Monday, August 08, 2005

Is Depleted Uranium the New Agent Orange?

Depleted uranium is getting a lot of play as the new Agent Orange. BrooklynDodger is still agnostic on this question.

That's why BrooklynDodger posted the abstract below, although the Dodger confesses to not reading the full text. BrooklynDodger is puzzled how a 144 ug/kg dose in the rat could generate a 2.6 ug/g or 2600 ug/kg concentration in the kidney as quoted in the abstract. Perhaps a misprint, now traversing the globe as a virus in the abstract spread by medline? Or a notable concentration effect.

BrooklynDodger understands the notable use of DU is a kinetic energy round: jacketed by steel, an artillery sheel cored with DU penetrates armor, releasing hot uranium which burns inside the other guy's tank. DU rounds hitting targets - estimated at 10% of what's shot off - would generate uranium oxide fume in some quantity. DU rounds which missed might be lying on the ground, and perhaps further dispersed by explosives in the warhead, even as uranium oxide. BrooklynDodger also understands that DU is used in the armor itself, sandwiched between steel to resist and react to penetration by the other guy's shells hitting our guy's armored vehicles.

Apparently there is a lot of DU around for non warlike uses. There's also a lot of undepleted uranium around in dirt, not concentrated enough to be recovered, but enough to generate some background radioactivity.

Absorbed DU is the issue; alpha particles don't penetrate the skin much. Absorbed DU ought to be easy to find through urine testing. Here's the best that BrooklynDodger could do with minimal effort:


Health Physics. 87(1):51-56, July 2004.
McDiarmid, Melissa A. *; Squibb, Katherine +; Engelhardt, Susan M. ++

...Two hundred and twenty-seven veterans submitted samples for analysis from January 2000 through December 2002, which included a 24-h urine sample for determination of total urinary uranium concentration and completed questionnaires describing their wartime exposure experiences. Thirty questionnaire items characterizing DU exposure opportunities were collapsed into 19 exposure categories. Urine uranium (U) results were stratified into low and high uranium groups with 0.05 [mu]g U g-1 creatinine as the cut point. Exposure scenarios in the high and low uranium groups were similar in frequency and type with only the presence of retained shrapnel being predictive of a high urine uranium value, as found in the first phase of this surveillance of 169 veterans performed prior to 2000. Twenty-two veterans exhibited U levels in the high range. Isotopic analysis, available for 21 of these 22, revealed that all but three of these samples contained natural and not depleted uranium. These three participants had retained DU shrapnel as a result of their past injuries. Thus, even with an enlarged cohort, elevated urine uranium values in the absence of retained DU fragments are unlikely. The utility of isotopic analysis to more fully characterize uranium biomonitoring results is also demonstrated. Health Phys.

BrooklynDodger hasn't read the full text. Exposure histories were misleading in relation to agent Orange.

Toxicology Volume 212, Issues 2-3 , 1 September 2005, Pages 219-226

The brain is a target organ after acute exposure to depleted uranium
P. Lestaevela, , , P. Houperta, C. Bussya, B. Dhieuxa, P. Gourmelonb and F. Paqueta a

Institut de Radioprotection et de Sûreté Nucléaire, Département de Radio-Protection de l’Homme, Laboratoire de Radio-Toxicologie Expérimentale, BP 166, 26702 Pierrelatte, FrancebInstitut de Radioprotection et de Sûreté Nucléaire, Département de Radio-Protection de l’Homme, BP 6, 92265 Fontenay aux Roses, France

The health effects of depleted uranium (DU) are mainly caused by its chemical toxicity. Although the kidneys are the main target organs for uranium toxicity, uranium can also reach the brain. In this paper, the central effects of acute exposure to DU were studied in relation to health parameters and the sleep–wake cycle of adult rats. Animals were injected intraperitoneally with 144 ± 10 μg DU kg−1 as nitrate. Three days after injection, the amounts of uranium in the kidneys represented 2.6 μg of DU g−1 of tissue, considered as a sub-nephrotoxic dosage. The central effect of uranium could be seen through a decrease in food intake as early as the first day after exposure and shorter paradoxical sleep 3 days after acute DU exposure (−18% of controls). With a lower dosage of DU (70 ± 8 μg DU kg−1), no significant effect was observed on the sleep–wake cycle. The present study intends to illustrate the fact that the brain is a target organ, as are the kidneys, after acute exposure to a moderate dosage of DU. The mechanisms by which uranium causes these early neurophysiological perturbations shall be discussed.

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