A knowledgeable media report on DU

[Muckerheide <muckerheide@mediaone.net>]

By the Independent News, UK

Regards, Jim
muckerheide@mediaone.net
=======================

The sceptics' case: DU is neither very radioactive nor especially rare

By Steve Connor, Science Editor

10 January 2001 

Given what is known about depleted uranium (DU), it is difficult for
scientists to be universally convinced that the substance is the cause of
the cancers and other illnesses seen in soldiers and civilians caught up in
the Gulf War and the Balkans conflict.

Uranium occurs naturally in the soil in an average concentration of about
three parts per million, the equivalent of a teaspoon of the metal in a
lorry load of dirt. We naturally ingest small amounts of uranium in food and
water. 

More than 98 per cent of the element exists in the formuranium-238, and less
than 1 per cent as the more radioactive isotope, uranium-235. Uranium
processing removes most, but not all, of the more dangerous uranium-235.

DU is what is left behind after mined uranium ore has been processed during
the manufacture of fuel for nuclear reactors. The processing removes about
40 per cent of the radioactivity, making DU considerably less hazardous than
the ore itself. 

DU is thus on a par with the natural sources of radiation that most people
come into contact with at some time in their lives. However, being a heavy
metal, DU is chemically toxic if ingested in high enough doses.

DU has several characteristics of interest to the military. It is cheap,
widely available and extremely dense ­ nearly twice the density of lead ­
and therefore ideal for packing the necessary punch to crack open heavy
armour. 

Unlike tungsten, the other heavy metal used in powerful armour-piercing
weapons, DU possesses the unique characteristic of "self sharpening" during
impact with a tank's armour. Whereas the tungsten shell forms a mushroom
shape, the tip of the DU projectile burns away at the edges during the split
second of impact, aiding its penetration through several inches of
armour-plating. 

Research into DU weapons began in the 1970s, and DU was first used on the
battlefield during the Gulf War of 1991. DU's defensive capabilities were
shown in one exchange between an American M1A1 main battle tank protected
with DU armour and three Iraqi T-72s. The M1A1 took three direct hits with
conventional shells before dispatching the T-72s with a single DU round to
each tank. 

The main radiological hazard of DU is its emission of "alpha particles",
which do not penetrate clothing or skin but can be dangerous if ingested or
inhaled. Nevertheless, in terms of alpha emissions, DU is about a million
times less toxic than plutonium.

The primary health risk of DU arises from its chemical toxicity as a heavy
metal. Animal experiments show that in heavy doses DU can, like other heavy
metals, build up in the body and cause potentially serious damage to
kidneys. 

When DU shells explode they scatter uranium powder that can readily be
inhaled or ingested. The burning of uranium during an explosion also
produces various oxides, which can dissolve in body fluids. Once dissolved,
uranium readily reacts with biological molecules to toxic effect.

However, the US Department of Defense said that it had failed to find any
evidence that soldiers exposed to exploded DU had suffered any ill effects.

The American authorities cite a study of 33 veterans of the Gulf War who
were exposed to DU as a result of being mistakenly attacked during "friendly
fire" incidents. About half of them have DU fragments still embedded in
their bodies. 

"For the 33 veterans in the programme, tests for kidney function have all
been normal. In addition, the reproductive health of this group appears to
be normal in that all babies fathered by these veterans between 1991 and
1997 had no observable birth defects," says the Defense Department.

Scientists have also failed to find any significant health risks, such as
blood cancers, in uranium workers who have been exposed to some of the
highest levels of uranium contamination on the planet.

Leo Kinlen, a cancer epidemiologist at Oxford University, said that in
trying to assess the cause of the leukaemias in soldiers who took part in
the Balkans conflict it is first essential to determine whether there is a
genuine "excess" of cancers among all of those who took part, and not just
in a selected minority.

"You've got to know whether there is a real excess. Anecdotal reports are
quite another thing," Professor Kinlen said.

"I would then want to know details of exposure to depleted uranium, no
matter in how crude a form this information can be gathered."

Cancer epidemiology is difficult. It is one thing for the media to note a
possible link between DU and cancer. Scientific proof is another matter. 

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