Gulf War and Health, Volume 2, is the second in a series of congressionally-mandated studies by the Institute of Medicine that provides a comprehensive assessment of the available scientific literature on potential health effects of exposure to certain biological, chemical, and environmental agents associated with the Gulf War. In this second study, the committee evaluated the published, peer-reviewed literature on exposure to insecticides and solvents thought to have been present during the 1990-1991 war. Because little information exists on actual exposure levels ? a critical factor when assessing health effects ? the committee could not draw specific conclusions about the health problems of Gulf War veterans. However, the study found some evidence, although usually limited, to link specific long-term health outcomes with exposure to certain insecticides and solvents. The next phase of the series will examine the literature on potential health effects associated with exposure to selected environmental pollutants and particulates, such as oil-well fires and jet fuels.