What causes Mesothelioma?

Mesothelioma is a rare and aggressive cancer. In nearly all cases, it is caused by one thing: exposure to asbestos.

But that simple answer often leads to more questions. How exactly does asbestos cause cancer? How much exposure is dangerous? And why can mesothelioma take decades to appear?

This article explains how asbestos exposure leads to mesothelioma, who is most at risk, and what to do if you’re concerned about your past exposure.

Asbestos: The only known cause of Mesothelioma

Asbestos is a group of naturally occurring minerals made up of thin, durable fibres. For much of the 20th century, it was widely used in Australia in construction materials, brake pads, insulation, and roofing due to its heat-resistant and fireproof properties.

The danger lies in the fibres themselves. When materials containing asbestos are disturbed — through cutting, drilling, demolition or even deterioration — they release microscopic fibres into the air. These fibres can be inhaled or swallowed, embedding themselves in the thin lining that surrounds the lungs, abdomen, heart, or testes.

In Australia, asbestos use was only fully banned in 2003 — and many buildings and materials still contain it today. That’s why exposure remains a concern, even now.

Learn more at the Asbestos Safety and Eradication Agency.

How Asbestos exposure leads to Mesothelioma

When asbestos fibres enter the body, they are difficult to remove. The immune system tries to attack them, but can’t break them down. Over years — often decades — the presence of these fibres causes chronic inflammation, scarring, and damage to nearby cells.

Eventually, some of those cells can mutate and become cancerous. In mesothelioma, the cancer forms in the protective linings (mesothelium) of internal organs — most commonly the lungs (pleural mesothelioma) or abdomen (peritoneal mesothelioma).

This slow and silent process is why mesothelioma typically doesn’t appear until 20 to 50 years after the original exposure.

Who is most at risk of exposure?

Some people exposed to asbestos remember the moment clearly — others never knew it happened. That’s what makes this disease so difficult and unjust.

People at highest risk include:

• Tradespeople — Builders, plumbers, electricians, carpenters and roofers who worked in homes or buildings built before the 1990s.
• Shipyard and factory workers — Especially those in industries using insulation, gaskets, or asbestos textiles.
• Veterans — Particularly Navy personnel, due to asbestos in ships.
• DIY renovators — Many home handymen and women were exposed while cutting or sanding asbestos sheeting.
• Family members — Fibres brought home on clothing or in the car have caused second-hand exposure and disease in spouses and children.

In many cases, the person affected had no reason to believe they were in danger. That’s why public awareness and accurate information remain so important.

Is Mesothelioma ever caused by something else?

In Australia, asbestos is overwhelmingly the cause of mesothelioma.

However, researchers continue to investigate a small number of rare cases with no clear asbestos exposure. Possible factors in these extremely rare cases might have involved contaminated talc products or exposure to erionaite or radiation. While these are areas of scientific interest, they represent such a tiny fraction of total cases. For practical and public health purposes, mesothelioma is considered an asbestos-caused disease.

How can I know if I’ve been exposed?

Some people are aware of their past asbestos exposure, especially if it was work-related. Others may only discover the risk years later, when health problems appear or a loved one is diagnosed.

If you believe you were exposed — even decades ago — it’s worth speaking to your GP. Keep a record of the kind of work or activity involved, whether protective equipment was used, and if you experienced prolonged or repeated exposure.

You may be eligible for free health monitoring through a state-based occupational health program.

For confidential guidance, you can also contact ADDRI’s Mesothelioma Support Nurse, who can help you understand your options and next steps.

Next steps: Support and resources

Mesothelioma is preventable — and entirely unjust. But if you or someone close to you has been affected, support is available.

• Learn more about the disease on our page What is Mesothelioma? Causes, Diagnosis, and Support
• Connect with our Support Nurse for personalised advice
• Explore our Research Projects
• Listen to the Dust Diseases Podcast
• Subscribe to our newsletter for updates and community stories

At ADDRI, we’re working toward a future where no one loses their life to asbestos. Until then, we’re here to support, advocate and inform — every step of the way.

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