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Critique of Depleted uranium#Health considerations section.

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Generally the only real costs are those associated with conversion of uranium hexafluoride (UF₆) to metal.

DU is 67 percent denser than lead, only slightly less than tungsten and gold, and just 16 percent less dense than osmium or iridium, the densest naturally occurring substances known.

Here is the section with my improvements:

Health considerations

DU is considered both a toxic and radioactive hazard that requires long term storage as low level nuclear waste. Its use in incindiary ammunition is controversial because of potential adverse health effects and its release into the environment. Besides its residual radioactivity, U-238 is a heavy metal whose compounds are known from laboratory studies to be toxic to mammals.

Metalic uranium is prone to corrosion and small pieces are pyrophoric in air. When depleted uranium munitions penetrate armor or burn, it creates depleted uranium oxides dust that can be inhaled or contaminate wounds. Additionally, fragments of munitions or armor can also become embedded in the body.

Chemical toxicity

Health effects of DU are determined by factors such as the extent of exposure and whether it was internal or external. Three main pathways exist by which internalization of uranium may occur: inhalation, ingestion, and embedded fragments or shrapnel contamination. Properties such as phase (e.g. particulate or gaseous), oxidation state (e.g. metallic or ceramic), and the solubility of uranium and its compounds influence their absorption, distribution, translocation, elimination and the resulting toxicity. For example, metallic uranium is relatively non-toxic compared to hexavalent uranium(VI) uranyl compounds such as uranium trioxide. The chemical toxicity of depleted uranium is about a million times greater in vivo than its radiological toxicity.

Uranium is pyrophoric when finely divided. It will corrode under the influence of air and water producing insoluble uranium(IV) and soluble uranium (VI) salts. Soluble uranium salts are toxic. Uranium accumulates in several organs, such as the liver, spleen, and kidneys. The World Health Organization has established a daily "tolerated intake" of soluble uranium salts for the general public of 0.5 µg/kg body weight, or 35 µg for a 70 kg adult.

While epidemiological studies on laboratory animals point to it as being an immunotoxin, teratogen, neurotoxic, with carcinogenic and leukemogenic potential, there has been no definite link between possible health effects in laboratory animals and humans. A 2005 report by epidemiologists concluded: "the human epidemiological evidence is consistent with increased risk of birth defects in offspring of persons exposed to DU."

Early studies of depleted uranium aerosol exposure assumed that uranium combustion product particles would quickly settle out of the air and thus could not affect populations more than a few kilometers from target areas, and that such particles, if inhaled, would remain undissolved in the lung for a great length of time and thus could be detected in urine. Burning uranium droplets violently produce a gaseous vapor comprising about half of the uranium in their original mass. Uranyl ion contamination in uranium oxides has been detected in the residue of DU munitions fires.

Radiological hazards

External exposure to radiation from depleted uranium is less of a concern because the alpha particle emitted by its isotopes travel only a few centimeters in air or can be stopped by a sheet of paper. Also, the uranium-235 that remains in depleted uranium emits only a small amount of low-energy gamma radiation. According to the World Health Organization, a radiation dose from it would be about 60 percent from purified natural uranium with the same mass. Approximately 90 micrograms of natural uranium, on average, exist in the human body as a result of normal intakes of water, food and air. The majority of this is found in the skeleton, with the rest in various organs and tissues.

The radiological dangers of pure depleted uranium are lower (60 percent) than those of naturally-occurring uranium due to the removal of the more radioactive isotopes, as well as due to its long half-life (4.46 billion years). Depleted uranium differs from natural uranium in its isotopic composition, but its biochemistry is for the most part the same. For further details see actinides in the environment.

Gulf War syndrome and soldier complaints

Approximate area and major clashes in which DU bullets and rounds were used in the Gulf War.

Main article: Gulf War syndrome

Increased rates of immune system disorders and other wide-ranging symptoms, including chronic pain, fatigue and memory loss, have been reported in over one quarter of combat veterans of the 1991 Gulf War. Combustion products from depleted uranium munitions are being considered as one of the potential causes by the Research Advisory Committee on Gulf War Veterans' Illnesses, as DU was used in 30 mm and smaller caliber machine-gun bullets on a large scale for the first time in the Gulf War. Veterans of the conflicts in the Gulf, Bosnia and Kosovo have been found to have up to 14 times the usual level of chromosome abnormalities in their genes. produces congenital disorders, and in white blood cells causes immune system damage.

Human epidemiological evidence is consistent with increased risk of birth defects in the offspring of persons exposed to DU. A 2001 study of 15,000 February 1991 U.S. Gulf War combat veterans and 15,000 control veterans found that the Gulf War veterans were 1.8 (fathers) to 2.8 (mothers) times more likely to have children with birth defects. After examination of children's medical records two years later, the birth defect rate increased by more than 20%:

"Dr. Kang found that male Gulf War veterans reported having infants with likely birth defects at twice the rate of non-veterans. Furthermore, female Gulf War veterans were almost three times more likely to report children with birth defects than their non-Gulf counterparts. The numbers changed somewhat with medical records verification. However, Dr. Kang and his colleagues concluded that the risk of birth defects in children of deployed male veterans still was about 2.2 times that of non-deployed veterans."

