What is Asbestos?
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- Created on Thursday, 22 September 2011 14:24
Asbestos refers to a naturally occurring family of magnesium silicate mineral fibers that have been commonly used for a variety of commercial applications due to the desirable physical attributes of the minerals themselves. Asbestos is actually a rock, an individual fiber is microscopic and lighter than air. This identity as a very fine fiber is what allows it to infiltrate the lungs and corrupt the cells in the chest cavity.
Corporations valued asbestos for its unparalleled strength to weight ratio and its ability as a flame retardant. Asbestos is also extremely resistant to chemical, electrical, or other type of damage. It is also valued for its sound absorption. Given these desirable properties and the fact that extraction was cheap, many commercial entities referred to asbestos as the miracle mineral.
Asbestos, despite being a rock, can be woven into a cloth and is virtually indestructible. There are six types of naturally occurring asbestos fibers – chrysotile, amosite, crocidolite, anthophylite, actinolite, and tremolite. These are divided into two main categories of asbestos –
- amphibole asbestos or,
- serpentine asbestos
Every type of asbestos fiber, aside from chrysotile, belongs to the amphibole asbestos classification.
Chrysotile is the only asbestos which is in the serpentine category and accounts for almost all the asbestos that was used in asbestos-containing products. The second group of fibers are longer than chrysotile fibers, but often contaminated chrysotile deposits such that many of these fibers also found their way into asbestos containing products.
Chrysotile accounts for almost 95%of asbestos contamination in buildings in the U.S. Given that chrysotile asbestos is more flexible than the other types of asbestos, it was often used when the desire was to spin or weave the asbestos into cloth or fabric. It was also commonly used in joint compounds. Some of the most common applications of chrysotile asbestos were for asbestos cement roof sheets or as flat sheets for ceilings. It was also commonly used in insulation, brake linings, and floor tiles.
Asbestos begun to gain prominence as a commercial ingredient around the time of the Industrial revolution, in the late 19th century. In the Americas, the first commercial asbestos extraction mine was put into operation in 1874, in Quebec. From its initial uses as insulation, it also formed the basis for the first fire prevention interventions placed into materials. In an attempt to harness that fire retardant capability, asbestos was placed into bricks, drywall, insulation, flooring, roofing, joint compounds, concrete, fireplaces, and numerous other uses.
The next major application was the use of asbestos on Navy ships. Asbestos was commonly used to wrap pipes, line engines, and in boilers. In many cases, sailors’ bunks were located directly beneath pipes wrapped in asbestos, which would result in their exposure to asbestos every day they were on that ship. The men and women who built those ships were also at increase risk of exposure to asbestos. In areas where these ships were commonly built, there is an extremely high incidence of asbestos related diseases. More recently, asbestos was used in brakes, brake linings, shifters and clutches.
You should know that while it is possible to see asbestos when it is woven together as part of a fabric, individual asbestos fibers are extremely small, and invisible to the naked eye. Thus, one does not have to “see” asbestos to be exposed to it. In addition, asbestos has been found in many of the “substitutes” which companies used for asbestos. These include vermiculite and talc. It was recently discovered, for example, that children’s crayons made with talc actually contained asbestos as the talc used in the crayons was itself contaminated.
Though the first confirmed deaths and injuries related to asbestos were first reported in the early 1900s, it is likely that there were asbestos related injuries occurring earlier. The companies mining asbestos and using it in their products had their own internal data that showed the harmful effects of asbestos, but chose to keep using it and hide this data from the public and their employees. As a result, hundreds of thousands of people were needlessly exposed to the risk of developing an asbestos related illness.
As awareness has spread publicly, however, regulations have been enacted to attempt to prevent asbestos from coming into contact with the public. As an example, when older buildings are demolished, many states require that all asbestos be removed before demolition. A second method, called “wet” demolition, has been touted as safe, though it seems dubious at best to assume this process prevents all asbestos exposure to the same degree as removal. Nevertheless, asbestos is not technically banned and it is possible for people to still be exposed.
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