What Causes Mesothelioma? 

Asbestos exposure is the No. 1 cause of mesothelioma. Mesothelioma develops decades after microscopic asbestos fibers are inhaled or ingested. The fibers get trapped in a thin layer of tissue called the mesothelium. This smooth tissue lines the lungs, abdomen, heart and testes.

Asbestos fibers can pierce this lining. They cause inflammation and damage to the mesothelial cells. Over time, this damages the DNA of your cells and can cause mesothelioma tumors to form.

Key Facts About Mesothelioma Causes
  1. Out of all people with heavy, prolonged exposure to asbestos, 8% to 13% develop mesothelioma.
  2. Asbestos workers with years of exposure have the highest risk of developing mesothelioma.
  3. Because there is no safe amount of asbestos exposure, limited exposure can also cause mesothelioma.

Most mesothelioma cases are caused by asbestos exposure at work or in the military. Some people also develop mesothelioma because of secondhand contact. Workers have inadvertently brought asbestos home on their bodies, clothing or gear, exposing their families.

Asbestos-contaminated talc can also cause mesothelioma. Other risk factors can raise the chance of cancer in those exposed to asbestos. Examples include family history, genetics and exposure to radiation.

“Mesothelioma is caused by exposure to asbestos,” says Dr. Marcelo DaSilva, chief of thoracic surgery at AdventHealth Cancer Institute. “Patients inhale asbestos, which causes chronic inflammation that changes its DNA into a cancer cell.”

How asbestos causes mesothelioma to develop
Asbestos damages mesothelial cells and mutates them into cancerous mesothelioma cells.

Mesothelioma Risk Factors

Asbestos exposure is the biggest risk factor for a mesothelioma cancer diagnosis. Risk factors are characteristics that increase the likelihood of developing a particular disease. Other risk factors include genetics, age, gender and other exposures.

Exposure to asbestos can occur in the workplace, older homes, public buildings and the environment. While many people know if they’ve been exposed to asbestos, others may not be aware of their exposure.

Risk Factors for Mesothelioma
  • Environmental asbestos exposure
  • Family history
  • Gender & age
  • Lifestyle (diet, smoking and other choices)
  • Military asbestos exposure
  • Occupational asbestos exposure
  • Secondhand exposure to asbestos

There are several types of asbestos exposure: Occupational, military, secondary and environmental. Asbestos fibers were used in construction, auto parts and machinery for their heat resistance. But they can break down and create toxic dust. Home exposure happens when homeowners or others in the house come in contact with older construction products that used asbestos.

Raeleen Minchuk, a peritoneal mesothelioma survivor from Canada, was exposed to asbestos in her grandparent’s home. She was just a baby when her grandfather renovated his home. Raeleen crawled on the floor covered with asbestos dust. At the time, the public wasn’t aware of the dangers of asbestos.

Occupational Asbestos Exposure

Occupational asbestos exposure poses the highest risk of disease. This is especially true for miners and factory workers who made asbestos products.

Construction workers and firefighters today encounter legacy asbestos when working in older buildings. The risk is high during renovation, demolition or disaster response. Other occupations at risk of mesothelioma include industrial, factory and textile mill workers. Shipyard, boiler and power plant workers also worked around many asbestos products.

Historically, men were more likely to have jobs with a greater risk of contact with asbestos. This has traditionally led to higher mesothelioma incidence rates in men than women. The U.S. Centers for Disease Control recently reported a sharp rise in mesothelioma cases in women.

The duration and intensity of asbestos exposure can affect a person’s risk of developing mesothelioma. This is called a dose-response relationship. However, any amount of asbestos exposure can potentially lead to mesothelioma.

Military Asbestos Exposure

Veterans also experience higher rates of mesothelioma because of asbestos exposure. Every branch of the military used asbestos extensively on bases and in vehicles, ships and planes.

