Introduction This report describes the research undertaken by the Ohio State University Nuclear Reactor Laboratory in cooperation with the American Petroleum Institute involving measurement of the lung burden of raw and spent shale in the tissue of cynomolgus monkeys. This effort is part of an overall study done by API on the physiological effects of shale dust on mammalian respiratory systems. Lung burden data is used in conjunction with histopathological studies to more strongly correlate observed effects with dust exposure. Estimates of lung burden were obtained using instrumental-method neutron activation analysis (INAA). Several experiments were performed@ including a preliminary study of both pure shale material and representative lung tissues@ pure shale analysis@ and analysis of lung tissue. The preliminary study demonstrated the viability of INAA for lung burden estimates@ and the analysis of the pure shale material and lung tissues provided data on the actual lung burden. The remainder of this report will discuss the research in more detail. Chapter 2 briefly covers some of the basic principles of INAA. Chapter 3 describes the experimental procedures used in all experiments. Chapter 4 presents the experimental results@ while Chapter 5 discusses these results and makes some conclusions based on them.