The primary cause of mesothelioma is asbestos. The asbestos fibers stick to the lining of the lungs and other organs, eventually causing mesothelioma. The main mesothelioma risk factor is asbestos exposure. Other risk factors for mesothelioma are occupational and secondhand exposure, age and gender.
Written by: Dr. Daniel Landau | Edited By Amy Edel | Last Update: July 30, 2025
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Dr. Marcelo DaSilva: What causes mesothelioma?
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Expert Take
Dr. Marcelo DaSilva: What causes mesothelioma?
Asbestos exposure is the main 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.
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Get Your Free GuideKey Facts About Mesothelioma Causes
Most mesothelioma cases come from asbestos exposure at work or in the military. Some people develop mesothelioma from secondhand contact. Workers have accidentally carried asbestos home on their bodies, clothes or gear. This has put their families at risk.
Other risk factors can raise the chance of cancer in those exposed to asbestos. Doctors have researched other potential causes and risk factors. Some of these possible causes include genetics and exposure to radiation.
Mesothelioma cancer develops after asbestos fibers get stuck in the mesothelium and cause irritation over time. This leads to inflammation and scarring. These fibers can make unstable tiny particles called free radicals that can damage DNA, causing cells to become cancerous.
The duration and intensity of asbestos exposure impact how much DNA damage occurs. More exposure means a greater risk of getting mesothelioma. This is called a dose-response relationship. Even one heavy exposure can lead to a mesothelioma cancer diagnosis decades later.
For example, the toxic dust cloud from the 9/11 attack in New York exposed many people to a single instance of a large volume of asbestos. Many of these people, including first responders, developed mesothelioma.
The biggest risk factor for mesothelioma is asbestos exposure. Risk factors are characteristics or behaviors that increase the chances of developing a specific disease. Other risk factors include genetics, age, gender and different types of asbestos exposure.
Mesothelioma Risk Factors
Exposure to asbestos can happen at work, in older homes, in public buildings and in the environment. Asbestos fibers were used because they make products heat resistant but they can break down and create toxic dust. Workers in commercial and industrial sectors have faced higher exposure risks.
Pleural mesothelioma survivor Terry Latham’s asbestos exposure happened during 10 years of construction work. Terry tells us he received his diagnosis decades later. Now, he’s one of the longest-living pleural survivors. He shares, “People should know you can get through it, but you can’t stop fighting. Whatever you do, don’t give up.”
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Get Help NowOccupational asbestos exposure is the No. 1 cause of mesothelioma. Among the highest-risk groups are miners and industrial workers, who have long faced significant exposure. Shipyard workers, as well as those in boiler rooms and power plants, are also at risk.
Additionally, legacy asbestos present in older buildings continues to pose a hazard. Construction workers and firefighters encounter risks related to legacy asbestos, especially during renovation, demolition or disaster response. Auto mechanics remain exposed when working with legacy asbestos brakes and clutches.
Veterans get mesothelioma from military asbestos exposure. The U.S. military used asbestos extensively in bases, vehicles, ships and planes. Navy personnel faced higher risks because asbestos was widely applied on ships to reduce the spread of fire. In addition, boiler workers, pipefitters and shipyard workers involved in military shipbuilding and maintenance used asbestos products heavily during their operations.
Navy veteran John Conway tells us he remembers stripping asbestos insulation as part of his job. Decades later, John shares with us that he developed pleural mesothelioma. “It used to look like it was snowing down there,” John recalls about the airborne asbestos fibers he witnessed.
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 shares with us.
Secondary asbestos exposure happens when workers bring tiny asbestos fibers home on skin, clothes, shoes, or tools. These fibers can spread into the air and settle on surfaces, putting family members and others close by at risk of breathing asbestos. This take-home exposure is the most common secondary form. It can lead to serious illnesses years later.
For example, barbers and ceramics workers used asbestos-contaminated talcum powder. Taking these fibers home raised the risk of cancer among family members. An engineer exposed to asbestos at work could also carry fibers into a shared office with people who don’t work directly with asbestos, but are exposed as fibers spread in the shared space.
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.
Living near asbestos deposits carries a risk of exposure. Tiny fibers can remain airborne in these areas, posing a potential health hazard. The danger is greatest close to old asbestos mines and factories.
Although the risk of disease from living near asbestos mines is lower than from working directly with asbestos, research suggests it accounts for about 3% of all mesothelioma cases. For women, that number rises significantly to 19%.
Some minerals, such as eronite, often occur near asbestos deposits. Eronite isn’t a form of asbestos but contains long, thin fibers similar to asbestos. Because of this, eronite deposits can present an additional exposure risk in affected areas.