Veterans at Risk of Mesothelioma
  • Aircraft mechanic
  • Boatswain’s mate
  • Boiler technician
  • Coast Guard members
  • Electrician’s mate
  • Fire control technician
  • Maintenance technician
  • Merchant Marines
  • Military base residents
  • Navy veterans
  • Pipefitter
  • Shipyard workers
  • Welders

Those who served in the Navy faced the highest risk of exposure. Asbestos reduced fires on ships. It was also used in protective gear, like respirators and heat-resistant gloves, for operating gun turrets.

Retired Navy veteran John Conway worked as a boiler technician. He remembers stripping asbestos insulation. Decades later, John developed pleural mesothelioma. “It used to look like it was snowing down there,” John said.

Survivor Story
Survivor Story
John Conway Pleural mesothelioma

Navy Boiler Technician Exposed to Asbestos

John Conway worked as a Navy boiler technician when ships heavily used asbestos. He then worked for the Merchant Marines for 24 years. “I was proud to serve. It was fun, too. It took me around the world three times,” he told us. “When I was stripping asbestos insulation from below-deck steam pipes it looked like it was snowing down there. I never thought about any long-range danger.

Read John’s Story

Environmental Asbestos Exposure

Living near large asbestos deposits in hilly areas risks exposure. Minimal amounts of microscopic fibers can linger in the air in these regions. This is most dangerous near former asbestos mines and manufacturing plants.

In June 2009, the U.S. Environmental Protection Agency declared a public health emergency in Libby, Montana. The hazard arose from an asbestos-contaminated vermiculite mine in the town. Thousands of Libby residents have been diagnosed with asbestos-related diseases, including mesothelioma. 

The risk of disease from living near asbestos mines is lower than from working with asbestos. Research suggests that this may cause 3% of all mesothelioma cases and 19% of cases in women.

Secondary Exposure

Secondary exposure happens when someone carries asbestos fibers home. It gets carried on their skin, hair, clothing, footwear or tools. Those fibers could then spread into the air, putting those around them at risk of exposure. People with high-contact jobs with asbestos were most at risk. They could bring home fibers on their bodies, uniforms or work tools.

My mesothelioma was caused by my father’s work clothes. He had been a lagger and worked with asbestos all through my childhood. He died of mesothelioma in 1989.

The widespread use of asbestos in many products puts thousands at risk for primary and secondary exposure. For example, barbers and ceramics workers used talc contaminated with asbestos. Bringing these fibers home caused cancer in many of their family members. Women and children are more likely to have secondary exposure.

Gender,  Age and Genetics

Men are more likely than women to develop mesothelioma. Men are also more likely to have occupational asbestos exposure. Mesothelioma occurred 2.4 times more often in men than in women in 2020. This is the most recent data from the U.S. Centers for Disease Control and Prevention and SEER. Women are more likely to be exposed to asbestos through contaminated talc used in talcum powder.

One piece of advice who I would give to a woman who has been recently diagnosed with mesothelioma is this. Let me encourage you for a moment. You have access to treatments, different treatments. You have the right to get a second opinion. You have the right to ask questions. You have the right to find the specialist who you want for your journey.

The CDC reported in 2020 that most people get diagnosed between ages 75 and 79. Mesothelioma risk increases with age because mesothelioma takes 20 to 60 years to develop after exposure. This does not mean that young people do not get mesothelioma from asbestos exposure. Cases of asbestos-related mesothelioma have occurred in teens and young adults in their 20s.

Genetic factors can increase the risk of various types of cancer. Mutations of a gene called BRCA-associated protein 1 (BAP1) often exist in mesothelioma cancer cells. These mutations can be inherited from a parent or acquired during a person’s lifetime. Mesothelioma is not inherited. But if a person inherits this specific mutation, it will increase their risk of mesothelioma.

Other Potential Risk Factors

Other risk factors include exposure to radiation, Simian Virus 40 and asbestiform minerals like erionite. Tobacco smoking, diet and nutrition are not risk factors for mesothelioma. But smoking combined with asbestos exposure significantly increases the risk of lung cancer.

