HAMPTON ROADS, VA.   December 13, 2004

After $247 Million, What Is There to Show? 

CHAPTER 3: THE SILVER BULLET

The fight over depleted uranium weapons isn't about how well they work.  It's about how safe they are after the fighting is finished.
BY BOB EVANS
247-4758

December 13, 2004.

 

 Photo Gallery
The weapons systems.
The weapons systems.

 Chapter 3 in brief

M1 Abrams tank benefits two ways
The main U.S. battle tank, it uses depleted uranium sandwiched between steel slabs for defense, creating an armor never penetrated in war. In the 1991 Persian Gulf War, its depleted uranium weapons allowed it to destroy Iraqi tanks before the enemy got in range to fire effectively.

A-10 "Warthog" is a rapid-fire tank killer
Though slow, it's deadly and accurate. It's fired the most rounds of depleted uranium in actual warfare.

Navy's Phalanx is last-ditch defense
The weapon is designed to shoot down missiles or airplanes that get close to a ship after eluding other defense weapons. The Navy is switching from depleted uranium to tungsten for the Phalanx but denies that the switch is for safety reasons.

Gatling gun for A-10, Phalanx
Both weapons use similar technology to fire 4,200 rounds a minute. Most miss, but only one shot is needed to do the job.

Small but effective 30 mm cartridge
The depleted uranium rounds fired by the "Warthog" and the Phalanx aren't much bigger than a finger, once you take away the protective housing that helps launch the weapons. Yet they can still take down a tank or missile.

Area veteran was in weapons' dust
Matt Rohman, a veteran of the Gulf War from York County, spent months working in the dust created from depleted uranium weapons. He began losing his teeth and his strength within weeks and was totally disabled in a few years. Government doctors have been unable to explain his illnesses.

Duke professor says dust is a danger
Mohamed B. Abou-Donia, professor of pharmacology and cancer biology at Duke University, has spent years studying the effects of depleted uranium on the body to try to find the cause of Gulf War veterans' illnesses. He says that exposure to the mildly radioactive toxic dust resulting from use of depleted uranium weapons is one reason Rohman and others are so sick.

Munitions expert defends weapons
James Naughton, former head of the Army's munitions program, says the weapons are safe and give the U.S. military a decisive advantage in combat.

Pentagon says study shows no major risk
Lt. Col. Mark Melanson, director of the Army's health physics program, says the recently completed Capstone Study documents the low level of risk to soldiers and civilians from inhaling depleted uranium dust on the battlefield. Army procedures call for wearing safety masks and clothing when going into vehicles hit with the weapons, but Melanson says you'd have to go into and onto thousands of them before endangering your health.

Some Web sites on depleted uranium
www1.va.gov/RAC-GWVI
This is the site for the Veterans Administration Advisory Committee on Gulf War Illnesses, a panel of scientists, researchers and veterans advocates appointed in 2001 to help the government's research efforts. Its recent report is here, along with links to much of the research available.

www.gulflink.osd.mil
This is the Pentagon's official web site for health issues related to Gulf War service, mostly concentrated on the 1991 war.

www.ngwrc.org
This is the web site of the National Gulf War Resource Center, a veterans' advocacy group that focuses on troops from 1991 to present. Once you've accessed the home page here, you can link to specific topics related to Gulf War issues and research, including issues facing current troops in Iraq and Afghanistan.

 ABOUT DU

What is it?
It's a byproduct of making "enriched uranium" for nuclear weapons and fuel. "Enriched uranium" is somewhat misleading because processors take uranium with natural levels of radioactive isotopes, primarily Uranium 238 and Uranium 235, and remove as much of the U-235 as possible. Weapons makers and nuclear plant owners want almost-pure, highly radioactive U-235. What's left behind is primarily U-238 (other isotopes remain, in very small quantities). That substance has about 40 percent less radioactivity than natural uranium and is "depleted uranium."

What makes it so important?
It's proven to be the most effective tank-killing weapon ever. A round of depleted uranium no bigger than your little finger can stop a top-of-the line tank without depleted uranium armor. The weapons get sharper as they hit and plow through thick steel. They also create fireballs of thousands of degrees, a potent combination.

What is the controversy?
As they strike, the weapons get sharper by peeling off millions of shards of burning depleted uranium. Those burning pieces become microscopic dust that can be inhaled. Depleted uranium is a mildly radioactive, toxic substance that can cause damage to live tissue and cells once inside the body.

