The literature on pneumoconiosis resulting from exposure to carbon (7440440) was reviewed. Occupational exposure to coal dusts occurs in a variety of industries, including: coal mining; granite mining and milling; steel and cast iron manufacturing; and printing, paper and paint manufacturing. The results of epidemiologic studies on the mortality and respiratory morbidity in exposed populations were summarized. The primary lesion of coal workers' pneumoconiosis, also known as "Black Lung", was the coal macule. Coal micronodules and nodules developed and in severe cases, massive consolidated lesions resulted in progressive massive fibrosis. There were no pathognomonic signs or symptoms of coal workers' pneumoconosis. Clinical manifestations and pulmonary function tests were the same as those of common nonoccupational lung diseases. Chest x-rays and a history of occupational exposure to carbonaceous dust were required to confirm the diagnosis of coal workers' pneumonconiosis. On chest x-ray, simple coal workers' pneumoconiosis was characterized by rounded opacities predominately in the upper lung zones. In progressive massive fibrosis, radiographic opacities varied greatly in size and shape. Typically, multiple irregular masses, predominately in the upper lung zones, migrated towards the hila by contraction of fibrotic tissue. No effective treatment was known for coal workers' pneumoconiosis. Government programs and standards for limiting dust exposure and medical surveillance were enacted as preventive measures, which may greatly reduce the prevalence of coal miners' pneumoconiosis. Areas in need of further research were identified.