The purpose of the work described in this report was to measure the effects of diesel engine emissions on the air quality of work areas in a coal mine. Concentration measurements of several diesel- related air contaminants were made at the Martin County Coal Corp. mine in Inez, Kentucky. Compounds measured included carbon monoxide, carbon dioxide, formaldehyde, nitric oxide, and nitrogen dioxide. In addition, concentrations of the two classes of odorous compounds, aromatic hydrocarbons and oxygenates, were obtained along with aldehyde concentrations. Surveys of the mine were made by odor analysts to determine the perceived intensity of diesel-produced odors. It was found that the concentrations of the measured species were well below their threshold limit values. Odor intensity levels in the moderate-to-strong range were observed in the mine.