 THE SERIES

Part One: Looking for a cause, looking for a cure

Part Two: From the nose to the brain
 
The United States began developing depleted uranium weapons in the 1950s. But the first one wasn't fired in combat until the 1991 Persian Gulf War.

It didn't take long for the weapons to show that the wait was worth it.

Soldiers on the battlefield were so impressed, they quickly began calling depleted uranium "The Silver Bullet," in recognition of its seemingly magical capabilities and exterior metallic color. They also began calling it "DU."

Although the U.S. tank gunners firing the weapons had never used them before - even in training - they were immediately able to hit and destroy heavy Soviet-made Iraqi tanks and armored vehicles from two miles away, military officials crowed in congressional hearings afterward.

The weapon that it replaced, made from tungsten, wasn't effective from more than a mile and a half, they said. That's the equivalent of two boxers squaring off, one with 4-foot-long arms, the other with 3-foot-long arms.

"What we want to be able to do is strike the target from farther away than we can be hit back, and we want the target to be destroyed when we shoot at it," Col. Jim Naughton, then-head of munitions for the Army Materiel Command, said just days before Operation Iraqi Freedom began last year. "And we don't want to fight even. Nobody goes into a war and wants to be even with the enemy. We want to be ahead, and DU gives us that advantage."

This battlefield benefit might be in danger, though. A growing number of medical researchers are finding evidence that the residue of depleted uranium weapons might be deadly to our own troops.

Every time that a depleted uranium weapon hits its target, it leaves behind millions of tiny pieces of black dust that are mildly radioactive. The vast majority of those pieces are small enough to be inhaled. Researchers have found evidence that even a single piece of the dust in direct contact with a human cell begins the kind of genetic transformations thought to be the first steps toward cancer. They've also found evidence that inhaled uranium can be transferred to the brain.

A number of researchers think that proof of the dust's migration to the brain might explain some of the widespread neurological illness among veterans of the 1991 Gulf War.

The Pentagon has dismissed this possibility, saying it's an unproven theory. As for the other risks, they say even the highest dose of depleted uranium dust likely to be experienced in battle isn't enough to hurt someone. The Army says a recently completed $6 million study of the effects of inhaled depleted uranium demonstrates that it isn't a significant health risk, especially when the other risks on a battlefield are part of the calculations.

Theories and data abound to support both sides. No one disputes that the stakes are high.

On one side is the huge advantage that the weapons provided in the Gulf War and last year's Operation Iraqi Freedom. Pentagon officials say many soldiers are alive today because of depleted uranium's effectiveness.

On the other hand, there's the possibility that depleted uranium played a part in the illnesses suffered by many of the 697,000 men and women who fought in the 1991 war. More than 26 percent of that war's veterans are on disability, a rate nearly three times higher than experienced in any U.S. war in the past 60 years. Gulf War-related experiences don't account for all those disabilities, but the reason why so many are so sick remains a mystery. Some scientists suspect that it could be a combination of factors, including the black dust.

WHY THE WEAPON IS SO POWERFUL

The dust is an unavoidable result of depleted uranium weapons, which are especially effective arms for a number of reasons.

Depleted uranium is extremely dense, which means it is very heavy relative to the space that it takes up.

In the Gulf War, U.S. forces fired thousands of projectiles with depleted uranium - about 320 tons worth. That sounds like a lot, Naughton said, but if you squished it all together, it would make a cube only 8 feet long on each edge.

This high density - 1.7 times that of lead - offers important offensive and defensive capabilities in warfare.

On defense, it makes for nearly impenetrable armor. Slabs of depleted uranium sandwiched between sheets of tough steel are used in the main U.S. battle tank, the Abrams. Depleted uranium armor has never been penetrated in combat, only in testing under controlled conditions, the Pentagon says.

The armor is so good that after the Gulf War, Pentagon officials were fond of telling members of Congress the story of a U.S. Abrams tank crew that suddenly found itself in point-blank proximity to three Russian-made Iraqi tanks in the fog of war. The Iraqis fired first, but their shots bounced off the Abrams' armor, causing at most a crease in the metal.

The Abrams' crew then fired 1-2-3 and destroyed all three Iraqi tanks. The last shot went through a sand berm that completely concealed the enemy tank from view after it tried to run and hide, the story went.

