Asbestos Essay Research Paper Asbestos is the

Asbestos Essay, Research Paper Asbestos is the only natural inorganic fibrous material that has attained commercial importance, and particularly in the last twenty years. The current period after World War II has witnessed a vigorous development in all technological areas where asbestos plays a part (Oesper 1). The word asbestos is derived from a Greek adjective meaning inextinguishable. The “miracle mineral” as it was referred to by the Greeks, was admired for its soft and plain properties, as well as its ability to withstand heat. Asbestos was spun and woven into cloth as the same manner as cotton. It was also utilized for wicks in sacred lamps. In technology and industry the term asbestos is applied to the fibrous crystalline varieties of five distinct natural

silicates. Only those asbestoses with fiber lengths that permit their textile processing were really desired. Asbestos is a naturally occurring mineral. It is distinguished from other materials by the fact that its crystals form long, thin fibers. The primary sites of commercial production of asbestos are: Canada, the Soviet Union, and South America. Asbestos is also mined commercially in the United States. An asbestos fiber is defined as a particle which has a length to width ratio equal to or greater than 3:1 and a length greater than 5 um. Asbestos was first used in the United States in the early 1900’s, to insulate steam engines. But until the early 1940’s, asbestos was not used extensively. However, after World War II, and for the next thirty years, people who

constructed and renovated schools and other public buildings used asbestos and asbestos -containing materials (ACM) extensively. They used ACM primarily to fireproof, insulate, soundproof, and decorate. The Environmental Protection Agency (EPA) estimates that there are asbestos containing materials in most of the nation’s approximately 107,000 primary and secondary schools and 733,000 public and commercial buildings (Asbestos in Buildings 2-5). These minerals are hydrated silicates of magnesium with variable amounts of metals. Three varieties have commercial importance: chrysotile (white), amosite (brown) and crocidolite (blue). As a group, these minerals have good thermal and electrical insulating properties, good tensile strength, low chemical activity and do not burn. As a

result, they were used in over 4000 products. Chrysotile asbestos is mined in Canada and has been the most commonly used. The use of crocidolite asbestos has been banned since 1978. We have learned to depend on these mineral fibers. Fire does not burn them. Alkalis do not eat them. Water does not destroy them. Vermin do not attack them. They do not decay, rot, or corrode. Surely asbestos is a magic mineral (Strack 54). Serpentine rock often contains chrysotile asbestos, especially near fault zones. Serpentine rock is abundant in the Sierra foothills, the Klamath Mountains, and Coast Ranges. Serpentine rock is typically grayish-green to bluish-black in color and may have a shiny appearance. Asbestos is not found in all serpentine rock or fault zones, but when it does occur, it is

typically present in amounts ranging from less than 1% up to about 25%, and sometimes more. Asbestos is released from serpentine rock when it is broken or crushed. This can happen when cars drive over unpaved roads or driveways which are surfaced with serpentine rock, when land is graded for building purposes, or at quarrying operations. It is also released naturally through weathering and erosion. Once released from the rock, asbestos can become airborne and may stay in the air for long periods of time (Oespert 98). Asbestos has been used in hundreds of products. Collectively, these are frequently referred to as asbestos-containing material. Asbestos gained widespread use because it is plentiful, readily available, and low in cost. Because of its unique properties: fire