Asbestos is the single greatest cause of work related deaths in the United Kingdom
Human lungs have a sophisticated system of measures to prevent harm from airborne particles but the unique properties of asbestos can bypass these defences.
The upper respiratory systems uses hairs to filter large particles and mucous membranes serve as a barrier to smaller, microscopic particles and organisms. As you go deeper into the respiratory tract you encounter yet more mucous membranes, these being responsible for the catarrh and phlegm that is produced as a reaction to infection from bacteria and viruses.
Deep inside the alveoli (the small pockets where oxygen is exchanged from the air into the blood stream) microscopic invaders are dealt with by the white blood cells. These leukocytes work by engulfing foreign bodies and then breaking them down so that they can be passed through the body and expelled with the rest of its waste.
Because asbestos fibres break down into smaller pieces as they are disturbed they can hang in the air for a long time and are not blocked by the upper respiratory tract’s defences. That enables them to pass deeper and to lodge within the tissue of the lungs. Despite this the fibres can remain large enough that they cannot be fully encapsulated by the white blood cells. That has a twofold effect of preventing the leukocyte from dissolving the fibre and subsequently causing the white blood cell to actually damage the surrounding tissues. The result is damage to the lungs and a number of very serious conditions, some of which can take decades to be apparent.
The experience and severity of asbestos related disorders is increased by being exposed to higher concentrations, being exposed for longer periods of time and being exposed more often. Strict regulations exist to reduce all three factors for those that are likely to work with or around asbestos containing materials.
Inhaling the more durable, longer fibres, such as tremolite and other amphiboles, can contribute to the severity of asbestos related disorders.
Main Diseases Associated with Asbestos Exposure
Asbestosis is not a cancer but is a progressive, serious disease of the lungs with long term effects. Lung tissues are irritated and inflamed by inhaled asbestos fibres causing scarring. This scarring makes breathing difficult and inhibits the exchange of gasses, oxygen and carbon dioxide. Symptoms can typically take ten to twenty years to show and vary from very minor to disabling and possibly fatal.
Mesothelioma is a cancer of the lining around the lungs -the pleura – and the lining around the lower digestive tract – the peritoneum. It is very rare and almost always cause by exposure to asbestos. By the time it is diagnosed it is frequently fatal.
Heavy exposure to asbestos can lead to abnormalities and thickening of the pleural membrane that lines the cavity around the lungs.
Symptoms in extreme cases can include shortness of breath and pain or discomfort in the chest due to squeezing of the lungs.
Asbestos related lung cancer looks and behaves just like that which is caused by other factors such as smoking. It is a malignant tumour that obstructs the air passages of the lungs.
Symptoms are, most commonly, couching and wheezing, weight loss, laboured breathing and coughing up blood. Sufferers also report shortness of breath, hoarseness, anaemia and persistent pain in the chest.
There is some suggestion that exposure to asbestos may be responsible for other conditions, such as non-respiratory cancers but the evidence is inconclusive at this time.