Lest the military value of depleted uranium be lost in the health controversy, the story is recounted on a Department of Defense Web site established in reaction to allegations that depleted uranium weapons are responsible for some Gulf War veterans' illnesses. Depleted uranium's high density also gives the weapons awesome power. Other than what's necessary to launch a depleted uranium weapon in flight toward a target, it carries no other explosive and isn't a "shell." It is simply a pointed rod of almost pure depleted uranium metal hurling through the air, with fins on the back to give it the stability necessary to ensure that it reaches the target. The deadly darts fired from Abrams tanks are about 2 feet long and less than an inch in diameter. They weigh from 8.5 to 10.6 pounds.

Smaller guns equipped to use the weapon shoot even smaller sticks of depleted uranium. But they can be just as effective. The Air Force's A-10 "Warthog" tank-killer aircraft can spit out 4,200 rounds a minute, each about the size of a finger and weighing only two-thirds of a pound, Pentagon officials say.

Each one of those fingers can destroy a tank.

Launching depleted uranium weapons involves mounting them in cuplike fittings called sabots and then loading them into the weapon. The sabots give the depleted uranium rods a sort of vehicle to ride through the barrel of the gun and out of the muzzle, so the projectile can begin the journey to the target. Once the sabot and depleted uranium rod and its fins clear the muzzle, the sabot falls to the ground.

About that point, the depleted uranium weapon is traveling at Mach 3, or three times the speed of sound, says Don Noble, a retired military munitions expert from Williamsburg who helped test the weapons in the 1970s.

WHY THE WEAPON IS SO DEADLY

Once a depleted uranium weapon reaches its target, the high density, small diameter of the projectile and all that speed means there's a lot of energy packed into a narrow space.

Packing lots of energy into a small space is what power is all about.

Noble notes that depleted uranium has some very special properties that enhance that power.

Unlike most metals, a narrow, sharp-tipped depleted uranium rod doesn't get blunt when it strikes a hard object. It just gets sharper, shedding little bits of depleted uranium - like shavings in a pencil sharpener - as it plows through a hard object such as armor.

Those little bits are also on fire - about 3,200 degrees Fahrenheit, a study by the Canadian armed forces found. Researchers call the tiny pieces "fireflies," and they're abundant and visible when a weapon hits the target. For a time, some of these flaming bits become liquid before cooling into tiny irregular-shaped pieces of dust.

The depleted uranium rod itself, known as a penetrator, is also on fire at 3,200 degrees as it slides through the hard target, the study says.

That's because depleted uranium is pyrophoric, which means that it's capable of igniting spontaneously in the air. If left alone and exposed to air, it will turn black over time. When it strikes something, its exterior bursts into flames but it retains its mass and relative shape, not getting blunt.

By the time the weapon has penetrated its target, it's become a fireball that ignites any combustible material nearby - such as fuel, clothing or oxygen - leaving behind the black dust of incinerated particles of depleted uranium as it goes.

"As the penetrator enters the crew compartment of the target vehicle, it brings with it a spray of molten metal, as well as shards of both penetrator and vehicle armor, any of which can cause secondary explosions in stored ammunition," a primer on the weapons for U.S. Marine and Navy medics reads.

'THE DUST AND THE ASHES COVERED EVERYTHING'

That primer was written years after the Persian Gulf War, when a young soldier named Matt Rohman from York County - along with hundreds of other combat engineers - were handed the job of emasculating Iraqi leader Saddam Hussein's military in the 1991 war.

After the fighting stopped, U.S. military commanders knew that they'd have only a short time before they'd be ordered back to their barracks. They wanted to make sure that none of the munitions, tanks or vehicles they'd encountered could be used again by Saddam, whether those objects be intact or partly destroyed.

So combat engineers like Rohman spent months speeding across the desert, rounding up things to blow up. They quickly came to recognize those struck by depleted uranium (as opposed to other weapons) by the small holes in the pierced armor.

That and the dust were usually the only visible evidence of why the vehicles had exploded in fire, Rohman says.

No one ever mentioned that the dust might be dangerous.

Now Rohman, 40, is one of the thousands of Gulf War vets who are disabled by various maladies, including muscle and neurological problems, stomach disorders, and extreme pains in his head and joints. His medical problems began within weeks of his return from the war in 1991, and government and civilian medical doctors can't explain what caused them. He's been unable to work since 1997.

