New Zealand
Defence Force
Questions and Answers Regarding
Depleted Uranium
AD
HOC Committee on Depleted Uranium (AHCDU)
Question: What is depleted uranium?
Answer: Depleted uranium (DU) is a heavy metal that is also slightly
radioactive. Heavy metals (uranium, tungsten, lead, etc) have chemical
toxicity properties that in high doses can cause poisoning and adverse
health effects. For perspective, we can compare this to natural uranium.
Uranium ore is present in most rocks and soils as well as in many rivers
and in seawater. Uranium is found in concentrations of about four parts
per million in granite, which makes up 60 per cent of the earth's crust.
There are normally between two and four tons of naturally occurring uranium
in the top foot of soil per square mile. Like DU, natural uranium's primary
health hazards are associated with its chemical properties, not its radiological
properties. Natural uranium is one of the least radioactive substances
among unstable isotopes (a form of an atom which has a different atomic
weight from other forms of the same atom but the same chemical structure)
on the planet because of its high percentage of Uranium 238. DU is approximately
40 per cent less radioactive than natural uranium and is classified in
the lowest hazard class of all radioactive materials. DU is the inert
by-product of converting or enriching natural uranium for use in nuclear
power plants. During the enrichment process for nuclear fuel, Uranium-236
is removed from uranium ore. The byproduct of this process is DEPLETED
URANIUM (DU). To summarise, natural uranium has very low radioactivity
and is a naturally occurring substance in the environment which we come
into contact with everyday. DU has 40 per cent less radioactivity than
naturally occurring uranium and is an inert man-made substance that is
a by-product of enriching natural uranium for other uses.
Question: How Is depleted uranium used in commercial and military
applications?
Answer: DU's physical properties make it desirable for both commercial
and military applications. It is a very dense mater ial-nearly twice as
dense as lead. DU is used commercially in medicine (radiation shields),
aviation (counterweights), space (satellite ballast), and petroleum exploration
(drilling equipment). For military-applications, DU's density makes it
a desirable material for both munitions and armour plating-primarily for
tank warfare. DU can be applied defensively to protect against penetration
by projectiles made of less dense metals, such as tungsten-carbide projectiles,
or offensively as projectiles to defeat armoured targets. DU munitions
were first used in combat by the United States during Operation Desert
Storm (the Gulf War) with great success. The primary uses in the Gulf
War were by tanks protected with DU armour using 105mm DU rounds and attack
aircraft (notably USAF A-IC 'Warthog' and USMO AV-SB 'Harrier) firing
30mm and 25mm DU rounds. The British, French, Russian, and Chinese military
forces also have DU armour piercing projectiles for anti-tank warfare.
The Australian Defence Force (ADF) used DU munitions in certain Navy ships
prior to 1986 as part of the Phalanx anti-missile system on these ships.
After 1985, the Royal Australian Navy switched to a tungsten carbide based
munition for these weapon systems.
Question: How was depleted uranium used in the Balkans? How many
depleted uranium munitions were fired?
Answer: Because of the very limited (if any) use of ground forces
in a combat role by North Atlantic Treaty Organisation (NATO) in the Balkans,
NATO's DU usage in the Balkans was primarily through aircraft firing DU
rounds (30 mm and 25 mm rounds) during the bombing campaigns that occurred
in Kosovo. Approximately 31 000 rounds (nine tons) of DU munitions were
fired at Serb targets during NATO's 1999 campaign (Operation Allied Force)
to drive the Yugoslav Army out of Kosovo. These rounds were fired into
approximately 112 sites in Kosovo. Approximately 10 000 rounds (three
tons) were also fired into neighbouring Bosnia in 1994-95. According to
the United Kingdom Ministry of Defence, 'very little' of the DU munitions
were expended in what is now the British sector of Kosovo. For perspective,
approximately 320 tons of DU munitions were expended during the Gulf War,
a much greater amount than was expended in the Balkans.
Question: What are the health hazards associated with depleted
uranium?
Answer: The health hazards from DU munitions are generally classified
into two categoriesradiological and chemical. Most of what we know regarding
health effects from CU munitions comes from studies performed as a result
of the Gulf War, It is very important to recognise that health hazards
from DU are likely to affect only very specific personnel in very specific
circumstances. Additionally. just because you happened to be in the Balkans
does not mean that you were necessarily exposed to DU. For example, as
a result of some of the very high intensity tank battles that occurred
during the Gulf War, 'friendly fire' incidents involving US tanks flung
DU munitions at US tanks protected by DU armour occurred. These incidents
resulted in DU exposure to inhabitants of the tank (with DU fragments
embedded in their bodies) and combat rescue personnel entering the tank
immediately after the incident (breathing fumes from vaporised DU munitions
that entered the tank). This represented the highest level of DU exposure
during the Gulf War. Because of the nature of the battle in the Balkans
(e.g. no ground combat by NATO forces of this nature), it is reasonably
safe to say that peacekeepers in the Balkans were not exposed to intense
levels of DU. The chemical and radiological hazards are explained in detail
below.
Question: What are the radiological health hazards associated
with depleted uranium?
Answer: Based on best available information, the external radiological
hazards associated with DU appear to be very slight. Once in the body,
DU can potentially cause damage by ionising radiation. The principal radiation
hazard from internal deposits at DU is the intense ionisation in tissue
produced by alpha particles emitted during the radioactive decay process.
