What is Asbestos?
Asbestos is a naturally occurring mineral It differs from other minerals in its crystal development. The crystal formation of asbestos is in the form of long spindly fibres.
Asbestos is divided into 2 mineral
groups: Amphibole and Serpentine
The division between the two types of asbestos is based upon the crystalline structure. Serpentines have a
sheet or layered structure where amphiboles have a chain-like structure.
How is it formed?
The chief commercial variety is chrysotile. It has crystalline fibres composed of magnesium silicons hydrogen and
oxygen. As the only member of the serpentine coup, chrysolite is the most common type of asbestos found in buildings. Also known as 'white asbestos' chrysolite makes up approximately 90%-95% of all asbestos contained in buildings in the United States. Other varieties are amosite (brown asbestos), which is exceptionally long-fibred, and crocidolite (blue asbestos), which is valued for its strength.
Where is asbestos found?
Asbestos has been mined or quarried in various countries all over the world. One such mine was Wittenoom in Australia where thousands died as the result of mining this mineral.
Where do I look for it?
Over the years, asbestos has had many uses. Its primary use is as
an insulator or fire retardant, but can also be used as a binder. Due to
this versatility, asbestos can be found in many types of building
materials.
Even though the Federal Government of America placed a
moratorium on the production of most asbestos products in the early
1970's, installation of these products continued through the late 1970's
and even into the early 1980's
What can it do?
A natural mineral fibre that is either mined or quarried, asbestos
can be spun, woven, or felted, almost like cotton and wool. It has been
valued since ancient times for its resistance to fire. It is composed of
strands that are flexible and very strong. Airborne asbestos fibres
have been shown to cause cancer. Some manufacturers of asbestos
products have been sued by people who have been exposed in some
way to these fibres and later got cancer Asbestos can also cause a lung
disorder known as asbestosis. Only the longest asbestos fibres, called
spinning fibres, are made into threads and yarns. From them are woven
tough fabrics for making brake-band linings, clutch facings, gaskets,
wicks, fireproof theatre curtains, fire fighters' suits, gloves and
conveyor belts for hot materials. The shorter, or non spinning fibres,
are used for moulded brake linings, acid filters, soundproofing
materials, and paints. They are combined with magnesia for heat insulating
materials and are made into paper for covering pipes and
wires. The brittle, smooth-surfaced asbestos fibres are usually blended
with a rough-surfaced fibre, such as cotton, which may constitute 10 to
25 percent of the blend. At the mill the fibres are freed from rock by
hand sledges or by machines that crush, dry, re-crush, and screen the
rock. The fibres are then separated from the surrounding material and
graded. ln a natural state, asbestos fibres are tightly packed in veins
and pockets of rocks.
Why is asbestos a problem?
Asbestos tends to break down into a dust of microscopic size fibres, unless it is completely sealed into a product. A single fibre of asbestos magnified 1,000 times looks slightly larger than a strand of human hair. Because of their size and shape, these tiny fibres remain suspended in the air for long periods of time.
When inhaled or ingested, they can easily penetrate the body tissues. Because of their durability, these fibres can remain in the body for many years and can cause a number of different diseases.
Asbestos is made up of microscopic bundles of fibres that may become airborne when distributed. These fibres get into the air and may become inhaled into the lungs, where they may cause significant health problems. Researchers stall have not determined a 'safe level' of exposure but we know the greater and the longer the exposure, the greater the risk of contracting an asbestos related disease.
Back to Home Page |