Like many of the sick veterans from that war, there were many possible hazards to choose from.

Life in the desert was hard, hot and dirty, Rohman says. A mixture of sand, depleted uranium dust and soot from continuing oil well fires in the area coated everything, including his skin, uniform and often his food.

"For over 30 days, we did not wash and clean," Rohman wrote in a sworn affidavit in 1998, in an attempt to get veterans benefits after he'd been deemed physically unable to work at any job. "I stayed in the same uniform through our march, and usually, I was so dirty from the air, ashes and dust that I could not be identified. The dust and ashes covered everything on me and around us. We could not escape it."

The dust and dirt was on their food, too, he says, and it was impossible to get it all out of your mouth.

Rohman spent nearly four months that way, his military records show.

FIRST, ROHMAN LOST HIS TEETH, AND THEN HE LOST HIS HEALTH

Shortly after the war, Rohman's teeth started coming out. Military dentists yanked nine teeth in Germany before they sent him home. His records show the Army gave him an early honorable discharge and a 20 percent disability because of a knee injury that he'd suffered in the early days of the war, scrambling into an armored car during a missile attack on his outfit.

By 1993, nearly all the other teeth were gone, he says. By then, he was going to Naval Medical Center Portsmouth for treatment.

"The doctor over at Portsmouth told me that the only way they could all go that quick was if they'd come in contact with radiation," Rohman says. Losing teeth like that didn't run in his family, he adds. Before the war, "I didn't have a cavity."

Rohman says the doctor at Portsmouth asked him whether he'd been exposed to radioactive materials. Rohman says he didn't know about depleted uranium back then, so he told the dentist that he didn't know.

By the time Rohman learned that the black dust was mildly radioactive, all his teeth were gone, he had severe nerve damage in his hands and feet, almost daily migraine headaches and breathing problems, among other ailments.

His lawyer filed in 1998 to get the dental and other records from the Naval Medical Center to help Rohman's claims for benefits. But the hospital sent a form letter, saying it had no records at all of Rohman being seen there for anything.

Rohman has a stack of copies of medical records from Portsmouth, verifying visits and treatments there. But he has only some of his records, and none of the ones that he got and kept were for the dental work.

He says the dentist who treated him wanted to put something about possible service-related exposure to radioactivity on one record but was overruled by a supervisor. He also says he saw some of his records shredded during one of his visits, but doesn't know what those papers contained.

Now, Rohman says, he realizes that he might have been eating small bits of depleted uranium, and with the poor sanitation available, those bits of dust were stuck on and between his teeth for days and weeks.

What he swallowed wasn't a big problem. Scientists know that nearly all the uranium that's swallowed passes through the intestines quickly, is excreted and causes no danger.

What stayed in his mouth for a while is another matter.

Rapid loss of teeth is a common result of direct radiation to the mouth and jaw from medical treatments or other sources, if preventive measures aren't taken, according to medical journals. Radiation affects the saliva glands, which in turn can't perform the natural cleansing that helps keep teeth and gums healthy and free of germs.

There's also the danger of tissue damage to the gums from direct contact with radiation sources. When gums get weak, teeth fall out.

While in the desert with the 3rd Armored Division, constantly on the move to collect and destroy all that hardware, there were days at a time when there was limited drinking water. Rohman recalls that everyone's mouth was dry and that brushing your teeth was out of the question.

According to data compiled by the Veterans of Foreign Wars, loose teeth and gum problems are common among veterans of the Persian Gulf War. The American Legion also did a survey of members who'd been to the gulf during the war and found the same thing. But that survey was never handled as a scientific survey, says Steve Smithson, director of the legion's veterans affairs and rehabilitation division.

Dental problems aren't on the list of typical Gulf War illnesses compiled by researchers and the Veterans Affairs Department, however.

Mohamed B. Abou-Donia, a professor of pharmacology and cancer biology at Duke University, led a review of medical and scientific data on depleted uranium that was published this year. He says that he found no evidence of references to dental problems but that it might simply be one of many gaps in our knowledge about the veterans' health problems.

THE PROBLEM GOES PUBLIC WITH A 1998 STATEMENT

One of the big obstacles to figuring out the cause of these illnesses is the government's failure to accurately survey all those who served and to compare their experiences, Abou-Donia and other researchers say. If that data is ever collected, they say, they might gain many insights into the veterans' health problems and the causes.

