Uranium’s Effect On DNA EstablishedThe use of depleted uranium in munitions and weaponry is likely to come under intense scrutiny now that new research that found that uranium can bind to human DNA. The finding will likely have far-reaching implications for returned soldiers, civilians living in what were once war-zones and people who might live near uranium mines or processing facilities.
Uranium - when manifested as a radioactive metal - has profound and debilitating effects on human DNA. These radioactive effects have been well understood for decades, but there has been considerable debate and little agreement concerning the possible health risks associated with low-grade uranium ore (yellowcake) and depleted uranium.
Now however, Northern Arizona University biochemist Diane Stearns has established that when cells are exposed to uranium, the uranium binds to DNA and the cells acquire mutations, triggering a whole slew of protein replication errors, some of which can lead to various cancers. Stearns' research, published in the journals Mutagenesis and Molecular Carcinogenesis, confirms what many have suspected for some time - that uranium can damage DNA as a heavy metal, independently of its radioactive properties. "Essentially, if you get a heavy metal stuck on DNA, you can get a mutation," Stearns explained. While other heavy metals are known to bind to DNA, Stearns and her team were the first to identify this characteristic with uranium.
http://www.scienceagogo.com/news/20060307010324data_trunc_sys.shtml The Health Effect of DU Weapons in IraqBy Thomas Fasy MD PhD
Dr. Fasy is an Associate Clinical Professor of Pathology at the Mount Sinai School of Medicine in New York City. He has longstanding interests in carcinogenesis and environmental toxicology. In the past two years, he has lectured at conferences and university campuses on the toxic effects of inhaling uranium oxide dusts derived from depleted uranium weapons.SNIP
Uranium is radioactive and it is a toxic heavy metal. Inside the body, uranium exists as uranyl ions. Much of the toxicity of uranium is chemically mediated, in addition to the effects mediated by radiation.
SNIP
By the early 1900s, uranium was well recognized to be a kidney toxin. By the mid-1940s, uranium was known to be a neurotoxin. By the early 1970s, uranium was recognized to be a carcinogen based on mortality studies of uranium workers and on experiments with dogs and monkeys. The first evidence that uranyl ions bind to DNA was reported in 1949 and by the early 1990s, uranium was shown to be a mutagen. Also, in the early 1990s, uranium was shown to be a teratogen, that is, an inducer of birth defects. The toxic effects of uranium on the kidney and on the nervous system typically occur within days of exposure and radiation probably plays little or no role in mediating these effects. In contrast, the carcinogenic effects of uranium have a delayed onset. The teratogenic effects of uranium might be due to exposure of one parent prior to conception as well as to exposure of the mother to uranium early in pregnancy.
Now let us briefly consider the routes of exposure to uranium. In the context of the dust particles derived from depleted uranium weapons, this means exposure to uranium oxides. By far the most dangerous route of exposure to uranium oxides is the inhalational or respiratory route. Absorption of uranium oxides through the gastrointestinal tract, the skin and the conjunctivae is possible but quite limited.
Following impact with hard targets, uranium metal undergoes combustion releasing large quantities of very small uranium oxide dust particles into the environment.
These dust particles derived from depleted uranium weapons are drastically different from the natural uranium that is normally present in rocks and soil.
Soil particles contain uranium at very low concentrations, typically less than 5 parts per million; the vast majority of these soil particles, however, are too large to be inhaled deep into the lungs. In contrast, the dust particles derived from depleted uranium weapons contain very high concentrations of uranium, typically more than 500.000 parts per million; moreover, most of the D.U. dust particles are sufficiently small to be inhaled deep into the lungs. Thus, compared to the uranium naturally present in the environment, D.U. dust contains uranium in a form that is vastly more bio-available and more readily internalized.
Uranyl ions bind to DNA; they bind in the minor groove of DNA. While bound to DNA, uranyl ions are chemically reactive and can give rise to free radicals which may damage DNA. Chemically mediated DNA damage of this type may contribute to the ability of uranium to induce cancers.
I would now like to present some epidemiologic data from the Basra governate in the south of Iraq. In February 1991, more than 300 tons (possibly much more than 300 tons) of D.U. weapons were used in South of Iraq. After 5-6 year latent periods, increases in childhood cancers and birth defects were documented in the Basra governate. The most recent data indicate a four fold increase in pediatric malignancies and a seven fold increase in congenital malformations compared to 1990, the year preceeding the war.
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