The latest review by the Institute of Medicine on studies performed on veterans of the 1990-91 Gulf War concluded that there is no cluster of health symptoms that constitutes a syndrome unique to those veterans. The study noted that researchers lack the data needed to determine long-term health problems because there were inadequate screenings and medical exams before the troops were deployed and limited exams of returning personnel. The report called for improved monitoring of personnel exposure to contaminants in the field. Earlier studies report that Gulf War veterans were potentially exposed to sarin gas, pesticides, air pollutants, vaccines, solvents, and pharmaceuticals, but the data are often based on subjective self-reporting. The 850 studies examined by the IOM Committee on Gulf War & Health did indicate some potential health issues. There is evidence suggesting a possible association of developing amyotrophic lateral sclerosis with Gulf War service and that the veterans have reported higher that normal rates of fibromyalgia, chronic fatigue syndrome, and chemical sensitivity. The committee did not find any overall increases in cancer rates. The study was sponsored by the Department of Veterans Affairs.