Page last reviewed: 13/07/2011

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 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. Under EU legislation you can no longer buy,use or re-use asbestos products in Ireland.

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 many years

Mesothelioma, which is also asociated with exposure to asbestos, 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.

Mesothelioma in contrast to asbestosis can be caused by relatively small amounts of asbestos exposure.

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


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.

Health risk

Asbestos can be a very dangerous material. If it is undisturbed, it does not present a health risk. However, if materials that contain asbestos are chipped, drilled, broken or simply allowed to deteriorate – for example, due to exposure to weather – they release a fine dust that contains tiny asbestos fibres.

If someone breathes in the dust, the asbestos fibres enter the lung and can cause disease. For asbestosis to develop, prolonged exposure to relatively high numbers of the fibres is necessary. See Asbestosis - symptoms for more information about the symptoms of asbestosis.

Mesothelioma, which is a type of cancer caused by asbestos, can occur after much less exposure. For this reason, all exposure to asbestos should be avoided if possible.

Page last reviewed: 13/07/2011

The symptoms of asbestosis usually begin 15-20 years after the initial exposure to the material. Symptoms usually begin gradually before becoming more noticeable and troublesome over the space of many years.

Symptoms of asbestosis include:

  • shortness of breath (initially after physical activity, but eventually while resting as well),
  • cough, and
  • chest pain.

A less common symptom of asbestosis is the ends of the fingers become swollen, misshapen, and red, as a result of a build-up of fluid in the tissue of the fingers. This is known as finger clubbing.


Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.
Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.
Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.

Page last reviewed: 13/07/2011

Asbestos fibres

Asbestosis is caused by asbestos fibres. Usually, when you breathe in a foreign body, such as a particle of dust, or metal, small cells, known as macrophages, will break down these particles before they reach your lungs.

However, asbestos fibres are too tough for the macrophages to break down. In an attempt to break down the asbestos fibres, the macrophages release substances that are designed to destroy the fibres. These substances damage the tiny air sacs in your lungs which are known as alveoli.


When you breathe in, the alveoli help transfer oxygen from your lungs into your blood. Also, when you breathe out, the alveoli help to transfer carbon dioxide out of your blood, through your lungs, and out of your mouth.

If you have experienced a prolonged exposure to asbestos fibres lasting for many years, the damage to the alveoli becomes more severe and causes scarring. This scarring is known as fibrosis.

Once the alveoli become scarred, their ability to inhale oxygen, and exhale carbon dioxide, becomes adversely affected, resulting in the symptoms of breathlessness.

Occupational risk factors for asbestosis

The use of asbestos significantly increased after World War Two, peaked during the 1970s and then slowly declined during the 1980s and 1990s. If, during this time, you worked in an industry, or occupation, that used asbestos, you may have been exposed to it.

Occupations that are known to be associated with exposure to asbestos during these times include:

  • insulation workers,
  • boilermakers,
  • plumbers, pipefitters, and steamfitters,
  • shipbuilders,
  • sheet metal workers,
  • plasters,
  • chemical technicians, and
  • heating, air-conditioning, and refrigeration mechanics.

Industries that are known to have used asbestos during these times include:

  • construction,
  • shipbuilding and repair,
  • chemical manufacturing,
  • non-metallic mineral stone production,
  • railways,
  • yarn, thread, and fabric mills,
  • rubber and plastic production, and
  • trucking services.


Body tissue is made up of groups of cells that perform a specific job, such as protecting the body against infection, producing movement or storing fat.  
Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.
Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.

Page last reviewed: 13/07/2011

Before confirming a diagnosis of asbestosis, your GP will ask you about your symptoms and listen to your lungs with a stethoscope. If your lungs have been affected by asbestosis, when you breathe they will make a distinctive crackling noise.

Your GP will require details of your work history, including any times when you may have been exposed to asbestos, the length of any possible exposure, and whether you were issued with any safety equipment, such as a face mask.

If your GP suspects asbestosis, a diagnosis can usually be confirmed by running a series of additional tests. These tests are described below.


A spirometer is a machine that measures how much oxygen you can breathe in, and how much carbon dioxide you can breathe out. These measurements can be used to assess how effective your lungs are.


X-rays can detect abnormalities in the structure of your lungs that are caused by asbestosis.

