Uranium is a naturally occurring, radioactive heavy metal found in the earth’s crust. It is composed of three isotopes: U-234, U-235, and U-238. Depleted uranium, or DU, is created as a by-product of the uranium enrichment process and is about 60% less radioactive than natural uranium. However, DU retains the same chemical toxicity as natural uranium.
The effects of DU are still far from being completely and uniformly understood. However, it has been strongly suggested that DU could be a contributing factor for a number of illnesses, including cancer. Researchers have also argued that there is a strong correlation between DU environmental exposure and birth defects. DU can enter the human body in four ways: inhalation of DU dust; ingestion of DU-contaminated food or water; embedding of DU shrapnel or dust in a wound; and dermal absorption of DU dust.
DU in modern warfare
For decades, the US Navy, by its own admission, has been conducting war game exercises in US waters that use, amongst other things, weapons that contain DU. DU is extremely dense – about 65% more dense than lead – and is highly pyrophoric, meaning that it ignites spontaneously in the air. The military value of DU ammunition derives from their ability to pierce tanks, armoured vehicles, and reinforced bunkers. DU ammunition are also not equipped with an explosive charge like other shells – rather, they penetrate the target and create fires through the pyrophoric release of heat energy.
DU and tungsten are the two heavy metals best suited for use as kinetic energy penetrators. However, DU is available in larger quantities and at a cheaper price than tungsten, and also outperforms tungsten alloy in armour piercing. An additional advantage of DU is that it is a readily available waste material from the uranium industry. Because of their toxicity and radioactivity, wastes from the uranium industry need to be safely deposited for a very long time through processes that are expensive – so, to save money, the uranium industry has been argued to give away DU or sell it cheaply to institutions and others interested in it. Countries that use DU usually have nuclear energy programs and an abundant, low-cost, or even free supply of DU to use in munitions. The use of DU in munitions has also been argued to help governments minimize the sensitive public policy issue of nuclear waste management.
DU weapons were first used on a large-scale in the First Gulf War in 1991 by US and British coalition forces. They were also used in Bosnia-Herzegovina in 1995, in Serbia and Kosovo in 1999, and in the 2003 war in Iraq. They were also used after 2001 in Afghanistan, where they are apparently still used today.
Today, at least 17 countries are thought to have weapons systems containing DU. However, most DU ammunition has been used by the UK and the US. Both the UK and the US claim that the use of DU ammunition is a military necessity on account of its superior ability to penetrate armour compared to tungsten, which is the main alternative. Of course, DU is also cheaper and more widely available. However, tungsten is not without its controversies either, given that it has also been argued to have health-risks and potentially be carcinogenic.
As recently as 2018, local authorities in Serbia officially began investigations into whether NATO’s use of DU ammunition in 1999 has increased the number of cases of cancer. For its part, NATO has consistently claimed that DU ammunition used in the 1999 bombardments in the former Federal Republic of Yugoslavia more broadly cannot be linked to negative health effects.
At present, there is no treaty explicitly banning the use of DU weapons. However, there are pockets of resistance in the international community. In 2008, the European Parliament called for a global ban on the use of DU weapons. Belgium became the first country in the world to ban the use of inert ammunitions and armour plates containing uranium on its territory in 2007, with the law coming into effect in 2009. Costa Rica became the second country to do the same in 2011.
The UN General Assembly has also passed a number of Resolutions since 2007 highlighting serious concerns over the use of DU weapons. These concerns include a lack of transparency over where DU weapons have been fired, the costs and technical difficulties in managing contaminations, uncertainties over the environmental consequences of DU, and the ongoing concerns of affected communities. The UK, the US, France and Israel have consistently voted against the Resolutions.
The legality of the continued use of DU weapons has been argued to be questionable, given that its effects may affect civilians and therefore breach the principle of distinction between civilians and combatants – a key principle of international humanitarian law. DU exposure has also been argued to have repercussions on the health of veterans. Given the uncertainties that surround DU, its ongoing use in modern warfare therefore merits closer scrutiny.