In early 2004, the UK Pensions Appeal Tribunal Service attributed birth defect claims from a February 1991 Gulf War combat veteran to depleted uranium poisoning. Children of British soldiers who fought in wars in which depleted uranium ammunition was used are at greater risk of suffering genetic diseases such as congenital malformations, commonly called "birth defects," passed on by their fathers. In a study of U.K. troops, "Overall, the risk of any malformation among pregnancies reported by men was 50% higher in Gulf War Veterans (GWV) compared with Non-GWVs."

The U.S. Army has commissioned ongoing research into potential risks of depleted uranium and other projectile weapon materials like tungsten, which the U.S. Navy has used in place of DU since 1993. Studies by the U.S. Armed Forces Radiobiology Research Institute conclude that moderate exposures to either depleted uranium or uranium present a significant toxicological threat.

File:Basrah birth defects.gif

Graph showing the rate per 1,000 births of congenital malformations observed at Basra University Hospital, Iraq

One particular subgroup of veterans which may be at higher risk comprises those who have retained internally fragments of DU from shrapnel wounds. A laboratory study on rats produced by the Armed Forces Radiobiology Research Institute showed that, after a study period of 6 months, rats treated with depleted uranium coming from implanted pellets, comparable to the average levels in the urine of Desert Storm veterans with retained DU fragments, had developed a significant tendency to lose weight with respect to the control group. Substantial amounts of uranium were accumulating in their brains and central nervous systems, and showed a significant reduction of neuronal activity in the hippocampus in response to external stimuli. The conclusions of the study show that brain damage from chronic uranium intoxication is possible at lower doses than previously thought. Results from computer based neuro-cognitive tests on veterans have indeed showed a correlation between the levels of urinary uranium and "problematic performance" on tests assessing performance accuracy and efficiency. Also, veterans with internally retained DU fragments might be more exposed to cancer and leukemia risks.

Studies indicating negligible effects

Many studies in 2005 and earlier concluded that DU ammunition has no measurable detrimental health effects. A 1999 study conducted by the Rand Corporation stated: "No evidence is documented in the literature of cancer or any other negative health effect related to the radiation received from exposure to depleted or natural uranium, whether inhaled or ingested, even at very high doses," and a RAND report authored by the U.S. Defense department undersecretary charged with evaluating DU hazards considered the debate to be more political than scientific.

A 2001 oncology study concluded that "the present scientific consensus is that DU exposure to humans, in locations where DU ammunition was deployed, is very unlikely to give rise to cancer induction". Former NATO Secretary General Lord Robertson stated in 2001 that "the existing medical consensus is clear. The hazard from depleted uranium is both very limited, and limited to very specific circumstances".

A 2002 study from the Australian defense ministry concluded that “there has been no established increase in mortality or morbidity in workers exposed to uranium in uranium processing industries... studies of Gulf War veterans show that, in those who have retained fragments of depleted uranium following combat related injury, it has been possible to detect elevated urinary uranium levels, but no kidney toxicity or other adverse health effects related to depleted uranium after a decade of follow-up.” Pier Roberto Danesi, then-director of the IAEA Seibersdorf +Laboratory, stated in 2002 that "There is a consensus now that DU does not represent a health threat".

The International Atomic Energy Agency reported in 2003 that, "based on credible scientific evidence, there is no proven link between DU exposure and increases in human cancers or other significant health or environmental impacts," although "Like other heavy metals, DU is potentially poisonous. In sufficient amounts, if DU is ingested or inhaled it can be harmful because of its chemical toxicity. High concentration could cause kidney damage." The IAEA concluded that while depleted uranium is a potential carcinogen, there is no evidence that it has been carcinogenic in humans.

A 2005 study by Sandia National Laboratories’ Al Marshall used mathmatical models to analyze potential health effects associated with accidental exposure to depleted uranium during the 1991 Gulf War. Marshall’s study concluded that the reports of cancer risks from DU exposure are not supported by veteran medical statistics, but Marshall did not consider reproductive health effects.

Other contamination cases

On October 4, 1992, an El Al Boeing 747-F cargo aircraft Flight 1862, crashed into an apartment building in Amsterdam. Local residents and rescue workers complained of various unexplained health issues which were being attributed to the release of hazardous materials during the crash and subsequent fires. Authorities conducted an epidemiological study in 2000 of those believed to be affected by the accident. The study concluded that there was no evidence to link depleted uranium (used as a counter balance in the plane) to any of the reported health complaints.

In 2005, uranium metalworkers at a Bethlehem plant near Buffalo, New York, exposed to frequent occupational uranium inhalation, were found to have some of the same patterns of symptoms as Gulf War Syndrome victims.