The environmental effects of DU were studied comprehensively by a wide
range of organisations both before and after the Gulf War. The most recent
toxicological profile developed by the US Agency for Toxic Substances
and Disease Registry (ATSDR) confirmed that the health hazard from DU
was primarily as a heavy metal, chemical toxicity concern and not a radiological
hazard. The ATSDR cites that no human cancer of any type has ever been
seen as a result of exposure to natural or DU and further states that
because of the low radiation from natural and DU, 'no radiological health
hazard is expected from exposure to natural or DU'. To illustrate this,
the most exposed US Army personnel in the Gulf War were involved in friendly
fire incidents where a DU round penetrated a tank with DU armour. This
exposure, based on test data and this worst case scenario, estimated the
radiation exposure was equivalent to the dose a person would get from
living in the US for four years. It is also important to note that the
most exposed personnel from the Gulf War, including those with embedded
DU fragments in their bodies, have been studied by the US Department of
Veteran's Affairs. These studies have shown no untoward medical effects
to date from DU radiological or chemical toxicity. In similar studies
for those personnel possibly exposed at a lower level, risk assessments
indicated that radiological and chemical risks for those events were well
within legal limits for industrial workers.
Question: What are the chemical health hazards associated with
depleted uranium?
Answer: DU is a toxic heavy metal which may cause kidney problems
because of its toxicity. DU may pose a long-term health hazard to personnel
if it gets into the body via metal fragments or is ingested/inhaled through
dust-like particles. The magnitude of this effect depends on factors such
as the size of the particles, solubility, and the amount of uranium uptake.
Inhalation of DU is the most significant mode of entry. DU particles can
be dispersed in the air by fires involving DU or from DU ammunition impacting
armoured surfaces. Only very small particles can be inhaled. Of those
inhaled particles, some will be soluble in lung fluid and others will
not. Those particles that are soluble will be absorbed by the body to
become a heavy metal poison (chemically toxic) primarily to the kidneys.
The particles in the lungs that are not soluble will remain in the lungs
and may be a radiation hazard. The body dispels insoluble particles that
remain in the lungs very slowly. Uranium can be toxic to the kidneys.
Uranium that makes it into the bloodstream (soluble) damages the very
small tubules in the kidney. However, even after exposures to high levels
of uranium the kidneys recover. A recent review done by the US Institute
of Medicine for Gulf War Health concluded that there is limited/suggestive
evidence of no association between exposure to uranium and clinically
significant kidney dysfunction. Research on DU associated health hazards
are continuing as a result of inquiries resulting from the Gulf War.
Question: Would I experience adverse health effects from either
radioactivity or chemical toxicity by handling an unfired depleted uranium
round?
Answer: No. The DU penetrator rod is encased within the munition
One would have to hold the rod, which is not possible in an unfired munition,
in their bare hands for over 200 consecutive hours-not a common practice.
Question: If I found a fired depleted uranium penetrator rod on
the ground and handled it, would I experience adverse health effects from
either radioactivity or chemical toxicity by handling this?
Answer: In a word-no. Even when the bare DU penetrator rod is
outside the munition, one would have to hold the rod in their bare hands
for over 200 consecutive hours-not a common practice. Incidentally, the
risk from handling unexploded ordnance would certainly be much higher
and much more acutely hazardous to your health.
Question: Are there any health effects expected from firing depleted
uranium rounds (e.g. at the firing point) from a tank or an aircraft?
Answer: No. As detailed above, the DU penetrator rod is physically
encased within the munition when it is loaded and fired. Of the various
risk groups to DU exposure that were generated from the Gulf War, personnel
who actually fired DU munitions (either in tanks or aircraft) were not
included in any DU exposure group. Again, the group at risk of highest
DU exposure from the Gulf War included personnel riding in or on a vehicle
struck by a DU munition and those that performed combat rescue on these
personnel. Prior to the Gulf War, it was believed that personnel that
were riding in or on a vehicle struck by a DU munition had very little
chance of surviving this event, making long term risks from inhaling dust
generated from the vaporisation of the DU round immaterial. However, as
a result of the various friendly fire incidents that occurred, it was
learned that these incidents were survivable. These personnel have since
been enrolled in medical monitoring studies that specifically address
DU exposure. To date, none of these personnel have experienced adverse
health effects related to their exposure to DU. These studies are continuing.
Question: If the health hazards from depleted uranium are so limited,
why are recent media reports highlighting possible links between depleted
uranium and cancer or leukaemia?
Answer: As mentioned above, the external radiation health hazard
from DU, which is one commonly associated with various forms of cancer,
is very slight. The form of external radiation emitted by a fired DU munition
that might be found in Kosovo or Bosnia primarily consists of alpha particles.
These particles would present a potential hazard only if internalised
(e.g. as in the case of shrapnel in the body or inhaling particles immediately
after a DU round has vaporised-as in the case provided above). Therefore,
extreme caution should be exercised when considering recent media reports
that appear to link radiological hazards from DU exposure to leukaemia
and cancer cases in Balkan veterans that have been recently reported.
These reports do not appear to be consistent with medical or scientific
research or literature reviews conducted to date.
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