"Once security and political conditions permit the United Nations to do work inside Iraq, we would approach the US and the UK and request to conduct research," UNEP spokesman Michael Williams told AFP.

"The United States and the United Kingdom have stated that they are still using weapons with DU in them ... and whenever DU is used it is worthwhile analysing the sites for radioactivity," he said.

Williams said research conducted in the Balkans, where DU was used in the 1990s, showed "no reason for alarm".

"Nevertheless we could find some remaining uncertainties about how DU can behave in terms of being re-suspended into the air and breathed in, and whether it could eventually contaminate ground water," he said.

In a statement released Sunday in Amman and Nairobi, UNEP executive director Klaus Toepfer said early studies of DU use in Iraq "could either lay these fears to rest or confirm that there are indeed potential risks".

"It could also show if there are any risks remaining from the period of the 1991 Gulf war," Toepfer said.

"Given the overall environmental concerns during the conflict and the fact that the environment of Iraq was already a cause for serious concern prior to the current war, UNEP believes early field studies should be carried out."

"This is especially important to protect human health in a post-conflict situation," he said, adding that UNEP will publish an initial environment study on Iraq by the end of April to pave the way for eventual field research.

Before launching the war on Iraq on March 20, US military officials said Abrams battle tanks and A-10 attack aircraft would use DU-tipped rounds because they were the most effective in slicing through enemy armor.

The officials also denied Iraqi claims that the use of the mildly radioactive DU rounds in the 1991 Gulf war had resulted in a high rate of cancer and leukemia among children in southern Iraq.

Some 320 tonnes of depleted uranium were expended in ammunition during the Gulf War.

SPACE.WIRE