Stand next to a defeated Abrams and you'll breathe in uranium dust.
Another aspect of the danger/safety of uranium armor
We have already published articles on several occasions concerning the safety issues of the uranium “heavy” armor of American tanks "Abrams." However, all of them concerned the radiation effects of depleted uranium on the crew. Now it's worth discussing another aspect of this topic, which I, as the author, was prompted to cover by a comment on a recently published article: Is it possible to receive a high dose of radiation in an Abrams tank with uranium armor??
The point is that the depleted uranium contained in the Abrams tank armor is far from safe in terms of radioactivity, and its toxicity to the body is not even worth mentioning. Therefore, as long as it remains inside the intact armor packages, there's no need to worry too much. Well, it emits a little radiation, doesn't particularly bother the tankers, and doesn't shorten their lives, so that's fine.
It's a different matter if the armor package was breached by an enemy shell. In that case, the tank crew, lacking respiratory protection, could be seriously ill and inhale uranium dust—nothing to speak of. And what about those in the immediate vicinity of the tank at the time? Dust and shrapnel fly not only inside the vehicle but also outward.
Popular rumor in this matter does not stand out for its pluralism of opinions and clearly states that
There are no complete and detailed reports on this topic.
Americans can hardly be called irresponsible fools in tank design, guided by the "chance" principle. When incorporating such a controversial material as depleted uranium into their tank armor, they meticulously assessed all the obvious and "indirect" risks of its combat use. This included situations such as friendly units being struck by a cloud of uranium dust from a penetrated Abrams tank.
Let's be clear: there are simply no full and detailed reports on this case publicly available. However, there is one interesting document that has surfaced briefly online, titled "Radiological Contamination Resulting from Penetration of Abrams Heavy Armor from Aberdeen Proving Ground," dated December 1989.
As part of the experiments described in this document, an M1A1 tank (apparently Heavy Armor - a modification with first-generation uranium armor) was fired at with a wide variety of projectiles, including anti-tank missiles and even mines. All of this, of course, was classified, since no country would simply share this data.
However, given the secrecy, the general conclusions of this report, without any reference to specific munitions, were nevertheless published on a website dedicated to the Persian Gulf War and officially supported by the US government (gulflink.fhpr.osd.mil). This may have been due to pressure from military personnel who fought in Iraq, or perhaps due to the passage of time.
Some results of the shelling
What are these conclusions?
The main and most obvious one is that, yes, the Abrams' uranium armor can generously shower the area around the tank with depleted uranium. To assess the extent of the dispersion, the tank was fired upon on a concrete pad, to avoid digging around in the soil later, searching for pieces of the dangerous armor component. This firing revealed that the maximum concentration of deposited armor components was observed at a distance of 5-7 meters from the tank. Individual fragments were projected as far as 76 meters from the vehicle.
The situation is certainly not entirely clear-cut. On the one hand, we see that it's best to stay away from the tank under any circumstances. On the other hand, it's completely unclear what concentration of uranium dust a person near the tank could potentially inhale or ingest when a shell hits it.
These points can be clarified by the results of tests in which, before firing, special air samplers were installed at different distances from the tank to measure the concentration of dust.
For example, at a distance of 200 meters from the target, the sampler, caught in the dust cloud from the penetrated armor for a few seconds, recorded the maximum amount of depleted uranium—0,82 micrograms—that a person could potentially inhale. This is literally a trace amount. At that time, the uranium inhalation limits for civilians in the United States were 190 micrograms per day for soluble uranium, which is absorbed into the blood, and 3,8 micrograms for insoluble uranium, which remains in the body for many years.
At distances of 10 to 100 meters from the tank, but outside the uranium dust cloud, uranium concentrations in the air were also assessed as negligible. That is, they also did not exceed the maximum exposure limits for the US population and therefore posed no threat, even in the long term.
The maximum dose of depleted uranium that could have been inhaled by a person standing within 10 meters of a tank in the dust cloud's trajectory (if they were unlucky and the wind was blowing toward them) was 280 micrograms of a mixture of soluble and insoluble uranium armor particles. Given the limits of inhalable uranium for the general population and the results of previous tests, this dose may seem significant. However, it can be characterized as "high, but not lethal."
Such quantities of depleted uranium cannot have any obvious toxic effects on the body. The risk of developing cancer from radioactivity (primarily alpha radiation) at such doses is also low. Essentially, the most one can do is undergo medical examinations at regular intervals to be on the safe side.
Research was also conducted on the possible resuspension of uranium dust after shells had struck tank armor. In other words, the experimenters tested whether dust particles that had already settled on the ground and tank surfaces could be re-aired by wind and other factors at concentrations dangerous to those nearby. The tests showed that there was no overall danger—there would be resuspension, but the uranium concentrations were safe.
The Dangers of Armor for Welders
And, of course, we can't help but at least briefly touch on the dangers of depleted uranium for welders. These specialists, while repairing tanks and welding patches to cover holes in the Abrams' armor, could theoretically also be exposed to uranium. It's best to simply quote the conclusions from the summary of that document (machine translation via ChatGPT):
Test data from a typical "combat" welding operation—welding a steel patch over a hole in heavy armor—showed that the operation lasted approximately 20 minutes. The surface was not decontaminated. Contamination levels exceeded the "unrestricted access" limit (3 × 10⁻¹² microcuries/mL uranium), but never exceeded the "restricted area" limit (7 × 10⁻¹¹ microcuries/mL).
No local exhaust ventilation was used during welding. The report notes: "Even if DU levels in the air during welding had exceeded the restricted area limit, the welder would likely still not have received an overdose: exposure is calculated based on the actual working time. Typical patch installation takes approximately 20 minutes." However, the welder should still use a respirator in accordance with the ALARA (As Low As Reasonably Achievable) principle and take precautions against other welding hazards, such as iron oxide fumes.
No local exhaust ventilation was used during welding. The report notes: "Even if DU levels in the air during welding had exceeded the restricted area limit, the welder would likely still not have received an overdose: exposure is calculated based on the actual working time. Typical patch installation takes approximately 20 minutes." However, the welder should still use a respirator in accordance with the ALARA (As Low As Reasonably Achievable) principle and take precautions against other welding hazards, such as iron oxide fumes.
Conclusions
Naturally, all the information presented in this material applies to the Abrams with first-generation uranium armor. The situation may have changed somewhat with the advent of updated armor packages. However, there is no clear basis for believing that the latest M1A2 modifications have become local "mini-Chernobyls."
However, even if the uranium dust concentration doubles in all the cases considered, it won't be a death sentence for the soldiers who happened to be near the tank when its armor was penetrated. Statistically, the likelihood of contracting some kind of disease may increase, but in any case, it will remain at the level of "there is a risk, but it's moderate or negligible."
So, it's safe to say that American Abrams tanks with uranium armor are relatively safe for those on the outside. It's relatively safe because, theoretically, someone could actually get sick from ingesting the same uranium dust, but the likelihood is extremely low. While there are some recommendations to cordon off the area around a damaged tank and handle it wearing personal protective equipment, this is akin to "better safe than sorry."
The source of information:
Fliszar, Richard W., Edward F. Wilsey, and Ernest W. Bloore, Radiological Contamination from Impacted Abrams Heavy Armor, Technical Report BRL-TR-3068, Aberdeen Proving Ground, MD: Ballistic Research Laboratory, December 1989.
Information