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2003 June 11 Wednesday.
Yesterday I found the 2003 April 17

Alexandra Miller DU story

on a site run by The Guardian (Britain). The article suggests that new research indicates a possible synergy between the radioactivity of depleted uranium and its toxicity, leading (possibly) to an eightfold increase in the damage potential of DU. (Point: the article does not use the word "synergy," but the word seems applicable.)

Today I tried to follow up this story by punching "Alexandra Miller" into Google's search box, but I didn't have much luck. Then I went to:-

The New Scientist

Punching "Alexandra Miller" into the search box on the actual webpage itself led me to an article dated 14 April 2003, summarized as "To overcome Iraqi forces, coalition troops fired thousands of shells tipped with DU - but its long-term health effects are still not fully understood".

The article is here:-

Depleted uranium casts shadow over peace in Iraq

This answered one of the questions I had: is Alexandra Miller the only person thinking that maybe DU's radioactivity and chemical toxicity are team players?

Answer: no.

DU is both radioactive and toxic. Past studies of DU in the environment have concluded that neither of these effects poses a significant risk. But 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, says Alexandra Miller, a radiobiologist with the Armed Forces Radiobiology Research Institute in Bethesda, Maryland. "The bottom line is it might contribute to the risk."

She is not alone. The idea that chemical and radiological damage are reinforcing each other is very plausible and gaining momentum, says Carmel Mothersill, head of the Radiation and Environmental Science Centre at the Dublin Institute of Technology in Ireland. "The regulators don't know how to handle it. So they sweep it under the carpet."

Apparently some of Miller's research has been published in print. At a couple of points the article in The New Scientist gives citations. One is Military Medicient, vol 167, p120, and the other is Molecular and Cellular Biochemistry, which is described as being "in press".

The New Scientist uses the "synergy" label to describe what is suspected when it writes:-

Britain's Royal Society briefly referred to these synergistic effects in its report last year on the health effects of DU munitions. "There is a possibility of damage to DNA due to the chemical effects being enhanced by the effects of the alpha-particle irradiation." But it makes no recommendations for future research to evaluate the risks.

The article in The New Scientist is very readable but a little more detailed than the article in The Guardian.

One of the big questions about radioactivity is whether we can argue from the math to the health result, or whether we have to look at the health result and, from that, figure out what the math must be.

In the article in The New Scientist there's another hint that the math may be wrong.

When I read what the article says about "the bystander effect," the image that leapt into my mind was tenpin bowling. When you roll a ball at a bunch of pins, you may hit one but knock down two or three. The damage you do to the stability of the one has negative implications for its neighbors.

About "the bystander effect" the article says this:-

Miller points to another reason to be concerned about DU: the so-called "bystander effect". There is a growing consensus among scientists that radiation damages more than just the cells it directly hits. In tests using equipment that allows single cells to be irradiated by individual alpha particles, gene expression increases both in irradiated cells, and in neighbouring cells that have not been exposed. "At high doses, 'bystander' is not an issue because you are killing so many cells. But at low doses that's not really true," says Miller. There is a danger that experiments not specifically looking for this effect could miss an important source of damage.

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.

Now, on top of that, considered as a toxic chemical, uranium is genotoxic, meaning that it "chemically alters DNA, switching on genes that would otherwise not be expressed".

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 (Molecular and Cellular Biochemistry, in press).

The article in The New Scientist is linked to an

editorial

which includes this message:-

"Evidence of the absence of any health impacts would be reassuring but all we have at present is an absence of evidence."

The theme of the editorial seems to be that, in the current state of scientific uncertainty, reassuring noises made about depleted uranium are just that - reassuring noises.

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A scientific study is underway called:-

Carcinogenic Potential of Depleted Uranium and Tungsten Alloys

Today's new piece of jargon is HMTA, meaning heavy metal tungsten alloy.

Exposure of cultured human bone cells to DU or HMTA resulted in a transformation of those cells to a type with biochemical and growth characteristics typical of tumor cells. The magnitude of transformation observed with DU and HMTA was similar to that observed with the known heavy metal carcinogen, nickel. These cells, once transformed, produced tumors when injected into immune deficient mice. DU and HMTA were also shown to be genotoxic and mutagenic in model system studies.

The estimated completion date for the study above is 2003 December 31.

If you happen to be interested in real science, real science done by real scientists who spend their working days doing horrible things to rats, then this page seems to be a good place to start, since it has a bunch of links to pages with sexy titles like "Neoplastic transformation of human osteoblast cells to the tumorigenic phenotype by heavy metal-tungsten alloy particles: induction of genotoxic effects".

(It's at moments like this that one really appreciates the virtues of cut-and-paste.)

Let's explore one link from the list of "Most Recent Publications":-

Miller AC, Mog S, McKinney L, Lei L, Allen J, Xu J, Page N. Neoplastic transformation of human osteoblast cells to the tumorigenic phenotype by heavy metal-tungsten alloy particles: induction of genotoxic effects. Carcinogenesis, 22(1):115-25, Jan 2001. Abstract

This gives a good indication of some of the unknowns in modern science as it relates to the use of military metals:-

Heavy metal-tungsten alloys (HMTAs) are dense heavy metal composite materials used primarily in military applications. HMTAs are composed of a mixture of tungsten (91-93%), nickel (3-5%) and either cobalt (2-4%) or iron (2-4%) particles. Like the heavy metal depleted uranium (DU), the use of HMTAs in military munitions could result in their internalization in humans. Limited data exist, however, regarding the long-term health effects of internalized HMTAs in humans.

The point here is that, in addition to DU, other military metals may also constitute a health hazard, and that the dimensions of this health hazard are currently unknown.

And I think this is as far as I can go today. I've been up since 0400 and it's now coming up to 0600, and time for breakfast, and work.

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