Physicians for Social Responsibility Issues Brief on Depleted Uranium

Report says Every effort should be made to curb or prohibit its use.

Editor's note. The following issue brief was originally published on The Physicians for Social Responsibility web site at

Issue Brief. Depleted Uranium Weapons

July 1999


The extraordinary effectiveness of ammunition made from depleted uranium (DU) has made it a weapon of choice for the United States and other countries. 1.7 times as dense as lead, DU is not only an effective offensive weapon, but is also utilized for armor plating in tanks, ballast material in aircraft and as shielding in some medical equipment. The use of this by-product of the Uranium enrichment process in conventional weapons in the 1991 Persian Gulf War and, most recently, in the Balkans has sparked widespread debate regarding its impact on human health.

Source, Properties, and Use

The large-scale extraction of the Uranium-235 isotope from natural Uranium for use in nuclear fuel and nuclear weapons has spawned a massive pile-up of its by-products, most significantly non-fissionable U-238, also known as depleted uranium. DU is so named because it is largely "depleted" of the other two isotopes found in naturally-occurring uranium, U-234 and U-235. Because naturally-occurring uranium contains approximately 99% of the U-238 isotope, large quantities of U-238 are accumulated in the U-235 enrichment process. DU has a half-life of 4.5 billion years1.

DU has some unique physical properties that make it both an effective, armor-piercing weapon and a source of concern with regard to its long-term effects. DU's density of 19.3 g/cm3 (tungsten, the "normal" material used in ammunition, is also 19.3 g/cm3) makes it almost twice that of lead. Additionally, DU is pyrophoric, meaning it has a tendency for fine particles to spontaneously ignite, or aerosolize, on impact with a target or upon burning. These dust particles may further endanger survivors or bystanders if embedded, ingested, or inhaled, and may also find easier access to the surrounding air, water, and soil.

Use of Depleted Uranium

The United States has retained stockpiles of depleted uranium since the inception of its nuclear weapons program in the 1940's. Because of the costs associated with storing such an extraordinary quantity of material, estimated to be more than 500,000 tons, employing DU in munitions became a viable method of reducing storage costs. DU is considered a more effective (i.e. more capable of piercing tank armor) and less expensive alternative to other munitions metals, such as tungsten2. The U.S. first began producing DU ammunition in 1978 and has used it primarily in long cannons found in tanks and in some aircraft guns, such as the A-10 Warthog and the AV-83. In addition, DU is also used for armor plating in tanks (first used in 1988 on M1 Abrams tanks), ballast material in aircraft and shielding in some medical equipment. While there is some current speculation that DU is being used in Tomahawk missiles, the most current and reliable data do not verify these allegations; the use of DU in Tomahawks is restricted to test purposes only4.

DU ammunition was first used by the U.S. in wartime in the Persian Gulf War, with an estimated 300 metric tons fired3. Weapons employing DU included the American M1 Abrams tank, the Bradley armored personnel carrier, and the A-10 Warthog aircraft, which fired twin 30-millimeter guns with small-caliber DU bullets. Final reports estimate that tanks fired 14,000 large caliber DU rounds and that U.S. planes fired 940,000 small caliber rounds5. Additionally, the British are estimated to have fired 100 rounds from tanks6.

Depleted uranium has also been used by the U.S. in Kosovo. Major General Chuck Wald, a Department of Defense spokesman, acknowledged that DU was being used in Kosovo during a May, 1999 press briefing. When asked by reporters if the U.S. was using DU in Kosovo, he answered:

"Yes. And the 30mm on the A-10. I think it's almost -- I've heard that question a lot, and I've been thinking about it. I've been around the A-10s for a long time. I know that I see the munitions handlers put these bullets in the aircraft, holding on to them for 20 years, so they've done a lot of scientific studies on these things, and there doesn't seem to be a problem. So I don't think there's a problem at all with that, and it hasn't been a problem for any of us, so it's kind of old news."7

The U.S. A-10 Warthog can fire DU coated ammunition from its 30mm Gatling gun at 3,900 rounds per minute. DU rounds were also employed in the AV-8B fighter. A NATO report stated that DU has been used against Serbian forces though "it has not been used extensively," according to a NATO spokesman. "It has never been proved that the use of DU endangers the health of people. It is no more dangerous than mercury."6

While DU use has been mostly confined to the Gulf and to the Balkans, there are other incidents of DU use that are worthy of note. In April, 1999, the U.S. Navy accidentally fired hundreds of DU rounds on Vieques, Puerto Rico, which has only exacerbated already tense relations over other issues with the U.S.8 A similar event in Japan, where Marines fired DU bullets on an uninhabited island, prompted apologies from U.S. defense officials.9

In addition to the U.S. and Britain, there are other countries that possess DU. U.S. arms dealers sell DU to 16 countries, including Thailand, Taiwan, Bahrain, Israel, Saudi Arabia, Greece, Korea, Turkey, Kuwait, and other countries, which the Pentagon will not disclose for national security reasons6,10. A number of other countries are also eligible for shipments, including Jordan, Australia, Egypt, and Japan11.