Given the circumstances that veterans like Rohman were working in during and after the war, "the teeth part could be related very directly to the depleted uranium," Abou-Donia says. He says it's also possible that few veterans got as high a dose as Rohman.

At the time that Rohman says he got dental exams at Portsmouth, allegations of hazards from depleted uranium's use on the battlefield hadn't become known yet outside the group of people who develop weaponry for the military.

Not until 1998 did the U.S. government publicly acknowledge that it shouldn't have let Rohman and hundreds of others work closely with the vehicles and other objects struck by those weapons without wearing masks or suits to protect them. The first government official appointed to oversee research on the cause of the veterans' health problems issued this statement:

"Combat troops or those working in support generally did not know that DU-contaminated equipment, such as enemy vehicles struck by DU rounds, required special handling. The failure to properly disseminate such information to troops at all levels may have resulted in thousands of unnecessary exposures."

The statement occurred after veterans' groups, members of Congress and others successfully pushed the Pentagon to admit that the illnesses suffered by the men and women who'd fought the war weren't simply the result of too much stress. It also occurred as government officials began to acknowledge that there was a significant problem that had to be addressed.

CONCERNS WERE DOCUMENTED DURING THE 1980s

The government and military were backpedaling in many areas. Within months, Pentagon and CIA officials acknowledged that earlier statements dismissing the presence of nerve gas and other toxins on the battlefield were erroneous and that there were widespread incidents that could have affected troops during the war and its aftermath.

By the time that a presidential assistant acknowledged the failure to warn troops about the dangers of depleted uranium, the Army had issued a technical bulletin calling for troops in such situations to wear protective clothing, boots, and masks with filters to prevent breathing the dust. It called for them to be able to shower immediately afterward and remove any "contaminated clothing," not just after the day's work but "if feasible, at the site." The need to take those precautions wasn't a secret among the people who'd been working to develop the weapons more than a decade earlier.

When Noble was part of a team evaluating depleted uranium weapons' ballistics in the 1970s, members examined the area with Geiger counters before entering areas where the projectiles hit targets, he says.

Even after the Geiger counters showed low levels of radiation, his team wore protective suits and breather masks where the weapons hit, he says. They also took regular doses of aspirin because the drug was supposed to help cleanse their bodies of the toxins from the uranium and other chemicals that they worked with.

Other military officials who helped develop depleted uranium weapons knew about the possible risk to soldiers' lungs and began trying to get a grasp on the problem a decade before the war.

A study to figure out how much dust might be inhaled after a typical explosion - and what it would do once it got in the lungs and body - was conducted from 1981 to 1983 by the Air Force. Much of the work took place at the same New Mexico laboratory where rats now breathe uranium bits to test whether the uranium goes to their brains. The 1981-83 study by the Air Force was titled, "Preliminary Study of Uranium Oxide Dissolution in Simulated Lung Fluid." It tried to estimate how much radiation the lungs might be getting before the particles dissolved in the fluid and then into the bloodstream, where they would pose a possible toxicological danger to the kidneys and other parts of the body but also would be flushed out of the body in urine.

The study pointed out lots of pitfalls that future researchers would run into while trying to settle the problem for good. It came to no firm conclusions about risks - in part because the uranium bits don't break down into predictable sizes and shapes. Much of the study resulted in educated guesses based on mathematical models. More work was needed, it said.

Pentagon officials say the final reams of data on that topic were collected and published this year. Their five-year $6 million study involved shooting real depleted uranium weapons into a real tank, real tank hulls and turrets, and a real Bradley Fighting Vehicle. The depleted uranium dust that resulted was caught in filters, weighed, analyzed and soaked in simulated lung fluid to see how long it would take to dissolve halfway.

For most of the particles, it took more than 100 days, which means there would be some mildly radioactive dust in the lungs or lymph nodes for years. The study said the smallest particles took the longest time to dissolve halfway. But it calculated that because they were so small, there shouldn't be a significant health risk from inhaling those particles, based on industrial standards for nuclear workers and government-approved standards for uranium intake.

Soldiers like Rohman, who weren't in a tank hit with one of the weapons, would be able to enter hundreds to thousands of vehicles covered with the dust before reaching the threshold of risk, according to the study.

