|Fig. 1: The DU Penetrator of a 30mm Round. (Source: Wikimedia Commons)|
Naturally occurring uranium is composed of the three isotopes U-235, U-238, and U-234. [1,2] After uranium has been enriched and used in fuel or weapons, all of the U-235 is consumed, and the resulting product is around 40 percent less radioactive.  It contains mostly U-238, with small amounts of U-235 and U-234. [1,2] It is also incredibly dense, approximately 1.6 times the density of lead.  As a result of this density, depleted uranium has found favor as the primary metal of choice for a number of military projectiles, such as the 30 mm round (Fig 1). Using depleted uranium allows for projectiles to be much more effective, as they are able to be made smaller, and thus retain more kinetic energy. Due to its hardness and density, DU has also found favor over steel as armor on tanks and other military vehicles. 
While U-235 levels are much lower in depleted uranium, it still remains somewhat radioactive. Furthermore, it is a poisonous heavy metal, and can have negative effects on human health.  Studies have suggested that significant exposure to depleted uranium can lead to impairment or cancer of the kidneys and lungs.  However, these are not entirely conclusive, and the UN suggests that there is not enough evidence to declare depleted uranium a health hazard.  However, the government of the United States has nonetheless created an official policy of only using such weapons against armored targets, and avoiding their usage in civilian areas.  Depleted uranium was first used in combat by the United States during the Gulf War, when US tanks used depleted uranium shells in their fight against Iraqi tanks. Despite the policy against usage against soft targets, the weapons were also used in civilian areas in Iraq in 2003, and most recently, against ISIS targets in Syria in 2014.  This usage in densely populated civilian areas caused outrage internationally, and Iraqi doctors have reported large increases in cancers and birth defects in areas in which such projectiles were used. [6,7] Depleted uranium fragments can become embedded in skin, or inhaled.  Those who say that they have been exposed to depleted uranium report health problems, and express concern over being exposed to radiation. 
While the United States is gradually phasing out the usage of depleted uranium weapons and armor in favor of newer technologies, the ramifications of their usage remain.  At least 300 sites in Iraq are contaminated by depleted uranium, and their cleanup cost has been estimated at around $30 million.  While the verdict is still out on whether or not depleted uranium is the cause of significant health problems in those who are exposed to it, the full effects of their usage may not manifest themselves for many years.
© Estrada BernardIII. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 "Facts About Depleted Uranium," Washington Post, 12 Jan 01.
 D. Hambling, "Why Deadly Depleted Uranium is the Tank Buster's Weapon of Choice," The Guardian, 18 May 00.
 S. Agaian, "Health Effects of Depleted Uranium," Physics 241, Stanford University, Winter 2011.
 E. Adijanto, "Hazards of Depleted Uranium," Physics 241, Stanford University, Winter 2012.
 R. Edwards, "US Fired Depleted Uranium at Civilian Areas in 2003 Iraq War, Study Finds," The Guardian, 19 Jun 14.
 T. Gibbons-Neff, "The Pentagon Said it Wouldn't Use Depleted Uranium Rounds Against ISIS. Months Later, it Did Thousands of Times," Washington Post, 16 Feb 17.
 B. Koeppel, "How the U.S. Made Dropping Radioactive Bombs Routine," Newsweek, 04 Apr 16.