Depleted Uranium Forums (DU-BBS)

The following question was answered by an expert in the appropriate field:
Q: How are bullets made by depleted uranium, and what reactions do they cause when they enter into contact with the ground and with humans?
A: Because of its very high density—nearly twice that of lead—and certain other properties, depleted uranium is used in certain kinds of munitions because of its ability to penetrate heavily armored vehicles such as tanks and armored personnel carriers. Depleted uranium (DU) is not used in small cartridges or bullets for rifles or machines guns but alloyed DU is used in the 25, 105, and 120 millimeter (mm) kinetic energy cartridges used primarily as antitank munitions. DU is also a component in some tank armor and sometimes used as a catalyst for land mine systems.

Since depleted uranium is weakly radioactive, the public has been concerned about the possiblility of adverse health effects from DU. DU is a heavy metal, and like all heavy metals such as mercury and lead, is toxic. However, except in certain very unusual situations, it is the chemical toxicity and not the radioactivity that is of concern. And, from a chemical toxicity standpoint, uranium is on the same order of toxicity as lead. Largely from work with animals along with a few instances in which humans inhaled very large amounts of uranium, the chemical toxicity of uranium is known to produce minor effects on the kidney, which in humans who have suffered large acute exposures have been transitory and wholly reversible. Because depleted and natural uranium are only weakly radioactive, radiological effects from ingested or inhaled uranium have not been detected in humans.

Human experience with uranium has spanned more than 200 years. In the early part of the twentieth century, uranium was used therapeutically as a treatment for diabetes, and persons so treated were administered relatively large amounts of uranium by mouth. Tens of thousands of persons have worked in the uranium industry over the past several decades, and have been followed up and studied extensively as have populations in Canada and elsewhere who have high levels of uranium in their drinking water. Results of these studies have not revealed any ill health in these populations that is attributable to the intake of uranium. This is not surprising, as the risk from the radiation dose from uranium is far overshadowed by its potential chemical toxicity, and intakes of uranium of sufficient magnitude to produce chemotoxic effects are unlikely in and of themselves. Any such effects from ingestion or inhalation of uranium would likely manifest themselves first in the form of minor effects associated with the kidneys. That military personnel and others who may have had contact with depleted uranium from munitions are suffering from various illnesses is not in dispute. That their illnesses are attributable to their exposure to uranium is very, very unlikely. Health physicists are deeply concerned with the public health and welfare, and as experts in radiation and its effects on people and the environment, are quite aware that something other than exposure to uranium is the cause of the illnesses suffered by those who have had contact with depleted uranium from munitions. A truly enormous body of scientific data shows that it is virtually impossible for uranium to be the cause of their illnesses. Despite this body of scientific data to the contrary, misguided or unknowing people continue to allege that the depleted uranium, and specifically the radioactivity associated with the depleted uranium is the cause of these illness. This is indeed unfortunate, for health physicists and other scientists and physicians already know that depleted uranium is not the cause of these illnesses and thus any investigations into the cause of these illnesses should focus on other possible causes.

If we are to offer any measure of relief or solace to these suffering people, and to gain some important additional knowledge of the cause of their illness, we should not waste our valuable and limited energies, resources, and time attempting to point the finger at depleted uranium as the culprit, when it is already known that uranium is almost certainly not the cause of the problem. With respect to reactions with the soil, in time depleted uranium will likely leach into the soil and become mixed with it. It will for all practical purposes be chemically indistinguishable from the natural uranium that is already present in the soil all over the earth. One could create all kinds of scenarios, but probably the best way to think about DU in the soil is to compare it with lead. Because lead and uranium are so similar from a toxicological standpoint, the concerns are about the same.

Ronald L. Kathren, CHP
Professor Emeritus Washington State University

Definitive statements about DU's health risks to humans are not easy to make, scientists say.

"We don't know everything we'd like to know," says Ron Kathren, a physics professor and director of the US Transuranium and Uranium Registries in Richland, Wash. Attached to Washington State University, the registry has studied uranium and its effect on industry workers for 30 years.

"The reason people get panicky is because DU is radioactive, but [the battlefield dose] is so small that it never approaches chemical hazard," says Mr. Kathren.

Part of the problem with DU is public misperception, says John Russell, the associate director of the registries: "You say 'uranium,' and people think of the bomb. That's not the case here."

"You're not playing with anything innocuous," says Leonard Dietz, a nuclear scientist who worked for 28 years at the Knolls Atomic Power Laboratory in New York.

In 1979, DU particles escaped from the National Lead Industries factory near Albany, N.Y., which manufactured DU penetrators. The particles traveled 26 miles and were noticed in a laboratory filter by Mr. Dietz. The factory was shut down in 1980 for releasing more than 0.85 pounds of DU dust into the atmosphere every month - a fraction of the 320 tons fired during the Gulf War.

"It's still hot forever," says Doug Rokke, a Pentagon DU expert until last year. "It doesn't go away, it only disperses and blows around in the wind."

The British Atomic Energy Agency, at the behest of the Ministry of Defense in 1991, tried to quantify the risk. Based on an early estimate of just 40 tons of DU used during the Gulf War, it said that that amount could cause "500,000 potential deaths."

Recently declassified, its report says this purely theoretical calculation is "obviously not realistic" because it would require every single person to inhale similar quantities. But the sheer volume does "indicate a significant problem."

The Pentagon rejects that. "The problem is that all of that stuff has to be put into people. It physically can't happen," says Col. Eric Daxon, the radiological staff officer for the Armed Forces Radiobiology Research Institute. The possibility of DU causing serious health problems in Iraq, he says, is "exceptionally small, to the point where it should be absolutely at the bottom of the list."