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UNMIK/FR/006/01 FEATURE RELEASE - 19 January, 2001
Depleted uranium: More media hype than science
On Monday four specialists from the World Health Organization
(WHO) will begin assessing public health aspects of depleted uranium (DU)
residues at the 112 sites where NATO used DU-tipped weapons during its 78-day
bombing campaign in 1999.
Invited by UNMIK, which is taking the DU issue seriously in the context of
international concern over possible risks, they will examine all existing
information from a health and environment perspective and make recommendations
accordingly. Other Administration measures include:
- Secondment of a WHO staff member to coordinate all non-military health
activities related to DU, and to liaise with all national and international
bodies with a direct interest in the DU issue.
- Forming a committee of Kosovar medical experts on cancer (with emphasis on
leukaemia), heavy metal poisoning and radiation.
- A public information campaign to inform Kosovars on what is known about DU
and to explore possible links between illnesses, leukaemia especially, and
ingestion of DU dust.
- Requesting TMK members to fence off and put up notices at identified sites
with the wording: CAUTION - AREA MAY CONTAIN RESIDUAL HEAVY METAL TOXICITY -
ENTRY NOT ADVISED.
- Requesting specific advice and assistance from organizations concerned with
environmental issues regarding long-term initiatives.
UNMIKand NATO problems are different. While NATO is having to justify to
the world its deployment of DU munitions, and to explain more precisely its
consequences for troops and civilian populations,UNMIK obligation is to
sensitize Kosovo residents to the potential dangers in areas where such
munitions were used. Outside Kosovo furor prevails and confusion reigns among
European governments (and even more in their media) over the use of DU weapons
in principle. Inside, many accept DU as collateral damage sustained in a war
about crimes against humanity. Or they ignore the risks, if they exist,
altogether.
UNMIK believes that at the very least, sensible precautions for DU are
required, as already taken for land mines and unexploded ordnance, and with
respect touranium heavy metal cousin, lead. This means greater understanding of
the possible threat level to civilian populations, for example in disabled
tanks where DU shells may have exploded and its toxic, mildly radioactive dust
may still persist as a result.
Dust: the real hazard
Firstly we must differentiate between dust and lumps of metal. DU, as
manufactured, is metallic and is handled industrially like lead. Workers
wear protective clothing, especially gloves, and are directed to wash
frequently. Thus, keeping a piece of DU metal at home as a war souvenir is a
bad idea.
Unlike lead, DU is radioactive, but only mildly so. Its alpha rays are
easily stopped, even by human skin or a sheet of paper. Otherwise DU
itself would not be used as a shielding material, to protect people against
stronger radiationClike gamma and X-rays in medical radiotherapy units
and during transport of radioisotopes. Because its density (1.7 times that of
lead), it is also widely used as counterweights in airplanes and in boat keels.
As with lead,DU hazards are potentially much greater when in dust form, when it
can be breathed in, eaten or passed into the body through open wounds. And
dust, unfortunately, is what results from DU-tipped shells when the military
fires them into solid objects such as armoured tanks. The DU burns at 10,000 C
and converts to dust particles that are easily ingested or inhaled.
So far, so uncontroversial. The scientific disagreements are over DUdust impact
on human health. Complex and insufficiently studied, the effects are assumed to
follow similar, but less deleterious, patterns to natural uranium. The
complexity stems from the chemical form of the DU entering the body and the
resulting combination of chemical and radiological mechanisms. The health
effects depend on the route and magnitude of the exposure, and the physical and
chemical characteristics of the DU dust itself.
Adding to the problems of scientifically assessing the incremental risks from
DU dust, nearly all of us have some exposure to uranium and have some uranium
already inside us. The top 1 metre of earthcrust contains on average between 2
and 8 tons of uranium per square kilometre. Thus, the 9.3 tons dropped by NATO
during the bombing campaign (9.3. tons) could have at least have doubled that
average exposure but only if the DU residues were evenly distributed all over
the territory, which they were not.
As result of normal intakes of food, air and water from the normal environment,
our bodies contain, on average about 90 Fg of uranium. Two thirds resides in
our bones, one sixth in our livers, one twelfth in our kidneys. If we did take
in some uranium dust, over 95 per cent of the chemical uranium would be
excreted directly. And of the amount absorbed in the blood, two thirds would be
filtered in the kidney and excreted in urine within 24 hours. The remainder
would follow a pattern similar to lead: assuming no further exposure, half the
amounts taken up by the kidney, bones and liver would be excreted in urine over
periods of 6 to 12 months.
How dangerous?
Depleted uranium has already had most of its highly radioactive component
(U-235) removed. This leaves it about half as radioactive as the natural
product. Its alpha rays are also the least harmful form of atomic radiation.
They do not even pass through external skin layers.
Internal body parts are of course more susceptible. Alpha rays do attack lung
tissue, blood and other organs and would increase the risk of cancer in those
organs. The cancer risk from low exposure levels, however, is thought to be
very low. To date, WHO reports no adverse health effects have been established
by epidemiological studies of internal exposure to radiation due to ingestion
and inhalation of DU particles. Even in war zones, under the worst conditions
shortly after impact, the radiation exposure from the maximum amount of dust
that could be inhaled would be about half the annual dose limit permitted for
radiation workers.
But, as a heavy metal, uranium is also chemically toxic. It causes kidney
damage in experimental animals; evidence suggests that long-term exposure may
damage kidney functions in humans. Indications would be increased glucose and
protein levels in urine.
The danger in Kosovo therefore depends where and who you are. The bombing
campaign will have increased the DU dust risks, but only for people living or
moving in the 112 areas in the West and South where NATO planes fired at tanks.
Unlike the Gulf region, where DU munitions were anyway used in much larger
quantities, rains will have carried much of the dust into the soil. Prevented
from blowing about, DU dust is a far lower risk for civilians living nearby.
Any problem, if one exists, would probably be confined to water wells close to
DU sites, experts say.
In the sites themselves, a UNEP investigating team looking at 10 per cent of
the sites found only slightly elevated radioactivity at eight of them. The
radiation risk was characterized as being less than that from have a tooth
X-rayed.
To summarize: science has been unable to provide specific answers regarding the
health consequences from contact with depleted uranium. Any risks within Kosovo
are probably slight, confined to known areas which are now being sign-posted to
warn the general public.
UNMIK action to form a working group of Kosovar specialists reflects the need
to reassure more than nervous concern.
Contact: P. Ellwood
(038) 504 604 Ext. 5471
ellwood@un.org
Public Health
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