CT scans

CT scans are more detailed than X-rays and can often be used to detect asbestosis in its earliest stage.

Page last reviewed: 13/07/2011

There are four main components to the treatment of asbestosis:

  • quitting smoking (if you are a smoker),
  • vaccinations against potentially dangerous lung conditions, such as influenza (flu),
  • using medicines to make breathing easier, and, if necessary,
  • using equipment, such as oxygen cylinders, to help with breathing.

While none of these components will be able to cure asbestosis, they can help control symptoms and improve your quality of life.

Quitting smoking

If you have been diagnosed with asbestosis, and you smoke, it is very important that you give up as soon as possible.

Smoking will make your symptoms of breathlessness worse, and it will also significantly increase your chances of developing lung cancer.

It is thought that smoking and asbestosis have a synergistic effect on the risk of developing lung cancer. This means that the combined risk associated with smoking and asbestosis is far higher than the sums of their individual risks.

For example, a non-smoker who has asbestosis is approximately three times more likely to develop lung cancer than a non-smoker who does not have asbestosis.
A smoker who does not have asbestosis is five-and-a-half times more likely to develop lung cancer than a non-smoker without asbestosis. However, a smoker who also has asbestosis is 14 times more likely to develop lung cancer than a non-smoker without asbestosis.

Speak to your GP to get help with giving up smoking. They will be able to advise you about nicotine replacement therapies and prescription medicines, such as bupropion, which can greatly increase your chances of quitting successfully. They can also put you in touch with local support groups and one-to-one counsellors.


If you have asbestosis, your lungs will be more vulnerable to the effects of infection. Therefore, it is recommended that you receive vaccinations against influenza and the pneumococcus bacteria, which can cause serious chest infections. Your GP will be able to arrange these vaccinations for you.

You will require a dose of the influenza vaccine every year. Most people only require one dose of the pneumococcus vaccine, although additional booster shots may be recommended if your general health is poor.


Medicines known as bronchodilators are widely used to treat asbestosis. Bronchodilators are usually taken using an inhaler.

Bronchodilator inhalers deliver a small dose of medicine directly into your lungs, causing the muscles of your airways to relax and open up, making breathing easier.

Theophyllines are another type of medicine that is used in the treat asbestosis. This oral medication helps to widen your airways by relaxing the muscles around them.

In some people, theophyllines have been known to cause a number of side effects including:

  • headaches,
  • nausea,
  • insomnia,
  • vomiting,
  • irritability, and
  • stomach upsets.

Oxygen therapy

If your shortness of breath is particularly bad, your body may not be getting all the oxygen that it needs. If this is the case, oxygen therapy will be required using a machine called an oxygen concentrator.

The air that we breathe has quite a low amount of oxygen in it. In fact, oxygen only makes up about 21% of the atmosphere. An oxygen concentrator is plugged into a mains socket and purifies oxygen from the air in the room, producing a more oxygen-rich supply of air. You can then breathe the oxygen-rich air though a mask. The tube connecting the mask is very long, so you will be able to move around your home freely.

Do not smoke when you are using an oxygen concentrator. The increased level of oxygen that is produced is highly flammable, and a lit cigarette could trigger a fire, or an explosion.

In addition to the oxygen concentrator, you may also be given a small, portable oxygen tank and mask that you can use when you leave your house. This is known as ambulatory oxygen.


Corticosteroid is a naturally occurring hormone produced by the adrenal gland, or a synthetic hormone having similar properties. It is used to reduce inflammation, so reducing swelling and pain.
Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.
Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.

Page last reviewed: 13/07/2011

The Health and Safety Authority (HSA) has legal powers under the European Communities (Protection of Workers) (Exposure to Asbestos) Regulations ,1989(as amended) to ensure the protection of workers from the risks related to exposure to asbestos at work.

The Office of Public Woks is responsible for monitoring asbestos in all government buildings, including schools.

The Environmental Protection Agency deals with the licensing of storage for hazardous waste ,like asbestos.

Local authorities are responsible for the investigation of any incidents of air and water pollution in their areas (e.g.,incorrect dissposal of asbestos.)


Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.

Useful Links

health and safety authority

Citizens Information (Asbestos)


Content provided by NHS Choices and adapted for Ireland by the Health A-Z.

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