pneumoconiosis (nōˌməkōˌnēōˈsĭs) [key], chronic disease of the lungs. Primarily an occupational disease of miners, sandblasters, and metal grinders, it is a result of repeated inhalation of dusts, including iron oxides (e.g., rust and filings), silicates (e.g., talc and rock dust), and carbonates (especially coal dust). Particles collect in the lungs and become sites for the formation of fibrous nodules. As the disease progresses, fibrous tissue increasingly replaces elastic lung tissue. Loss of lung function is signaled by shortness of breath, wheezing, coughing, and difficulty in expectorating. A heart deficiency called cor pulmonale may develop in severe cases. Sufferers are particularly vulnerable to infectious lung diseases such as tuberculosis. Pneumoconiosis is incurable and treatment is purely symptomatic. Because the inhaled dusts cause darkening of the lung tissue, the disease is also known as black lung. Silicosis, the form of the disease prevalent among miners, is commonly called miner's lung.