Asbestos
Six naturally occurring mineral fibers that are used for commercial purposes have been given the term "asbestos." Nearly every country across can be found to contain this substance. The six asbestos fibers that make up what is commonly referred to as asbestos come from two separate mineral groups, serpentine and amphibole.
What is Asbestos?
Serpentine asbestos fibers are usually found in a curly form and amphibole asbestos fibers are needle-like and straight. While the United States government only regulates six forms of asbestos, the U.S. Bureau of Mines has deemed 100 different mineral fibers to be "asbestos-like." Asbestos fibers are not able to be seen by the human eye except under a microscope. They are extremely fine and hundreds of times thinner than human hairs.
Types of Asbestos
Six different forms of fibers are recognized as asbestos minerals. These fibers are considered silicates, or molecules that include silicon and oxygen.
- Chrysotile – Appearing as a curly, whitish form, this fiber constitutes 95 percent of asbestos that is used.
- Crocidolite – Known as blue asbestos, this form is composed of straight-like fibers and has primarily been mined in southern Africa and Australia. Scientists believe this to be the most toxic form of all asbestos minerals.
- Amosite – Trade name for "amosite" is an acronym for Asbestos Mines of South Africa, after the Amosa mines located there.
- Anthophyllite- This form of asbestos has been found to have excellent resistance to chemicals and heat. It is brittle, white and contains various different forms of iron.
- Tremolite- While appearing white and chalky in its rough form, tremolite is found naturally in other forms of minerals different from asbestiform.
- Actinolite- Typically flat in structure, actinolite comes in forms other than asbestiform and comes with a poor resistance to chemicals.
Amphibole fibers are much more toxic and complex than chrysotile. Due to their makeup, amphibole fibers tend to stay lodged in the lungs longer than chrysotile, leading to the increased risk of an asbestos-related disease. Amphibole fibers have not been used as extensively in commercial applications due to their complexity. However, doctors have hypothesized that even the exposure to a small amount of amphibole fibers is the cause of numerous cancer deaths.
Where can Naturally Occurring Asbestos be Found?
Asbestos is widely found in the numerous mountainous areas in the United States. Areas such as New Jersey, Georgia, Alabama, Virginia, Vermont, Maine, Michigan, Washington, Oregon, Arizona and California are all home to known asbestos sites courtesy of the U. S. Geological Survey databases. The largest asbestos deposit in the world is found in California at the Clear Creek Management Area.
Why is Asbestos Used?
Asbestos is an easily mixable and usable material that is highly resistant to heat and fire. Because it is an excellent form of insulation and has a reluctance to conduct electricity, asbestos is an ideal material to use for insulation applications. Saltwater, corrosive chemicals and chemical or biological processes largely do not have an effect on asbestos fibers. Asbestos fibers do not dissolve or evaporate in water, making them easy to mix with a soluble mixture.
Why is Asbestos so Dangerous?
Asbestos fibers have been proven to be toxic to humans when inhaled or ingested. The microscopic fibers are easily separable and become lodged in the lining of the lungs and abdomen once inside the body. Asbestos fibers can cause inflammation and cell damage while inside the body and asbestos-related disease can develop as a result.
Although many U.S. residents believe asbestos was banned in the United States in the late-1980s, it has only become more regulated. Even with its hazards, asbestos is still a common material found in many products used around homes.