The controversy over a possible link between uranium-tipped weapons and illness among troops who served in the Balkans looks set to continue as European countries await more information from Nato.
The World Health Organisation has said that soldiers and civilians exposed to depleted uranium in the Balkans had probably not been exposed to enough radiation to cause leukaemia, but called for more research.
Dr Mike Repacholi, the WHO's coordinator for occupational and environmental health, told swissinfo that although there was confusion about what exactly had caused the deaths of a number of troops who had served in the Balkans, there were ways of testing for exposure to depleted uranium.
"We know for example that uranium exposure targets the kidneys first," said Repacholi. "An individual who inhales uranium dust will probably suffer kidney malfunction within a short time, but it would take a lot of uranium to cause such a condition."
Repacholi believes there are many other factors that need to be investigated, and points out that leukaemia can be caused by a number of things, including long term exposure to motor vehicle exhaust.
"The benzine in exhaust fumes is a known leukemogen," he said, "so this is something that needs to be looked into. In fact, what we need is an in-depth study into all the environmental health factors in the affected region, not just a medical survey of people who have served there."
In the meantime many European countries, including Switzerland, are advising the troops concerned to undergo medical check-ups.
The Swiss army is offering voluntary blood tests to all 900 Swiss soldiers who served in Bosnia and Kosovo, and army doctors are considering a more comprehensive lung screening as well.
"No test can be a guarantee," says chief medical officer, Dr Peter Eichenberger. "It is only a picture of someone's condition on a given day. And even if everything looks fine, there's no way of knowing whether that individual will become ill at a later date."
To complicate matters further, Eichenberger maintains that any illness a soldier may suffer in the future can never be linked, with certainty, to time he may have spent in the Balkans.
"It's just not possible to prove such a thing," he said. "But we can reassure our troops that we knew about the depleted uranium question back in 1999. We did comprehensive tests then, and we determined that the health risk was very slight."
The Swiss army has already set up a hotline for its troops and has had dozens of calls so far. Many of them have come from soldiers who brought back pieces of spent ammunition from the Balkans as souvenirs.
The army advises people to hand in such souvenirs for checking, as they may contain traces of uranium. It said several soldiers had reported bringing back ammunition, which the army said it would start collecting on Wednesday.
Meanwhile, Eichenberger believes there are many unanswered questions about the long-term health risks posed by modern warfare.
"We know about the connection between irradiation and cancer," said Eichenberger. "But modern weapons systems are something new. We really don't know enough about them and the effects of using them."
Dr Mike Repacholi of the WHO agrees. "This is something that needs comprehensive research. The WHO would be prepared to coordinate and oversee such an inquiry. There are a lot of politics and questions of national pride involved in such things, so an investigation needs to be seen to be independent. People just want to know the facts."
by Imogen Foulkes