The US Defense Department says its aircraft are firing depleted uranium (DU) munitions in the conflict with Serbia.

A questioner at a DoD briefing asked: "The DU shells. Have the A-10s actually been firing them in addition to simply carrying them?"

A Pentagon spokesman, Major-General Chuck Wald, replied: "Yes". DU is a byproduct of the enrichment of uranium for military and civilian uses.

Nato spokesman Major Dan Baggio: The munitions contain no more radioactivity than is used in glow-in-the-dark watches

It is 1.7 times as dense as lead, and weapons made with it are used for punching their way through armour.

It is both radioactive and toxic, though Nato insists that it is no more dangerous than any other heavy metal.

The UK Defence Ministry says it thinks it unlikely that DU contributed to Gulf War syndrome, although many veterans believe it is implicated.

Risks are real

BBC reporter Janet Cohen tries to assess the environmental time bomb that might have been planted in the Balkans

There are extensive reports from southern Iraq of stillbirths, birth defects, leukaemia and other cancers in children born since 1991.

Published material suggests official reassurances may be misleading. The US army's Environmental Policy Institute reported in 1995: "If DU enters the body, it has the potential to generate significant medical consequences".

"The risks associated with DU are both chemical and radiological."

A-10 tankbusters are using DU weapons

A 1990 study prepared for the army by Science Applications International Corp said DU was "linked to cancer when exposures are internal, [and] chemical toxicity causing kidney damage".

At least 18 tonnes of DU weapons have been test-fired in Britain at army ranges in Kirkcudbright and Cumbria. Most of the munitions landed in the Solway Firth, where they remain.

The Military Toxics Project and Dr Hari Sharma, of the University of Waterloo, Ontario, have published the results of a study into the use of DU munitions in the Gulf.

Appeal to ban DU weapons

They say the result is likely to be an increase of between 20,000 and 100,000 fatal cancers in veterans and Iraqi citizens.

Dr Sharma is writing to all Nato heads of state to ask them to eliminate DU munitions from their arsenals.

Concern also persists over the wider ecological consequences of the war with Serbia.

The World Wide Fund for Nature says an environmental crisis threatens Yugoslavia and its neighbours, particularly further down the Danube and in the Black Sea.