According to Pooley (1972), Piney was the  first author to use the word “asbestos” referring to a fibrous mineral of Greek derivation which means “inextinguishable” or “unquenchable”. The word “asbestos” is defined in Webster’s Medical Dictionary as “a mineral that readily separates into long flexible fibres suitable for use as noncombustible, non-conducting, chemically resistant material”. 

  Asbestos is a naturally occurring hydrated mineral silicate that crystallizes in fibrous form (Mossman et al., 1990b). Mineralogically asbestos can be classified into two major groups; the Serpentine, which includes the most abundant variety of asbestos i.e. Chrysotile and the Amphibole which includes Actinolite, Amosite, Anthophyllite, Crocidolite and Tremolite (Mossman et al., 1996, ATSDR, 2001). Both groups have different physico–chemical nature. Chrysotile is curly and stranded structure whereas amphiboles are straight and rod like structures (ATSDR). Amphiboles are generally more brittle and appear to be dustier and more fibrogenic than chrysotile (Mossman et al., 1990 ; Mossman and Gee, 1989).

Asbestos fibres bear unique properties of a high tensile strength, resistance to heat and many chemicals without having any detectable odor. Mineralogists some times refer that the minerals crystallize into bundles of thousands of flexible fibrils that look like organic fibres. Terms that are sometimes used to describe asbestos or similar minerals include fiber, fibrous, asbestiform and acicular. The term fibrous is used to describe a crystallization habit in which the fibres have a high tensile strength and flexibility than crystals in other parts of the same mineral; asbestiform is generally synonymous with fibrous or sometimes it means “like asbestos”; and acicular” refer to a crystal that has a needle-like form.

 Even though the use of asbestos was known to medieval India, it was commercially exploited only since the beginning of this century. Asbestos is attractive in a broad variety of industrial applications because of its resistance to heat and chemicals, high tensile strength, and lower cost compared to man-made minerals. At the peak of its demand, about 3,000 applications or types of products were of asbestos-based (Ramanathan and Subramaniam, 2001). Asbestos is used for the manufacture of a variety of asbestos-based products mainly as asbestos-cement (AC) sheets, AC pipes, brake shoes, brake linings, clothes and ropes. AC industry is by far the largest user of asbestos fibre worldwide accounting for about 85% of all uses. Asbestos is also incorporated into cement construction materials (roofing, shingles, and cement pipes), friction materials (brake linings and clutch pads), jointing and gaskets, asphalt coats and sealants, and other similar products.  As a result of these applications, an estimated 20% buildings  including hospitals, schools and other public and private structures contain asbestos containing materials (ACM). Asbestos in building does not spontaneously releases fibres, but physical damage to ACM by decay, renovation or demolition can cause release of airborne fibres.  Asbestos in air at work environment is a major cause of adverse effects on health of industrial workers. Industrialization and modernization  with recent developments enhanced the demand and consumption of asbestos thus increasing the risk of exposure to asbestos.