October 21, 2011

Asbestos types

Most people do not know that asbestos is a natural substance. They assume it to be a substance made by man for commercial purposes. Asbestos is a fibrous mineral found in nature and mined by man to use for various purposes. The wonder of this mineral is that it is fire resistant, chemical resistant, highly strong, and completely flexible and has very low electrical conductivity. Due to the above reasons, asbestos is used for a variety of purposes in various industries. Some of them are:
  • Asbestos is widely used in the construction industry because of its fireproof quality.
  • Asbestos can be easily woven into cloth and is thus used to make fire poof clothing.
  • Asbestos is used to make gaskets and pipes.
  • It is used in the shipbuilding industry.
  • This popular substance was first used in 1828, in steam engines, as a lining material.
  • For many years, it was used to make floorings, brake linings and clutch facings in automobiles.
  • It is shocking to note that asbestos was used in making toothpaste and surgical incision thread too.
Broad classification of asbestos
There are two broad categories into which all Asbestos types can be classified. They are as follows:

Serpentine group:

This type of asbestos has a layered form and the fibers are curly. This is why it is called as 'serpentine'. This group has just one member, called chrysolite. Basically, This is the most common type of asbestos.Amphibole group This is considered to be the most hazardous type of asbestos. It has straight fibers. Unlike the serpentine group, it has a chain like structure. Five kinds of asbestos are found in the amphibole group.
Sub classification of asbestos

There are six types of asbestos found on earth. Let us see about each of them below:

Chrysolite:

It is also popularly called as white asbestos, chrysolite is the most common type of asbestos. It belongs to the serpentine group. The construction industry makes vast use of this type of asbestos. Since this type of asbestos is widely used, the majority of the asbestos-related health problems globally are caused due to chrysolite. It is used in the following materials:
  • fire proofing materials,
  • insulation,
  • woven to form asbestos clothes,
  • cement pipes,
  • cement Sheets,
  • automobile brake shoes,
  • clutches,
  • disk pads,
  • textiles,
  • plastics,
  • paper,
  • rubber and
  • even in nuclear industry.
It has been proved by medical science that chrysolite also leads to various asbestos- related diseases, including mesothelioma. However, the asbestos industrialists are trying to hush up these studies. They keep claiming that it is not harmful. They do all that is possible in their power to stop the government from banning chrysolite. The result is that asbestos is still widely used in India, Canada, Africa, China and some other countries.

Though the developed countries have banned asbestos some years back, it is still found in many buildings and commercial products. If this is the case in developed countries, it is frightening to think of the future situation in the other countries.

Amosite:

This belongs to the amphibole category of asbestos. It has very stiff and Strong fibers. These fibers get easily air borne and are Very dangerous when inhaled through the nose or mouth. It is known as brown asbestos. It is mostly used for insulating purposes. Most of the countries have banned this amosite several decades ago itself. After chrysolite, this was the most popularly used type of asbestos.

Crocidolite:

This is a very rare type of asbestos belonging to the amphibole category. It is mostly used to reinforce plastics as it is highly strong. It is slightly blue in color. It is also used in thermal insulation.

The other three types of asbestos are not used to make any commercial products and thus, cause no harm.
How asbestos leads to mesothelioma?

When asbestos is mined and manufactured, a lot of asbestos dust and asbestos fibers are released into the atmosphere. Man can easily inhale this dust because it is light, invisible and airborne. Once it enters the body, either through nose or mouth, it travels throughout the body. The body organs like lungs, heart and abdomen have a lining called as mesothelium lining. When asbestos comes into contact with this lining, it starts behaving abnormally. It starts to divide rapidly and begins to outlive the other cells, leading to tumors in that area. This may also spread to the other parts of the body, leading to the terrible disease called as mesothelioma cancer. Thus, it would be in the best interest of all if this dangerous mineral, asbestos, were banned globally.