Other conditions associated with asbestos exposure

Asbestosis

Asbestosis is a lung disease characterized by replacement of the normal lung tissue with fibrous tissue. It occurs as a consequence of exposure to asbestos: inhaled asbestos fibers cause an inflammatory reaction within the lung and replacement of normal tissue with collagen. There is loss of the normal structure of the lung, with destruction of the structures that allow gas exchange (alveolar spaces).

The severity of asbestosis relates to the the number of asbestos fibers carried within the lungs. Important factors in the severity and progression of asbestosis are the level and duration of asbestos exposure, cumulative exposure and fiber type (pure chrysotile exposure being less likely to cause asbestosis, but still capable of it). Like mesothelioma, asbestosis occurs many years after the initial exposure. There is no evidence that smoking increases the severity of asbestosis, although it may enhance the retention of asbestos fibers within the lungs. Patients with asbestosis are also at risk of lung cancer and mesothelioma.

Asbestosis usually causes restriction of normal lung function, so that it typically produces symptoms of increasing and distressing shortness of breath. Victims may go on to develop a persistent cough (usually dry, but may produce phlegm in smokers). Some people complain of chest tightness or pain. The disease is diagnosed on the basis of a relevant history, appropriate symptoms and chest x-ray. A lung biopsy can confirm the diagnosis (cells containing asbestos fibers are seen within the lung tissue as 'asbestos bodies') but is not usually required. Late in progressive disease, the sufferer may develop lung and heart failure; these (together with cancer) are common causes of death.

There is no cure for asbestosis. The most important interventions are to stop exposure to asbestos and to stop smoking. The disease continues to progress in some people even when they are no longer exposed to asbestos, probably because of previous cumulative exposure. Oxygen therapy may help the symptoms of the disease.

Asbestosis affects thousands of Americans and results in the death of around 1400 people each year. As with mesothelioma, asbestos mining and milling industries became aware of the link between asbestos and asbestosis decades ago, but failed to protect or educate workers or the public.

Caplan syndrome is a condition that may arise in asbestosis sufferers who also have rheumatoid arthritis, causing distinctive scarring nodules in the lungs. The scarring may trap and narrow blood vessels in the lungs, causing heart failure.