Asbestos was used very widely in construction materials, small appliances, protective heat-resistant fabrics, and industrial machinery prior to the 1980s. Asbestos is strong, light, chemically inert, and inexpensive to mine. Unfortunately, asbestos exposure can also cause a cancer called mesotheliom
Asbestos Exposure and Cancer
Exposure to asbestos is dangerous because of the shape of the fibers, and the fact that the body cannot expel fibers that have been inhaled or otherwise ingested. When viewed under the microscope, asbestos fibers appear to be long, thin, needle-like fibers. This structure contributes to the danger of asbestos exposure: when inhaled, fibers easily become trapped in the soft tissue of the lung. Due to the physical and chemical inertness of asbestos, the body can’t break down the fibers. They stay in the lungs, and can cause chronic inflammation and irritation.
All of these qualities combine to make asbestos carcinogenic. In the long term, an environment in which inflammation is constantly occurring is a mutagenic one, meaning that cellular mutations occur more frequently. This means the likelihood that a malignant mutation will occur. In mesothelioma, cells of the lining of the lungs mutate in a way that causes malignancy.
About Mesothelioma
The lining of the lungs is comprised of cells called mesothelial cells. When these cells become malignant, they begin dividing ceaselessly and without restraint, as in any other kind of cancer. The end result is the formation of thickened lung tissue and eventually the development of tumors.
The development of malignancies occurs over a very long time. It is common for three or more decades to elapse between initial asbestos exposure and the onset of noticeable mesothelioma symptoms. This has, in the past, made diagnosis difficult. Another factor that increases the difficulty is that by the time noticeable symptoms appear, the cancer is often already untreatable.
Types of Mesothelioma
The most common type of mesothelioma is pleural mesothelioma, which occurs in the lungs. However, there are three other known types of mesothelioma.
Pericardial mesothelioma develops in the lining of the heart, called the pericardium, while peritoneal mesothelioma develops in the lining of the abdominal cavity. Finally, there is testicular mesothelioma, which is very rare, and is not always associated with asbestos exposure.
Around 70% of reported cases of mesothelioma are pleural, 25% are peritoneal, and less than 5% are pericardial. Testicular mesothelioma is much rarer; there have been fewer than 100 reported cases of this kind worldwide.
References
Mesothelioma
Mesothelioma is a type of cancer caused by exposure to asbestos. This cancer affects mesothelial cells, which are present in membranes that line most organs and body cavities.