Mesothelioma: Risk Factors
Malignant mesothelioma is a rare cancer that affects the mesothelial tissue. Certain risk factors can increase an individual’s chance of acquiring a disease such as mesothelioma. What risk factors increase the chance of acquiring mesothelioma?
Asbestos exposure remains the number one risk factor for the development of mesothelioma. The association of asbestos and mesothelioma has caused the use of asbestos to almost be discontinued. Since then, cases of mesothelioma have stopped increasing. What exactly is asbestos?
Asbestos refers to a family of fibrous silicate minerals once used in products such as:
- door gaskets
- insulation
- soundproofing material
- floor tiles
- roofing
- fireproof gloves
- patching compounds
- brake pads
- ironing board covers
However, asbestos is a naturally occurring mineral found in dust and rocks in around the world.
The EPA (Environmental Protection Agency) estimates that up to 733,000 public buildings and schools may still contain asbestos insulation. The removal of asbestos remains a risk factor for developing mesothelioma. Individuals that are exposed to a higher level of asbestos are more likely to develop mesothelioma.
Certain occupations which may be at an increased risk include:
- Insulation manufacturers
- Railroad workers
- Miners
- Factory workers
- Ship builders
- Gas mask manufacturers
- Construction workers
Family members exposed to individuals who have been exposed to asbestos are also at an increased risk. This occurs when the individual brings the asbestos fibers home on one’s clothing. Asbestos can be found in 2 main forms:
- Amphiboles: Thin, rod-like fibers which include amosite, crocidolite, anthrophylite, tremolite, and actinolyte. The amphiboles are considered to be very carcinogenic (cancer causing).
- Serpentine: Curly and pliable fibers which includes chrysotile. Chrysotile is the most widely used form of asbestos.
How does asbestos cause mesothelioma?
Inhaled asbestos fibers can lodge at the ends of the small airways. Asbestos fibers may further penetrate the pleural lining of the lung and chest wall which may damage or injure the mesothelial cells. The formation of mesothelioma takes time, approximately 20-50 years from the first occurrence of exposure.
Asbestos fibers can also cause lung cancer or asbestosis (the formation of scar tissue in the lungs). Peritoneal mesothelioma may also form. This occurs when inhaled asbestos fibers are coughed up and swallowed. Peritoneal mesothelioma will affect the abdomen in this case.
Other risk factors for developing mesothelioma include:
- Exposure to Simian Virus 40 (SV40): This virus was originally found in monkeys but research shows a correlation between SV40 and mesothelioma formation. Between 1955 and 1963, monkey cells (containing the Simian Virus) were used to develop the polio vaccine. Once the correlation was discovered, this method was discontinued. Much is unclear of what exact connection SV40 plays in the formation of mesothelioma; more research is needed in this area.
- Exposure to Thorium Dioxide: Thorium Dioxide or Thorotrast was once used in x-rays between 1920 and 1950 but was later found to cause cancer. The use of Thorium Dioxide has been discontinued in x-rays. A few research studies have found a correlation between Thorium Dioxide and the formation of mesothelioma.
- Exposure to Zeolite: Zeolite is commonly found in the soil of Turkey, Anatoli region. Zeolite is chemically similar to asbestos, in which zeolite is a silicate mineral. This area of Turkey has reported many cases of mesothelioma which may be caused by this mineral.
- Tobacco Use: Smoking has not been directly correlated with increasing your risk of mesothelioma development. However, the combination of asbestos exposure and smoking greatly increases your risk of developing lung cancer.
Many risk factors may contribute to the development of mesothelioma but only one definitely stands out; asbestos exposure. Even though, you may be exposed to asbestos sometime throughout your life does not necessarily mean that you will develop mesothelioma. Each disease has different risk factors. Learn more about mesothelioma signs and symptoms.
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