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Why is Asbestos a Hazard?
Asbestos is made up of microscopic bundles of fibers that may
become airborne when distributed. These fibers 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 fibers are inhaled, they may become trapped in
the lung tissue. The body tries to dissolve the fibers 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.
Despite the common misconceptions, asbestos does not cause
head-aches, sore muscles or other immediate symptoms. As mentioned
above, the effects often go unnoticed for 15-50 years. 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 fibers 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. |
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| Copyright: EPA |
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