Risks and causes of mesothelioma

Asbestos is the biggest cause of mesothelioma in the UK. There are some other risk factors that can increase your risk.

Anything that can increase your risk of getting a disease is called a risk factor.

Different cancers have different risk factors.­ Having one or more of these risk factors doesn't mean you will definitely get that cancer.

Asbestos

Mesothelioma can start in the layers of tissue that cover each lung (pleural mesothelioma). Or it can start in the layer of tissue that covers the organs in your tummy (peritoneal mesothelioma).  

We know that asbestos causes most cases of pleural mesothelioma.  Exposure to large amounts of asbestos for a long period of time increases your risk. Many people with peritoneal mesothelioma have also been exposed to asbestos. 

The link between mesothelioma and asbestos was found in the 1960s. This is because of the heavy use of asbestos in industry from the end of the second world war up until the mid 1970s.

Mesothelioma is a rare cancer. In the UK, exposure to asbestos causes:

• more than 95 out of 100 cases (more than 95%) of mesothelioma in men
• almost 85 out of 100 cases (almost 85%) of mesothelioma in women

But some people with mesothelioma say they have no history of any exposure to asbestos.

What is asbestos?

Asbestos is an insulating material that’s heat and fire resistant. The use of asbestos was banned in the late 1990s in the UK. It was widely used in:

• building industry
• shipbuilding
• manufacturing of household appliances
• motor industry
• power stations
• telephone exchanges

There are 3 main types of asbestos – blue, brown and white. Blue and brown asbestos are strongly linked with mesothelioma. White asbestos is now also thought to be harmful.

How asbestos causes mesothelioma

Asbestos is made up of tiny fibres. You can breathe these fibres in when you come into contact with asbestos.

The fibres work their way into the pleura lining the lung. They irritate the pleura and may cause gene changes (mutations) that lead to the growth of cancer. Some of the fibres can be coughed up and swallowed. This is probably the cause of peritoneal mesothelioma.

There is some evidence that families of people exposed to asbestos have a higher risk of developing mesothelioma. This is because you can carry asbestos fibres home on clothes.

Highest risk groups

Mesothelioma is most common in those who have been exposed to asbestos at work, for example, they have:

• worked in manufacturing using asbestos
• used asbestos products, particularly in construction or engineering

This could be in a range of jobs including:

• metal plate workers (mainly in shipbuilding)
• carpenters
• plumbers
• mechanics

Mesothelioma may not develop until 15 to 60 years after you have been exposed to asbestos. In recent years there has been a decrease in cases in men. The number of people dying from mesothelioma each year is expected to keep falling over the next 10 to 20 years.

Working as a painter

You might have a higher risk of mesothelioma, if you worked as a painter. This is because up until the 1990s some paints contained asbestos. You might also have been exposed to asbestos in work sites.

Other minerals

In Turkey, researchers looked at a mineral similar to asbestos called erionite. They found this increased the risk of mesothelioma. But this has not been found elsewhere.

Another mineral called fluro-edenite in Italy, also increases the risk of mesothelioma.

Other possible causes

Stories about potential causes of cancer are often in the media. It isn’t always clear which ideas are supported by good evidence.

You might hear about possible causes we haven’t included here. This is because there is no evidence about them or because the evidence isn’t clear.