Case Study: A White Supremacist Dirty Bomb?

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By Dr. Andrew Karam

What Was Found

In the summer of 2010, when I was working for the New York City Department of Health and Mental Hygiene (DOHMH) I received a call from a colleague in the Fire Department of New York (FDNY). He told me that an elderly gentleman had recently died and, when his apartment was being cleared out, workers found some alarming items – a box full of Nazi paraphernalia, a number of what appeared to be hand grenades and mortar and artillery shells, and a sealed box marked “radioactive” and labeled with radiation stickers. This raised some concerns, especially given the heightened profile of various hate groups around the world.

The person discovering these materials called the city’s emergency phone number, and the person taking the call, following procedure, notified the Fire and Police departments. The possible presence of radioactive materials led to the call to DOHMH; specifically, to the Bureau of Environmental Emergency Preparedness and Response, in which I headed the Radiation Unit. So I grabbed some of our instruments and one of my staff and headed on over to the scene.

When we arrived, two FDNY trucks had blocked off both ends of the street and an NYPD helicopter was hovering overhead. In addition to FDNY, representatives from the NYC Department of Environmental Protection (DEP) were also present. Cops from the Emergency Services Unit (ESU) Hazardous Materials (HazMat) Unit were in charge of the scene; the HazMat Unit’s senior lieutenant was someone I knew well so I found him and let him know we were on the scene.

What the Instruments Told Us

DEP had arrived about a half hour before us – they’d been notified earlier and their office was much closer to the scene (in Queens) than was our Manhattan office. So by the time we arrived our instruments were superfluous since DEP had already covered that ground. What they’d identified was radium – specifically Ra-226 – which is one of the radionuclides that worries me. Radium used to be widely used in the pre-WWII days, and it remained in common use through the 1960s and even into the 1970s for self-luminous watch and instrument dials, and although many of the 50 states have made herculean efforts to recover and dispose of as much of it as possible, dangerous sources still show up from time to time. What I always remember is the young women who painted watch dials in the 1920s who died from ingesting radium when they “pointed” their brushes by licking them. So the presence of radium, in conjunction with the other materials in the basement, certainly gave me pause. I also remembered that it is not uncommon for U-235, the isotope of uranium used to make nuclear weapons, is often mis-identified as Ra-226 due to both radionuclides having very similar gamma “fingerprints;” in this case, however, I was fairly certain that we didn’t have to worry about a nuclear weapon, if only because the “radioactive” box was not very large.

The other bit of radiological information was that radiation dose rates near the box were not very high – only a few tens of microGray per hour at a distance of about 30 cm from the box. This told me that, whatever radionuclide was present, there couldn’t be very much of it. Certainly not dangerous levels.

“Some bomb technicians were entering the building to investigate the explosives – Checking not only for evidence that they were to have been used for an attack, but also for evidence that they might be set to explode if moved, or for evidence of deterioration and instability.”

Investigating and Resolving the Matter

When I reported to the ESU lieutenant he asked me what radium is used for, so I quickly ran through what it had been used for. The biggest, of course, was the glow-in-the-dark watch and instrument dials I already mentioned – but about a century ago, radium was used in a huge number of self-luminous products that included fishing tackle, small buttons to help locate items in the dark, paint (a company I once worked for had to remove a 3-meter tall flagpole painted with radium paint in the 1920s), and much more. Not only that, but radium was widely used in medicine – both for cancer therapy as well as for more dubious potions – in radioactive sources for industry and research, and so forth. Although it was, for a time, the most expensive element on Earth, it proved so useful that industry quickly learned to produce it in relatively large quantities. And radium is fairly potent – 1 gram contains about 37 GBq of radioactivity, which is more than sufficient for several thousand radioactive sources or tens of thousands of watch dials. So the questions we had to answer were how much radium was present and what physical form (metal foil, radioactive sealed source, powder, liquid etc) it might be in.

As the ESU lieutenant was reporting this to his Chief, some bomb technicians were entering the building to investigate the explosives – checking not only for evidence that they were to have been used for an attack, but also for evidence that they might be set to explode if moved, or for evidence of deterioration and instability. They emerged from the home and reported that everything in the basement was for display only – all of the explosives had been removed some time ago. This ramped down the level of concern greatly.

