What is Asbestos?
Asbestos is the name applied to a group of six naturally occurring fibrous minerals (chrysotile, amosite, crocidolite, plus the fibrous varieties of actinolite, tremolite, and anthophyllite). Non asbestos (non fibrous) forms of tremolite, actinolite, and anthophyllite also are found in nature.The most common mineral types are white (chrysotile), blue (crocidolite) or brown (amosite). Asbestos can be found naturally in the earth in some parts of Australia. For example, in Australia blue asbestos deposits were mined at Wittenoom, W.A. and white asbestos at Woodsreef, N.S.W.
Crocidolite (blue) asbestos in its natural rock form
Blue asbestos in asbestos cement sheeting
Chrysotile (white) asbestos in its natural rock form
White asbestos in a gasket
Asbestos fibres were once valued for their resistance to heat and most chemicals plus their high tensile strength. Asbestos fibres have been mined for use in a wide range of man-made products, mostly in building materials, friction products, and heat-resistant materials. Therefore materials containing asbestos can be found almost anywhere. Asbestos fibres do not evaporate into air or dissolve in water. Small fibres and fibre-containing particles may remain suspended in the air for a long time and can be carried long distances by wind or water currents before settling. This means buildings containing a large amount of for example sprayed asbestos, even after removal works may still contain dangerous amounts of asbestos carried by internal air movement in cavities and inaccessible areas (The Mr. Fluffy homes in the ACT and NSW are good examples of this).
In indoor air, the concentration of asbestos depends on whether asbestos was used for insulation, ceiling or wall linings, or other purposes, and whether these asbestos-containing materials are in good condition or are deteriorated and therefore easily crumbled by hand (known as its friability.) For example loose fill asbestos insulation that has fallen out of the ceiling onto the floor is a much greater hazard (friable) than good condition asbestos containing vinyl tiles (non friable or bonded).Diseases recognised as caused by asbestos include lung cancer, asbestosis, mesothelioma and pleural plaques. All are as a result of inhalation or ingestion of asbestos fibres. Other diseases and cancers are also suspected to be caused by or linked to asbestos however further research is required to prove a direct link. There are also causative links so if you are exposed say to cigarette smoke or other cancer causing agents this may increase the likelihood of getting an asbestos related cancer.