Mesothelioma Causes

What’s the Primary Cause of Mesothelioma?

Mesothelioma is primarily caused by asbestos exposure. Many people diagnosed with mesothelioma were exposed to asbestos while working certain jobs that required them to handle asbestos-containing products, or were exposed while serving in the military.

Mesothelioma was virtually unknown until the 20th century. Mesothelioma incidence rates rose as industries expanded the use of asbestos.

How Does Asbestos Cause Mesothelioma?

When asbestos is inhaled or swallowed it becomes trapped in mesothelial tissues, where the asbestos fibers create the inflammation, scarring and cell damage that cause mesothelioma.  

There is a dose-response relationship between asbestos and the development of mesothelioma, which means your risk of getting this cancer increases with every exposure. However, not everyone exposed to large amounts of asbestos will develop the disease.  

When asbestos fibers travel through the body they can cause different types of mesothelioma. For example, when fibers get stuck in the pleura, which is the lining of the lungs, pleural mesothelioma can develop. When fibers are deposited in the peritoneum, which is the lining of the abdominal cavity, peritoneal mesothelioma can develop. 

In rarer cases, asbestos travels through the bloodstream to the heart or testes, causing pericardial or testicular mesothelioma, respectively.

Watch: Learn how mesothelioma can develop in different parts of the body from mesothelioma specialist Dr. Marcelo DaSilva.

Asbestos and Uncontrolled Cell Growth

Mesothelioma develops as a result of cell and DNA damage primarily caused by asbestos fibers. Cells are small biological structures that make up every part of the human body. DNA is the hereditary material in our cells that is passed down from our parents and makes up our genes. DNA contains a code that tells our cells how to function properly, and asbestos fibers can damage this code.

Once asbestos is inhaled, the body has a hard time getting rid of the fibers. The fibers become lodged in tissues and accumulate with repeated exposure. After many years, asbestos causes inflammation and scarring that damages DNA and turns normal cells into cancer cells. This results in uncontrolled cell growth, abnormal cell accumulation and the development of mesothelioma tumors.

It takes an average of 20 to 60 years for asbestos fibers to turn normal mesothelial cells into cancerous mesothelioma cells. The time between exposure and development of disease is known as the latency period. It takes decades for asbestos fibers to cause damage that leads to mesothelioma, but once mesothelial cells turn cancerous, they can quickly form mesothelioma tumors that grow and spread within months or a few years. 

Mesothelioma starts in mesothelial cells, which make up the protective membranes of the mesothelium that covers the lungs, abdomen and heart.

Mesothelioma Causes vs. Risk Factors

A mesothelioma risk factor is anything that increases the odds of developing a disease. For example, working in the construction industry is a risk factor for mesothelioma, it does not mean the industry causes mesothelioma. Asbestos remains the primary cause of mesothelioma. 

Most mesothelioma risk factors involve different sources of asbestos exposure. Other risk factors, such as genes you inherit or exposure to simian virus 40, known as SV40, have not yet been proven to cause mesothelioma.  

More than 125 million people throughout the world are currently at risk of exposure to asbestos in the workplace, according to the World Health Organization. About 1.3 million workers in construction and general industry remain at risk of asbestos exposure in the U.S.

PRIMARY RISK FACTORS FOR MESOTHELIOMA

• Military asbestos exposure
• Occupational asbestos exposure
• Living with someone who worked with asbestos
• Environmental asbestos exposure
• DIY automotive and home renovation projects

Other potential risk factors that remain unproven causes of mesothelioma include genetic factors and exposure to radiation, zeolite minerals and the polio vaccine between 1955 and 1963 that was contaminated with simian virus 40 (SV40).

Because the combination of smoking cigarettes and exposure to asbestos greatly increases the risk of developing lung cancer, smoking often gets mistaken as a mesothelioma risk factor. Smoking on its own or in combination with asbestos exposure does not increase the risk of developing mesothelioma.

Occupational Asbestos Exposure

Asbestos exposure primarily happens in a workplace setting, and it can result in secondary exposure to family members. Exposure can also happen in the natural environment or through asbestos products at home, but these types of exposures are less likely to lead to mesothelioma.

