Defense Environment Alert
June 17, 2003

GAO ANALYSIS DISMISSES DOD'S GULF WAR CHEMICAL AGENT FINDINGS

The General Accounting Office (GAO) in a recently released preliminary assessment dismisses the Defense Department's conclusions regarding U.S. troops' exposure to chemical warfare agents during the 1991 Gulf War, saying they were based on flawed modeling of the agent plume.

And the congressional investigative branch does not believe any revised modeling efforts would provide any more accuracy, given the lack of reliable data on the chemical agent plumes that were emitted when the U.S. military detonated Iraqi chemical munitions stockpiles or production sites.

GAO is therefore recommending that all people in the theater at the time should be presumed exposed, a GAO source says. At stake are potential health-care benefits. The report is available on InsideEPA.com. See page 2for details.

GAO's preliminary conclusions were made in written testimony submitted to the House Government Reform subcommittee on national security, emerging threats, and international relations, which held a hearing on the issue June 2. GAO plans to release a final assessment by the fall; the preliminary assessment contains a substantial portion of the expected final report, the GAO source says. According to its web site, the subcommittee at the hearing planned to examine the strengths and weaknesses of methods used to model the spread of chemical, biological or radiological agents in the air, with an aim toward improving force protection and homeland security. Rep. Christopher Shays (R-CT), the subcommittee chairman, requested the report.

In question is which troops were potentially exposed to chemical agent dispersed in the air when the United States at the conclusion of the war destroyed a chemical stockpile at Khamisiyah, Iraq, a forward-deployed site, and during the war when U.S. and coalition forces bombed other Iraqi chemical agent sites. Many of the approximately 700,000 veterans have undiagnosed illnesses that some believe may stem from various exposures during the war, including chemical agent exposure, GAO says. Sixteen sites bombed in Iraq were categorized as nuclear, biological or chemical facilities, some of which were close to troop locations, the report says.

DOD and the Central Intelligence Agency (CIA) originally concluded no troops were exposed. But since then, additional information has come in and the numbers have risen. Between 1996 and 2000, DOD revised estimates for the number of troops exposed several times, each time upping the number based on additional modeling. DOD now estimates that about 100,000 troops were potentially exposed. A new 2000 model reclassified over 30,000 of these troops as unexposed, and another 36,000 as exposed.

The department has concluded that there is no significant difference between the rates of illnesses among those troops exposed and those not exposed. But GAO in its preliminary assessment finds that conclusion invalid, saying it "is highly questionable" because it is based on DOD and CIA plume modeling that is unreliable and replete with uncertainties. "In general, modeling is never precise enough to draw definitive conclusions, and DOD did not have accurate information on source term and meteorological conditions." Source term refers to the attributes of all the material involved in the detonations, the GAO source says.

Further, DOD's reliance on the results of the modeling to determine whether a soldier was exposed or not could have led to misclassifying their exposure. "Consequently, the study misclassification resulted in confounding -- that is; distorting -- the results, making the conclusion questionable," the report says.

GAO gives six reasons for questioning DOD's conclusions. First, DOD and the CIA did not select models that had been fully developed and validated, and some of the assumptions they used about what materials were involved in the actual sites detonated were not accurate. These assumptions were "based on incomplete information, data that were not validated, and testing that did not realistically simulate the actual conditions at Khamisiyah," it says.

Third, they underestimated the height of the plume, and fourth, they considered the health effects of a single bomb, rather than multiple detonations. "Fifth, post-war field testing done at Dugway Proving Ground did not realistically simulate the actual conditions of bombing at any site."

Finally, the models DOD used gave differing results as to the size and path of the plume. As a result, it made a composite model because it would have been impossible to select the most affected areas otherwise. And the department ignored results of modeling done by Lawrence Livermore National Laboratory using meteorological and dispersion models, which showed larger areas of coverage than DOD's composite model.

"DOD potentially may have misclassified a large number of troops truly exposed to chemical warfare agents in the putatively non-exposed group." If this exposure resulted in deaths or hospitalization, such a misclassification would falsely increase illness rates in the non-exposed group, GAO says.

Further modeling is not recommended, however, GAO says. "It is likely that if fully developed and validated models and more realistic data for source term were included in the modeling, particularly plume height and exposure duration, the exposure footprints would be much larger and most likely to cover most of the areas where U.S. and other coalition forces were deployed," GAO says. "However, given the weaknesses in the data available for any further analyses, any further modeling efforts on this issue would not be any more accurate and helpful."