Defense Department and CIA officials reported today the results of a year long effort to learn the extent to which U.S. troops may have been exposed to harmful agents when Iraqi chemical weapons were destroyed at Khamisiyah on March 10, 1991. Their analysis confirmed that no U.S. units were close enough to the demolitions to experience any noticeable health effects at the time of the event.

Based on new data, computer models and interviews with troops involved in the demolitions, officials now believe 98,910 service members were in an area generally south of Khamisiyah and were possibly exposed to a very low level of nerve agent vaporized during the weapons destruction. Little is known about delayed effects from a brief, low-level exposure to nerve agents such as might have occurred in this case, however, current medical evidence indicates that long term health problems are unlikely. The Presidential Advisory Committee on Gulf War Veterans' Illnesses, in its Dec. 31, 1996 Final Report, wrote, "Current scientific evidence suggests that subclinical exposure to OP (organophosphate) CW (chemical warfare) nerve agents does not result in long-term neurophysiological and neuropsychological health effects." There is, however, limited medical information on the impact of such low level, short duration exposures. Therefore, the Departments of Defense and Veterans' Affairs recognized the need for further research in this area.

Officials calculate the dose of agent was greater than the general population level of 0.01296 milligram-minutes of sarin per cubic meter, but well below the noticeable health effects level of 1 milligram-minute per cubic meter. The general population level, established by the Centers for Disease Control in 1988, is a level which "long term exposure to these concentrations would not create any adverse health effects." It takes an exposure of 35 milligram-minutes of sarin per cubic meter to incapacitate an individual and 100 milligram-minutes per cubic meter to produce fatalities.

Although there is no medical evidence suggesting a clear connection between low level exposure and health problems, the DoD is notifying people who were possibly exposed. A letter to these people encourages those with health concerns related to their service in the Gulf War to enroll in the DoD Comprehensive Clinical Evaluation Program by calling 1-800-796-9699 or the Department of Veterans' Affairs Persian Gulf Registry, 1-800-749-8387.

Since its announcement about Khamisiyah on June 21, 1996, the Pentagon has been working with the CIA to determine how widely and in what concentration chemical agents may have dispersed when U.S. troops unknowingly destroyed large quantities of Iraqi chemical munitions at the sprawling ammunition storage site in southern Iraq shortly after the Gulf War ended. Experts hypothesized that a cloud of vaporized nerve agent, formed when the weapons were destroyed, would have been carried by the prevailing winds over a large area. Determining this area and identifying the troops who were in it has come to be known as the Khamisiyah plume analysis.

As part of the effort over the past year, the Department of Defense and Central Intelligence Agency have interviewed soldiers who conducted the demolitions, conducted field tests to simulate the explosions, developed improved data on the day-to-day location of units, and combined a variety of computer models to better understand this event. These efforts reduced the uncertainties and better identified key data to be fed into the combined computer models. For instance, officials now believe:

• There were 1,250 unmarked chemical rockets in the open "pit" on March 10, 1991. About 500 of these were affected by the demolition.
• Only 18 per cent of the nerve agent was released into the atmosphere.
• Nerve agent released was composed of one percent that vaporized, one percent that was released as liquid droplets, six percent that evaporated from soil and ten percent that evaporated from wood.

"We're very confident of the accuracy of the analysis released today, because of the rigor of the scientific research we've applied to better understanding this event," said Dr. Bernard Rostker, the DoD special assistant for Gulf War illnesses. "Based on recommendations by the independent panel of experts from the Institute for Defense Analyses, the Pentagon and CIA have applied multiple models to determine the likely path of the agent which was vaporized in the explosion."

While no deaths or noticeable health effects were reported at the time of the demolitions, the effort to determine exposure levels is important to the ongoing investigation looking for potential causes of Gulf War illnesses. Because scientific evidence on brief, low level exposure is limited, the Departments of Defense and Veterans Affairs are committed to gaining a better understanding of the potential health effects and are funding several projects to learn more about them.

Efforts to find the causes of Gulf War illnesses were stepped up considerably after President Clinton announced a coordinated approach involving the Departments of Defense, Veterans Affairs, and Health and Human Services on March 6, 1995.

Shortly after the President's announcement, the Central Intelligence Agency conducted a comprehensive review of intelligence on the issues related to the Gulf War. By late 1995, information resurfaced which mentioned the presence of chemical munitions at Khamisiyah discovered by a United Nations Special Commission (UNSCOM) which had visited the site in October 1991. UNSCOM reinspected Khamisiyah in May 1996 and on June 21, 1996, DoD publicly announced UNSCOM's findings.

In an effort to better understand the possible effects on troops in the area of Khamisiyah, the CIA began efforts in 1996 to model the demolitions. The task proved extremely complex, due to computer model limitations and scant source data (agent purity, wind direction, etc.). In October 1996, former Deputy Secretary of Defense John White ordered an effort to reach out to and seek the help of about 20,000 Gulf War veterans who were within 31 miles (50 kilometers) of the Khamisiyah site from March 4 through March 15, 1991. This was not an exposure estimate. It was expected that anyone who was within 25 kilometers of the detonation would have experienced some symptoms from a chemical agent release. Because of the absence of reliable meteorological data at the time, and because of a desire to be conservative, this area was doubled for the circle with a 50-kilometer radius that was drawn from the site.

Later that October, White appointed Dr. Rostker as the Special Assistant for Gulf War Illnesses and took a number of other steps to strengthen clinical and research programs, review intelligence data and subject current projects to review by expert panels of outside experts.

Since Dr. Rostker's appointment, DoD has expanded the number of people involved in the search for information about Gulf War illnesses to more than 150. Rostker's staff is investigating and publishing reports on incidents to determine whether they may shed light on the unexplained illnesses. Dr. Rostker has also opened a dialogue with thousands of Gulf War veterans in meetings across the country, telephone interviews and interactive computer links.

Rostker stressed investigations on Khamisiyah and other Gulf War activities will not end with today's announcement. "We have several investigations ongoing 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 we've received from Gulf veterans." He urged Gulf War veterans with information to contact DoD at 1-800-472-6719 or at DSN 878-3261.

Rostker concluded, "The health of Gulf War veterans is extremely important to us. The DoD and VA are committed to providing the best possible medical care to all veterans and equally committed to gaining a full understanding of all the possible health effects of service during the war. As We learn more about the events during the Gulf War, we will continue to keep veterans informed."