Asbestosis 

Asbestosis is a chronic (long-term) lung condition caused by prolonged exposure to asbestos. Asbestos is a soft, greyish-white material that does not burn. In the past it was often used in building construction to protect against fire and as a form of insulation (see below).

Breathing in asbestos dust can scar the lungs, which can lead to:

• shortness of breath
• cough

The interval between exposure to asbestos and the onset of symptoms varies, but it can be several decades.

Asbestosis means that the lung tissue has become scarred due to previous asbestos exposure. Pleural plaques or pleural thickening caused by asbestos are not the same as asbestosis. In these conditions, the lining of the lung is damaged by asbestos, but the lungs themselves are unharmed.

Asbestos

Asbestos is a general term that refers to a group of minerals made of long, crystalline fibres. Asbestos fibres are very strong and resistant to heat, electricity and chemicals. In the past, asbestos was widely used in industries such as:

• insulation
• shipbuilding and railways
• electricity generation
• building and construction

There are three main types of asbestos:

• crocidolite – ‘blue asbestos’
• amosite – ‘brown asbestos’
• chrysotile – ‘white asbestos’

All types of asbestos are hazardous, but blue and brown asbestos are much more dangerous than white asbestos. 

The most commonly used type of asbestos for industrial use was white chrysotile asbestos. Amosite and crocidolite were banned in the 1980s, although voluntary bans on the industrial use of both these materials came into force earlier than this. No crocidolite was imported into the UK after 1970. Chrysotile was not banned until 1999.

How common is asbestosis?

Asbestosis is a relatively rare condition because the amount of exposure required to cause it is fairly considerable, and regulations to restrict the intensity of exposure have been in place for over 40 years. Since 2004, the number of people developing asbestosis has decreased. In 2008, there were 127 deaths caused by asbestosis. During that year 1,110 people were awarded industrial injuries disablement benefit for the condition.

In contrast with the decrease in the number of cases of asbestosis, cases of mesothelioma are increasing and are not expected to reach their peak until 2013-2016. Mesothelioma is cancer of the mesothelial cells, the cells that make up the lining that covers the outer surface of most of the body’s organs, including the lungs.

This difference in the number of cases of asbestosis and mesothelioma is explained by the fact that mesothelioma can be caused by relatively small amounts of asbestos exposure, but asbestosis cannot. This shows that the legislation introduced in 1970 to prevent high levels of asbestos exposure in the workplace helped to reduce the risk of asbestosis.

See the Health A-Z topic about Mesothelioma for more information about the condition.

Outlook

There is no cure for asbestosis once it has developed because it is not possible to repair lung damage caused by asbestos. Some people with asbestosis find that their condition progresses over time, although many do not.

The most important thing someone with asbestosis can do is to stop smoking (if they smoke). This is because the progression of asbestosis is more common in smokers compared to non-smokers.

People with asbestosis have a higher risk of developing other serious conditions, such as:

• lung cancer – one of the most common and serious types of cancer
• mesothelioma – a type of cancer that affects the membranes that cover many of the body’s organs, including the lungs
• pleural disease – the membrane that covers the lungs (pleura) becomes thicker. If the thickening is localised to a few patches, the condition is known as pleural plaques, which do not cause symptoms. However, if the thickening becomes generalised, it is known as diffuse pleural thickening. This can contribute to breathlessness and chest discomfort. Most people (about 95%)  with asbestosis also have pleural thickening or pleural plaques

Very severe cases of asbestosis can place a significant strain on a person’s health and shorten their life expectancy. However, in many cases, the condition does not progress. More people with asbestosis die as a result of one or more of the cancers mentioned above rather than from asbestosis itself.

Treatment can significantly improve the quality of life of someone with asbestosis. See Asbestosis - treatment for more information about how the symptoms of asbestosis can be managed.

There are also a number of measures in place to help prevent future exposure to asbestos in the workplace. See Asbestosis - prevention for more details about this.