Health Effects

Health effects of DU exposure are typically divided into two broad categories, chemical and radiological. Further delineation is also made between internal and external routes of entry. A number of factors will determine the chemical or radiological affects DU may have, including dose, route and magnitude of exposure, and location of embedded fragments. While the most obvious health risk DU poses is to soldiers in tanks that sustain DU hits, there are others that may be affected as well. Survivors of such hits, soldiers investigating the wreckage, and those responsible for transporting or de-contaminating DU-laden tanks are all at risk to receive potentially harmful exposure to DU. With a half life of 4.5 billion years, DU may also cause harm to surrounding air, water, and soil resources and harm civilians returning to DU contaminated areas.

Of the two potential dangers DU poses, chemical affects are generally considered the most dangerous. Like other heavy metals, such as lead, sufficient DU exposure can be toxic to humans. On impact with tank armor or other vehicles, the pyrophoric nature of DU promotes oxidation of the uranium metal to uranium oxides, which results in some portion of the uranium round becoming aerosolized and converted into dust particles small enough to be easily ingested or inhaled by humans in the vicinity, such as soldiers examining the wreckage of a tank. Upon ingestion, the uranium oxides are mostly metabolized to the uranyl ion (UO2++), and, if solubilized in the blood, up to 90% of it may be excreted by the kidney in the urine. Excretion takes approximately 3 days if DU is internalized, though uranium in the urine may appear persistently if DU has been embedded externally in the skin. Methods of DU detection include 24-hour urinalysis, spot urinalysis, and whole body scans, especially for embedded fragments1. The International Commission on Radiological Protection (ICRP) has established 3 µg/g (stated as a whole body count) of kidney as the permissible radiological limit. The ability of the body to expel ingested uranium is not absolute; much of it may stay in the body, particularly the kidneys and skeleton, for extended periods of time. Similar to other heavy metals, uranium, solubilized in solution, can react with many biological molecules, including phosphate residues (glucose phosphate, phosopholipids, nucleic acids) or sulfydryl groups (cysteine, glutathione and oxyanions). In addition to targeting the kidneys and skeleton, uranium not expelled by the body may also distribute to soft tissue, including the liver, lung, fat, and muscle1.

Radioactive elements, including uranium, produce three types of ionizing radiation, alpha, beta, and gamma, each impacting human physiology differently. Uranium is primarily an alpha emitter, which travels about 30 µm in soft tissue, making penetration of paper, glass, or skin virtually impossible. Danger to human health would increase, however, if DU were internalized and lodged near critical cells or tissue1. Although uranium is primarily an alpha emitter, its decay process will also result in beta and gamma radiation, which are more capable of damaging human tissue1. The Encyclopedia of Occupational Health and Safety warns that uranium can cause lung cancer, bone cancer and kidney disease. Other concerns include DU's negative impact on reproductive capability.

Conflicting Claims of Impact on Human and Environmental Health

Since DU use began in the 1991 Gulf War, its health effects on humans have been hotly debated. Veterans have argued that DU is one of many causative agents in Gulf War Syndrome. The military has denied any such link. To investigate their claims, the Department of Defense commissioned the RAND Corporation, a military contractor, to do a study of Gulf War Syndrome, which included a lengthy analysis of DU. The final RAND report, A Review of the Scientific Literature as it Pertains to Gulf War Illness: Volume 7 Depleted Uranium, was released in April, 1999. The RAND analysis was a literature review of currently existing data; RAND conducted no new research on DU. Since very little research has been done on depleted uranium, the authors instead reported on the much more abundant body of literature pertaining to natural uranium, which, they argue, exhibits similar chemical properties and is actually more radioactive than depleted uranium1. Having claimed that depleted and natural uranium are analogous in their chemical and radiological properties, they assert that health effects of each are similarly analogous. The report essentially finds no conclusive data tying negative health effects to natural uranium and therefore concludes that depleted uranium should have no negative health effects as well. The report's conclusions are particularly reinforced with regard to the radiological potential of DU. Since natural uranium is more radioactive than DU and, according to RAND data, poses no significant health risk, depleted uranium, which is 40% less radioactive than natural uranium, should pose even less of a radiological risk.

The RAND Report was not without its caveats and qualifiers. The report stressed that little information exists regarding actual DU - most of their conclusions are based on data extrapolated from natural uranium - and that more research needs to be conducted. They cite, for example, the DU Follow-Up Program at the Baltimore Veterans Administration Medical Center, which is tracking a number of Gulf War veterans with embedded DU fragments. The follow-up program has noted "several biochemical perturbations in neuroendocrine parameters related to urinary uranium concentrations..." in its patients1.

