In Kosovo, many of the attacks made on what appeared to be Serb tanks in fact were aimed at dummies. Depleted uranium is left over after the most radioactive isotopes have been removed from uranium ore for use in nuclear fuel or nuclear weapons. The depleted portion is still radioactive and will remain so for an immeasurably long time. Depleted uranium has also been used to balance airplanes, and the United States Department of Transportation has warned personnel to handle it with caution. If particles are inhaled or ingested, they can be chemically toxic and cause a significant and long-lasting irradiation of internal tissue.
Experts differ widely on the scale of the threat to human health.
What is at issue is not the radiation level of the ammunition, which is weak and can barely be detected even a short distance from the source. The chief question is how much of the uranium becomes harmful when it turns into dust and is inhaled. Some experts say it would have to be inhaled in enormous quantities and is most detrimental to the liver or kidneys because it is a heavy metal. But others disagree. In Spain, a spokesman for the Defense Ministry said that Spain has had 32,000 people stationed in the Balkans since 1992 and that the two confirmed cases of leukemia one patient now dead, one undergoing treatment represented a statistical average for the population.