There is growing concern across Europe at the possibility that depleted uranium (DU) munitions, used in Bosnia and Kosovo, could still be a threat years after the conflicts ended.

BBC News Online's environment correspondent Alex Kirby answered your questions on this issue.

Transcript

Alex Kirby:
The amount of radioactive dust generated when a DU shell explodes varies according to circumstances but NATO, the Pentagon, and the UK Ministry of Defence argue that however much dust there is, it stays put very close to the site of the explosion.

What is worrying is the fact that the dust moves around: in one accident in the US, DU dust was found 42 kilometres from the place the accident happened. So it can be transported over long distances and it can also filter down into ground water. Cleaning up what you find on the surface is good so far as it goes, but doesn't go nearly far enough.

Trish Carter:
Surely, apart from being possibly radioactive, uranium is a highly toxic heavy metal.

Alex Kirby:
Yes it is a highly toxic heavy metal, and the risk of chemical poisoning caused by it is recognised. There is a risk to the kidneys of anyone who swallows or breathes in a particular of DU or who has a piece of shrapnel embedded in them. But we need to remember that DU appears to be a double risk, both chemically and radioactively poisonous.

Shqipe Pantina, Pristina, Kosovo:
I live in Kosovo where a lot of noise is made here concerning Uranium that was used here during the NATO bombings. There is a fear among my people that in ten years we will have a lot of handicapped babies born. What has really happened here (concerning uranium) and what will be the consequences?

Alex Kirby:
I don't think anyone really knows what has happened there or what may happen. But the experience of Iraq suggests that there may be a problem. Far more DU weapons were used there than in Bosnia and Kosovo and so the scale of any problem is much larger. But many people inside and outside Iraq believe that the use of DU weapons there contributed to Gulf War Syndrome.

The group of complaints from which many veterans of the war are suffering, and also is partly responsible for what is said to be a far higher rate of various cancers and birth defects in Iraq itself. What Iraq needs is a proper testing programme to establish the scale of the problem, but the sanctions policy makes impossible. I hope that Kosovo and Bosnia may manage to avoid what appears to be a horrific problem in Iraq.

Andrew Thompson:
Obviously there must be those scientists who work for the government who deny any connection between DU pollution and other problems. What is their reasoning?

Alex Kirby:
I have no idea how they can fly in the face of what seems very clear evidence. For example a 1995 report from the US Army Environmental Policy Institute said: "If DU enters the body, it has the potential to generate significant medical consequences."

I suspect that part of the reasoning of those who insist that DU cannot be a problem is that weapons made from it are very valuable to the armed forces. In March 1991, a Colonel Ziehman from Los Alamos National Laboratory wrote a memo which said: "There has been, and continues to be, a concern regarding the impact of DU on the environment. If no one makes the case for the effectiveness of DU on the battlefields, DU rounds may become politically unacceptable and be deleted from the arsenal."

There is also the argument that any uranium absorbed by someone in the Balkans or Iraq will have worked its way out of their body within about 10 years. So if tests for DU are indefinitely delayed, the evidence will have disappeared.

Paul Sweeney:
Exactly what is DU?

Alex Kirby:
DU is what is left over after ordinary uranium has been enriched for use either in nuclear weapons or in reactors. It is mildly radioactive but in its solid form is little if any risk. The risk comes when a DU round strikes a solid object like a tank. It then bursts into a burning spray of radioactive dust. That is where the problem starts.

Alan Prosser, The Hague, Holland:
Many people who helped dig their 747 out of the apartment block at Bijlmermeer (Amsterdam) are reportedly suffering from a similar illness and yet El Al insist there is no serious risk? (DU was evidently used to weigh down the nosecone.)

Alex Kirby:
The 747 which crashed in Amsterdam was one of a generation of aircraft which were built with DU weights in part of the airframe to balance them. Nowadays tungsten is used instead. There was another 747 crash in the UK in 1999 close to Stansted Airport when DU was also involved. El Al will insist that there is not a serious risk because it wants to be able to go on flying sensitive cargoes through Amsterdam Airport. There are reports that many of the items on the plane which went down were far more dangerous than DU.

B. Samson, Oxford, UK:
I wonder if the stubborn refusal of US, UK and NATO officials to admit any possible health damage from depleted uranium might be explained by a very risk, if they do, to face questions and prosecution about civil victims of this weapon in Bosnia and Serbia?

Alex Kirby:
I think you may well be right about that. They will also be concerned at the possibility that thousands of veterans of the Gulf War and the Balkan Wars will seek compensation.

Pal, Budapest, Hungary:
Hungarian officials are telling us that our soldiers who were or are on peacekeeping duty in the former Yugoslavia have never faced any risks resulting from the use by NATO of DU. Is this true?

Alex Kirby:
I don't know if it true, but I hope it is. The risks vary according to the sector in which the peacekeepers are serving. Italian peacekeepers, who have suffered six deaths from leukaemia, are operating in the sector of Kosovo where a lot of DU weapons were used. It would have been easier to assess the risks more accurately early on if NATO had agreed to provide the information the UN asked it for.

Cyrus Medora:
Having served in an armoured regiment for two and a half years as an operations and training officer, I know that the moral and confidence of troops, especially those handling large shells is vital. I think the fears must be addressed soon and thoroughly. I know of men who now refuse to touch the things - not good in war!

Alex Kirby:
I couldn't agree more. If British forces have to go to war they should have the weapons which will let them end it as quickly and humanely as possible. The trouble is that DU appears to be as much of a risk to them as those on whom it is targeted. I hope that everything will come out very soon and that men and women who served their countries will get the treatment and consideration they deserve.

Stephen Morris, Peterborough:
I understand the effects of DU particles emitted post-detonation of tipped weapons, but why is it used?

Alex Kirby:
There is a clear military argument for using DU weapons, because the uranium component is very heavy and dense, almost twice as dense as lead. So it will easily punch its way through the side of an armoured vehicle. But it appears that the price of this success is a serious question mark over the health of the soldiers using it and of civilians living in the area where it was used very many years afterwards. Perhaps armies will now try to find something that is as effective but less dangerous.

Mike Bird, Toronto, Canada:
Can anyone really believe that NATO or the Americans would approach this issue honestly? Look at how ignorant and intransigent the Americans were when confronted with the health risks of Agent Orange. Can anyone really trust them?

Alex Kirby:
You wouldn't expect me to comment on the trustworthiness of NATO or the Pentagon or the British Defence Ministry - would you? There do seem to be strong grounds for believing that all of them have been economical with the truth, that they have not warned their own troops whose welfare should be their priority of the dangers to which military policy was exposing them. But then again people have been getting away with murder (literally) for centuries in the name of military priorities. I hope you and I are not cynical, but always sceptical.

Paul Mainwood:
Why is the discussion focussing on the (very low level) radiation of these things. Surely heavy metals are poisonous in their own right. Official denials have only focussed on the radiation from the DU.

Alex Kirby:
I am interested that you are so confident that the radiation level of DU particles if very low. A 1992 document from the US Defence Nuclear Agency described DU particles as a "serious health threat". No one pretends that there is no risk of chemical poisoning from DU but a lot of people have insisted for a long time that that is the only threat. There is increasing evidence that they should think again and face up to their responsibilities for their countries' troops.