Depleted uranium weapons: Key Issues
Depleted uranium (DU) is a by-product of the uranium enrichment process, which contains proportionally less of the fissionable uranium isotope U235, and more of the isotope U238 than natural uranium. As a material it is highly dense and pyrophoric, meaning that it has an incendiary effect upon impact. This effect can generate an aerosol of micron and sub-micron particles that can spread between tens and hundreds of metres from the target. DU is used by a number of states in armour-piercing tank shells and bullets. Six states are known to produce DU weapons, and it is thought that around 20 currently possess them in their stockpiles. DU ammunition is fired by tanks, armoured fighting vehicles and aircraft.
DU weapons have been controversial since their first major use in the 1991 Gulf War. The radioactive and chemically toxic nature of DU weapons has meant that their use has been followed by claims that they are responsible for increased rates of cancer and birth defects in the areas where they have been used.
The use of DU creates hotspots of persistent contamination that present a hazard to civilians long after conflict ends, particularly when used in populated areas. Buildings and civilian infrastructure have been targeted with DU and its use can contaminate soils and groundwater and create vast quantities of contaminated military scrap. Effectively managing DU's post-conflict legacy places a significant financial and technical burden on affected states.
Since 2007, the United Nations General Assembly has passed a number of resolutions on DU weapons. They recognise their potential risks to health and the environment and call for a precautionary approach to their use and clean-up. The resolutions also call on users to release data on where the weapons have been used to help aid clean-up. The most recent resolution, in 2016, was supported by 151 states and opposed by just four - the US, UK, France and Israel.
The European Parliament has repeatedly called for a moratorium on DU munitions, a sentiment echoed by the Latin American Parliament. In 2016, the European Parliament called on EU members to develop a common position in favour of a ban and to support affected communities and decontamination efforts in Iraq.
The developing global consensus on the unacceptability of DU weapons has led to changes in state practice and DU weapons' growing stigmatisation. The US and UK are investing heavily into research to find alternative materials, while users and their partners have avoided using DU in recent conflicts or have sought to distance themselves from allegations of use.
The DU story is far from closed, on the contrary a mixture of laboratory and field research continues to provide new insights into the operational use and legacy of DU munitions. ICBUW has identified a range of key DU issues based on this research, which are summarised below.
Following the use of DU weapons, DU contamination can potentially find its way into the human body. The WHO has reported that: "people living or working in affected areas may inhale re-suspended contaminated dusts". However, to date no sufficiently robust and focused studies have been undertaken into the long-term health of civilian populations living in contaminated areas. The complex and detailed studies required are challenging to undertake in post-conflict settings, particularly when there is no access to targeting data, health records and detailed environmental measurements. DU contamination is persistent and recent studies from UK firing ranges have shown that particles produced by DU impacts can remain unaltered and hazardous for at least 30 years.
In common with other radiation incidents, the known or suspected presence of DU in communities can have a significant psychosocial impact on civilians, an impact that can continue even after sites have been remediated by the authorities. Effective risk communication is difficult without transparency on DU use and comprehensive environmental assessment. It is particularly challenging in highly politicised post-conflict settings.
Historic risk assessments on DU's effect on the human body have tended to focus on the radiological risk of lung cancer and the chemical effects of DU on the kidney. The last decade has seen a considerable volume of peer-review research published that has sought to analyse DU's interactions with DNA in more detail. Overall the studies have confirmed that DU is a genotoxic agent i.e. it is capable of damaging DNA, which can lead to the development of cancers. As an alpha radiation emitter, when inside the body; for example through inhaled dust; DU is classed as a Group 1 Carcinogen by the WHO's International Agency for Research on Cancer.
As armour-piercing incendiary ammunition, DU is promoted for use solely against armour. However evidence from the Balkans and Iraq has demonstrated that it has been used against a far wider range of targets, from buildings and civilian infrastructure to non-armoured vehicles and unmounted troops. Medium calibre DU ammunition fired from aircraft and armoured fighting vehicles is particularly problematic in this respect. DU's use against non-armoured targets can radically increase the likelihood of civilian exposure, both during and after conflict. Meanwhile DU's incendiary nature may result in indiscriminate damage or cause cruel or inhumane injuries.
DU was originally developed with Cold War battlefields in mind. It has subsequently been used in often densely populated areas, areas where civilians live, work and play. This has markedly increased the likelihood that civilians will be exposed to DU residues, particularly where national authorities have struggled to effectively manage contamination.
Since 2010, UN resolutions on DU have requested greater transparency from DU users over where the weapons have been fired and in what quantities. Users have argued that only they alone should decide on when and how such data should be shared. Transparency over firing coordinates is crucial for the effective post-conflict management of DU and in reducing the risks it poses to civilians. The presence of DU may be difficult to identify without specialist equipment and awareness of DU has historically been low among deminers. The IAEA, WHO and UNEP have all highlighted the need for remedial work at affected sites. However without disclosure of firing coordinates, such work is impossible, and civilians and a range of other actors will continue to be placed at unnecessary risk of exposure.
Decades on from the 1991 Gulf War, the Iraqi government still requires assistance to manage the legacy of DU use in the country. In addition to the comprehensive assessment and remediation of contaminated sites, an effective long-term waste management strategy has yet to be implemented for contaminated military wreckage and soils. Other states affected by DU have also found management problematic, from a lack of hazardous waste storage facilities to gaps in technical and analytical expertise, DU use and the contamination it generates pose significant financial and logistical challenges for states, typically at times when they are in a poor position to resolve them. Lack of effective DU management increases the risk of civilian exposure.
While it has suited DU users to promote a simplistic DU narrative, where exposure risks are generalised based on limited datasets, and where civilian health concerns are trivialised, the reality is that affected sites must be dealt with on a case by case basis. The behaviour of DU in the environment is highly variable and dependent on a range of environmental factors. This variability was reflected in 2012's UNGA resolution, which recalled UNEP's 2010 call for a precautionary approach to DU. While much research has been undertaken on DU, comparatively little has been undertaken in real world settings, and almost none on civilians living in contaminated areas. Nevertheless, the fact that DU is a carcinogen and a long-term environmental contaminant is now inescapable.
ICBUW believes that a truly precautionary approach to DU would require that DU munitions be banned. History has demonstrated that during conflict many all too predictable factors combine, some of which are outlined above, to result in civilians being placed at risk of exposure to a material that is widely recognised as hazardous, and subject to strict regulatory control in those same states that employ it in weapons.
From benzene and lead, to CFCs and smoking, history is littered with examples of where uncertainty has been used by vested interests to justify regulatory inaction. DU weapons are indiscriminate, presenting risks to civilians; their use has a profound psychological impact on communities and places an unacceptable burden on states recovering from conflict. These are not problems that can be resolved through regulating their use. Furthermore it is highly unlikely that DU munitions will become more acceptable as our knowledge of their risks increases, and nor will the legacies of past DU use resolve themselves without intervention.
DU is a complex and emotive issue. But scientific and technical arguments aside, there is a simple principle at play: is it acceptable to disperse large quantities of a chemically toxic and radioactive heavy metal, which is widely recognised as hazardous, in conventional warfare?
To learn more about DU weapons, check our publications.