Mesothelioma Causes 1

Mesothelioma is a rare cancer affecting the mesothelium. This is the layer of tissue covering the body’s internal organs and the surfaces of the body cavities containing the organs. Mesothelioma is caused by a combination of environmental factors. In terms of what causes mesothelioma, asbestos exposure is the only known origin. However, other risk factors may increase your chances of developing mesothelioma, such as smoking and medical family history.

What Causes Mesothelioma?

Mesothelioma is caused by exposure to asbestos. Asbestos is a natural mineral that has been used for centuries for its strength and heat resistance. Asbestos is a component of many building materials and products, including:

  • Automobile brakes
  • Ceiling and floor tiles
  • Insulation.

When materials containing asbestos are disturbed (during the manufacturing or removal process), they can release asbestos particles into the air. These airborne particles can be inhaled or ingested. Once in the body, these particles can cause mutations in the cells of the mesothelium. Several different body systems can be affected, each resulting in a different type of mesothelioma:

  • Abdominal organs (peritoneal mesothelioma)
  • Heart (pericardial mesothelioma
  • Lungs (pleural mesothelioma).

Though asbestos is the only proven cause of mesothelioma, other factors can increase your risk of developing this type of cancer.

Smoking and Mesothelioma

Smoking is a risk factor in many lung diseases, including cancers. However, unlike other cancers of the lung, mesothelioma can’t be caused by smoking; rather, it is caused by asbestos exposure. Though smoking doesn’t cause mesothelioma, it can increase risk for developing the disease. If you work with asbestos or have had exposure to asbestos in the past, you should avoid smoking.

Simian Virus 40 (SV40) and Mesothelioma

Though a definitive link hasn’t been found, some research suggests a link between mesothelioma and a virus, called Simian Virus 40 (SV40). When compared to those not affected by SV40, individuals affected by this virus seem more likely to develop mesothelioma when exposed to asbestos. Some polio vaccines given the late 1950s and early 1960s were contaminated with this virus. However, the virus has been found both in individuals with mesothelioma and in healthy individuals. Thus, the connection between SV40 and mesothelioma is not well-established.

Other Mesothelioma Risk Factors

Secondhand exposure may also pose a hazard. For example, say you live with an individual who is exposed to asbestos in the workplace. Asbestos particles carried on clothing or hair may be released into the air at home, where they can be inhaled or ingested by family members. If a loved one works with asbestos, you should take precautions to prevent exposure.

Family history may also pose an additional risk for developing mesothelioma. However, more research is needed to document this theory and determine whether there is a connection between mesothelioma and family history.

It is important to reiterate that none of the aforementioned risk factors alone cause mesothelioma. Rather, they increase your risk of developing mesothelioma if you have been exposed to asbestos.


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Mayo Clinic Staff. (n.d.). Mesothelioma: Risk factors. Retrieved January 7, 2010, from the Mayo Clinic Web site: