The Ohio State University Asbestos Management Program
Asbestos is a generic name for a group of naturally occurring hydrated mineral silicates of the serpentine or amphibole series that are characterized by fibers or bundles of fibers of fine single crystal fibrils. It should be noted that these minerals may occur in a non-fibrous form, in which case they are not considered as asbestos. The six major recognized species of asbestos minerals are chrysotile of the serpentine group (white asbestos) and amosite (brown asbestos), crocidolite (blue asbestos), anthophyllite, tremolite, and actinolite of the amphibole group.
The specific attributes and characteristics vary with the different mineral types and fibrous forms. In general, commercially valuable asbestos minerals form fibers that are light weight, are incombustible, have high tensile strength, good thermal and electrical insulating properties, as well as moderate to good chemical resistance. Fibrous asbestos may be packed, woven, or sprayed. These characteristics and those of durability, flexibility, strength, and resistance to wear have allowed asbestos to be used in more than 3,000 commercial products. As a building material, asbestos has been used as thermal systems insulation on plumbing lines and related equipment, spray fire proofing on structural steel, surfacing decorative plaster, roofing and flooring materials, friction products, and adhesives. Chrysotile asbestos is the primary mineral form used in these building and commercial applications.
Naturally occurring asbestos is found in various parts of the world, including the southwest portions of the United States. Chrysotile asbestos was the first commercial mineral form to be mined. This operation began in Quebec, Canada in the 1870’s and continues today. Amosite asbestos comes from South Africa, which started mining operations in 1916. Crocidolite, another amphibole of lesser economic importance, is mined in South Africa and China.
Inhalation is the primary means by which buoyant asbestos fibers may enter the body. In addition, asbestos fibers may enter the body by ingestion as a result of inadvertent consumption of liquids and foods contaminated with this material. The mineral fibers are retained in the tissues of the body throughout a person’s life, even after the cessation of exposure. Fibers have been known to migrate to other organs following retention in the lungs. The three main diseases associated with asbestos exposure include:
Asbestosis: A non-cancerous scarring of the lung tissue that causes shortness of breath, breathing difficulty, and often heart failure. The latency period is generally 10-20 years following exposure.
Lung Cancer: A cancer that impacts the lung tissue, which often takes as much of twenty years to develop. Lung cancer may develop independent of the development of asbestosis. Persons who have industrial exposures to asbestos have a five (5) times greater chance of developing lung cancer than those persons who do not work with the material. It has been found that there is a synergistic affect associated with cigarette smoke, asbestos and lung cancer. Asbestos exposed workers who smoke can expect a 50 times greater chance of lung cancer than those persons who do not smoke or work with asbestos. The latency period can often be 20 or more years for the cancer to develop.
Mesothelioma: A rare form of cancer that attacks the lining of the chest and abdominal cavity, as well as the lining of the heart. This disease is usually fatal. The latency period is generally 20-40 years.
TO CONTINUE READING THIS ARTICLE: OSU Asbestos Management Guidelines