U.S. troop exposure during Khamisiyah demolitions not found at dangerous levels
WASHINGTON, August 19, 1997 (GulfLINK)--The Department of Defense and the CIA jointly announced the results of extensive efforts to determine what happened when U. S. troops destroyed chemical weapons at Khamisiyah, an ammunition storage facility in southern Iraq, on March 10, 1991. The investigation to determine who may have been exposed to the nerve agents sarin and cyclosarin as a result of the demolition has been completed.
Based on multiple computer models of the plume, simulated field testing, and interviews with troops present at the demolitions, DoD and CIA officials announced that nearly 99,000 service members were possibly exposed to a very low level of nerve agent vaporized during the weapons destruction. The analysis indicates that no U.S. units were close enough to the demolitions to experience any noticeable health effects at the time of the event. While little is known about delayed effects from this type of low-level exposure, current medical evidence indicates that long term health problems are unlikely.
The announcement is part of an aggressive probe initiated by President Clinton, to find solutions to the illnesses suffered by some veterans who served in the Gulf War. Since the fall of 1996, Dr. Bernard Rostker, the special assistant for Gulf War illnesses, has coordinated a comprehensive investigation involving inter-agency cooperation and outreach to thousands of veterans to resolve the health concerns arising from the Gulf War.
The DoD investigation has included declassification of 40,400 documents of health-related information, publication of case narratives to inform the public, initiation of 1-800 numbers to accelerate information exchange with veterans, advanced computer modeling and field testing to reconstruct events, and a call for research on the long term health effects of low-level exposure to chemical warfare agents.
The Khamisiyah findings are significant because they provide an analysis of how the nerve agent was dispersed by winds after weapons were destroyed in an open pit at Khamisiyah on March 10, 1991 and an estimate of the extent to which U.S. troops may have been exposed to nerve agent.
Our best assessment is that current medical science indicates no long term effects," explained Rostker during the press briefing on July 24, 1997. "This was a relatively brief exposure measured in hours at very low levels, not measured in days or weeks as one would have with chemical workers or agricultural workers." Rostker stressed that the data derived from the modeling will become an important contribution to ongoing and future epidemiological studies.
"What you have to have in an epidemiological study is not only the effects on people, but also what the dosages were, what they were exposed to," he said. "Previously, we frankly had no idea of what they were really exposed to at Khamisiyah. These are our best assessments of what their exposure was, and will be, I think, a very valuable piece of information as we continue our medical research and our epidemiological research."
In 1996, the CIA was asked by the Presidential Advisory Committee On Gulf War Veterans Illnesses and the National Security Council (NSC) to model two key events: the bombing of Bunker 73 and the demolition of the open pit.
"We were able to complete the modeling of Bunker 73 because we had had ground testing in the 1960s that gave us very important data on what chemical agent would do when destroyed inside a building. We did not have comparable data for what happened when destroyed in an open pit, and it made it very hard to do the modeling. On top of that, we had great uncertainties in the weather conditions, so the modeling came to a halt," said Robert Walpole, the special assistant to the director of Central Intelligence for Persian Gulf illnesses.
To reduce uncertainties and move the process forward, the Institute for Defense Analysis (IDA) was commissioned to assemble a national panel of technical experts to recommend the most appropriate meteorological, transport and diffusion models to reconstruct the Khamisiyah pit release.
"They provided a significant amount of meteorological expertise and made recommen-ations that we were able to follow in this modeling process. We were able to come up with new sources of meteorological data," Walpole said.
In May 1997, the DoD and the CIA performed a series of small scale demolition tests at Dugway Proving Grounds, Utah, to reconstruct the demolitions in the pit area at Khamisiyah. These tests were designed to clarify how 122mm rockets and warheads filled with simulant explode in a pit and how much material vaporizes or spills into the ground. The DoD and CIA interviewed the soldiers who set the charges in the pit area, so the Dugway tests could be performed the same way.
"Finally, we were able to refine the source term. If you cant get a handle on how many rockets were there and what the agent purity was, you would have to run multiple parametric variations to try to track that. Instead, we were able to refine those numbers to a best estimate," said Walpole.
