What is asbestos? Asbestos is a naturally occurring mineral and deposits of asbestos are found throughout the world, including the United States. It is commercially mined, mainly in Canada and South Africa. It is distinguished from other minerals in that its crystals form long, thin fibers. What appears as a fiber is actually an agglomeration of hundreds or thousands of fibers, each of which can be divided into microscopic fibrils. Once mined, the asbestos rocks are crushed and milled and the resulting fibers are used in various products.
In what types of products can asbestos be found? Because of its unique properties heat and fire resistance, high tensile strength, poor electrical conductivity, and chemical resistance asbestos proved well suited for many uses in construction. It has been used in literally thousands of products. A partial list includes fireproofing, pipe insulation, floor tile, sheet flooring, ceiling tiles, acoustical plaster, fume hood panels, laboratory countertops, transite siding shingles, roofing materials, brake shoes, gaskets, and construction mastics.
How can you tell if something contains asbestos? The only way to determine if a material contains asbestos is to have it analyzed by a microscope, usually a Polarized Light Microscope. The material needs to be taken to an accredited laboratory to officially determine the asbestos content. The Environmental Protection Agency (EPA) has defined an asbestos-containing material (ACM) as a material containing more than 1% asbestos.
Why is asbestos harmful? When asbestos fibers become airborne, they can be inhaled and can become lodged in lung tissue. When this occurs, large cells (called macrophages) attempt to engulf the particles and eliminate them from the body. However, the macrophages are often not able to digest the fibers, resulting in scarring of the lung tissue. This condition is known as asbestosis. Asbestosis is not a cancer, but makes it very difficult to breathe. Asbestos exposure has also been linked to cancer. When asbestos fibers become lodged in the mesothelial cells, which line the chest and abdomen, it can cause a cancer called mesothelioma. Asbestos exposure has also been shown to cause lung cancer. People who smoke and are exposed to asbestos greatly increase the risk of developing lung cancer. Ingestion of asbestos fibers has also been linked to gastrointestinal cancers.
Is there a safe level of asbestos exposure? The vast majority of people who have developed an asbestos related disease have experienced what is described as an occupational exposure, where they have breathed millions of fibers per day for many months or years, due to the requirements of their job. But there have been documented cases of persons developing disease from a minimal exposure. For this reason, it is generally held that there is no safe level of asbestos exposure. Additionally, asbestos exposure is often difficult to recognize, because there are no acute symptoms. The typical latency period (the amount of time between exposure and onset of symptoms) is 20-40 years.
Is it safe to be near an asbestos abatement project? There are numerous regulations, guidelines, and specifications which govern how an abatement project is performed. All abatement workers must be trained, as well as the monitors who inspect the removal process. The asbestos is normally removed from within a plastic containment, which is placed under negative pressure with HEPA filtered negative air machines. Air sampling is required for most abatement activities and clearance samples are taken inside the abatement containment before the containment is removed. Exterior area samples are also taken near the containment during the removal activities to confirm the air surrounding the containment is safe. So, yes, because of these stringent abatement requirements, it is safe to work adjacent to an asbestos abatement project.
Who can I contact for more information about asbestos? At UVA, Environmental Health & Safety maintains records of all past asbestos inspections within UVA buildings, as well as daily reports and air sample analyses of past abatement activities. These records are maintained and updated by accredited Asbestos Project Designers, Inspectors, Management Planners, and Monitors.