Senior U.S. officials, acknowledging concern about a potential Iraqi poison gas attack on Western troops dispatched to the Middle East, warned yesterday that such an attack would provoke a "severe" U.S. military response and invite strong, worldwide condemnation.

Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, told a news conference that "it is a threat that we're concerned with," and that the U.S. troops had been equipped with suits designed to protect them against deadly nerve agents and toxic mustard gas.

President Bush, asked at a news conference about intelligence reports that Iraqi chemical munitions had recently been loaded aboard combat aircraft, said, "Any time you deal with somebody who has used chemical weapons on the battlefield, you are concerned about it." He was referring to Iraqi President Saddam Hussein's decision to authorize the repeated use of chemical weapons, including nerve and blister agents, during the Iran-Iraq war ending in 1988.

"I would think . . . that he'd know that, given the way the world views the use of chemical weapons, that it would be intolerable, and that it would be dealt with very, very severely," Bush said.

Iraq was one of 150 nations at a special Paris conference organized by the United States in January 1989 that pledged not to use chemical weapons and to condemn their use by others. Since then, however, it has enlarged its arsenal and taken steps to become self-sufficient in poison gas production, according to U.S. intelligence officials.

Powell, noting that reports about the arming of Iraqi planes with gas bombs were "somewhat ambiguous," said he did not want "to heighten tension over that issue" by providing additional details. Other U.S. officials said his remarks reflected the Bush administration's desire to warn Saddam strongly away from using the weapons while avoiding any appearance that the threat of their use is sufficiently worrisome to give him a powerful lever in the dispute over Kuwait's future.

House Armed Services Committee Chairman Les Aspin (D-Wis.) said he was told that Iraq had "rather publicly loaded and then downloaded {chemical weapons} from aircraft. And they did it rather in the open expecting us to see it. . . . I think it was a rather deliberate move on their part, probably . . . as {a military} deterrence to us."

Military officials and independent experts said an Iraqi chemical attack was regarded as unlikely in the face of a threatened, devastating U.S. retaliation with sophisticated conventional weapons, partly because the potential military gains would be slight.

Maj. Joe Padilla, an Army spokesman, said the gear issued to U.S. soldiers as they boarded airplanes for the Persian Gulf provides good protection against the type of weapons held by Iraq. He said that in addition to a mask that covers the mouth, nose, eyes and ears, each soldier carried a two-piece garment with separate rubber boots and gloves.

The mask alone "provides complete protection against {the Iraqi nerve agents} tabun and sarin," because these must be inhaled to cause immediate death, said Harvard chemistry professor Matthew Meselson, a chemical weapons expert and consultant to the Army on protective gear.

An Army report lists these clinical signs of exposure to sarin: drooling, excessive sweating, cramping, vomiting, diarrhea, involuntary urination, fatigue, muscle twitching, headache, confusion, irregular heartbeat, convulsions and coma. A single, deep inhalation can bring death in 10 minutes.

However, only the full rubber suit can provide adequate protection against the Iraqi arsenal of mustard gas, which causes extensive tissue and cell damage, including temporary blindness, when it comes into contact with exposed or moist skin on the face, groin, back or armpits. Experts say the suit is extremely cumbersome and hot and that any soldier wearing it in the blazing Middle East climate would probably be forced to rest every 20 minutes.

The suits are impermeable for only 10 to 24 hours, moreover, and must be replaced from stockpiles deployed with each military unit.

U.S. soldiers were also equipped with atropine, a nerve gas antidote, and special towelettes to wipe away mustard gas, Padilla said. The soldiers are trained to inject the atropine themselves, but only after they observe symptoms of nerve gas poisoning; otherwise, it blocks perspiration and causes heat exhaustion.

Experts say no antidote exists for mustard gas and that the best recourse is swift evacuation from the scene of any contamination. Hundreds of thousands of men were injured by exposure to the "King of Gases" in World War I, primarily because they were pinned down in trenches without protective gear.

Meselson maintains that the record of poison gas attacks in the Iran-Iraq war and other conflicts suggests that it was never "any more than marginally effective against forces with anti-chemical protective equipment and training."

Seth Carus, a Naval War College expert on the Iraqi chemical program, agreed that "nothing indicates that {poison gas} . . . was of decisive value" in the conflict with Iran, but he said Saddam "doesn't perceive it as different from other kinds of weapons" and was willing to grant authority for its use to relatively low-ranking field commanders.

Iraq is known to have packed highly toxic mustard gas and the deadly nerve agents tabun and sarin into artillery, battlefield rockets and aircraft bombs. Intelligence officials say the Iraqis were sighted loading some of the munitions aboard combat aircraft in an apparent threat to the United States.

It is not known if any U.S. chemical weapons have been transported to Saudi Arabia to combat the Iraqi threat.

THE U.S. ARSENAL The U.S. military maintains a modest, aging arsenal of poison gas bombs, spray tanks and artillery shells. It also has produced several thousand modern artillery shells filled with nonlethal chemicals that are automatically combined to produce sarin once the shell is fired.

Tens of thousands more decrepit, gas-filled land mines, rockets, mortar shells, artillery projectiles, bombs and spray tanks produced by the United States are currently stored at eight Army depots, awaiting incineration.

KEY TYPES Mustard Gas: Used extensively in the final years of World War I, this blister agent is still regarded as one of the most effective chemical weapons due to its relative persistence and the threat it poses to any exposed or moist skin. The oily liquid and its vapor also damage eye tissue, irritate the lungs and throat and can cause permanent damage to blood cells. Mustard gas is considered highly carcinogenic.

Nerve Gas: The two orignial types, sarin and tabun, were developed as nerve gases in Germany in the 1939s. By affecting the body chemical that causes muscle contractions, these gases send victims into spasms. The agents are so dealdy they can kill or disable in seconds if an extremely small amount is inhaled.


Soldiers working where chemical weapons have been used must wear masks or sophisticated protective equipment that includes special clothing and activated carbon decontamination kits.

Soldier shown with protective clothing and mask