Count of Troops Exposed to Toxic Cloud May Triple

The Pentagon warned Tuesday that the number of U.S. troops who may have been exposed to toxic agents at two Iraqi chemical weapon sites just after the 1991 Persian Gulf War could be at least three times as large as the 5,000 it has estimated so far.

The higher figure is expected to result from a revised estimate based on new calculations by the CIA, scheduled to come out later this month, on how far the chemical agents might have been carried by winds on the days that the weapon caches were blown up.

Defense Department spokesman Kenneth H. Bacon said that, based on the quantity of toxic weapons involved and on initial indications about wind patterns and the disposition of U.S. forces, “I think we have to think in terms of big numbers, bigger than 15,000, certainly.”

The latest revelation, the third time in three months that the Pentagon has boosted its estimates of how many U.S. soldiers might have been exposed, was expected to add fuel to the debate over the department’s investigation into the possibility of a “Gulf War illness.”

Although veterans have been complaining for years about possible side effects, ranging from joint aches to reproductive problems, the Pentagon has maintained for five years that it had been unable to find any evidence that U.S. troops were exposed to chemical agents.

In June, the department announced that new evidence obtained by a special United Nations commission showed that an Iraqi ammunition bunker at Khamisiyah destroyed by troops from the Army’s 37th Engineering Battalion contained shells with chemical warheads.

At that time, the Pentagon estimated that as many as 400 soldiers might have been exposed to toxic agents.

Last month, however, officials here disclosed that additional U.S. demolition operations at an open ammunition pit in Khamisiyah could boost the number of troops exposed to as many as 5,000. They warned then the figure could go still higher.

The revelations have forced the Pentagon to launch a major review of its handling of the investigation into a possible Gulf War illness.

Analysts said that, if the totals turn out to be as high as some officials now expect, the veterans’ complaints could become a major national issue, much as the fight over the effects of Agent Orange in the years after the Vietnam War. After a lengthy controversy, the government now grants benefits to veterans who are ill from exposure to Agent Orange, a powerful defoliant used by the United States in Southeast Asia.

Deputy Defense Secretary John P. White said Tuesday that he had asked the National Academy of Sciences and the Institute of Medicine to reevaluate the department’s overall approach to Gulf War syndrome, both in investigating the issue and in treating veterans who are ill.

He also asked the groups, which are made up of distinguished scientists, to advise the military on a long-term strategy for protecting U.S. troops who may be deployed in future conflicts that involve “unfamiliar environments.” The review is expected to take a year.

The CIA report expected later this month is designed to provide the Pentagon with a computer model that it can use to estimate the extent to which any U.S. military units in the area might have been exposed to chemical agents released in the two Khamisiyah explosions.

The explosions took place on March 4 and March 10, 1991, in a section of southern Iraq about 15 miles southeast of the town of An Nasiriyah, which was a known chemical weapon depot. During the war, the allies did not know that Khamisiyah contained agents as well.

Although thousands of U.S. troops were in the Khamisiyah area, which covered about 15 square miles, not all of them necessarily were exposed to toxic fumes. Most of the ammunition did not contain chemical agents, and no deaths or serious illnesses were reported at the time.

But now, U.S. officials fear that thousands of soldiers may have been exposed at least to low-level doses at Khamisiyah, depending upon how big an explosion occurred at the bunker and accompanying pit area and whether the chemical vapors were carried to the troops.

The CIA model is expected to deal with such questions as how large a cloud each of the explosions produced, which way the wind was blowing and where U.S. troops were in relation to the moving cloud.

That in turn will involve computation of how many shells were destroyed, how far they were thrown out of the bunker or the pit when they exploded and such weather conditions as temperature and cloud cover. “It’s not an easy calculation to make,” Bacon told reporters.

U.N. reports, based on Iraqi estimates, have suggested that there were as many as 2,160 artillery shells and rockets in the bunker and accompanying pit, about evenly split between the two sites. It is not known whether these estimates are reliable.

However, an earlier CIA study, dealing solely with the bunker, estimated that, although the cloud in that explosion probably spread as far as 17 miles, only a small portion of it would have been lethal. Most of it would have produced minimal effects.

U.S. officials said that, while the winds seemed to have been blowing to the northeast during the March 4 explosion at the bunker, they apparently shifted on March 10, when the 37th Engineering Battalion blew up the ammunition pit.

Officials said it was likely that the U.S. soldiers who took part in both events at Khamisiyah were not wearing special chemical-protection suits, largely because they were not expecting to encounter toxic agents.

The Iraqi munitions were reported to contain sarin, a virulent nerve agent used in a Tokyo subway bombing in 1995. U.S. commanders had expected Iraq to fire chemical weapons at allied troops during the Gulf War, but Baghdad did not use the weapons in the face of allied threats of retaliation.