Asbestos is a natural fibre which you can find around the world, mainly in South Africa and Canada. It occurs in three forms known as blue, brown and white asbestos. In the past, asbestos was used in a lot of industrial construction, as it is resistant to heat, electricity and sound. You would find it in insulation and brake-linings. But asbestos can be very harmful to your health, so it has been phased out of use.


Asbestosis is a type of fibrous (scarring) of the lungs caused by asbestos fibres. These fibres get lodged in the lung when they are breathed in. The fibrosis causes the lungs to shrink, resulting in breathlessness. 

You would need to inhale a substantial amount of asbestos for asbestosis to develop. For many people, it usually presents itself 20 to 30 years after the start of the exposure.

Other diseases caused by asbestos

Asbestos causes many diseases other than asbestosis, but this term is most used in the media to describe any disease caused by asbestos. It is important to know about the differences of the different conditions that can be caused by asbestos.

Pleural thickening 

The pleura is a two-layered membrane which surrounds the lungs and lines the inside of the rib cage. Some asbestos fibres inhaled into the lungs work their way out to the pleura, causing fibrosis or scarring to develop there. This leads to the thickening of the pleura which may show up on a chest X-ray.

Pleural thickening takes two forms:

  • Diffuse pleural thickening - covers a large area and can restrict the lungs expanding, leading to breathlessness.

  • Pleural plaques - localised areas of thickening, which usually do not interfere with breathing.


Mesothelioma is a malignant tumour which starts in the pleura or the peritoneum, the lining of the abdominal cavity. Asbestos and similar fibres found in the soil in some parts of the world are the only known causes of this. You are at a higher risk of mesothelioma if you have had a lot of exposure to asbestos, but some can have the condition with only a small amount of exposure.

Lung cancer

Exposure to asbestos can increase the risk of developing lung cancer. It is very important to know that if you smoke and have been exposed to asbestos, this can produce a very high risk of lung cancer. People who have been exposed to asbestos can greatly reduce the risk of lung cancer by not smoking.


Strict regulations now exist to prevent people being exposed to dangerous levels of asbestos.  

Asbestos in buildings

You can still find asbestos in a lot of buildings, often in the walls and ceilings, along with lagging around steam pipes and boilers. If the asbestos is well maintained and covered by an impermeable layer of paint or other material, this helps to protect you.

It is only loose asbestos fibres from the dust that causes disease, so if it is well maintained there should be no reason to be alarmed.

Occupational lung disease team contact information


Department of Occupational and Environmental Medicine, Emmanuel Kaye Building, 1B Manresa Road, London, SW3 6LR

Tel: 020 7351 8341

Useful information

Visit the Lungs at Work website - this website has more information about what to expect from your appointment with the team, and all the research carried out by them.