Excerpt:

V Corps Command Sgt. Maj. Kenneth Preston said depleted uranium emits only extremely low levels of gamma radiation and low levels of alpha and beta particles that are easily blocked by skin and clothing.

He said passengers on a long airline flight are exposed to more radiation risk than soldiers hypothetically enclosed for one year in a tank surrounded by armor and shells with depleted uranium.

Sigmon said no special warnings have been issued to Iraqis about depleted uranium, but leaflets and other information are being circulated warning everyone, especially children, to stay away from all unexploded ordnance.

Preston said the vast ammunition and weapons caches of the former regime posed a far greater hazard than depleted uranium shells.

Preston, an expert on tank ammunition, said depleted uranium, a byproduct from the process of enriching uranium for use as fuel or in nuclear weapons, emits 40 percent less radiation than uranium occurring in its natural state. Depleted uranium is also 1.7 times heavier than lead, and thus does not stay suspended as dust particles for very long.

Impearls: 2003-08-10 Archive
Earthdate 2003-08-15 Posted by Michael McNeil
Depleted Uranium — the Science

Here is a well-referenced blog entry that expresses some of the basic arguments against DU being overly dangerous.

Best I can make out, the depleted-uranium agitation by the antiwar left is more than just exaggeration, it's pretty much invented whole cloth — garbage, in other words. You recall the naive old saying, “Where there's smoke there's fire”? From what I've seen of propaganda mills blasting away full bore (full of lies), I'm much more taken by the comeback, attributed to John F. Kennedy, I believe: “Where there's smoke, you'll usually find somebody running a smoke-making machine!”

Depleted uranium has two possible modes of instigating biological damage — ionizing radiation due to the fact that it's a radioactive metal, and biological toxicity due to the fact that it's a “heavy” metal. Regarding the first of these, radioactively “depleted uranium” is basically as little radioactive as it's possible to be and still be radioactive and not inert. This may sound like a quibble, but the half-life of uranium-238, the major radioactive component of depleted uranium (since it's been “depleted” of other uranium isotopes) is 4.5 x 109 (i.e., billion) years (not "109" years as news pieces have erroneously reported). In other words, over the entire 4.6 billion year age of the Earth, the quantity of uranium-238 on this planet has decreased by only half. That is barely detectably radioactive at all, on the human timescale.

... (in comments section)
Clayton is correct that alpha radiation occurring within a living organism is a totally different bear from alpha radiation simply impacting the skin of that organism (which typically blocks it without harm). Recall, however, that depleted uranium's rate of alpha emission is still subject to U-238's extraordinary 4.5 billion year half-life. Thus the proper question to ask is whether that alpha emission occurs at a rate which produces damage that is detectable — and the answer which comes back from all the studies is that it does not. That answer is obtained, as it should be, not only from theoretical considerations but also from practical medical investigations of people and patients, including detective-like following and connecting of dots with regard to places where exposures to toxicologically questionable materials could have occurred, versus where individual people were who have been reported sick.

Depleted Uranium Expert Shares Knowledge WASHINGTON, January 3, 2000 (GulfLINK)

This gets my vote for the best short explaination of the position that DU is not particularly dangerous simply because uranium is not particularly dangerous. It is an interview article with Dr. Naomi H. Harley, a radiation physicist.

EXCERPT: "Well, to begin with, most people don't realize that they live with an enormous amount of uranium already," Harley says. "All soil contains uranium. In normal soil, it's not unusual to find a ton of natural uranium per square kilometer." She agrees that in a battle zone much of the depleted uranium ammunition, which strikes hard targets such as tanks, will be dispersed in fine aerosol particles and settle over the ground.

"However, compared with Mother Nature," she says, "what you spread on the Earth's surface is almost indistinguishable from what was there already. This was certainly true in the Gulf War. There were follow up measurements made of soil in the battle areas and you really could not distinguish what's there normally from what was put there by the weapons."

In other words, she says these fine particles are mixed in with existing uranium without measurably increasing the amount present. And what about reports that before it settles, a cloud of aerosolized uranium could pose a danger to people who inhale particles miles away?

"Fortunately, it's really impossible to breathe in enough depleted uranium to do you any serious harm," Harley says. "If you work in an industry that uses uranium, you're allowed concentrations in the air of 0.2 of a milligram per cubic meter, which means in a work day you might inhale two milligrams. This is the kind of air concentration you find right near [an armored vehicle] where a DU round hits it. When you breathe it in, you breathe in some uranium, but the risk is so low it's very hard to calculate."

Although Dr. Harley covers many aspects of the DU question in this interview, she does neglect the issues of internal alpha emmissions and the possible binding of uranium atoms to DNA.

