Risk factors and causes of mesothelioma

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

On this page

• Asbestos
• Exposure to asbestos
• The link between asbestos and lung disease

Occasionally, mesothelioma develops in people who have never 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.
Mesothelioma is not infectious and can’t be passed on to other people. It isn’t caused by inherited faulty genes, so family members don’t have an increased risk of developing it, unless they have been in contact with asbestos.

Asbestos Back to top

Asbestos is a natural mineral found in many countries. Asbestos acts as an insulator (to keep heat in and cold out); it has good fire protection and it protects against corrosion.
There are three main types of asbestos: blue asbestos (crocidolite), brown asbestos (amosite) and white asbestos (chrysotile). Asbestos was commonly used in UK industries until the ban on imports of blue and brown asbestos in the 1980s. The use of all types of asbestos was banned in 1999.

Exposure to asbestos Back to top

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

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

These jobs were mostly done by men. Mesothelioma is five times more common in men than in women.
People who have not worked directly with asbestos can also sometimes develop mesothelioma. These 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, which were disturbed or damaged.

The link between asbestos and lung disease Back to top

When asbestos is disturbed or damaged, it releases tiny fibres that can be breathed into the lungs. Asbestos fibres are very fine and can make their way into the smallest airways of the lung. 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 to settle in the outer lining of the lung (the pleura). Over many years they can cause mesothelioma or other lung diseases to develop.
Asbestos fibres can also be swallowed, and some of the fibres can stick in the digestive system. They can then move into the outer lining of the abdomen (the peritoneum), where they cause swelling and thickening.
 Mesothelioma doesn’t usually develop until many years after exposure to asbestos. It can take any time from 10–60 years, although the average is about 30–40 years after exposure.
Around 2,300 people are diagnosed with mesothelioma in the UK each year. This number is expected to rise over the next few years. Doctors have been investigating the link between asbestos and lung disease for over 100 years. The first definite link between mesothelioma and asbestos was made in 1960.
Blue and brown asbestos have been most commonly linked with mesothelioma. However we now know that all types of asbestos exposure are harmful.