Asbestos was widely used in thousands of commercial, industrial and domestic products. Examples include drywall, insulation, piping, glues and adhesives, ceiling tiles, cement and shingles.

The risk for asbestos-related illnesses is highest for people who worked with the raw mineral or with asbestos-containing products daily. Workers who manufactured or used asbestos products were exposed to asbestos on the job. Research shows approximately 8% to 13% of asbestos workers eventually develop mesothelioma. 

HIGH-RISK OCCUPATIONS FOR MESOTHELIOMA CANCER

• Shipyard workers
• Construction workers
• Power plant workers
• Chemical plant workers
• Industrial workers
• Insulators
• Boiler workers
• Auto mechanics

Construction tradesmen and firefighters can be exposed to asbestos while working in old homes and structures built with contaminated materials. Exposure can happen during a renovation, demolition or disaster response. 

Veterans also cope with higher rates of mesothelioma because the U.S. armed forces used asbestos in every branch of the military. Those who served in the Navy faced the highest risk of exposure because asbestos was used to prevent fires in shipyards and vessels.

Secondhand Exposure to Asbestos

When the asbestos industry was booming, families of workers were also at risk. Workers often came home with asbestos fibers on their hair, work clothes, shoes and tools. This exposed family members to the toxic substance and increased their risk for mesothelioma and related diseases.

Those who worked with asbestos-contaminated talc products, such as barbers and ceramics workers, also unknowingly brought asbestos fibers home, which caused mesothelioma among their children and spouses.

“My father worked in steel mills for years and I remember washing his clothes, which were covered in dust. “

Judy Goodson

Diagnosed with peritoneal mesothelioma in 2013

Environmental Asbestos Exposure

Because asbestos is a naturally occurring mineral, people living near large deposits in hilly or mountainous regions also face exposure. Minimal amounts of the mineral can fill the air in these regions. Still, environmental exposure is most dangerous near former asbestos mines. 

For example, in June 2009, the U.S. Environmental Protection Agency declared a public health emergency in Libby, Montana, stemming from an asbestos-contaminated vermiculite mine in the town. The agency has cleaned up the town, but thousands of residents have been diagnosed with asbestos-related diseases, including mesothelioma.

Preventing Mesothelioma

Occupational asbestos exposure is the primary cause of mesothelioma. The best way to prevent mesothelioma is to follow workplace safety regulations. Protect yourself by learning more about how you might be exposed to asbestos at work and at home. 

Those who work with asbestos products should follow safety procedures to protect themselves and decontamination protocols to prevent secondary asbestos exposure among family members they live with. 

Be cautious of materials in old homes that may contain asbestos. Test for asbestos before starting renovations and hire a professional asbestos abatement company to remove materials containing asbestos.If you or a loved one has a history of asbestos exposure — especially in the workplace — don’t wait for symptoms to arise. Instead, be proactive and talk to your doctor. Early detection offers the best opportunity for effective mesothelioma treatment.

Common Questions About Mesothelioma Causes

Is asbestos the only cause of mesothelioma?

Approximately 80% of mesothelioma cases are caused by known exposure to asbestos. Studies have shown that radiation treatment for other cancers or certain genetic markers may increase the risk of developing mesothelioma. However, asbestos remains the only proven primary cause of the disease.

Who is at risk for mesothelioma?

Occupational asbestos exposure is the primary cause of mesothelioma. Construction workers, firefighters, industrial workers, power plant workers and shipyard workers have the greatest risk of asbestos exposure.

Families of blue-collar workers are at risk of secondary asbestos exposure and mesothelioma. People who worked with asbestos would often carry fibers home on their skin, hair, clothes and tools.

There is no safe amount of exposure to asbestos due to the size and shape of asbestos fibers. The risk of developing mesothelioma is greater with increased exposure to asbestos. Trace amounts of asbestos on clothes and skin are enough to cause mesothelioma by secondary exposure.

What should I do if I think I am developing mesothelioma?

If you are experiencing respiratory symptoms or other signs of mesothelioma and have a history of asbestos exposure, talk with your physician about being screened for the disease.

Mesothelioma doctors will order CT imaging scans and other tests based on your history of asbestos exposure to determine if you are developing mesothelioma.