Volume 7 - Depleted Uranium
National Defense Research Institute, © 1999 RAND

Here is the highly-cited Rand Corporation report on depleted uranium.

Among other conclusions, the following is stated:

• Although any increase in radiation to the human body can be calculated to be harmful from extrapolation from higher levels, there are no peer reviewed published reports of detectable increases of cancer or other negative health effects from radiation exposure to inhaled or ingested natural uranium at levels far exceeding those likely in the Gulf. This is mainly because the body is very effective at eliminating ingested and inhaled natural uranium and because the low radioactivity per unit mass of natural uranium and DU means that the mass of uranium needed for significant internal exposure is virtually impossible to obtain.
• External radiation in the form of alpha radiation cannot penetrate cloth or skin and would therefore have no negative health effect. Beta and gamma radiation, which can have negative health effects, have been measured at levels below those expected to be of concern.
• Large variations in exposure to radioactivity from natural uranium in the normal environment have not been associated with negative health effects.

Backgrounder Documentation BG-00.0019 May 2000
DEPLETED URANIUM

An extended introduction to DU. This document comes out decidedly in favor of the interpretation that DU armaments pose little radiological threat, even on the battlefield.

Click for selected quotes: Safe on battlefield   Safe debris   Safe to breathe

This document should provide an excellent starting point for debate.  

Depleted intelligence, not uranium, the problem in Kosovo By Zbigniew Jaworowski and Roger Bate Copyright 2001 Junkscience.com January 10, 2001

This very brief, but often-cited, article assures us there is no connection between DU and any "Balkan Syndrome."

Quote:
The total mass of depleted uranium dispersed over Kosovo was at most 25 tons. The radioactivity of one round was about 10 megabecquerels (MBq). Assuming that 30,000 rounds were fired, about 300,000 MBq of uranium-238 activity were dispersed in Kosovo's environment (10,887 square kilometers). Yet, the natural uranium-238 in a one-centimeter layer of Kosovo soil emits about 100,000,000 MBq. Thus, the surface layer of soil in Kosovo contains about 300 times more natural uranium than was dispersed there by NATO weaponry.

Environmental Exposure Report
Depleted Uranium in the Gulf (II)
Under direction of: Bernard Rostker, Special Assistant for Gulf War Illnesses, U.S. Department of Defense
Last Update: December 13, 2000

This massive report, produced by the military, unsurprisingly concludes that DU has minimal negative consequences which do not outweigh its usefulness on the battlefield.

Quotes from Conclusions:

Meanwhile, it is important to note that to date the VA DU Medical Follow-up Program has not detected adverse clinical outcomes associated with DU's chemical or radiological toxicity in any participants. Since 1993, the Baltimore VA Medical Center has monitored 33 Level I veterans seriously injured in friendly-fire DU incidents; about half the group retains DU metal fragments in their bodies. While these veterans have definite medical problems from their wartime wounds, they do not have medical problems due to DU's chemical or radiological toxicity. Since monitoring began in 1993, the veterans retaining DU fragments consistently have had higher-than-normal amounts of uranium in their urine. The VA therefore is following them very carefully, administering a broad battery of medical tests to determine whether the depleted uranium fragments are causing any health problems. The last testing reported (1997) shows no adverse clinical outcomes from DU.

The Agency for Toxic Substances and Disease Registry's and RAND Corporation's reviews of the medical and scientific literature on uranium's and DU's effects support the conclusion that the exposures Gulf War veterans experienced are unlikely to cause illnesses. The recent Institute of Medicine (IOM) study further supports these reviews by concluding that there was "limited/suggestive evidence of no association" between uranium exposure and renal dysfunction or lung cancer at cumulative exposures of less than 20 rem, an amount roughly four times the highest Gulf War estimates. The IOM report also stated there were inadequate or insufficient data to determine whether an association exists between exposure to uranium and a variety of health conditions, including bone cancer, lung cancer (at cumulative exposures greater than 20 rem), lymphatic cancer, nervous system disease, nonmalignant respiratory disease, and other various health outcomes.[193]

Taken together, the USACHPPM assessments, the medical follow-up findings, and the recent scientific reviews form an increasingly solid body of medical and scientific evidence that DU is not causing Gulf War veterans' illnesses.

From the "Identifying Misinformation" section of the US State Department Web site USinfo.state.gov. This info source explicitly frames accusations against DU as a "ConspSiracy Theory." This is as close to straight from the horses mouth as you'll ever get. Recommended!

