Why is Asbestos a hazard?
Indicating how the asbestos cancer attacks the lung (see image).
Asbestos is made up of microscopic bundles of fibres that may become airborne when distributed. These fibres get into the air and may become inhaled into the lungs, where they may cause significant health problems. Researchers still have not determined a "safe level" of exposure but we know the greater and longer the exposure, the greater the risk of contracting an asbestos related disease. Some of these health problems include:
- Asbestosis - a lung disease first found in naval shipyard workers. As asbestos fibres are inhaled, they may become trapped in the lung tissue. The body tries to dissolve the fibres by producing an acid. This acid, due to chemical resistance of the fiber, does little to damage the fiber, but may scar surrounding tissue. Eventually, this scarring may become so severe that the lungs cannot function. The latency period (meaning the time it takes for the disease to become developed) is often 25-40 years.
- Mesothelioma - a cancer of the pleura (the outer lining of the lung and chest cavity) and/or the peritoneum (the lining of the abdominal wall. Thsi form of cancer is peculiar because the only known cause is from asbestos exposure. The latency period of mesothelioma is often 15-30 years.
- Lung Cancer - caused by asbestos. The effects of lung cancer is often greatly increased by cigarette smoking (by about 50%). Cancer of the gastrointestinal tract can also be caused by asbestos. The latency period for cancer is often 15-30 years.
And what’s causing it? An asbestos fibre magnified a few 100 times, with the cancer starting to form around it (see image).
Asbestos is not always an immediate hazard. In fact, if asbestos can be maintained in good condition, it is recommended that it be left alone and periodic surveillance to monitor its condition. It is only when asbestos containing materials (ACM) are disturbed or the materials become damaged that it becomes a hazard.
When the materials become damaged, the fibres separate and may then become airborne. In the asbestos industry, the term "friable" is used to describe asbestos that can be reduced to dust by hand pressure. "Non-friable" means asbestos that is too hard to be reduce to dust by hand. Non-friable materials, such as transite siding and floor tiles are not regulated provided it does not become friable. Machine grinding, sanding, and dry-buffing are ways of causing non-friable materials to become friable.