Mesothelioma Risk Factors
The No. 1 risk factor for developing mesothelioma is asbestos. In fact, nine out of 10 cases of mesothelioma are linked to some form of asbestos exposure. The patients in the other 10 percent of cases usually have suspected but unproven asbestos exposure at some point in their lives.
The demographics that most commonly develop mesothelioma are miners and construction workers who directly deal with the naturally occurring asbestos mineral. (However, secondhand exposure is a problem, too, such as with the wives of asbestos miners developing mesothelioma.) Due to its durability and its high resistance to heat, electricity, and chemical wear, asbestos was used as insulation for pipes, hot water heaters, homes, schools, and other buildings for many decades. When asbestos is in place, it poses no health risk. Once it is disturbed, it can put everyone in the vicinity at a higher risk of developing mesothelioma.
Asbestos fibers are tiny, and when they get kicked into the air during the mining process or during installation, they can very easily be breathed in or swallowed. In the body, they can cause damage to sensitive tissues, including the lungs and the mesothelium that surrounds the stomach and the pleura – the thin cavity between the lungs and the ribcage. Asbestos fibers are, for the most part, not affected by the immune system, so once they are in the body, they can stay there.
Exactly how mesothelioma develops is not entirely understood. However, like all cancers, the condition starts when normal cells become damaged and mutated, which then multiply and form cancer. In mesothelioma, these cell changes are caused by asbestos, which damages the DNA of healthy mesothelium cells. These mutations take a long time to accumulate to the point where the cells can be defined as cancer and cause physical harm to a patient. This is why it often takes many years after the initial asbestos exposure to develop mesothelioma.
Other Causes of Mesothelioma
Other risk factors for mesothelioma are unconfirmed and require more scientific analysis before they can be seen as actual causes of the disease. These possibilities include infection with simian virus 40 (SV40), a virus that was found to contaminate polio vaccines given between 1955 and 1963. Thorium dioxide, a radioactive compound that was used in x-ray imaging until the 1950s, is also suspected to cause mesothelioma. Lastly, the effects of smoking on mesothelioma are still debated. While smoking may increase the risk of developing mesothelioma, it has never been shown to cause the disease in people who were not exposed to asbestos.