You Are In: USINFO > Resource Tools > Identifying Misinformation
False Allegations Regarding Depleted Uranium Rumors of adverse health effects proved inaccurate

POSSIBLE LONG TERM HEALTH CONSEQUENCES OF GULF WAR EXPOSURES: AN INDEPENDENT EVALUATION - United States Senate Committee on Veterans’ Affairs
(Alternate link)

The original PDF file is missing, but this Google cache is still available. The rest of the Senate Committee on Veterans’ Affairs musings can be found here using Google. There ain't much.

This report concludes that, although the military doesn't know what causes Gulf War Syndrome, it just couldn't possibly be depleted uranium, and it only takes a few sentences to explain why.

Exposure to uranium, depleted or non-depleted, is not known to produce adverse effects on the nervous system (Thun et al., 1985; Leggett, 1989; Morris and Meinhold, 1995). Reports of exposure to depleted uranium to soldiers in the Persian Gulf, although uncertain, suggest limited numbers of involved personnel. These facts make extremely unlikely that exposure to depleted uranium during the Gulf War is responsible, wholly or in part, for the array of symptoms observed among Gulf War veterans. (p.8)

This quote is from the first part of the report, HEALTH EFFECTS OF EXPOSURES TO NEUROTOXIC AGENTS USED IN THE PERSIAN GULF WAR (pp.3-14), which gives approximately equal consideration to DU and DEET. Uranium is not mentioned again in the entire 92 page report save for a category in the table, Frequency of Self-Reported Environmental Exposures in Gulf War Veterans (GWV) a and Active Duty Service Member (ADS) on p. 82.

On the same veterans.senate.gov site, you can read the very recent testimony of Ms. Ellen Embrey Deputy Assistant Secretary of Defense for Health Affairs/ Force Health Protection & Readiness before the Senate Veterans Affairs Committee United States Senate, March 27, 2007 MEETING THE HEALTH CARE NEEDS OF RETURNING SERVICE MEMBERS AND NEW VETERANS, (alternate) where you can read this oft-repeated information:

We continue to monitor the health affects of our Service members exposed to depleted uranium (DU) munitions. DoD policy requires urine uranium testing for those wounded by DU munitions. We also test those in, on, or near a vehicle hit by a DU round, as well as those conducting damage assessments or repairs in or around a vehicle hit by a DU round. The policy directs testing for any Service member who requests it. More than 2,215 Service member veterans of Operation Iraqi Freedom have been tested for DU exposures. Of this group, only nine had positive tests, and these all had fragment exposures. Testing continues for veterans exposed to DU munitions from the 1990-1991 Persian Gulf War. The 74 individuals with the most significant exposures to DU in a Department of Veterans Affairs medical follow-up program have been extensively studied with physical exams and laboratory analyses for over 12 years. To date, none have developed any uranium-related health problems. This DU follow-up program is in place today for all Service members with similar exposures.

 

Depleted Uranium
HEALTH PHYSICS SOCIETY FACT SHEET

This short report from an apparently authoritative source concludes:

In summary, some minor health problems have been observed following exposure to DU, but ONLY with high levels of exposure. Exposures to airborne DU or to contaminated soil following military use are not known to cause any observable health or reproductive effects.

It also contains the following interesting statement:

Military operations with DU, however, may contaminate soil, groundwater, and breathing air. When used as a weapon, small particles of DU may be produced. These particles have high density and most fall to the ground very close to where they are produced.

This may overlook the possibility of wind blowing DU dust, children playing in destroyed equipment or people salvaging contaminated gear.

Here is a published statement endorsed by the society by HPS Past President, Ron Kathren:

Depleted Uranium: Not the Cause of Military Personnel Illnesses

Recently, there has been much concern expressed in the media and among the general public with respect to the hazardous nature of depleted uranium, including allegations of leukemias, cancers, and other deaths caused by this material. While it is in fact true that depleted uranium is weakly radioactive, it is also a heavy metal and, except in certain very unusual situations, it is the chemical toxicity and not the radioactivity that is of concern. And, from a chemical toxicity standpoint, uranium is on the same order of toxicity as lead.
...
Human experience with uranium has spanned more than 200 years. In the early part of the 20th century, uranium was used therapeutically as a treatment for diabetes and persons so treated were administered relatively large amounts of uranium by mouth. Tens of thousands of persons have worked in the uranium industry over the past several decades and have been followed up and studied extensively, as have populations in Canada and elsewhere who have high levels of uranium in their drinking water. The types of illnesses apparently suffered by those exposed to depleted uranium from weapons have never been observed in these groups.
(Click the link to see the rest. It's definitely worth reading!)

Now that's what I call harmless!