Mesothelioma and AsbestosThe main risk factor for developing mesothelioma -- the one most common
cause of the disease -- is exposure to asbestos. In the past, asbestos -- a family of magnesium-silicate mineral fibers -- was used widely
for insulation. Because it did not conduct heat well and did not burn or melt, it appeared to be a synthetic marvel. As the link between asbestos
and mesothelioma has become well known, however, the use of this material has decreased. Warnings must be given to those entering older buildings
with asbestos. Unfortunately, up to 8 million Americans have already been exposed to asbestos.
The United States Environmental Protection Agency reports that as many as 733,000 schools and public buildings in the country still contain
asbestos insulation. Passive time spent in these buildings can be completely harmless. People who may be at risk for occupational asbestos
exposure include some miners, factory workers, insulation manufacturers, railroad workers, ship builders, gas mask manufacturers, and
construction workers, that were likely exposed to asbestos during the insulation installation process. Some studies have shown that family
members of people exposed to asbestos at work have an increased risk of developing mesothelioma. It is assumed that this is not because the
disease is contagious -- it most certainly is now -- but because asbestos fibers may have been carried home on the clothes of the workers.
Serpentine and amphiboles are the two major types of asbestos. Serpentine fibers are curly and pliable, produced mostly under the name
Chrysotile. That was the most popular form of asbestos. On the other hand, Amphiboles are thin, straight fibers. These include crocidolite,
amosite, anthrophylite, tremolite and actinolyte. While not as common as Serpentine asbestos, Amphiboles have been the most carcinogenic,
It's likely that asbestos causes cancer by physically irritating the cells rather than a chemical effect. Inhaled fibers are cleared by
sticking to mucus inside the air passages and being coughed up or swallowed. The long, thin, fibers don't clear as easily and they may reach the
ends of the small airways, penetrating the pleural lining of the lung and chest wall. These fibers may then directly injure mesothelial cells of
the pleura, and eventually cause asbestos cancer -- or mesothelioma.
Asbestos fibers may also damage lung cells and result in scar tissue in the lung -- also knows as asbestosis. The risk of lung cancer among
people exposed to asbestos is significant. They are seven times as likely to contract the disease. Asbestosis, mesothelioma, and lung cancer are
the three most frequent causes of death and disease among people with heavy asbestos exposure. Forming in the abdomen, peritoneal mesothelioma
results from coughing up and swallowing inhaled asbestos fibers. While cancers of the larynx, pancreas, esophagus, colon and kidney have all been
linked to asbestos exposure, the greatest risk associated with asbestos remains lung cancer.
How much asbestos a person was exposed to and how long this exposure lasted are the key factors in the severity of the disease. Mesothelioma
does take a long time to develop. The time between exposure to asbestos and diagnosis of mesothelioma is usually between 20 and 40 years and it
is why it took so long to link asbestos with mesothelioma.
Genetic factors may also play a role in determining who develops the disease -- as well as who skirts the contraction. This explains why not
all persons exposed to high levels of asbestos dust develop mesothelioma.