Hey nnadir, can you tell us about radioactivity vs toxicology in DU?

[Massacure]

DU is a heavy metal that has toxicology effects similar to lead, right? Also I think I remember seeing somewhere that it is 40% less radioactive than natural uranium in the ground.

Some people seem to think DU will make the landscape in Iraq uninhabitable for 4 and a half billion years. Is it true?

I always thought it was the toxicology - not the radioactivity - that killed people. Am I wrong?

[NNadir]

1. I am impressed.

I know you are in your teens from our earlier conversations. I am very surprised to see that you immediately have a better understanding of the nature of Uranium - that mystical element - than 90% of the thousands of people with whom I've discussed this subject, many of them decades older than you. I hope you will consider a career in science. You may or may not get paid very well for it, but your planet will need you in your lifetime.

I've engaged in lots of threads on this subject over on SmirkingChimp - they pop up every two months or so like depressing clockwork.

Here are some main points:

1) Uranium's toxicity is different than that of lead mechanistically, but it is similar on a mass effect basis, although lead is probably more toxic than lead owing to lead's higher and broader solubility and to the fact .

2) Your figure of 40% of the radioactivity of DU vs. natural U is spot on. Most of the radioactivity from natural Uranium is associated with the decay products with which it is in equilibrium. During Uranium ore processing, these decay products are removed. Also the much more radioactive isotope U-235 is removed from the Uranium, leaving the less radioactive isotope U-238 behind. Therefore the radioactivity of "Depleted Uranium" is lower than that of natural Uranium.

3) There are billions of tons of Uranium on the planet and the element is widely distributed. Most of this distribution - the vast majority is distributed by geology and not technology. Until the 1940's and 1950's, Uranium was thought to be a very rare and exotic element, mostly because people didn't look for it - it had very few uses except for coloring glass and pottery glaze. It is now understood that Uranium is a fairly common element, about as common as the element tin. Thus if it were especially toxic, if it were a cause of "Gulf War Syndrome" this would probably have been noticed hundreds, if not thousands of years ago. There are no places on earth that have been rendered unihabitable by either natural or technological Uranium, although some places - Bikini in the South Pacific for instance and the Chernobyl exclusion zone, have been rendered uninhabitable by fission products.

4) None of the above statements are meant to imply that battlefields are not toxic. Many are. There are areas of Northwest France that are still uninhabitable from World War I that are considered unsafe for human habitation. This toxicity has myriad causes; many of them are undoubtedly connected to the chemistry of weapons, and not exclusively limited to chemical weapons or weapons containing DU. War is always wrong because the purpose of war is to kill people.

Here is a recent thread on SmirkingChimp where you can read both sides of the argument. (Warning: Pleae note that it is legal at SmirkingChimp for me to exercise my innate nastiness to a much fuller extent than I am permitted to do here.) The thread is entitled "Iraqi Cities "hot" with depleted Uranium."

http://www.smirkingchimp.com/viewtopic.php?topic=38626&forum=17

I encourage you to read primary scientific literature to get a taste for it. No one expects that you will understand all of it unless you are an extremely precocious young person, but it might, if you have patience, open a new vista for you. Here is a nice article from Chemical Reviews that discusses the toxicity and radiotoxicity of all the commonly found actinide elements, including Uranium.

Chemical. Reviews. 2003, 103, 4207-4282.

You can find it, and many other fascinating stuff like it at a local University science library if one is nearby.

The discussion of Uranium begins on page 4266. Some excerpts:

"There are several recent reviews in the actinide
literature covering specific areas of uranium chemistry
(organoactinide,372,373 solution and extraction
behavior,125,138 carbonate,7 and macrocycles,374,375),
but there has not been a comprehensive review of
uranium coordination chemistry in more than 20
years. Uranium is the second most common naturally
occurring actinide (after thorium), is more often
encountered, and is found in more applications than
thorium. Uranium is most commonly used as nuclear
fuel in fission reactors for civilian energy generation
purposes, but it has many other uses: as a pigment
in glass and ceramics, as fissile weapons material (in
the form of enriched uranium, 235U), as armor plating,
and in armor piercing projectiles (in the form of
depleted uranium, 238U, 99.3% of naturally occurring
uranium).4,124...