Mesothelioma is diagnosed more often in men than in women. Data shows men had an incidence rate 2.4 times higher than women, according to the most recent CDC and SEER statistics from 2020. However, the CDC has also reported a recent sharp rise in cases of mesothelioma in women.
Women’s asbestos exposure historically came mainly from secondary exposure or from living near asbestos sites. Today increased occupational exposure to legacy asbestos and use of asbestos-contaminated products like talc may be responsible for the rise in incidence. Better medical awareness also has helped doctors identify more cases in women than before.
Age is another important factor in mesothelioma risk. Most people receive their diagnosis between ages 75 and 79, reflecting how long the disease takes to develop after exposure. The latency period for mesothelioma is 20 to 60 years. However, cases have been found in teens and young adults in their 20s as a result of early-life asbestos exposure.
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.
Some genetic factors can increase a person’s chance of getting mesothelioma after asbestos exposure. Mesothelioma itself isn’t passed down from parents to children. It’s not inherited like some other diseases. However, a change or mutation in a gene called BAP1 can make someone more likely to develop mesothelioma if they come into contact with asbestos.
Genes carry instructions for how our bodies work, and mutations are small differences in those instructions. When the BAP1 gene has certain mutations, it can affect how cells grow and repair themselves. These changes are often found in mesothelioma tumors and can help explain why people with this mutation are at higher risk.
Because of this discovery, doctors now suggest that testing for BAP1 gene mutations should be part of diagnosing mesothelioma. This testing can help patients and their doctors better understand the disease and guide treatment choices.
Workers on nuclear submarines and in propulsion plants faced widespread asbestos exposure from insulation and fireproofing, putting them at higher risk for mesothelioma. Research indicates that the high doses of radiation these workers received on such vessels may add to their mesothelioma risk.
This radiation exposure differs greatly from the low levels people receive from medical imaging, such as X-rays and CT scans. Radiation from imaging scans has not been linked to mesothelioma risk.
Researchers have found Simian Virus 40, or SV40, in some cancer tumors. However, there is no evidence that SV40 causes mesothelioma. Scientists continue to study SV40 to understand if it plays any role in the disease.
Employers must provide safe working conditions to prevent mesothelioma. They’re responsible for keeping workplaces free of asbestos, providing personal protective equipment and conducting proper training. If workers notice safety violations, they should talk with their union representatives or file a report with the Occupational Safety and Health Administration. OSHA then investigates.
The public can lower their risk when they avoid asbestos products including consumer goods, home building materials and automotive parts. Older homes, salvaged and vintage materials and classic auto parts can contain legacy asbestos and put DIY-ers at risk.
Tips to Reduce Asbestos Exposure
If you’ve already been exposed and worry about your health, our Patient Advocates can connect you with a doctor to screen for mesothelioma. Early detection improves treatment options.
See your doctor promptly if you experience symptoms of mesothelioma such as shortness of breath, chest pain or abdominal discomfort. Patient Advocates can connect you with specialists who offer expert care.
“Asbestos exposure is the primary cause of mesothelioma. Still, there is no predictability as to who or when the exposure will progress to the development of mesothelioma and where it will manifest in the body.”
We asked our Patient Advocates about the questions people ask when they call us about the cause of mesothelioma. Here are some common questions and helpful answers.
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.
Mesothelioma is a rare form of cancer. There were about 2,800 new cases in the U.S. in 2021, the most recent year of available data. There is about 1 new case per 100,000 people annually. 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.
Asbestos can change healthy cells into cancer cells decades after exposure. The fibers start an inflammation that slowly harms genes and can lead to cancer 20 to 60 years later. After tumors form, mesothelioma can swiftly advance to stage 3 or 4. Symptoms may appear after this progression.
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.
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My family has only the highest compliment for the assistance and support that we received from The Mesothelioma Center. This is a staff of compassionate and knowledgeable individuals who respect what your family is experiencing and who go the extra mile to make an unfortunate diagnosis less stressful. Information and assistance were provided by The Mesothelioma Center at no cost to our family.LashawnMesothelioma patient’s daughter
Asbestos.com. (2025, July 30). Mesothelioma Causes & Risk Factors. Retrieved July 30, 2025, from https://www.asbestos.com/mesothelioma/causes/
"Mesothelioma Causes & Risk Factors." Asbestos.com, 30 Jul 2025, https://www.asbestos.com/mesothelioma/causes/.
Asbestos.com. "Mesothelioma Causes & Risk Factors." Last modified July 30, 2025. https://www.asbestos.com/mesothelioma/causes/.
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Dr. Daniel Landau is the Medical Director of Virtual Hematology at the Medical University of South Carolina in Charleston. He has served in several leadership roles and developed telehealth services at several cancer centers.
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