Asbestos

Asbestos is a mineral silicate fibre that occurs naturally. It is mined and used for its useful properties such as thermal insulation, thermal and chemical stability, and high tensile strength. Asbestos has been commonly used in a variety of building construction materials for insulation and as a fire-retardant. It can be found in pipe and furnace insulation, textured paints, floor tiles, and other coating materials used in older homes and buildings.

Asbestos is a hazard to human health because when it becomes airborne, it can be inhaled into the lungs, causing significant adverse health effects. Asbestosis is a disease caused by the body's reaction to asbestos fibres in the lungs. The body attempts to dissolve the fibres by producing acid in the lungs. While this does not affect the fibres, it does produce scar tissue which can eventually impede lung function. Mesothelioma is cancer of the outer lining of the lung and chest cavity or the inner lining of the abdominal wall. The only known cause for this type of cancer is asbestos exposure. Lung cancer can also be caused by exposure to asbestos.

Asbestos does not always pose a threat to human health. If the asbestos containing material is in good condition and does not release fibres into the air, then it poses little threat. However, materials that are friable or those that are encountered during renovations may pose a risk and should be treated as such.

There are three common types of asbestos (chrysotile, amosite, and crocidolite), each differing in crystalline structure. Chrysotile is the most common form of asbestos found in buildings. The presence and type of asbestos can only be determined by microscopy.

Additional information on asbestos can be found at http://www.epa.gov/asbestos/ .