Image: ERNST SCHMID/CHRISTOPH WIRZ
Used as ammunition, it penetrates the thick steel encasing enemy tanks; used as armor, it protects troops against attack. And when it was used in the Gulf War and later during the Allied bombing of Yugoslavia and Kosovo, depleted uranium (DU) was hailed as the new silver bullet that would solve most of the military¿s problems.
After the end of Operation Allied Force, however, several Italian soldiers were diagnosed with leukemia. Politicians and the media soon forged a link between the disease and depleted uranium use. They further drew a parallel with Gulf War Syndrome¿and in no time, depleted uranium became the Agent Orange of the Balkan conflict.
Despite the recent attention, depleted uranium is not all that new. The military has experimented with it since the 1970s. Military interest in the heavy metal is twofold: For one thing, uranium is almost twice as dense as lead, and thus packs a lot of punch as ammunition. Like its slightly denser cousin, tungsten, uranium can penetrate most heavy armor. But whereas tungsten projectiles become rounded at the tip upon impact, uranium shells burn away at the edges. This "self-sharpening" helps them bore into armor.
Also attractive to the military is depleted uranium's abundance. Depleted uranium is a by-product of the process by which uranium 235¿the most radioactive and most useful form of uranium¿is isolated from natural, mined ores (for more information, see the side bar). In 1998 the U.S. Department of Energy had about 500,000 metric tons of depleted uranium in storage.
Depleted uranium armor-piercing incendiary (API) munition comes in two main forms. One is fired from the suitably nicknamed "Tank Buster" A-10 Thunderbolt aircraft; the other shoots from M1 Abrams tanks, which are also enforced with DU armor. Both types of API munitions¿a total of 300 tons¿were used during the Gulf War. But only the A-10 kind was used during Operation Allied Force in Yugoslavia.
According to a statement by NATO Secretary-General Lord Robertson, some 31,000 rounds of DU ammunition were used throughout Kosovo during the 11 weeks of Operation Allied Force. Each round of A-10 DU ammunition contains a 300-gram DU penetrator slug, which brings the total amount of depleted uranium dropped during the conflict to a little less than 10 metric tons.
Radioactive and Toxic
Image: ERNST SCHMID/CHRISTOPH WIRZ
The question now is whether the metal that lies scattered over a wide area of the Balkans presents a health threat to soldiers and civilians. "There are clearly two issues" with DU, explains David Brenner of Columbia University's School of Public Health, "the radiation and the toxicological issue." Indeed, not only is depleted uranium potentially dangerous because of its radioactivity, it is also a strong toxin. "If there are effects, it would seem to me that the radiation effects would be the smaller of the two," adds Brenner, a specialist in the biological effects of radiation.
In fact, compared to other materials, uranium and depleted uranium are not terribly radioactive (see the side bar). The latter is used to actually shield radiation from fuel rods in nuclear power plants. But that's not to say that they couldn't have some deleterious health effects. As uranium and its daughter products decay, they emit alpha-, beta- and gamma-radiation¿all of which behave differently within the human body. Gamma-radiation can reach far into the body, but releases its energy gradually. As a result, it has little impact on any one part or organ. Alpha- and beta-radiation, on the other hand, are more hazardous because they have a short range and release all their energy within a small area.