The next step was to open the “radioactive” box, and this reduced the level of concern even more – it was filled with radioactive rocks and minerals. This was the second piece of good news. At this point, DEP entered the building and removed the box, packaging it for transport and eventual disposal. And then the best news of all – someone who knew the man who had died showed up and told us the rest of the story.

It turns out that he had been an American soldier in the Second World War, stationed in Europe. During his time there, he had picked up the Nazi paraphernalia as he fought across France. That explained that box in the basement, and it seemed reasonable to assume that the no-longer-explosive grenades and shells were display pieces from his time in the military. And the “radioactive” box? He was fascinated with radioactive rocks and minerals, so he collected them – but since he didn’t know much about radiation, he wanted to make sure that nobody opened the box to be exposed unless he was present.

While I (and almost everyone else) was relieved, the Special Operations Chief (ESU was a part of Special Operations) was somewhat perplexed. “What kind of idiot collects radioactive rocks?” he demanded. I spoke up at that point; “Well, Chief, a lot of people think they’re sort of cool. I’ve got a bunch at my apartment. I guess I should make sure to leave a note when I get older that they’re not dangerous.” The Chief just glared at me and stomped off to his car.

“Radium not only emits gamma radiation, but it is an even more potent alpha-emitter that was known to be responsible for dozens of deaths in the heyday of radium paints and products.”

A little about naturally radioactive rocks and minerals and why the instruments identified Ra-226 in the rocks

The reason our instruments identified radium in the rocks is because it was there – the result of the radioactive decay of naturally occurring uranium (specifically, the much less-fissionable isotope U-238). When U-238 decays it emits an alpha particle, turning into thorium (Th-234). This is also radioactive, decaying to protactinium (Pa-234), which decays to form U-234, and so forth – through over a dozen steps until it finally reaches stability in the form of lead (Pb-206). One of these steps is radium-226 – the isotope identified by our equipment. The reason that Ra-226 was identified and not some other radionuclide is that many of the intermediate steps emit only alpha or beta radiation, which can’t be detected by the isotope identifier, and because Ra-226 is the most easily-identified of the gamma-emitting radionuclides. It’s also the most widely-used – since the isotope identifier only had limited space to store these isotopic “fingerprints” it’s not uncommon to include only those that one expects to see or that pose the greatest risk. For these reasons, Ra-226 is in most libraries while other decay products are not.

With regards to the legality of owning radioactive rocks and minerals, there’s nothing wrong with it under US law – as long as the concentration of uranium is less than 0.05% by weight and as long as the amount a person owns is less than about 7 kg of total uranium among all of the rocks and minerals they possess. This is why it was legal for the man to own radioactive rocks and minerals, and why it’s legal for me to have my own collection (as well as why I could legally buy most of my minerals at rock and mineral shows as well as online).

Final disposition

I don’t know what happened to most of the materials that were found – only the radioactive rocks and minerals. They were carefully packaged by DEP personnel who were dressed out in coveralls, gloves, hoods, and respiratory protection; after this they were shipped off for disposal. On the one hand, this was a bit excessive since these rocks posed no risk and weren’t licenses. But let me explain why – as the situation unfolded – it made sense.

At the time DEP entered the building they had very little information – only that this was a potential case of domestic terrorism and that there was a box marked “radioactive” that seemed to contain radium. Radium not only emits gamma radiation, but it is an even more potent alpha-emitter that was known to be responsible for dozens of deaths in the heyday of radium paints and products. As an alpha-emitter, radium is a particular inhalation hazard – a milligram could give a person a fatal dose of radiation if inhaled. And on top of that, dried radium paint can be friable – it can be blown into the air by a passing gust of air. Not knowing the situation, it was perfectly sensible to wear this level of protective equipment. I would have recommended the same, had I or my staff been asked to recover the box.

About the Author

Andrew Karam is a radiation safety expert with 35 years of experience, beginning with 8 years in the US Navy’s Nuclear Power Program that included 4 years on an attack submarine. He has published over two dozen scientific and technical papers and is the author of 16 books and several hundred articles for general audiences. He has worked on issues related to radiological and nuclear terrorism for over 10 years.

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