Depleted Uranium Casts Shadow Over Peace in Iraq

July 18, 2003 -- Concern is mounting over the military use of depleted uranium and its possible effects on the health of soldiers and civilians.

Munitions containing rods of depleted uranium (DU) are used on the battlefield to destroy heavily armored vehicles, primarily by the Air Force. These munitions, known as penetrators, contain no explosive charge, but the extremely dense DU rod, travelling at high speed, is able to pierce the heavy armour of a modern battle tank.

A by-product of the uranium enrichment process, DU is chemically identical to natural uranium. However, most of the 235 isotope has been extracted leaving mainly the non-fissionable 238 isotope. It is used to make the tips of armour-piercing shells because it is extremely dense: 1.7 times as dense as lead. Also, unlike other heavy metals that tend to flatten, or mushroom, upon impact, DU has the ability to "self-sharpen" as material spread out by the impact ignites and burns off as the munition pierces its target.

Testing of DU munitions has taken place at Okinawa, Japan in 1995, and at Vieques Island, Puerto Rico in 1999. An estimated 11 tons of DU were used in munitions in the Balkans in the late 1990s. During the Gulf war in 1991, the US and the UK fired an estimated 350 tons of DU at Iraqi tanks. There is no confirmation of the extent of its use in Afghanistan, but a preliminary report suggests that between 100 and 200 tons of DU has been used so far in Operation Iraqi Freedom by US and UK forces. Most battles during this conflict have taken place in densely populated areas or in urban centers.

Wrecked tanks and vehicles litter the Iraqi countryside. Ruined buildings dominate towns and cities. Many were blown to pieces by shells tipped with DU, a material that the military says poses no long-term health or environmental risks. However, many Iraqis, and a growing band of scientists, are not so sure.

In the years since the 1991 Gulf war, doctors in southern Iraq have reported a marked increase in cancers and birth defects, and suspicion has grown that they were caused by DU contamination from tank battles on farmland west of Basra. As early as 1995, doctors were reporting a significant rise in leukemia in children there.

In 2001, the Royal Society published a report which concluded that troops in a tank who survived being hit by a DU shell could double their risk of dying from lung cancer. The society's team of 11 experts produced a second report in 2002 on the chemical and long-term environmental risks. This report concluded that most soldiers would not take in enough DU to damage their kidneys. However, it points out that soldiers in hit tanks, or those who spend time cleaning them up, could suffer heavy metal poisoning. It further states that soldiers who inhale or swallow high levels of DU on the battlefield could suffer kidney failure within days.

The Nuclear Policy Research Institute's (NPRI) new report, released on July 8, 2003, goes even further. It opens with the statement that "soldiers and civilians in the vicinity of exploded DU munitions are exposed to respirable-size particles of uranium trioxide that may be inhaled or ingested, exposing them both to chemical toxicity and low-level radiation."

It goes on to state, however, that "as the debate has become increasingly politicized and polarized, the rhetoric has gotten in the way of the science, as both activists and military officials have made claims not backed up by science." Claims by the military that DU munitions are the most effective are exaggerated, according to the NPRI, and equally effective substitutes without the detrimental effects of DU should be explored. Claims by activists that the effects of DU munitions cannot be palliated are also exaggerated, the NPRI advances, with specific recommendations for the military, to be immediately implemented.

The NPRI says that the health risks of DU "tend to be substantially understated by government bodies," and that children, not soldiers, are most vulnerable to exposure.

"In conflict areas such as Iraq, where residential areas have been ravaged by tanks and munitions, the DU-contaminated debris has become the children's new playground," cautions NPRI.

People's fears that DU leaves a deadly legacy must be addressed, says the UN Environment Program (UNEP). Evidence is emerging that DU affects our bodies in ways we do not fully understand, scientists say, and the legacy could be real.

DU is both radioactive and toxic. Past studies of DU in the environment have concluded that neither of these effects poses a significant risk. However, some researchers are beginning to suspect that in combination, the two effects could do significant harm. Nobody has taken a hard look at the combined effect of both.

The idea that chemical and radiological damage are reinforcing each other is very plausible and gaining momentum. Though DU is 40 per cent less radioactive than natural uranium, some scientists believe that its radiological and toxic effects might combine in subtle, unforeseen ways, making it more carcinogenic than thought.

Uranium is "genotoxic." It chemically alters DNA, switching on genes that would otherwise not be expressed. The fear is that the resulting abnormally high activity in cells could be a precursor to tumor growth. However, while the chemical toxicity of DU is reasonably well established, the radiological effects of DU are less clear.

To gauge the risk from low-dose radiation, researchers extrapolate from tests using higher doses. But the relationship between dose and effect is not linear: at low doses, radiation kills relatively fewer cells. Though that sounds like good news, it could mean that low radiation is having subtle effects that go unnoticed because cells are not dying.

Alexandra Miller, a radiobiologist with the Armed Forces Radiobiology Research Institute in Bethesda, Maryland, has discovered the first direct evidence that radiation from DU damages chromosomes within cultured cells. The chromosomes break, and the fragments reform in a way that results in abnormal joins. Both the breaks and the joins are commonly found in tumor cells.

More crucially, she has recently found that DU radiation increases gene activity in cultured cells at doses of DU not known to cause chemical toxicity

A body of research has also emerged over the past decade showing that the effects of radiation may not appear immediately. Damage to genes may be amplified as cells divide, so the full consequences may only appear many generations after the event that caused it.

And while the chemical toxicity of DU itself is more clear-cut, the possibility remains that there may still be some unforeseen synergistic effects at a genetic level. Other heavy metals, such as tungsten, nickel and cobalt are similarly genotoxic. When Miller and her team exposed human cells to a mixture of these metals, significantly more genes became activated than when the cells were exposed to the equivalent amount of each metal separately.