Italy has urged NATO to investigate the deaths of six Italian solders who died of leukemia after serving in the Balkans. Prime Minister Giuliano Amato believes they may have died from contact with depleted uranium munitions used by NATO forces. There are many ways to die in combat; but exposure to depleted uranium is probably not one of them.

The Italian government is right to be concerned about the deaths of its soldiers. Similar concerns have been raised about the illnesses contracted by U.S. soldiers after serving in the 1991 Gulf War. Then, too, investigators looked at depleted uranium as a possible cause. But repeated investigations have failed to establish a solid link, even in cases where depleted uranium is embedded in soldier's flesh.

The Gulf War was the first use of depleted uranium in combat. This very dense material, a by-product of enriching uranium for use in nuclear weapons and reactors, is about 40 per cent less radioactive than natural uranium (hence it is "depleted" of some of its low radioactive charge). Denser than lead, it is used to make armor-piercing rounds fired by tanks (120mm and 105mm), A-10 "Warthog" close-air support planes and Marine Corps AV-8B Harrier jets (30mm and 25mm). These rounds are very effective in piercing even the thickest tank armor. It is also used in steel "sandwiches" to add armor protection to U.S. tanks.

In the Gulf War, U.S. forces expended about 320 tons of depleted uranium, including almost 10,000 tank rounds, or enough to fill a box 16 feet on a side. Soldiers routinely handled the rounds and armor as they do not produce enough radioactivity to cause burns, poisoning or any other unusual effect. Aside from being directly hit or burned by round, the toxic effect of depleted uranium occurs from inhalation or absorption of particles or smoke. These particles would lodge in the body and emit small amounts of radiation (alpha, beta and gamma particles). These may cause cancer.

US soldiers were exposed to particle and fumes when the were in or near vehicles hit by "friendly fire" from US tanks and planes, or when they were near vehicles burning from US hits. Testing performed after the war of the most severe cases failed to detect any significant effects, including kidney or cell damage. (The complete report is available on the Department of Defense web site. Click here.)

The Agency for Toxic Substances and Disease Registry, for example, argues that although natural and depleted uranium is radioactive, it "poses little radioactive danger because it gives off very small amounts of radiation." The Army Environmental Policy Institute reported that a spent depleted uranium round could deliver a skin dose of about 0.2 rem per hour. By comparison, colbat-60, a radioactive material used in cancer treatment, delivers a radiation dose of more than 800,000 rems per hour. Even one minute's exposure (13,333 rem) would mean certain death as it is almost 17 times the lethal whole body dose. However, U.S. health standards establish a limit of 0.1 rem in a year for members of the public to protect against delayed effects, such as cancer, and 5 rem in a year for workers.

It is unlikely, but still possible, that the NATO soldiers' deaths were somehow caused by extraordinarily high exposure depleted uranium. Both the soldiers' families and NATO would be well-served by additional investigation.