...9.3. Depleted Uranium
In addition to the ever-increasing amounts of
uranium handled worldwide as the use of nuclear
power continues to expand,4,5,445 the use of depleted
uranium (DU) has added another dimension to
potential introduction of uranium into the human
body in the form of finely divided shrapnel.446-448 A
large fraction of the DU leaving enrichment facilities
in the United States is converted for use as military
ordinance and armor and as ballast in airplane
construction. A number of military personnel were
accidentally wounded by DU shrapnel during the
Gulf War, and the slowly dissolving, finely divided
DU fragments are continuous sources of systemic
uranyl ion (UO2
2+, uranyl). Persons wounded during
the Gulf conflict and in Kosovo with DU shrapnel
present a unique medical problem... The fragments of
the DU ordinance, many too small to remove surgically,
are chemically reactive and locally irritating,
and as they slowly dissolve, they are potentially
exposing the wounded individuals to chronic kidney
poisoning and an unacceptable amount of uranium
accumulation in the skeleton.446-448
Depleted uranium has been used in heavy armor
for tanks as well as in kinetic energy ammunition...

...The role of DU in the development of illnesses in
veterans of the Persian Gulf conflict has recently
been discounted, as the soldiers most directly in
contact with dust, namely those in or near explosions
of DU ordinance or armored vehicles or others who
treated or rescued the wounded, do not exhibit any
increase in the symptoms expected in those with
more direct exposure.449,450 Depleted uranium has
40% less specific activity than naturally occurring
uranium, but as a heavy metal, it is still chemically
toxic.450 ...

...Studies seeking to establish a connection between
Rational Design of Sequestering Agents for Actinides Chemical Reviews, 2003, Vol. 103, No. 11 4269
uranium exposure and bone cancers are inconclusive.
449 The potential for kidney damage or increased
bone cancer is still being followed in these patients,
and chelating ligands could be useful in reducing the
potential effects of uranium in wounds..."

Thanks for asking. Again, I am impressed that you ask.

[Massacure]

2. That arguement is an interesting read.

Environmental science is a hobby of mine. However I'm thinking of going to college for computer science or software engineering. Perhaps I can put software engineering to good use making models for the environmental sector though. It certainly wouldn't hurt to take a few side classes about environmental sciences either as those kinds of jobs are a lot harder to outsource to China and India.

[XemaSab]

3. Look into GIS

You can take both environmental and computer classes, and be *VERY* employable when you gradumacate. Outsourcing-proof, and pays good too.

It's basically environmental/land use data linked to maps, using software such as ArcGIS or sometimes AutoCad. It can be used to analyze things such as forest age, pollution concentration, traffic patterns, rainforest loss, tracking tagged animals, wetland buffers, heat islands, and other environmental concerns. It's also, strangely, used to figure out things like product placement in stores, where to put new McDonald's or Wal Marts, and other totally whorish corporate applications.

You can work for the government, the military, private consulting firms, businesses, nonprofits...basically you name it.

[midnight armadillo]

4. Radioactivity of U is low in any case.

while I wouldn't carry a chunk of U in my pocket, a piece of it on your desk isn't radioactive enough to do you any harm - the radiation is not high energy enough to penetrate far through the air. I knew a professor who used a kilo of it as a paperweight and conversation piece in his office.

There are byproducts of uranium fission which are extremely dangerous due to their radioactivity - the Russian sailors on that sub (the subject of the Harrison Ford 'Widomaker' movie) suffered severe radiation poisoning.

As NNadir mentions, the modern battlefield is full of contamination - mixtures of vaporized armor and ammunition, gunpowder, exotic high explosives, smoke, rotting bodies, and vehicle exhaust no doubt take a heavy toll on soldiers. DU is just a part of this chemical spectrum.

Oh, and regarding studying EE or comp sci - really, this is probably risky in this day and age of outsourcing. If you're really dedicated to it, I'd suggest a double major with a science, or a science degree plus comp sci minor. The physical sciences have a huge need for software engineering but don't train their own in those fields very well. In my doctoral physics program, I was the only entering member well versed in programming (from past work history, not school!).