The military not only dismisses the risk, it dismisses the statements of thousands of troops who say they were exposed.

HOW MANY INHALED? NO ONE REALLY KNOWS

Officially, the Pentagon says only a few hundred troops were involved in potentially dangerous duty involving depleted uranium in the 1991 war.

Veterans and many researchers disagree. There might have been relatively few soldiers like Rohman officially assigned to work in and on the damaged tanks and other vehicles struck with depleted uranium, they say, but tens of thousands of others were likely exposed.

Once the fighting stopped, just about anyone who came near a tank or other vehicle hit by depleted uranium scrambled over and into what was left to take a look. According to congressional testimony in 1997, a survey of more than 10,000 Gulf War vets showed that 85 percent of them had entered captured Iraqi vehicles. The reasons were many, ranging from official duties to getting their pictures taken or simply to satisfy curiosity.

Some vehicles hit by depleted uranium were hauled back to areas far behind the combat zone for possible return to the United States. The depleted uranium dust came with them.

According to a report to Congress by the Army Environmental Policy Institute, 19 U.S. tanks and Bradley Fighting Vehicles contaminated with depleted uranium dust were hauled back to King Khalid Military City in Saudi Arabia, far from the combat zone. The city was a central collection point for service personnel, media and others going to and from various parts of the war.

The unit responsible for disposing those vehicles didn't know about the hazards of the contamination and stored them "in a recovery yard without controlled access," according to the institute's report. The contaminated vehicles were there for three weeks before proper precautions were taken, the report says.

Tradition also might have played a part in spreading the black dust. Souvenirs - including parts from Iraqi tanks that had been hit by depleted uranium - were taken home in the bags and baggage of soldiers and units, the institute's report says. There were even attempts to bring back entire pieces of equipment as battle trophies.

When officials caught on to what was happening, some of the larger items were screened, and at least three Iraqi vehicles that units hoped to take home with them were found to be contaminated with depleted uranium and rejected for shipment, the institute's report says.

Items brought home without previous screening through official channels "may contain hazardous materials," the Army report says. There's no official count of how often pieces of metal, clothing or other items with black depleted uranium dust came home to soldiers' barracks, homes and families.

Military officials say it's extremely unlikely that anyone who came in contact with depleted uranium dust under such circumstances would become sick from it. Soldiers in those situations just didn't get a big enough dose, they say. The same is true about soldiers who might have inhaled some depleted uranium dust well after the end of a tank battle, they add.

That's because the documented cases of uranium poisoning in uranium millers and miners studied over the years show that exposures thousands of times greater than what could reasonably be inhaled in those scenarios must occur to cause the body harm, says Michael J. Kilpatrick, the Pentagon's doctor responsible for looking after the health of troops sent overseas.

WHAT'S A SAFE DISTANCE FROM DEPLETED URANIUM?

Anyone who stays at least 50 meters (165 feet) away from where depleted uranium struck an object has no risk of ill health from exposure, says one of the Pentagon's leading experts on the health effects of the weapons - Lt. Col. Mark Melanson, health physics program manager for the Army Center for Health Promotion and Preventive Medicine.

"Most of it settles out within 50 meters of the vehicle" that's been hit, he says. "Is it possible for a single atom of depleted uranium to carry beyond 50 meters? Yes. Is it a significant health risk? No."

Studies have found big differences regarding how much breathable dust depleted uranium weapons produce after they hit a target - and how far they might spread. The Army Environmental Policy Institute told Congress that the available research showed that anywhere from 18 percent to 70 percent of a depleted uranium projectile turns into breathable dust as it hits a target. It said 90 percent of the airborne depleted uranium would land within 50 meters of the explosion, in part because the dust is so heavy.

But it also said that the dust particles that went beyond the 50-meter mark were generally all small enough to breathe in. Scientists say those are potentially the most dangerous.

The environmental institute's report didn't go into how far the dust could go and what it would do in the heavy, sandstorm-driven winds of the Persian Gulf region. Much less how easily it could be kicked up by a moving truck or tank, then carried by one of those sandstorms. Melanson said later studies by the Army established the 50-meter standard.

The United States fired the most depleted uranium in the Gulf War, but the British and other allies used it too. And breathed the air. Since then, veterans in those countries have demanded to know why they're so sick.

