Irish scientists examining depleted uranium rounds fired during NATO attacks on Kosovo in 1999 have confirmed the rounds also contained plutonium.
A group from University College Dublin are studying the health effects of these rounds on people living near where they were used, after claims they were leading to cancers, notably leukaemia, and causing gross pollution of groundwaters. The Irish research has led to important new findings on the impact of the controversial anti-tank shells.
The UCD research group managed to recover intact depleted uranium (DU) rounds fired over Kosovo. They found radiation doses to the public from the DU were very low, despite the presence of the plutonium, which is a dangerous radioactive material.
The data also suggested the plutonium might have been from "weapons grade" material that got mixed up in the DU production cycle.
Dr James McLaughlin, director of Natural Radiation Studies within the UCD Physics Department, headed the work. The plutonium could be detected only in minute quantities, he said. "We are measuring it at very, very low levels. Even though it is that nasty word plutonium, the doses are insignificant compared to what the uranium is giving."
DU rounds are used in large calibre machine-guns as armour piercing projectiles. It is half again as dense as lead and is highly "pyrophoric", in that it disintegrates on impact and burns at a high temperature. It can melt through tank or personnel carrier armour, killing those inside.
The US confirmed it had fired about 31,000 DU rounds during the NATO-led attacks on Serbian positions inside Kosovo and Britain had fired about 6,000 rounds.
There were widespread claims of diseases including leukaemia caused by DU radioactivity earlier this year and NATO and a number of countries including Britain rushed to assess the possible health risks to military personnel who served in Kosovo.
Dr McLaughlin's study, which was conducted in cooperation with Dr Zora Zunic of the Vinca Institute of Nuclear Sciences in Belgrade, looked instead at the radiation left behind in the environment and how it might affect people living nearby.
"What we are more interested in is the general population in these areas. Is there a risk to them?"
The team went to inspect sites in Kosovo where DU rounds were used. Damaged and intact samples were collected and then analysed in Dublin by members of the UCD team including Dr Luis Leon Vintro and Mr Kilian Smith.
"We took one of the worst possible scenarios, if you inhaled the material," Dr McLaughlin said. The measurements suggested "the risk is minimal", he said. If a person inhaled a milligram of DU dust then its uranium content would deliver a dose of 0.15 millisieverts and its plutonium would give a dose of 0.7 naonsieverts (0.7 billionths of a sievert). The average exposure from natural sources is about three millisieverts per year.
"This is well below most radiological protection levels," Dr McLaughlin said. "They wouldn't breech them."
Local concern was raised about the dangers of these rounds. "The fact that people have a perception that stresses them is itself a health effect," he said.
Children and others might also receive unacceptable radiation doses via ground water. He cited a pilot study this year which showed that DU was found in urine samples from a small number of people in Kosovo and Bosnia where at least 10,800 DU rounds were fired during the conflict.
Urine samples from people in DU sites in Kosovo are being analysed at UCD and water supplies from these sites will also be studied as part of this joint ongoing programme with Vinca.
As to possible weapons grade plutonium being found in the DU rounds, Dr McLaughlin said processing centres such as that at Paducah, Kentucky were also sometimes involved in uranium enrichment for the nuclear industry or for weapons. These materials could get into the DU during subsequent processing. "There is some cross talk where trace amounts get into the depleted uranium," he said.
