Focus: Depleted Uranium

Frequently Asked Questions

What is DU?

  • 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, hard metal.
  • 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.

Is DU a Health Hazard?

  • 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.

Military Use of DU Rounds - What Happens After Impact?

  • 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.

How can People be Exposed?

  • 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.

Are Children or Pregnant Women Especially Vulnerable?

  • 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.

What do Studies of People Exposed to DU Show?

  • 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.