The CIA, Naval Surface Warfare Center, Defense Special Weapons Agency, and the Naval Research Lab applied the data derived from the Dugway experiments to computer models to predict the direction in which the chemical agent sarin may have traveled, how far it traveled, how fast, and at what concentration.
"IDA had recommended that we link these models, rather than just do a straight line method. After we did that, we were able to lay each of the plumes on top of each other and we ended up with a composite of the plumewhat I mean by that is a union of five plumes. We drew the outside boundary of all five models overlaid on each other to increase our confidence on what we were laying down and decrease any other uncertainties," explained Walpole.
Concurrently with this effort, selected officers from units in the vicinity of Khamisiyah met at the U.S. Armed Service Center for Research of Unit Records, at Fort Belvoir, Virginia to better identify the location of U.S. military units on the day Iraqi chemical weapons were destroyed in the pit area. These operations officers conferences improved the accuracy of the locations of soldiers from battalion level down to company level. Information from surveys sent to troops believed to have been within Khamisiyahs 50 kilometer radius and first-hand accounts of veterans present at the demolition amplified the analysis.
Extensive research gathered on the components of the moving cloud was then correlated with the movement of troops during a three day period in March 1991, and the maximum extent of the spread of the cloud, to determine exposure levels.
During the press conference on July 24, 1997, Rostker used maps to present a detailed analysis of the movement of the plume, the location of troops, and the standards used to describe exposure levels. Rostker divided his analysis of the impact of low-level short duration exposures into two parts: the first noticeable health-effect level of sarin exposure and the general population limit.
When describing levels of sarin exposure, the first noticeable health-effect level involves levels that are 100 times lower than the levels that can be fatal. Symptoms include pinpointing of the eye pupil (miosis), runny nose, tightness in the chest, and eye pain. Rigorous computer modeling and research indicates that no U.S. units were close enough to the weapons demolition to experience any noticeable health effects.
Rostker explained that the 50-kilometer zone surrounding Khamisiyah was used to identify a zone of potential health effects in October 1996, and that this was the best assess-
ment DoD had at that time.
"We looked at the literature, we made a general estimate at 25 kilometers being an area in which we might have seen first effects. Then we doubled it. Since there was great uncertainty about the wind, we drew a 360-degree circle at 50 kilometers, and our best assessment at that time was that we were talking about roughly 20,000 troops," he said.
DoD notified and surveyed those troops within the 50-kilometer circle to determine who may have experienced symptoms. Noting that dots on the map indicated the locations of company size units, Rostker described the fallout pattern of the plume.
"The plume pattern of first effects has this finger here, and this is an artifact of using a union approach, four models pointed due south, and one model moved slightly to the east, so were showing the union of that," he continued. "The particular wind patterns, the particular release indicates that there were no troops that would have felt first affects based upon the unit locations."
On the second day, the plume occupies an area of approximately five miles across and five miles down.
"What we had all thought was that there would be an instantaneous release into the atmosphere and what we found in Dugway was that a very important factor was the material going into the wood, going into the soil, and a later wick effect, being drawn into the atmosphere over the next several days to feed the plume," he said.
On the third day, the analysis indicates that the wind starts to shift. "On the third day, we have almost no measurable amount (of release) at Khamisiyah, according to our analysis," he said. Rostker noted that the survey results from the 20,000 troop questionnaires confirm the diffusion and weather analysis results.
"We sent 20,000 questionnaires out . We received 7,415 questionnaires back, and 99.5 percent of those questionnaires indicate that the people had no physical affects that could be correlated with possible sarin exposure," he noted.
This survey information is consistent with the fact that there were no reports of injuries which required medical treatment related to nerve agent exposure. Medical personnel who were near Khamisiyah in March 1991 have been interviewed. They said there was no evidence of health problems related to nerve agent exposure at the time.