The Royal Military College of Canada conducted its own testing after complaints by veterans. The publicly released version of its report didn't give a fixed distance from the site of an explosion, but it agreed that "at any distance from contaminated vehicles," the concentration of depleted uranium dust in the air "would be diluted to safe levels."

It also found that 91 percent to 96 percent of the bits of dust left after an explosion "are easily respirable," and that "these particles can remain in the air for a significant period of time (hours to days), most of which will remain inside the target vehicles, but with some likely to escape into the atmosphere through open hatches or remain outside the target."

Studies by the U.S., Canadian and Australian militaries found that though relatively heavy, depleted uranium dust particles are again suspended into the air when disturbed by vehicles, foot traffic or winds.

DETECTING ITS PRESENCE WITH A MASS SPECTROMETER

For much of the past 25 years, Leonard Dietz has been contemplating how far inhalable bits of depleted uranium can fly and how to detect it in the air and in soldiers' bodies. Dietz - a retired physicist in Schenectady, N.Y. - worked at the Knolls Atomic Power Laboratory, where General Electric did nuclear work for the Navy and the U.S. government years before the 1991 war. Dietz's primary expertise involves a device called a mass spectrometer. A mass spectrometer is used to analyze samples of unknown substances to figure out what they're made of.

Dietz patented a device built into mass spectrometers that's used to identify radioactive objects such as uranium and plutonium. He designed and built three mass spectrometers used to analyze uranium, plutonium and other elements.

General Electric had to monitor the air at the plant where Dietz worked. It also had to monitor the air around the perimeter of the plant's grounds to make sure that none of the substances it was using were escaping, Dietz says. One of his jobs was to figure out what was in the air filters to prove that his employer wasn't polluting.

The plant where he worked didn't use depleted uranium. But in 1979, all 16 filters caught tiny bits of depleted uranium - small enough that a human could inhale them, Dietz says.

"Every single filter contained depleted uranium." Dietz said, so they knew it wasn't a fluke.

Dietz and his co-workers finally figured out that the particles were coming from a plant in Albany, N.Y., making depleted uranium weapons for the Air Force.

The plant's smokestack was 26 miles from some of the filters, he says.

State and federal regulators caught on to the problem about the same time. They closed the plant, and since 1984, the U.S. government has been spending millions of dollars a year to remove the dangerous remnants of uranium.

The cleanup includes removing the top layer of soil from properties in a radius of about two-thirds of a mile from the plant, says James T. Moore of the Army Corps of Engineers, who's supervising the project. The soil was removed because it contained unacceptable quantities of small pieces of depleted uranium, small enough to be inhaled.

Two-thirds of a mile is more than 1,000 meters, or a kilometer.

In all, 53 nearby properties required soil removal. They included property in nearby Colonie, N.Y., and some railroad property, all of which "contain residual radioactive and chemical constituents above federal and state guidelines," according to a status report on the work by the Corps of Engineers.

Dietz says the 26-mile mark just happened to be where three of his filters were. They were the farthest from the plant where the depleted uranium weapons were made. He says his calculations show that while the contamination from the plant near Colonie came from a high smokestack, similar heights could easily be reached by depleted uranium dust particles rising from the heat and smoke of an exploding tank.

He says he has no doubt that depleted uranium particles from the weapons plant went much farther than 26 miles. Well-established laws of physics show that despite their heavy weight, inhalable-sized particles can carry for miles, can be kicked up and resuspended in the air, and can travel farther, depending on their shape, wind speed and other factors, he says.

Naturally occurring electrostatic charges would also cause them to cling to other dust particles that are even more aerodynamic, he says.

That would enable them to carry even further.

"They have an unlimited range," he says. "They can go anywhere dust goes."

Dietz wrote a technical paper for General Electric to document his findings on the airborne depleted uranium from the weapons plant. He retired a short time later but keeps following the trail of depleted uranium dust.

In 1995, a Kuwaiti scientist, Firyal Bou-Rabee, published a paper on possible contamination of Kuwait's soil, air and water in the international journal Applied Radiation Isotopes. The Pentagon's Web site on depleted uranium cites the scientist's research to demonstrate that the weapons' use there during the 1991 war didn't create undue radiological hazards in that nation.

Bou-Rabee's samples did show that the uranium in the air was about twice what you'd expect to find, given the level of uranium in the soils. He attributed this to "the relatively small contribution of depleted uranium dispersed after the Gulf War."

