PARIS — The cancer deaths of 24 European soldiers who served as peacekeepers in the Balkans and the illnesses reported by many others have stirred alarm in Europe about the use of depleted uranium in munitions fired from American warplanes during the conflicts in Bosnia and Kosovo.
No one has provably linked the use of depleted uranium to the deaths or illnesses of Balkan veterans, and many scientists consider such a link impossible. Nor is it clear that cancers are occurring at a higher rate among former peacekeepers than in the population at large.
But the fears often stirred by mention of radiation have sent doctors, military experts and politicians scurrying for explanations. Among the research they are re-examining is the work of a retired United States Army colonel who has insisted that some of the illnesses he has observed in Persian Gulf war veterans may be linked to the depleted uranium and uranium 236 isotope he says he found in their bodies.
Asaf Durakovic began examining gulf war veterans when he worked as chief of nuclear medicine at the Veterans Administration Hospital in Wilmington, Del., in the 1990's. Since that post was abolished in 1997, he has continued with his privately funded research in Toronto.
In a recent interview, he said his analysis over the last three years of body fluids of more than 40 American, British and Canadian gulf war veterans who have turned to him keeps turning up evidence of depleted uranium and uranium 236, a more radioactive uranium isotope.
Dr. Durakovic said that, unlike many other institutions involved in testing for uranium, he uses mass spectometry tests that measure the relative abundance of each isotope in the body.
He said he found depleted uranium, including uranium 236, in 62 percent of the sick gulf war veterans he examined. He believes that particles lodged in their bodies and may be a cause of their illnesses.
Radiation experts in France and Britain say they are now rereading his work because he was the first to report that he found uranium 236 in the urine as well as in the bone tissue of gulf war veterans. They suspect that its presence indicates that other contaminants may be present.
"This cannot be conventional depleted uranium," said Monique Sené, a physicist who is prominent in France's large atomic research establishment, when asked about Dr. Durakovic's findings. "The ratios he found do not exist in nature. This contains nuclear waste."
Dr. Durakovic's work has been circulating among NATO medical staff members. Several universities have asked him to collaborate, and he has been invited to brief the government in Italy, which raised the alarm about sick peacekeepers and where 10 soldiers have recently died.
Dr. Durakovic, 60, has worked in radiation biology for over 30 years in Britain, Canada and the United States. His work won plaudits from the Defense Nuclear Agency, the United States Army research center. Last year, he presented his studies at the conference of the European Association of Nuclear Medicine in Paris. His work is now also described in a newly published book, "Depleted Uranium, Invisible War," which has received broad news media attention in France.
Dr. Durakovic said that when he started tests on 24 American gulf war veterans he was asked to examine in 1991 by a colleague at a New Jersey hospital, urine samples were lost and his efforts to get more precise tests were discouraged. Eventually, he said, he was dismissed.
At the veterans hospital in Wilmington, a spokeswoman, Barbara Howell, said Dr. Durakovic's employment ended because "we did not need a full-time nuclear medicine physician." She said that no samples had been lost, and that in all samples tested the levels of uranium "were within normal limits." Dr. Durakovic said he never got test reports. NATO officials fear that the concern in Europe could lead eventually to a ban on munitions containing depleted uranium, which is an exceptionally hard metal and therefore suited for penetrating tanks.
Both NATO and the Pentagon have brought forward scientists and military experts with evidence that the munitions' low-level radiation is not harmful and that natural uranium is always present in the environment and in the body.
But European anxiety rose again this month when laboratories in Switzerland and Finland announced that they had found small amounts of uranium 236 in shrapnel from American weapons found in Kosovo.
Pierre Roussel, a physicist at the National Center for Scientific Research in Paris, noted that the ratio of uranium 236 found so far was tiny, but added, "The problem is that this isotope can only be produced in a reactor, where it is accompanied by far more radioactive elements."
A Pentagon spokesman who left office with the Clinton administration said on Jan. 18 that it was known that because of possible production flaws, some American depleted uranium contained traces of plutonium, neptunium and americium. He suggested, however, that the amounts were so minute that they posed no danger.
Experts in nuclear medicine in Britain, France and the United States said in interviews that they questioned the idea that there was no danger because experiments on animals had shown that uranium particles could get into the bloodstream, organs and bone, where they could deliver low-level radiation. They say the mechanism of radiation damage is still poorly understood and the debate about what might be a harmful dose is still open.
"Depleted uranium, mostly U238, has been found stored in bone, and if it gets into bone, it can reach the bone marrow," said Jean-François Lacronique, the director of the National Radiation Protection Agency in France, which oversees safety for workers in France's nuclear power plants. "Depending on the dose and the length of exposure, any kind of radiation can cause leukemia."
Dr. Durakovic said he believed that there was a fundamental difference between the effects of depleted uranium outside and inside the body.
Outside, he said, it does no harm. But when depleted uranium is blown up it burns at high temperatures, he said, and "it changes into uranium oxides — tiny, hard particles that are microns in size."
"They can stay airborne as aerosols, be blown around by the wind and fall down as dust. Because they are the size of microns, people can inhale them."
Once inhaled, Dr. Durakovic added, uranium can get into the bloodstream, be carried to bone, lymph nodes, lungs or kidneys, lodge there, and cause damage when it emits low- level radiation over a long period. Critics of Dr. Durakovic's work said his findings were inconclusive and did not provide a definitive link between uranium and the illnesses of veterans, but Dr. Durakovic says he does not make that claim but instead that his tests reveal the "distinct" presence of radioactive uranium particles in his patients.
Copyright 2001 The New York Times Company