Depleted Uranium is a waste product of uranium enrichment, containing approximately one-third the radioactive isotopes of naturally occurring uranium. Because of its high density it is used armor and tank piercing ammunition.
Depleted Uranium (DU) has been classified as an illegal weapon of mass destruction by the United Nations and DU particles are highly toxic when inhaled or ingested.
The United Kingdom Atomic Energy Authority has estimated that around 50 tons of DU dust from the first gulf war will lead to 500,000 cancer related deaths. Compare this to the 250,000 deaths caused by the bombing of Hiroshima and Nagasaki.
To date over 2000 tons of DU dust has been generated in the Middle East alone. DU has a half life of 4.5 billion years so Middle East will be radioactive for almost Eternity.