The RAND Report, because it was conducted by a military contractor, is bound to have its biases. Despite reviewing an extensive body of literature that included peer-reviewed journals, books, government publications, and conference proceedings, the report inevitably could not be completely comprehensive, a complaint voiced in a report by Dan Fahey, a former Naval officer who is now the research director at the National Gulf War Resource Center. His report, "DoD Analysis: The Good, the Bad and The Ugly," was a direct response to the RAND Report. Prepared for the Presidential Oversight Board for Department of Defense Investigations of Gulf War and Biological Incidents and the U.S. General Accounting Office in June, 1999, Fahey's report acknowledges and supports RAND's call for more research and testing. The Fahey report, however, outlines a large body of literature that the RAND report ignored, citing at least 62 relevant sources not reviewed by RAND. Fahey also takes issue with the short shrift given to studies which demonstrated clear health risks to humans, such as that being conducted by the Armed Forces Radiobiology Research Institute (AFRRI), which discovered "possible relationships between depleted uranium and neurological, immunological, carcinogenic, genotoxic, and mutagenic effects."12

Despite the claims outlined in the RAND Report, there are a number of other sources that raise questions about the validity of RAND's claims and the threat of DU to human and environmental health. These include:

In August 1995, Iraq presented a study to the United Nations demonstrating sharp increases in leukemia and other cancers as well as other unexplained diseases around the county's southern region. Iraqi scientists attributed some of the cancers to depleted uranium6 . Some Iraqi officials have reported up to a 20% increase in leukemia cases13. Other studies also suggest an increase in cancer rates in southern Iraq, with a statistically significant correlation between cancer cases and DU exposure14.

A study commissioned by the Military Toxics Project and conducted by Dr. Hari Sharma of the University of Waterloo concluded that DU use in the Persian Gulf will result in an increase of 20,000-100,000 fatal cancers in Gulf War veterans and Iraqi citizens15

Doug Rokke, a former U.S. Army officer and health physicist in charge of DU cleanup after the Gulf War developed health problems within two weeks of his return from the Middle East. Rokke and other members of his cleanup team developed ailments that included severe kidney and respiratory problems. Rokke's urinalysis, conducted in March of 1994, revealed urinary uranium 2,000 percent beyond normal levels. Perhaps most disturbing is the fact that Rokke's team never received specialized training or gear for DU cleanup, despite the fact that the Army understood DU's potential health hazard16,17.

At the Hague Peace Conference in May of 1999, Rosalie Bertell, Ph.D., outlined many health risks associated with DU, and, in opposition to the RAND report, stated that DU can be more radioactive than natural uranium given the higher concentrations at which DU is found18.

A recent article in the Croatian Medical Journal by Dr. Asaf Durakovic of the Department of Nuclear Science at Georgetown University Medical School examines the possible health risks of DU12.

The Glasgow Sunday Herald reported in April that DU use at a firing range in Duindrennan has been linked to the highest rate of childhood leukemia in the United Kingdom10.

Environmental Impact

The fact that DU is aerosolized on impact with its target and is transformed into small dust particles capable of being carried by the wind may threaten air, ground, and water resources, which all may become long-term repositories for DU. Long term impact is especially important considering the 4.5 billion year half life of DU. The Balkans Task Force of the United Nations Environment Program is currently conducting a scientific expedition in Yugoslavia. Made up of 14 experts, the task force will attempt to provide the international community with "a neutral and scientifically credible report" on the long and short term environmental impact of the war, according to Pekka Haavisto, chair of the task force19. The team will look at sites where DU is alleged to have been used, and will check for radioactivity and the presence of toxic heavy metals in the soil. While the report is not due until September, preliminary data points to DU as being "very dangerous and harmful."

The Regional Environmental Centre for Central and Eastern Europe recently prepared a more damning report for the European Commission, the European Union's executive arm. Their report described DU as "perhaps the most dangerous" of the "carcinogenic and toxic substances" that were released during the bombing of Yugoslavia19.

National and International Response

The United States

U.S. political and military leaders have largely ignored any warnings of human and environmental health risks posed by DU. The effectiveness of DU in piercing tank armor, the low cost and large abundance of DU, and the extraordinary cost associated with cleaning up contaminated areas have acted as major impediments to a change in U.S. policy.

Despite the government's response, two veterans groups, the Veterans of Foreign Wars and American Legion, have both adopted resolutions against DU3.

