Asbestos is the name given to a number of naturally occurring minerals that have been mined for their useful properties such as thermal insulation, chemical and thermal stability, and high tensile strength. The types of asbestos that are regulated are: Chrysotile, Amosite, Crocidolite, Anthophyllite, Tremolite, and Actinolite. Asbestos deposits can be found throughout the world and are still mined in South America, Australia, Canada, South Africa, and the former Soviet Union.
Why is Asbestos a hazard?
Asbestos is made up of microscopic bundles of fibers that may become airborne when disturbed. If these fibers get into the air, they can be inhaled into the lungs where they may cause significant health problems. Researchers still have not determined a “safe level” of exposure but we do know that the higher the concentration of fibers and the longer the exposure, the greater the risk of contracting an asbestos-related disease.
Some of these health problems include:
• Asbestosis – a lung disease that causes scarring of the lungs. Eventually, this scarring may become so severe that the lungs cannot function. The latency period (meaning the time between the exposure and the onset of disease) is often 25-40 years.
• Mesothelioma – a cancer of the lining of the lung and chest and/or the lining of the abdominal wall. Asbestos exposure is one of the few causes of this cancer. The latency period for mesothelioma is often 15-50 years.
• Lung Cancer – Lung cancer can be caused by exposure to asbestos. A person has a much greater chance (50 to 84 times greater) of developing lung cancer if they are exposed to asbestos and they smoke. Cancer of the gastrointestinal tract can also be caused by asbestos exposure. The latency period for these cancers is often 15-30 years.
Despite the common misconception, exposure to asbestos fibers does not cause headaches, upper respiratory irritation or other immediate symptoms. As mentioned above, the effects often go unnoticed for 15-50 years.
When is Asbestos a hazard?
Asbestos-containing materials (ACM) in good condition should not pose a hazard to building occupants. If these materials can be maintained in good condition, it is recommended that they be left alone and periodic surveillance performed to monitor their condition. It is only when ACM is disturbed or the materials become damaged that it becomes a hazard. When the materials become damaged, the fibers separate and may then become airborne. In the asbestos industry, the term ‘friable’ is used to describe an ACM that can be reduced to powder by hand pressure. ‘Non-friable’ means an ACM that is too hard to be reduced to powder by hand pressure. Mechanical grinding, sanding and dry-buffing are some ways of causing non-friable materials to become friable.