulking and patching tape; artificial ashes and embers for use in gas-fired fireplaces; plastics; vermiculite-containing consumer garden products; and some talc-containing crayons.
The possibility of lung cancer development can be greatly increased by smoking along with asbestos exposure.
Asbestos-containing materials were used in construction of many buildings, especially in systems of sound and thermal isolation. Sometimes technical ducts, false ceilings and other places of difficult firemen access were "stuffed" with asbestos. In the U.S. so called "popcorn ceiling", the type of acoustic ceiling that contained asbestos, have been used in apartments construction till 1986, although production of this type of materials was banned in 1978. It can be explained by the fact that the producers received permission to sell the remains of these materials. So now laboratory test is the only way to check the presence of harmful material in your house.
Although asbestos is hazardous to person's health, its thread can be reduced by special ways of application, because if its fibers cannot be inhaled, they pose no risk.
However, sometimes it's impossible to avoid asbestos fibers dislodging, for example during flocking or drilling, so maintenance personnel is in great danger while doing their job. It makes the removal of asbestos from a building quite complex. It requires temporary relocation of all users of the building. Besides of it, it's necessary to isolate the part of building from which asbestos is being removed in order to prevent the spreading of the fibers.
If the building is closed to normal users, it may be necessary to seal it off from outside atmosphere so that no accessible air is contaminated. Examples of asbestos removal enterprises include the Jussieu Campus (begun circa 1996 and still going on as of 2005) and the Tour Montparnasse (in 2005, projected duration was 3 years if the tower was emptied of its users, and 10 years if it was not).
