The chest roentgenogram shows small linear irregular opacities at the lung bases. Honeycombing is seen late. The physiologic findings indicate a decreased vital capacity with no evidence of major airflow obstruction except in smokers. The diffusing capacity is the physiologic hallmark of the disorder and is decreased in virtually all patients with asbestosis. The cancerous lesions may occur centrally or peripherally.
Pleural effects are the most common asbestos-related findings.
Unlike asbestosis, pleural plaques may occur in individuals with peripheral exposure such as working in a shipyard for one or two years during World War II, living next to an asbestos mine, or employment as an electrician, welder, or plumber. Generally single or even multiple plaques are not a cause of symptoms or clinically significant physiologic abnormalities. The chest roentgenogram is distinctive and shows plaques along the lateral pleural surfaces, diaphragmatic surfaces, or along the mediastinal or pericardial surfaces. This disorder has declined during the past 50 years in the United States due to the control of dust levels and improvement of mining techniques but has not been eliminated. Chronic cough is the most common symptom.