cause watery eyes, runny nose, tightness of chest, muscle twitching or other early signs of chemical warfare (CW) agent exposure; the second is a lower-exposure area where the estimated dosage was less than that needed to produce first noticeable effects (CIA–DoD, 1997). The CIA–DoD report estimated that approximately 10,000 U.S. troops had been located within a 25-km radius of Khamisiyah and thus might have been exposed over a period of hours to the lower exposure level (CIA–DoD, 1997). Uncertainties with the model led to DoD’s doubling these figures to 20,000 U.S. troops with possible exposure within a 50-km radius; however, the dose levels remained unaltered.
The CIA–DoD findings were challenged in a U.S. Senate report (Committee on Veterans’ Affairs, 1998). The Senate report took issue with the methodology, especially the reconstruction of the pit site, the nature of the demolition, and the number of exposed troops. At the request of the Senate Committee on Veterans’ Affairs, the Air Force Technical Applications Center (AFTAC) prepared another exposure model. The AFTAC report summary—the only portion of the report made public—indicates that AFTAC used different models than those employed by CIA–DoD to simulate atmospheric chemistry (Committee on Veterans’ Affairs, 1998). The report indicated additional geographic areas of low-level exposure not modeled by CIA–DoD. Neither the AFTAC nor the CIA–DoD report appears to have undergone independent peer review.
DoD is conducting a complete remodeling of the Khamisiyah demolition, which is projected to be completed by the end of 2000. This remodeling, unlike the initial effort, is expected to be peer reviewed. It incorporates improved intelligence information, improved transport and diffusion modeling, and improved knowledge of unit locations. The committee encourages DoD to complete its ongoing remodeling efforts and to publish results in the peer-reviewed literature to enable broad review and independent validation of its work.
Although exposure to sarin and cyclosarin was estimated by CIA–DoD modeling, there were no medical reports by the U.S. Army Medical Corps at the time of the release that were consistent with signs and symptoms of acute exposure to sarin (PAC, 1996). Further, a 1997 survey mailed by DoD to 20,000 troops who were within a 50-km radius of Khamisiyah found that more than 99 percent of respondents (n = 7,400) reported no acute cholinergic effects (CIA– DoD, 1997). Nevertheless, low-level exposure, as noted earlier, could have occurred without producing acute cholinergic effects.
Two other storage sites in central Iraq sustained damage from air attacks during the Gulf War, but chemical agent releases were too far removed from U.S. troops for exposure to have occurred (PAC, 1996). At one site (Muhammadiyat), munitions with 2.9 metric tons of sarin–cyclosarin and 1.5 metric tons of mustard gas were damaged. At the other site (Al Muthanna), munitions containing 16.8 metric tons of sarin–cyclosarin were damaged (PAC, 1996). Atmospheric modeling by the CIA and DoD determined that the nearest U.S. personnel—located 400 km away—were outside the range of contamination (PAC, 1996).
In summary, exposure models indicate that sarin–cyclosarin release occurred in March 1991 as a result of U.S. demolition of a storage depot in