Asbestos Overview
What is Asbestos?
Asbestos is a mineral that is naturally present at very low levels in a large proportion of the Earth’s crust, as well in larger amounts in deposits in many different locations. The substance has been used for thousands of years, by many different cultures, and has long been known as a material that does not burn. Although it has been used by many different cultures throughout history it wasn’t until the industrial revolution of the late nineteenth century that asbestos was used on a wide scale. During the twentieth century, asbestos was incorporated in an estimated three to five thousand different products.
Asbestos has some important chemical and physical properties that made it suitable for many industrial and commercial uses. Asbestos is insoluble in water, resistant to acid and chemical degradation, is fire-proof, and has a tensile strength higher than that of steel. In short, asbestos is highly durable a material that is inert and does not burn. For these reasons, and because asbestos was inexpensive to produce and use, it was an extremely common addition to many types of products.
Why is Asbestos Dangerous?
Unfortunately, some of the properties of asbestos that made it so popular in many industries are the very same properties that make it dangerous. Asbestos is largely inert, meaning that if fibers are inhaled, the body is unable to break them down.
Because of this, fibers that are inhaled remain in the lungs, and over time cause irritation and inflammation. With repeated or heavy exposure to asbestos, a condition called asbestosis can develop. This occurs when scar tissue forms in the lungs as a result of chronic inflammation. The scar tissue is inflexible and can not absorb oxygen, which means people with asbestosis have reduced lung function and experience pain when breathing.
A group of cancers—collectively called mesothelioma—is also caused by exposure to asbestos. These cancers can develop after relatively small amounts of asbestos exposure, and are particularly serious because they are difficult to diagnose and very difficult to treat. Mesothelioma can develop in several different locations within the body, but the prognosis is usually very poor for all patients.
Please see “Mesothelioma Overview” and “Other Asbestos-Related Diseases” for further information.
Is All Asbestos Dangerous?
The mineral group known as asbestos includes six slightly different minerals: chrysotile, amosite, actinolite, anthoplyllite, crocidolite, and tremolite asbestos.
Each type was commonly used in different types of products. Chrysotile asbestos was used most widely, as its curly fibers provided more flexibility than other types. Chrysotile accounts for around 95% of the asbestos used in construction products in America.
Chrysotile asbestos was also believed to be safer than other types; however subsequent long-term health studies carried out on workers exposed to chrysotile asbestos have shown that this is not necessarily the case. In fact, all six types of asbestos can cause cancer.
It’s important to note that asbestos is dangerous only when it is ingested—usually inhaled—into the body. Intact asbestos that doesn’t shed fibers is reasonably safe as long as it is left undisturbed; it’s only when asbestos fibers become airborne that they present a health risk. This means, for example, that if you’ve got asbestos tiles on your roof, you’re not at risk simply because the asbestos is there. The level of risk depends on what sort of condition the tiles are in, and if the tiles are intact and in good condition, the risk is low.
What was Asbestos used For?
Asbestos has been added to many different types of products, including construction materials, fire proof fabric and protective clothing, household electrical appliances, brake pads and linings, moldable plastics, and many other products. When added to products it could improve fire resistance, thermal insulation, electrical and sound insulation, and strength.
Asbestos was used in thousands of different types of building materials, and these were used in industrial, commercial, public, and residential buildings alike. Asbestos was particularly useful in industrial buildings because of its fire resistance. It was used around furnaces and boilers as insulation and fire-proofing, and even in heat-resistant protective clothing worn by people in certain professions.
Asbestos was also used in ship-yards and in the building of Navy, industrial, and commercial vessels, and in the manufacture of various other types of products, including brake pads and brake linings for the automotive industry, and even some electrical appliances.
Asbestos is also unintentionally present in some materials. One of these is Zonolite, a type of vermiculite insulation that is present in millions of American homes.
Who is at Risk of Asbestos Exposure?
In general, people at risk of exposure are those who worked with or around asbestos. People in many different industries are affected, because they worked with the substance, or the location where they worked contained machinery with asbestos-containing parts, or asbestos insulation or other materials. Those most at risk include construction and ship-yard workers, as well as people who worked aboard ships.
Family members of people working in industries where asbestos was used were at risk of exposure in certain situations. When workers weren’t provided with protective clothing to prevent exposure, they often arrived at home wearing work clothes laden with asbestos dust. This secondary exposure is less common, but there are still many recorded cases.
For further information, please see “Asbestos Exposure.”
Legal Issues Associated with Asbestos Exposure
One of the most important legal issues associated with asbestos is that many companies knew of the health risks of exposure, but continued to sell products containing asbestos. In addition, many companies failed to protect their workers from the danger, or even warn them that the danger existed.
People who develop asbestos-related disease can file a lawsuit to try and claim compensation for medical expenses, loss of income, and pain and suffering. An estimated 800,000 Americans have so far claimed compensation for diseases such as mesothelioma. Please see “Mesothelioma and your Legal Options” for further information.
Sources
http://environmentalchemistry.com/yogi/environmental/asbestosproperties2004.html
http://en.wikipedia.org/wiki/Asbestos
http://www.epa.gov/asbestos/pubs/asbbans2.pdf
http://www.lhc.org.uk/members/pubs/books/asbestos/asb03.htm
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