"The United States has conducted two nuclear wars. The first is against Japan in 1945, the second in Kuwait and Iraq in 1991." So declares activist Helen Caldicott in a half-page ad placed by a Japanese anti-nuclear group in the March 24 New York Times. If you didn't hear about the Persian Gulf Hiroshima, it's because she's actually referring to depleted uranium (DU) munitions. Former U.S. Attorney General Ramsey Clark says that these "are an unacceptable threat to life, a violation of international law and an assault on human dignity." Using them results in a "deterioration of genetic health" and "genocide," declares anti-nuke activist Tim Judson. The Green Party claims that they are "the likely cause of numerous health problems in thousands of Gulf War veterans and their families, including cancer, leukemia, tumors, and high rates of birth defects because of genetic damage."
DU is 1.7 times denser than lead, and munitions encased in it are self-sharpening, enabling them to drill 25 percent further through armor. (Armor-piercing tungsten alloy munitions, by contrast, blunt and mushroom when they hit.) This self-sharpening process produces DU dust, most of which falls to the ground within 50 yards of its impact.
Such weapons are used most frequently against enemy tanks. DU is also used to clad many U.S. armored vehicles, thus making them largely impenetrable to conventional anti-tank munitions. It is also used for counterweights in airplanes to help keep them level, and as radiation shielding to protect health care workers from exposure to medical X-rays.
DU is a by-product—activists would say a waste product—of the process of separating the highly fissionable U-235 isotope out of uranium to produce fuel for nuclear reactors. It is called "depleted" because most of the lighter uranium isotopes, U-234 and U-235, are removed from natural uranium, leaving behind uranium consisting of 99.8 percent of U-238. The result is 40 percent less radioactive than natural uranium.
Is it as dangerous as Caldicott and Clark claim? A Department of Defense-sponsored review of the scientific literature by the RAND think tank concluded that "there are no peer reviewed published reports of detectable increases of cancer or other negative health effects from radiation exposure to inhaled or ingested natural uranium at levels far exceeding those likely in the Gulf." One need not be a conspiracy theorist to believe that the Defense Department's analysis and reporting on the substance's health and environmental consequences might be biased. But many independent organizations and scientists find little to worry about either.
What happens to DU if someone eats it? According to a European Union study released in 2001, "most of the ingested DU (between 98% and 99.8%, depending on the solubility of the uranium compound) will be rapidly eliminated in the faeces." The vast majority of any remaining uranium will be "rapidly cleared from the blood" in a few weeks. Similarly, the majority of inhaled DU dust will also be cleared via the bloodstream and kidneys. The EU report concluded that "exposure to DU could not produce any detectable health effects under realistic assumptions of the doses that would be received."
That said, DU is a heavy metal; and like lead, nickel, and other heavy metals, it is chemically toxic when consumed in large quantities, especially harming the kidneys. However, studies looking at likely exposures to DU during and after battles have found that its effects on the kidneys of soldiers and civilians are mild and transient.
Another 2001 report to the European Parliament compared exposures to DU to those experienced by uranium miners and concluded, "The fact that there is no evidence of an association between exposures—sometimes high and lasting since the beginning of the uranium industry—and health damages such as bone cancer, lymphatic or other forms of leukemia shows that these diseases as a consequence of an uranium exposure are either not present or very exceptional."
The World Health Organization agrees that DU is not a great health risk. Its 2003 fact sheet on the topic declares that "because DU is only weakly radioactive, very large amounts of dust (on the order of grams) would have to be inhaled for the additional risk of lung cancer to be detectable in an exposed group. Risks for other radiation-induced cancers, including leukaemia, are considered to be very much lower than for lung cancer." Another WHO report found, "The radiological hazard is likely to be very small. No increase of leukemia or other cancers has been established following exposure to uranium or DU."
What about those military reports? Dan Fahey, a former naval officer who served in the first Gulf War and is a long-time anti-DU activist, asserts that Defense Department spokespeople "have lied about the health of US Gulf War veterans exposed to DU and exaggerated the importance of DU rounds." What was the alleged lie? The Pentagon has said that no veterans in a small follow-up study of Gulf War soldiers who had been exposed to DU have contracted cancer. Fahey cites a memo that states that one veteran who had been recently added to the study has had lymphatic cancer. Fahey does acknowledge that "it is possible that this veteran's cancer is not linked to his confirmed exposure to DU."
Fahey thinks the Pentagon exaggerates the importance of DU munitions and points out that DU rounds probably took out only one-seventh of the Iraqi tanks destroyed during the first Gulf War. But Fahey also admits that there is very little evidence that DU is severely toxic. He also refutes other activists' alarmist claims that civilians have been severely harmed by depleted uranium. "There are no credible studies linking exposure to DU with any cancers or illnesses among people in Iraq, the Balkans, or Afghanistan," he declares.
If DU is not notably harmful to human health or the environment, why the fierce opposition to it? A lot of it has to do with conventional anti-nuclear activism: Some people automatically object to anything that hints of nuclear radiation. Second, some of the opposition is the result of a successful Iraqi disinformation campaign claiming that exposure to DU had caused thousands of cancers and birth defects to innocent civilians. When the WHO offered to investigate the claims, Iraqi officials flatly refused the offer. Other than trying to gain international sympathy, Pentagon officials argue that one of the real aims of the Iraqi campaign was to get DU munitions outlawed internationally so they would not have to face them again.
In addition, many U.S. veterans who returned from the Gulf War believe that they are suffering from "Gulf War Syndrome," a constellation of disparate medical problems that they think can be traced to their service in that war. One suggested explanation for their problems might be exposure to DU dust. But as we've seen, no credible studies show that exposure to DU is likely to be causing their problems.
Finally, there is always a claque of activists who simply will pick up any stick with which to beat and demonize the United States. For them, the myth of severe DU toxicity is just another handy stick.