http://www.informationclearinghouse.info/article12903.htm
"Ingested DU particles can cause up to 1,000 times the damage of an X-ray", said Mary Olson, a nuclear waste specialist and biologist at the Nuclear Information and Resource Service in Washington D.C.
It is this difference in particle size as well as the dust's crystalline structure that make the presence of DU dust in the environment such an extreme hazard, and which differentiates its properties from that of the natural uranium dust that is ubiquitous and to which we all are exposed every day, which seldom reaches such a small size. This point is being stressed, as comparing DU particles to much larger natural ones is misleading.
The U.S. Military and its supporters regularly quote a Rand Corp. Study which uses the natural uranium inhaled by miners.
Particles smaller than 10 microns can access the innermost recesses of lung tissue where they become permanently lodged. Furthermore, if the substance is relatively insoluble, such as the ceramic DU-oxide dust produced from burning DU, it will remain in place for decades, dissolving very slowly into the bloodstream and lymphatic fluids through the course of time. Studies have identified DU in the urine of Gulf War veterans nine years after that conflict, testifying to the permanence of ceramic DU-oxide in the lungs. Thus the effects are far different from natural uranium dust, whose coarse particles are almost entirely excreted by the body within 24 hours.
The military is aware of DU's harmful effects on the human genetic code. A 2001 study of DU's effect on DNA done by Dr. Alexandra C. Miller for the Armed Forces Radiobiology Research Institute in Bethesda, Md., indicates that DU's chemical instability causes 1 million times more genetic damage than would be expected from its radiation effect alone.
Studies have shown that inhaled nano-particles are far more toxic than micro-sized particles of the same basic chemical composition. British toxicopathologist Vyvyan Howard has reported that the increased toxicity of the nano-particle is due to its size.
For example, when mice were exposed to virus-size particles of Teflon (0.13 microns) in a University of Rochester study, there were no ill effects. But when mice were exposed to nano-particles of Teflon for 15 minutes, nearly all the mice died within 4 hours.
"Exposure pathways for depleted uranium can be through the skin, by inhalation, and ingestion," writes Lauren Moret, another DU researcher. "Nano-particles have high mobility and can easily enter the body. Inhalation of nano-particles of depleted uranium is the most hazardous exposure, because the particles pass through the lung-blood barrier directly into the blood.
