Focus: Depleted Uranium
Frequently Asked Questions
- DU is a by-product left over when natural uranium ore is enriched
for use in nuclear reactors and nuclear weapons. It is a toxic, dense,
- During the enrichment process, most of the more radioactive isotopes
contained in uranium are removed - leaving the 'left over' DU about
40% less radioactive than uranium.
- DU does not add significantly to the normal background radiation
that people encounter ever day. It is weakly radioactive. For example,
DU is 3 million times less radioactive than radium still found in many
old luminous watches and 10 million times less radioactive than what
is used in fire detectors.
- The extreme density of DU, together with other physical properties,
make it ideal for military use in munitions to penetrate thick tank
armor and in defensive armor protection. It is not a nuclear weapon.
- Based on credible scientific evidence, there is no proven link between
DU exposure and increases in human cancers or other significant health
or environmental impacts.
- The most definitive study of DU exposure is of Gulf War veterans
who have embedded DU shrapnel in their bodies that cannot be removed.
To date none has developed any health abnormalities due to uranium
chemical toxicity or radio toxicity.
- It is a common misconception that radioactivity is the main health
hazard of DU rather than chemical toxicity. Like other heavy metals,
DU is potentially poisonous. In sufficient amounts, if DU is ingested
or inhaled it can be harmful because of its chemical toxicity. High
concentration could cause kidney damage.
- According to the World Health Organization (WHO), very large amounts
of DU dust would have to be inhaled to cause lung cancer from radio
toxicity. Risks of other radiation-induced cancers, including leukemia,
are considered to be very much lower still.
- When DU munitions hit an armored vehicle they form an aerosol containing
fine DU particles that may be inhaled. Most of the contamination stays
inside the vehicle that has been struck. However, some of the dust
will be dispersed into the environment and spread by wind or deposited
on the ground by rain. The bulk of DU dust remains within about a few
hundred meters of the hit target. Over time, fine DU dust particles
deposited on the ground will be absorbed into the soil, while bigger
DU fragments remain intact on the ground and start to corrode.
- In most cases, no more than 10% of the penetrators hit their intended
target. DU penetrators that do not hit a target or hit 'soft' targets
(non-armored vehicles) do not generate significant dust. Most munitions
that impact on soft ground, such as clay or sand, penetrate intact
into the ground (down to a few meters depending on the type of soil).
- The corrosion of DU penetrators varies. For example, in quartz sand
or acidic volcanic rock, high solubilization rates could lead to local
contamination of groundwater. However, the risk would be minimal to
people living in the area as dose rates are unlikely to be much greater
than normal background radiation levels.
- Inhalation: The main potential route of exposure
is inhalation of DU dust, generated when DU ammunitions hit hard targets.
Inhalation may lead to lungs and other organs being exposed. Those
near the target immediately following impact are most likely to receive
the highest doses. A potential pathway for those living in DU affected
areas is via the inhalation of DU particles that initially settle in
soil but are re-suspended through wind or human activities.
- Ingestion: Children playing and adults working or
living in former conflict zones could be exposed if they ingested,
inadvertently or deliberately, DU contaminated soil. Uranium is not
effectively transported in the food chain so transfer of DU from contaminated
soil to drinking water or locally produced food is unlikely to harm
people living or visiting the area.
- Body contact: Contact exposure through skin is typically
low and unimportant. Radiation skin burns (erythema) from touching
DU are unlikely, even if it is held against the skin for a number of
weeks. However, DU could enter the blood through open wounds or from
embedded DU fragments.
- Body retention: According to WHO: a)
Practically all (98%) DU entering the body is excreted and never reaches
the blood stream. b)Of the fraction of uranium absorbed into the blood,
around 70% will be filtered by the kidney and excreted in the urine
within 24 hours; this amount increases to 90% within a few days.
- It is not known whether children differ from adults in their susceptibility
to health effects from DU exposure. But in scientific experiments very
young animals were found to absorb more uranium into their blood than
adult animals when they were fed uranium.
- An assessment by WHO in 2001 excluded any link between exposure to
DU and the onset of congenital abnormalities.
- The most detailed ongoing study on the health effects of DU exposure
is of 33 friendly fire veterans of the Gulf War, most of whom have
embedded DU shrapnel in their bodies that cannot be removed. To date
none has developed any abnormalities due to uranium chemical toxicity
or radio toxicity, despite showing greatly increased levels of uranium
in their urine. However, it is generally accepted that more comprehensive
studies on long-term health effects are needed.
- United Nation's Environment Programme (UNEP) studies in 2001 (Kosovo),
2002 (Serbia and Montenegro) and 2003 (Bosnia and Herzegovina) - to
which IAEA experts contributed - found it was highly unlikely that
a reported increase in the risk of cancer in the Balkan regions could
be associated with the residues of DU munitions used there during the
war in the mid-1990s. It found the probability of significant exposure
to local population was very low.
- The IAEA remains vigilant on issues of public safety from radiation
exposure. It is actively involved in assessing any possible radiological
effects from DU residues.
- The Agency recently completed a study of the radiological conditions
in Kuwait concerning residues of DU munitions used during the 1990
Gulf War. A report is expected to be released in coming months.