Causes and risk factors of mesothelioma

Asbestos is the most common cause of mesothelioma. Over 9 out of 10 cases of mesothelioma are caused by exposure to asbestos fibres.


Over 9 out of 10 cases of mesothelioma are caused by exposure to asbestos fibres. Asbestos is a natural mineral found in many countries.

There are three main types of asbestos:

  • blue (crocidolite)
  • brown (amosite)
  • white (chrysotile).

They were used in UK industries until the ban on imports of blue and brown asbestos in the 1980s, and on all types in 1999. Exposure to blue, brown and white asbestos is linked with mesothelioma.

Mesothelioma does not usually develop until many years after exposure to asbestos. It can take 15 to 60 years. But the average time for pleural mesothelioma to develop after exposure to asbestos is about 30 to 50 years. It may be less time for peritoneal mesothelioma.

Sometimes mesothelioma develops in people who did not know, or perhaps cannot remember that they have been exposed to asbestos.

Pleural mesothelioma

When asbestos is damaged or disturbed (often by hitting, rubbing or handling), it releases tiny fibres. These fibres can be breathed into the lungs. Asbestos fibres are very fine and can get into the smallest airways of the lungs. Once the fibres are in the lungs, the body tries try to break them down and remove them. This causes inflammation in the lung tissue, which can cause lung disease.

The asbestos fibres can also travel through the lung tissue and settle in the outer lining of the lung (the pleura). Over many years, these fibres can cause pleural mesothelioma or other lung conditions.

We have more information on mesothelioma symptoms.

Peritoneal mesothelioma

Asbestos fibres can also be swallowed, and some can get stuck in the digestive system. They can then move into the outer lining of the tummy (abdomen), called the peritoneum. Here, they cause swelling and thickening of the lining. This can cause peritoneal mesothelioma.

Exposure to asbestos

People most likely to have been exposed to asbestos at work include:

  • joiners and construction workers
  • plumbers
  • electricians
  • boilermakers
  • launderers
  • dock workers and shipbuilders.
  • power station workers
  • people who served on warships.

Mesothelioma is 5 times more common in men than in women. This is because when asbestos was used in these industries, it was mostly men who did these types of jobs.

People who have not worked directly with asbestos can also sometimes develop mesothelioma. This is called environmental exposure. For example, this might include:

  • family members of people who have worked with asbestos and might have brought the dust home on their clothes
  • people who lived near asbestos factories
  • people who worked in buildings containing asbestos materials that were damaged or disturbed.

If you develop an asbestos-related illness, you may be entitled to certain benefits and compensation.

Other causes and risk factors

The other causes of mesothelioma are not fully understood. But things called risk factors can increase the chance of a person developing it. In rare cases, mesothelioma has been linked to:

  • exposure to radiotherapy
  • a mineral called erionite, which has been found in Turkey and North America
  • changes in certain genes – this may cause a higher risk of developing mesothelioma, but you would still have to be exposed to asbestos for it to develop.

Mesothelioma is not infectious and cannot be passed on to other people.

Doctors do not know why some people who are exposed to asbestos get mesothelioma and others do not.

We have more information about diagnosing mesothelioma.

About our information

  • References

    Below is a sample of the sources used in our mesothelioma information. If you would like more information about the sources we use, please contact us at

    Woolhouse I et al. British Thoracic Society Guideline for the investigation and management of malignant pleural mesothelioma. Thorax. 2018.

    Thomas A et al. Mesothelioma. BMJ Best Practice. 2019.

    Baas P et al. Malignant pleural mesothelioma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up.  Annals of Oncology. 26 (Supplement 5): v31–v39. 2015. Available from:

    Kusamara S et al. Peritoneal mesothelioma: PSOGI/EURACAN clinical practice guidelines for diagnosis, treatment and follow-up. European Journal of Surgical Oncology. March 2020.

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr David Gilligan, Consultant Clinical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

Date reviewed

Reviewed: 01 March 2021
Next review: 01 March 2024

This content is currently being reviewed. New information will be coming soon.

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