Risk factors and causes


Asbestos is the most common cause of mesothelioma. Up to 9 out of 10 cases of mesothelioma (90%) are caused by exposure to asbestos fibres. Asbestos is a natural mineral found in many countries. It acts as an insulator (to keep heat in and cold out) and it protects against fire and corrosion.

There are three main types of asbestos: blue (crocidolite), brown (amosite) and white (chrysotile). These 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 and brown asbestos is commonly linked with mesothelioma. However, exposure to all types of asbestos is harmful.

Mesothelioma doesn’t usually develop until many years after exposure to asbestos. It can take any time from 15–60 years, although the average is about 30–40 years after exposure.

When asbestos is disturbed or damaged, it releases tiny fibres. These can be breathed into the lungs. Asbestos fibres are very fine and can make their way into the smallest airways of the lungs. Once the fibres are in the lungs, the body’s defence mechanisms try to break them down and remove them. This leads to inflammation in the lung tissue.

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

Exposure to asbestos

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

  • joiners and construction workers
  • plumbers
  • electricians
  • boilermakers
  • shipbuilders.

As these jobs were mostly done by men, mesothelioma is five times more common in men than in women.

People who haven’t worked directly with asbestos can also sometimes develop mesothelioma. These can include:

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

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

Other causes

Occasionally, mesothelioma develops in people who have never knowingly been exposed to asbestos.

The other causes of the disease are not fully understood, but, in rare cases, mesothelioma has been linked to:

  • exposure to radiation
  • a mineral called erionite, which has been found in Turkey and North America.

Mesothelioma isn’t infectious and can’t be passed on to other people. It isn’t caused by inherited altered genes, so family members don’t have an increased risk of developing it, unless they have also been exposed to asbestos.

Back to Diagnosing