Asbestosis is a chronic fibrotic interstitial lung disease which is asbestos-induced. It is a non-cancerous condition. Fibrosis is a scarring of the lung. Interstitial refers to the lung tissue itself. In asbestosis it is the lung tissue, not the airways, that is damaged. The scarring results from asbestos fibres penetrating the lung tissue and causing inflammation. When this process continues then further scarring results. The alveoli (air sacks), where oxygen exchange occurs and oxygen diffuses into the blood steam, become scarred, damaged and obliterated. The scarring or fibrotic change within the lung tissue causes the lungs to be stiff and hence it is more difficult to breathe. The lung becomes inelastic; hence the lung does not exchange oxygen and CO2 adequately because eventually the alveolar gas exchange units are markedly reduced in number and function. Dyspnoea or shortness of breath on exertion is one of the symptoms of asbestosis.
Asbestosis refers to asbestos-induced fibrosis of the lung. Asbestosis is usually diffuse in that it is usually found throughout the lower sections of both lungs, and not isolated. The fibrosis associated with asbestosis is often roughly equal in both lungs. As the disease progresses, the upper lobes may be affected.
Asbestosis is usually a progressive disorder. Exertional breathlessness gradually worsens often over a period of years. As asbestosis progresses the scarring causes the lung to shrink and breathing becomes more difficult.
The damage to the lungs’ capacity may not be detected for many years due to the lungs’ reserve. As the disease progresses lung capacity reduces. Patients who suffer from asbestosis have an increased risk of developing bronchitis, pneumonia and heart disease. As a consequence asbestosis sufferers may present with heart-related symptoms such as abnormal heart rhythm and heart failure.
Nutrition is an important modality. Dieticians should be consulted. Please refer to the Eating with Asbestosis booklet.
The diagnosis of asbestosis, may be difficult to make. The diagnosis is made by obtaining a history of asbestos exposure, typical x-ray signs, lung function studies and clinical signs such as inspiratory (respiratory) crackling.
The advent of high definition CT scanning shows much more detail of the lung as compared to a simple chest x-ray and has given respiratory specialists much more information to make the diagnosis of asbestosis.