U.S. treatment of soldiers who have handled or been exposed to DU has been poor. Ignoring some of their own experts' advice, the Army has been remiss in promoting and enforcing proper DU handling techniques, thus exposing soldiers who are unaware of and unprotected from potential dangers of DU16,12. Debate is ongoing regarding DU and its role in Gulf War Syndrome, though many sources would not implicate DU as the lone causative agent in Gulf War Syndrome.

Perhaps most frustrating for those who oppose DU is the fact that alternatives exist. Tungsten, for example, has the same density as DU, but it has not been known to have negative consequences on human and environmental health. Developments in tungsten technology have made it "almost as effective as DU," according to Matt Kagan, a former munitions analyst for Jane's Defence Weekly. But tungsten is more expensive than DU, primarily because of the abundant supply - more than 500,000 tons - the U.S. has accumulated as a result of uranium fuel and weapons production5.

International Response

The international community has been a bit more responsive to exploring all of the consequences of DU use. As stated above, the UN and the EU are both currently studying DU use in Yugoslavia. Moreover, The UN Commission on Human Rights passed a resolution in 1996 urging all states to "curb the production and spread of weapons containing DU." 3 Currently, a number of NGO's are attempting to gather signatures of organizations for an International Declaration on Depleted uranium. In addition to studies and non-binding action, some have made claims that DU is illegal under international law, and a lawsuit against U.S. DU manufacturers is being considered by some groups.


The future of depleted uranium in conventional weapons remains uncertain. Its use in armed conflicts has clearly been hailed by some while being questioned by others. Leveraging enough political resistance to such an effective weapon may prove difficult, especially in light of the often disputed data currently available describing DU's long-term effects on human and environmental health. The need for further research on depleted uranium remains. Even the RAND Report acknowledges this point. The Baltimore VA follow-up study and the UN environmental impact study may provide more answers. More studies, such as that being conducted by AFRRI, should be encouraged. Additionally, the U.S. military, despite its current position on DU, should provide proper protection, training, and testing for soldiers who handle or contact DU. And despite the underlying fact that any armor penetrator's primary purpose is to kill, further exploration should be done regarding DU alternatives that have less harmful long term health effects. Until conclusive data is available to exonerate DU in causing long term health effects, every effort should be made to curb or prohibit its use.

Written by Curt Wozniak. For additional information, contact Robert Tiller at Physicians for Social Responsibility, phone (202) 898-0150 ext. 220, e-mail:

End Notes:

1. RAND Corporation. A Review of the Scientific Literature as it Pertains to Gulf War Illness: Volume 7 Depleted Uranium. April 1999.

2. Mittelstaedt, Martin. "‘Green’ Bullet Kills People, But Not the Environment." Toronto Globe and Mail. July 21, 1999

3. Military Toxics Project. Depleted Uranium; Agent Orange of the 90's: Another Pentagon Coverup. June, 1999.

4. "Final EA for Tomahawk Flight Test Operations on the West Coast of the U.S." page 3-24, Section 3.2.7. October, 1998.

5. Mesler, Bill. "The Pentagon’s Radioactive Bullet." The Nation. October 21, 1996.

6. Edwards, Rob. "Too Hot to Handle." New Scientist. June 5, 1999.

7. Department of Defense News Briefing. May 3, 1999.

8. Associated Press. "Puerto Rico, U.S. Ties Strained." The New York Times. July 17, 1999.

9. Japan Times. February 11, 1997.

10. Williams, Thomas. "Depleted Uranium in NATO Bombs Raises Health Issues." Hartford Courant. May 20, 1999.

11. Cardamone, Jr, Thomas A.. "News Briefs: Jordan Made Non-Nato Ally." Arms Trade News. December, 1996/January, 1997.

12. Fahey, Dan. "DoD Analysis; The Good, the Bad and The Ugly." June, 1999.

13. Reuters. "UN Agency May Urge Study of Iraqi Cancer Cases." October. 20, 1998.

14. Conference on Health and Environmental Consequences of Depleted Uranium used by U.S. and British Forces in the 1991 Gulf War. "Health Consequences of DU Weapons Used by U.S. and British Soldiers." December, 1998.

15. Military Toxics Project. "Press Release: Military Toxics Project Confirms NATO is Using DU Munitions in Yugoslavia and Releases Results of Medical Study Indicating Potential for Fatal Cancers." May 4, 1999.

16. Fahey, Dan. "Selected Quotes From Government Reports on Depleted Uranium". Military Toxics Project.

17. Richardson, J.J. "Depleted Uranium: The Invisible Threat." Mother Jones online. June 23, 1999.

18. Bertell, Rosalie. "Gulf War Veterans and Depleted Uranium." Hague Peace Conference. May, 1999.

19. Cook, Joe and Frances Williams. "Balkans: NATO Uranium ‘polluting Yugoslavia.’" Financial Times. July 22, 1999.

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