According to the EPA, asbestos is a mineral fiber that occurs in rock and soil. Because of its fiber strength and heat resistance, asbestos has been used in a variety of building construction materials for insulation and as a fire retardant. Asbestos has also been used in a wide range of manufactured goods, mostly in building materials (roofing shingles, ceiling and floor tiles, paper products, and asbestos cement products), friction products (automobile clutch, brake, and transmission parts), heat-resistant fabrics, packaging, gaskets, and coatings.
The following information outlines asbestos health effects, history, regulations, and related SCDES contact resources.
Since the mid-1900s, many studies have been performed to determine the possible health effects associated with exposure to asbestos fibers. The results of these studies have indicated that high levels of exposure to airborne asbestos fibers may cause a variety of pulmonary (involving the lungs and breathing) diseases.
The most notable of the diseases associated with asbestos is Asbestosis. Asbestosis is the scarring of the tissues of the lungs (including the alveoli, tiny air sacs where the primary exchange of oxygen occurs between the air and blood) which causes a reduction in lung capacity. The relationship between the development of Asbestosis and exposure to airborne asbestos is dose-related. The greater the asbestos exposure, the greater the likelihood of developing Asbestosis.
Although Asbestosis has been positively linked to asbestos exposure, it may be years after the exposure before disease develops. In fact, Asbestosis typically has a latency period of 15-30 years after exposure.
Other asbestos-related respiratory diseases include Mesothelioma, pleural (the body cavity that surrounds the lungs) abnormalities, and lung cancer. Studies have also shown exposure to airborne asbestos fibers may cause cancer of the esophagus, colon, pancreas, and stomach.
NOTE: Although it has been documented that exposure to asbestos may cause an increased risk of developing one of the diseases mentioned above, it should be made clear that the results of the studies are based on exposure to airborne asbestos fibers. If an asbestos-containing material is in good condition and is not damaged to the point that asbestos fibers are released, there is little chance of exposure to potentially dangerous airborne asbestos fibers.
Asbestos' resilient properties have made it a useful tool for centuries. The ancient Greeks took advantage of the durability of asbestos fibers by spinning asbestos fibers into cloth to be used as blankets and tablecloths. Since asbestos fibers are resistant to fire, the ancient Romans used asbestos in the wicks of their ceremonial candles.
Although the usefulness of asbestos has been known for centuries, it was not until the late 19th century when large deposits of asbestos were discovered in parts of Canada and the northern United States that the emergence of asbestos as a common construction material occurred. The relatively inexpensive production and mass abundance of asbestos-containing materials created a widespread desire to utilize asbestos in building materials. Experimentation with the mineral revealed that asbestos was an excellent fire retardant, an exceptional component of acoustical plaster, and a decorative material. The use of asbestos was not, however, limited to the construction industry. Asbestos was used in the making of fire-resistant clothing for firefighters and hot pads used in food production. Asbestos was also used by the automotive industry in such things as brake shoes and clutch fittings for cars and trucks. In fact, at one time asbestos could be found throughout the country in products ranging from thermal insulation to kitty litter.
It was not until the early 1970s, when studies began to show adverse health effects related to asbestos-containing materials, that the widespread use of asbestos began to slow. Companies began to develop substitutes for asbestos-containing materials and began to remove asbestos from the market. Regulations were developed dealing with the manufacturing and removal of asbestos-containing materials and the massive asbestos mining efforts were abandoned. In some cases, however, a reasonable substitute for asbestos could not be found. Therefore, a few asbestos-containing products are still manufactured today.