His research was financed by the Kuwaiti government - which, at the time, depended on the United States for its defense against Iraq.

Like most scientific papers, the data was included so other scientists could evaluate his findings and conclusions. Dietz says he used that data to compute how much depleted uranium was in a 2,500-square-kilometer (1,000-square-mile) area where battles were fought during the war.

The result, he says, was 10 metric tons of depleted uranium that had been added to the environment.

THE ONLY POSSIBLE SOURCE OF CONTAMINATION IS WEAPONS

There's no other source of the depleted uranium but the residue of the weapons, he says, because the characteristics of depleted uranium aren't replicated in nature and there are no other sources of the materials.

Bou-Rabee and the Pentagon pointed to the same data to show that because the total uranium in the air and soil was below government-established safety limits, there's no problem.

The U.S. government sent its own people with Geiger counters and other devices to measure the radioactivity of soils in Kuwait.

The same thing was done in Bosnia and parts of the former Yugoslavia, where depleted uranium weapons were used by U.S. and British forces in peacekeeping operations after the Persian Gulf War.

The U.S. government and the U.N. World Health Organization say their studies of the soils in those former battlefields show levels of radioactivity and uranium below what should cause alarm.

That's because they're within what's called the "natural background" levels that you'd find ordinarily.

Melanson says he's participated in some of that research, including the work to gather samples.

He and other government officials say there's no health risk there, even though thousands of small and large depleted uranium projectiles that missed their targets remain buried in the soil, mostly from the Air Force's A-10 aircraft.

Children often find the projectiles, play with them and carry them around.

A World Health Organization evaluation of the problem said that wasn't a good idea but wasn't an immediate health threat unless someone carried a projectile around for days or weeks.

CALCULATED RISKS DEPEND ON THE CALCULATIONS USED

Dietz says that he reviewed the data and methodology Melanson's lab used to produce these soil surveys and that the mass spectrometer it employed wasn't up to the job. He says it's incapable of accurately detecting depleted uranium in quantities of less than one part per million. That might sound like too small an amount to be concerned about, Dietz says, but when you're talking about particles measured in microns - one-millionth of a meter - it could mean a lot of uncounted depleted uranium.

Measuring total radioactivity isn't the point anyway, Dietz and others say. That's because the natural background doesn't involve a high quantity of radioactive dust on the surface, blowing around in the air. Much of the uranium in nature is in the ground, buried, and not so susceptible to inhalation.

There's plenty of natural uranium in Kuwait, but it wouldn't have the same health-threatening characteristics as the depleted uranium dust, Dietz and other scientists say. Naturally occurring uranium is dilute, locked up in sand and minerals. As a result, it would be relatively innocuous if inhaled.

The depleted uranium dust, on the other hand, is concentrated and does not quickly dissolve. Once it gets into the lungs, even the smaller pieces last for years - which means the alpha radiation that they exude will be banging on nearby lung and lymph-node tissue, causing possible damage.

Melanson says even if that's true, the total dose of uranium from these little pieces isn't enough to get close to the government's accepted standards for safe peacetime dosages.

Scientists who think more research is needed say the standards that the Pentagon used for even its most recent calculations don't take into account the latest research. The standards used in the most recent government study, published this fall, were adopted in the 1970s. The Capstone Study made no attempt to explore what might be the additional risk if the "bystander effect" of depleted uranium on nearby human cells is taken into account.

Dietz and other critics of the weapons say that even if the ultimate level of radioactivity isn't alarmingly high, it doesn't mean that the war and use of the weapons didn't increase the health risks.

The natural-background uranium level set by government agencies is merely a range of measurements taken in various places. Colorado and Florida, for instance, have higher natural background levels than Virginia, overall.

So it's a measurement of what exists, critics of depleted uranium weapons say - not necessarily what's safe.

Risk and safety in warfare are difficult to measure, Melanson says. Compared with the other risks on a battlefield and the alternative of not using depleted uranium weapons, inhaling the amount of dust that's likely simply isn't a significant factor, he says.

The normal risk of fatal lung cancer for all males in the United States is 23.6 percent.

Smoking raises that to nearly 31 percent, he says.

But according to the measurements and calculations in the Capstone Study, even the maximum dose of inhaled depleted uranium increases the risk less than 1 percen