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This page was medically reviewed by Benjamin Wei on November 22, 2019. For information on our content creation and review process read our editorial guidelines. If you notice an error or have comments or questions on our content please contact us.

Causes of Mesothelioma

When looking at what causes mesothelioma cancer, exposure to asbestos is the major risk factor for developing the disease.

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Key Points

  • 1

    Asbestos exposure is the most significant risk factor for developing mesothelioma.

  • 2

    The vast majority of patients who develop mesothelioma report a significant previous exposure to asbestos.

  • 3

    There are a variety of other risk factors that may increase the risk of developing mesothelioma.

  • 4

    There are ways to prevent exposure, likely also preventing mesothelioma.

Mesothelioma symptoms often take 10 – 50 years to develop, making it difficult to pinpoint the exact cause. Currently, asbestos is the only known and proven cause of malignant mesothelioma, making up 90% of reported cases. Research efforts continue to also look at mesothelioma etiology to understand any potential causes and more about asbestos.

Mesothelioma and Asbestos Exposure

When asbestos is disturbed, the fibers become airborne and may be swallowed or inhaled, eventually becoming lodged in the delicate lining of the lungs, abdomen or heart. The fibers cause irritation and scarring, which can mutate, inhibiting the body’s natural cancer defenses. Eventually, this scar tissue may develop into tumorous growths, leading to a mesothelioma diagnosis.

While the connection between asbestos and deadly lung diseases was known prior to the 1900s in asbestos mine workers, it wasn’t until the 1960s that an official study linked asbestos exposure with incidents of mesothelioma and other asbestos-related diseases.

One of the most common places that asbestos exposure occurs is in the workplace. However, dorms, schools and older homes have also been seen to contain asbestos that often becomes disturbed during renovations, repairs and expansions.

Common Occupations Risking Asbestos Exposure
  • Firefighters
  • Mechanics
  • Shipyard workers
  • Construction workers
  • Machine workers
  • Boiler workers
  • Demolition crews
  • Pipefitters
  • Steel mill workers
  • Asbestos product manufacturers
  • Power plant workers
  • Railroad workers
  • Auto shop workers
  • Miners
  • Roofers
  • Carpenters
  • Floor installers
  • Mill workers
  • Insulation installers
  • Oil refinery workers

Because asbestos is strong and water, fire and chemical resistant, it was used extensively in various products and manufacturing processes. Asbestos has been used in everything from machine shops and industrial spaces to floor tiles and insulation in older homes, making it a rather common ingredient in many products and materials still used today.

Common Materials Containing Asbestos
  • Insulation
  • Electrical wiring
  • Piping materials
  • Paint
  • Roofing
  • Flooring
  • Vehicle parts (brake pads)
  • Fireproof clothing
  • Potting soils
  • Contaminated talcum powder

If you suspect the presence of asbestos, contact a certified removal professional. Disturbance of the material could make the fibers airborne, exposing you to the cancer-causing material. A professional can test the materials for asbestos safely and determine if removal or containment is necessary.

Other Mesothelioma Risk Factors

While 90% of mesothelioma cases have been directly linked to asbestos exposure, research has suggested there are other mesothelioma risk factors that could be potential causes or contributors to mesothelioma development, including:

More Potential Mesothelioma Risk Factors
Radiation exposure

Some mesothelioma cancer patients feel that exposure to radiation caused their mesothelioma, without any asbestos exposure, though this is yet to be confirmed.

High aspect ratio nanoparticles (HARNs)

Some cases have demonstrated a link between HARNs (such as carbon nanoparticles) and mesothelioma, but without conclusive evidence.


Zeolites are silicone-based materials that exhibit similar characteristics to asbestos fibers, also acting as potential risk factors for the cancer. Erionite in particular has been associated with mesothelioma, especially within cases in Cappadocia, Turkey, where the mineral exists naturally.

Simian Virus 40 (SV40)

Research shows that the SV40 virus doesn’t appear to be a direct cause of malignant mesothelioma, but could be a contributing factor to some mesothelioma cases.

Who Is Most Susceptible to Developing Mesothelioma?

In addition to asbestos and other potential causes of mesothelioma, there are pre-existing risk factors that could make an individual more or less likely to develop the cancer.

  • Age: 91% of diagnosed mesothelioma patients are 55 years of age or older.
  • Gender: More than 75% of mesothelioma deaths are men.
  • Genetics: Mutation of the tumor-suppressing BAP1 gene can inhibit the body’s ability to fight cancer cells. While mesothelioma is not contagious or genetic, mutation of this gene can run in the family, creating a hereditary risk.
  • Duration of asbestos exposure: Increased exposure increases the likelihood of asbestos fibers entering the body, along with increased irritation, scarring, mutation and therefore increased chance of developing mesothelioma.
  • Smoker vs. non-smoker: While there is no proven direct link between smoking and mesothelioma, data has shown that smokers who have been exposed to asbestos are 50–90% more likely to develop lung cancer. Similarly, asbestos-exposed individuals that smoke are twice as likely to develop mesothelioma.

Mesothelioma Prevention

Asbestos has yet to be fully banned, and is therefore still present in many of our environments and products. Efforts continue to identify and eliminate sources of asbestos, with help from the Environmental Protection Agency (EPA) in instating asbestos laws and with continued mesothelioma research from organizations like the National Cancer Institute.

To prevent contact with the cancer-causing materials, individuals should educate themselves on asbestos, including what products still contain the toxin and where it has been found. If asbestos or asbestos-like mineral fibers are suspected, they should not be disturbed. A certified asbestos removal expert should be brought in to handle and dispose of the toxin.

Knowing the other known mesothelioma risk factors can help individuals be more conscious of a potential diagnosis. Furthermore, any suspected symptoms should be addressed with a health care provider immediately. Early detection is key to ensuring a wide range of cancer care treatment options and the longest life expectancy possible.