Estimate of Soldiers Exposed to Toxic Agents Widened

The Pentagon said Tuesday that the number of U.S. soldiers who may have been exposed to chemical agents during the demolition of the huge Khamisiyah Iraqi weapons depot in 1991 may top 20,000, rather than the 15,000 it had estimated a few weeks ago.

The revision came after authorities discovered battlefield logs from the period suggesting that U.S. soldiers may have been involved in another major demolition in the area that could have affected thousands more American troops as far as 30 miles away.

Authorities stressed that the new figure was only a ballpark estimate and could turn out to be substantially smaller--or larger--once the Defense Department completes its investigation of the Khamisiyah operation and its possible consequences for American troops.

Pentagon officials said the department now would begin surveying all 20,000 veterans of the Khamisiyah incident in an effort to determine precisely what happened during the operation and whether the troops who were exposed had suffered physical ailments as a result.

Before this, the Pentagon had intended to survey only 5,000 veterans--its estimate of how many may have been present within a 12 1/2-mile radius of the Iraqi weapons complex--and to use a new CIA model of wind patterns to pinpoint others who might have been exposed.

However, the CIA said last week that it would have to delay completion of its model indefinitely because of technical difficulties. Pentagon officials said they decided to use the 20,000 figure to avoid having to postpone their survey of veterans who may have been affected.

“We have decided after looking at the facts that it would be best to go out and aggressively reach out to these 20,000 people,” Pentagon spokesman Kenneth H. Bacon said, adding that only a few of the 5,000 on the original list had been contacted so far.

The announcement did not mollify veterans’ groups that have been critical of the Pentagon for not accepting their claims that many more soldiers may have been exposed to chemical agents.

James J. Tuite III, director of the Gulf War Research Foundation, an activist group, called the decision “too little in the face of the evidence.” The Defense Department “still needs to be much more forthcoming on this issue,” Tuite said in an interview.

Until last spring, the Pentagon maintained there was no evidence that any U.S. troops had been exposed to toxic agents during the war. Iraq itself is thought not to have used its chemical weapons, and no U.S. troops died on the battlefield as a result of toxic poisoning.

However, in June, the Defense Department said it had discovered evidence that U.S. troops had been involved in the destruction of a chemical weapons bunker at Khamisiyah on March 4, 1991, and that hundreds of them could have been exposed to sarin and mustard agents.

Two weeks later, officials reported that on March 10, 1991, U.S. forces also had blown up a second cache of Iraqi chemical weapons in a nearby pit in the same complex. Bacon then suggested the number of soldiers who might have been exposed could top 15,000.

On Tuesday, U.S. officials said they recently discovered battlefield logs from the same period suggesting that American troops may have been involved in yet a third operation on March 12--this one involving destruction of 840 Iraqi artillery shells.

A senior Defense Department official said authorities were not sure from the log whether the third set of explosions actually took place on March 12 or on the same date as the one at the pit--or even whether any of the 840 shells contained chemical weapons.

They said the 20,000 figure was arrived at by assuming that at least some of the shells contained chemical agents and that the third operation occurred on March 12. They also assumed the toxic agents released in the blast would be carried 30 miles on all sides.

Despite the larger total, Defense Department officials still believe that only about 1,100 U.S. soldiers were involved in the actual demolition of the three weapons sites. The remaining 19,000 or so were engaged in related jobs, but were potentially within range of toxic vapors.

Pentagon officials said the situation was made even more confusing because an initial investigation had shown discrepancies in the recollections of some of the troops interviewed, with conflicting reports of what may have occurred.

For example, one official said, although the soldier who kept the log of the March 12 operation insists his record is accurate, one of the ordnance specialists who rigged the explosives recalls vividly that the explosion was part of the March 10 operation.

Authorities said they hope to clear up some of the discrepancies by interviewing the 20,000 veterans who were within the 30-mile radius between March 4 and March 15, the day the last traces of toxic vapors likely would have dissipated.

Bacon said the Pentagon’s new survey would seek first to find out more about what happened at Khamisiyah and, second, to locate veterans who are sick and need treatment.