Exposure to ionizing radiation may be a risk factor for mesothelioma. X-rays, gamma rays and other forms of ionizing radiation can increase the risk of different types of cancer. Exposure to high doses of radiation may be a risk factor for mesothelioma. Radiation therapy for cancer is an example. Low doses of radiation from X-rays, CT scans and occupational exposure are not risk factors.

Simian Virus 40 is a virus linked to several types of cancer, including mesothelioma. SV40 does not usually cause illness in humans and is not known to cause mesothelioma. However, research indicates that many mesothelioma cases show the presence of SV40 in cancer cells. Ongoing research will determine whether it is a risk factor for mesothelioma.

Dr. Jacques Fontaine and Dr. Andrea Wolf
Find a Top Mesothelioma Doctor

Gain access to top mesothelioma doctors and get help scheduling appointments.

Connect Now

How to Lower Your Risk of Mesothelioma 

Preventing mesothelioma means reducing exposure to asbestos. It is the main cause of this cancer. Asbestos exposure at work is the main cause of this cancer. To prevent mesothelioma, we must follow asbestos workplace safety guidelines

“If you’ve been a construction worker or were repairing cars or were in the Navy, and you’re starting to experience shortness of breath or trouble breathing or pain in your chest, it’s important to speak about it with your physician,” says Dr. Jacques Fontaine, director of the Mesothelioma Research and Treatment Center at Moffitt Cancer Center.

Tips to Reduce Asbestos Exposure
  • Avoid wearing clothing, footwear and other work gear at home that could harbor asbestos fibers.
  • Be careful when buying vintage, antique, or upcycled items that may contain asbestos.
  • Discuss your work history with your doctor. Schedule tests for early detection.
  • Hire a reputable professional asbestos abatement company to test and remove asbestos from your home.
  • Purchase talc-free cosmetics and personal care items.
  • Talk to your employer about asbestos risks and the policies in place to mitigate those risks.

If you or a loved one has a history of asbestos exposure, talk to your doctor about screenings for mesothelioma. Early detection offers the best opportunity for effective mesothelioma treatment.

If you develop respiratory, abdominal or other mesothelioma symptoms, see your doctor right away. Initial symptoms of mesothelioma can include shortness of breath, chest pain or abdominal distress. Patient Advocates can help connect you with a specialist for a diagnosis, second opinion and specialized treatment.

Common Questions About Mesothelioma Causes

How much exposure to asbestos will cause mesothelioma?

Most people with asbestos exposure will never develop mesothelioma. However, any asbestos exposure can cause mesothelioma. Chronic exposure carries the highest risk, but even a single exposure can lead to mesothelioma.

How likely am I to develop mesothelioma?

Mesothelioma is a rare form of cancer. There are about 3,100 new cases per year in the U.S. There were 0.7 new cases per 100,000 people in 2018. Mesothelioma is very rare in people without any known asbestos exposure. High-risk occupations for asbestos exposure include construction, power generation, shipbuilding and industrial work.

How long does it take for mesothelioma to develop?

Asbestos fibers turn healthy cells into cancer cells decades after exposure. The fibers initiate an inflammatory process that slowly causes genetic damage and eventually cancer 20 to 60 years later. Once tumors form, mesothelioma can quickly progress to stage 3 or 4 before causing symptoms.

Does smoking cause mesothelioma?

No, smoking does not cause mesothelioma. The primary cause of mesothelioma is exposure to asbestos fibers. Smoking and tobacco use are linked to lung cancer and other cancers. But, they are not linked to a higher risk of mesothelioma.

Answered By: Anna Nowak, internationally renowned asbestos researcher and mesothelioma advocate.

Recommended Reading
  •  
  •  
  •  
Tell us what you think

Did this article help you?

Connect with Our Community

Get in Touch

Have questions? Call or chat with our Patient Advocates for answers.

Join Our Support Group

Join our support groups to connect and learn from others with mesothelioma.

Upcoming Events

Upcoming Events: Check the calendar for dates and details.