Referring again to the map for detail, Rostker addressed the area regarding low level exposure. Using a union of five models to increase scientific certainty, the models agree the wind pushes due south on the first day extending about 150 miles into Saudi Arabia. As the plume moves towards the south, approximately 19,000 troops were exposed at or somewhat above the level called the general population limit. Officials calculate the dose of agent was greater than the general population limit of 0.01296 milligram-minutes of sarin per cubic meter of air, but well below the first noticeable health effects level of 1 milligram-minute per cubic meter of air. These very low levels of sarin exposure would have been too low to activate chemical alarms or to cause any symptoms at the time. The general population limit was set at a very low level, so even if a person was exposed to this level continuously for 72 hours, he or she would not develop any noticeable effects. In addition, the general population limit was set at a much lower level than the occupational limit, which was set for factory workers or agricultural workers who handle pesticides similar to sarin.
On the second day the wind shifts and starts moving toward the west. "This was not an immediate single release where youd have a cloud and the cloud is moving downrange, but a phenomena of continual releasing of agent because of what was in the sand and in the wood. This means the plume was being refreshed and you can see elements tailing off towards the west," Rostker said. "The plume thickens as the wind moves towards the west and moves westward in Saudi Arabia. Some 79,000 troops were exposed that day." he said.
On the third day, a new cloud is formed based upon the evaporation which then moves up the Euphrates Valley. "The third day, moving up the Euphrates Valley, 3,000 troops were exposed," Rostker pointed out.
Conditions localized on the fourth day. "Thats the last day that we even are able to calculate to the general population limit," Rostker noted. On that day, two battalions of troops were in the vicinity of Khamisiyah, and about 1600 (troops) were exposed to low levels of sarin.
"We know of no unit -- either from our survey or from the analysis -- that received a dosage where people would have felt first affects, would have had any chest tightness, any watering of the eyes," said Rostker, summarizing the findings. "This goes a long way to explain the missing inconsistencies in the Khamisiyah story. There are a number of troops who may have been exposed to very low levels. They remain a concern of ours -- both immediately and in the long run -- to understand the impact of low level chemical exposure through epidemiological work and medical work."
The DoD has taken steps to augment its veterans assistance in support of this recent announcement. Letters of notification were sent to those 99,000 troops under the plume, explaining their possible exposure to very low levels of nerve agents and recommending that they seek medical evaluation if they have health concerns. A different letter was sent to about 8,000 individuals who were within the 50-kilometer circle and were previously surveyed , who were found not to be under the plume. The letter informs them that they were not exposed to even extremely low levels of nerve agents.
If a person were exposed to a low level of sarin for a brief time, the current medical evidence indicates that long term health effects would be unlikely. However, the scientific evidence on the long term effects is limited.
Since the release of information last year on possible low level exposure resulting from Khamisiyah, the DoD and VA have intensified research efforts to focus on the long term health effects of low level exposure to chemical warfare agents. Seven research grants to universities and non-government labs are in progress, focusing on low level exposures to nerve agents. These grants total almost $ 4 million in support.
"A call for proposals for research in this area was issued in January. In response to the solicitation, proposals totaling several millions of dollars have been selected for funding and will be announced in September," explained Dr. Thomas Garthwaite, Deputy Under Secretary for Health, Department of Veterans Affairs, during the press conference.
Dr. Rostker continues to stress that the knowledge of specific exposures is useful, but not necessary for the treatment of and provision of health care and benefits to Gulf War veterans. He ended his prepared remarks on July 24, with a reminder.
"If anyone has any concern about their health who served in the Gulf - whether they were at Khamisiyah or any place in the Gulf -- we implore them to come in and be examined whether at a VA facility or at a Department of Defense facility," he said. "There are people who are ready and able to answer their questions and make sure they get the medical treatment they need and deserve."
Gulf War veterans who have health concerns which might be related to their Gulf War service are encouraged to enroll in the DoD Comprehensive Clinical Evaluation Program by calling 1-800-796-9699, or in the VA Persian Gulf Registry by calling 1-800749-8387.
Rostker also stressed that the investigation of Khamisiyah is continuing. "We have several investigation going and welcome any information people have which will contribute to our efforts", he said. "Much of what we know about incidents like Khamisiyah is directly related to information weve received from Gulf War veterans." Gulf War veterans with information, including eyewitness experiences, can call the Persian Gulf Incident Reporting Hotline at 1-800-472-6719.
- end -