Mesothelioma Risk Factors
Asbestos Exposure as a Mesothelioma Risk Factor
The biggest mesothelioma risk factor is exposure to the silicate mineral asbestos either by inhaling or ingesting airborne particles. The two primary classes of asbestos that were used in construction were made from either the serpentine mineral group or the amphibole mineral group. Chrysotile, a serpentine mineral, comprises 95 percent of the asbestos used worldwide. In a study titled Chrysotile asbestos is the main cause of pleural mesothelioma, published September 1996 in the American Journal of Industrial Medicine, researchers emphasized the carcinogenic quality of chrysotile:
“Reported data do not support widely quoted views regarding the relative inertness of chrysotile fibers in mesothelioma causation. In fact, examination of all pertinent studies makes it clear that chrysotile asbestos is similar in potency to amphibole asbestos. Since asbestos is the major cause of mesothelioma, and chrysotile constitutes 95% of all asbestos use world wide, it can be concluded that chrysotile asbestos is the main cause of pleural mesothelioma in humans.”
Asbestos made from the amphibole mineral group can be one of five types: amosite, crocidolite, anthophyllite, tremolite, and actinolite. Amosite, or brown asbestos, and crocidolite, or blue asbestos, are considered to have the high amphibole est levels of carcinogenic properties.
The amphibole form of asbestos typically contains a high level of iron and it resists acid erosion and very high temperatures. As a result, it has been used extensively in industrial furnaces and heating systems. Inhaled amphibole fibers remain in the lungs indefinitely and they are likely to cause damage leading to cancer. Amphibole asbestos has been largely replaced because of its toxicity.
Asbestos Exposure and the Development of Mesothelioma
Mesothelioma remains latent for a long time before symptoms appear. The average time between asbestos exposure and development of the disease is estimated to be at least 32 years according to a study titledLatent period for malignant mesothelioma of occupational origin, published July 1992 in the Journal of Occupational Medicine.
The Surveillance and Epidemiology End Results (SEER) database of cancer statistics, part of the National Cancer Institute, has shown that the incidence of mesothelioma is significantly higher in men than in women. This has been attributed to the use of asbestos in construction, military, and manufacturing materials.
Other Mesothelioma Risk Factors
According to the Mayo Clinic, the following factors may also increase your risk for mesothelioma:
- Living with someone who works with asbestos. People who are exposed to asbestos may carry the fibers home on their skin and clothing. These stray fibers can put others in the home at risk of mesothelioma. People who work with asbestos should shower and change clothes before leaving work.
- Radiation. Some research links mesothelioma to the radioactive substance thorium dioxide, which was used along with X-rays to diagnose various health conditions from the 1920s to the 1950s. Mesothelioma has also been linked to radiation therapy treatments to the chest, such as those used to treat breast cancer or lymphoma.
- Family history. A family history of mesothelioma may increase your risk of mesothelioma, but more research is needed to understand this theory.
Smoking and Mesothelioma
The National Cancer Institute, which is a division of the National Institutes of Health, one of the agencies that make up the Department of Health and Human Services, has said that smoking doesn’t increase the risk for mesothelioma. However, the agency did add that the combination of smoking and asbestos exposure greatly increases the risk of developing cancer of the air passageways in the lung.