This is a condition of the lung and is similar to many diseases caused by the inhalation of mineral dust such as silicoses and coal miners' pneumoconiosis. It is the result of prolonged exposure to asbestos and/or asbestos dust. The symptoms are gradually developing breathlessness on exertion, often with a dry cough caused by shrinkage and scarring of the lungs. A diagnosis can be made from a chest x-ray and pulmonary function tests.