Investigations conducted by NIOSH under the Federal Coal Mine Health and Safety Act of 1969 are reviewed for fiscal year 1979 (FY 79). Laboratory investigations are described which include magnetic mapping of lung tissues from deceased coal and asbestos workers, development of a cell culture system to study fibrogenic potential of mineral dusts, experiments with interferon, and toxicity studies on laboratory animals with diesel exhaust and coal dust. A project to investigate workers fatigue resulting from various design features of respirators is described. Epidemiological studies on workers exposed to diesel emissions, on mortality rates among talc miners, and on the respiratory function status of metal and nonmetal miners are reviewed. The National Study of Coal Workers' Pneumoconiosis is discussed. Other programs underway in FY 79, including chest X-rays for coal miners; health hazard evaluations for coal, talc, and silica workers; mining surveillance; autopsy service; testing and certification of personal protective equipment; and coal mine dust sampling programs are cited.