Numerous European political leaders in recent weeks have demanded that NATO remove DU munitions from its arsenals. The leaders aren't claiming they have evidence that DU is hazardous. NATO is refusing to abandon the weapons but promises to investigate the reports. The military uses depleted uranium because of its extreme density, about 1.7 times that of lead. It is put in some anti-tank projectiles to increase their striking power, and in tank armor as reinforcement.
Natural uranium is a mixture of three isotopes, or atomic strains, of the element.
As subatomic particles go, alpha particles are extremely bulky and have very little penetrating power. Paper and skin stop them. The three isotopes decay into other radioactive elements over thousands or millions of years, some of which emit the more penetrating beta and gamma forms of radiation. Nevertheless, virtually all the radiation in samples of DU is alpha. Because of that, external exposure to DU poses no hazard, not even to the skin, researchers say.