Asbestos is the name given to a group of minerals that occur naturally in the environment, bundles of fibers that can be separated into thin, durable threads. These fibers are resistant to heat, fire, and chemicals and do not conduct electricity. For this reason, asbestos is widely used in many industries.
Chemical, asbestos minerals are silicate compounds, meaning they contain silicon and oxygen atoms in their molecular structure.
Asbestos minerals are divided into two main groups: Serpentine asbestos and amphibole asbestos. Serpentine minerals including chrysotile asbestos, which has long, curly fibers that can be woven. Chrysotile asbestos is the form that has been most widely used in commercial applications. Amphibole asbestos minerals contain actinolite, tremolite, anthophyllite, crocidolite and amosite. Amphibole asbestos straight, needle-like fibers are more brittle than serpentine asbestos and more limited in their ability to be made.
Asbestos has been mined and used commercially in North America since the 1800s. Its use greatly increased during World War II (3, 4). Since then, asbestos has been used in many industries. For example, industry, building and construction used to strengthen cement and plastics as well as for the absorption of insulation, roofing, fireproofing, and sound. Shipbuilding industry used asbestos to protect the boilers, steam pipes and hot water pipes. The automotive industry uses asbestos in vehicle brake pads and clutch pads. Asbestos is also used in ceiling tiles and flooring, paints, coatings and adhesives, and plastics. In addition, asbestos has been found in vermiculite-containing garden products and some talc-containing crayons.
In the late 1970s, the U. S. Consumer Product Safety Commission (CPSC) banned the use of asbestos in the wood-based compound and repairing gas fireplaces because the asbestos fibers in these products can be released into the environment during use. In addition, electric hair dryer manufacturers voluntarily stopped using asbestos in their products in 1979. In 1989, U. S. Environmental Protection Agency (EPA) banned all new uses of asbestos, however, uses developed before 1989 are still allowed. EPA also established regulations that require school systems to inspect damaged buildings of asbestos and to eliminate or reduce exposure to asbestos for passengers to remove asbestos or wrapping it up (2).
In June 2000, the CPSC concluded that the risk of children's exposure to asbestos fibers in crayons very low (1). However, U.S. manufacturers of these crayons agreed to eliminate talc from their products.
In August 2000 the Environmental Protection conducted a series of tests to evaluate the risk of adverse health effects to consumers associated with exposure to asbestos-contaminated vermiculite. EPA concluded that exposure to asbestos from some vermiculite products represent only a minimal health risk. EPA recommends that consumers reduce the low risk associated with occasional use of vermiculite in gardening activities by limiting the amount of dust generated during the use of vermiculite. In particular, the Environmental Protection recommends that consumers use outdoors or in vermiculite well-ventilated place, keep moist vermiculite in its use, to prevent dust from vermiculite at home on their clothing, and use potting soil mixed, less likely to lead dust (2 ).
Rules described above and other actions, coupled with public concern about the health hazards of asbestos, have resulted in a significant annual decline in U.S. use of asbestos. Domestic consumption of asbestos amounted to about 803 000 metric tons in 1973, but the figure had fallen to about 2,400 tons in 2005
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