Abstract
Employees who have inhaled insoluble minerals or organic dust for long periods contracted various environmental lung diseases, i.e. pneumoconiosis. Pathologically, such lungs show fibrotic and proliferative degeneration. When inhaled, some partcles are deposited in the airways or lungs themselves, depending on their size, weight and shape. Especially small particles (1-2 um in diameter) are depositied in the smaller airways and form fibrotic nodules in the walls of respiratory bronchioli. It is said that the earliest lesions occur in the small airways. The frequency and clinical importance of pneumoconiosis are increasingly recognized. At present, implementation of the causes of this disease is limited to mineral dusts (Silica, Asbestos and Coal dust, etc.) and is not related to organic dust. Chest X-rays provide important diagnostic information, however, they are not precise enough to elucidate the condition of small airway diseases in asymptomatic subjects. We performed health examinations on 1199 male employees who were working in heavy industries. MMF, PEFR, V 75, V 50 and V 25 provide effective diagnostic information in spirometric tests and flow tests.
