http://www.nationalinterest.org/Article.aspx?id=13132

Q&A on Polonium, the Poison Picked

11.30.2006

Polonium-210 has been in the spotlight since it was identified as the 
poison that killed Alexander Litvinenko, a former officer in Russia's 
internal security service. Karl K. Turekian, professor of geology and 
geophysics at Yale University, explains its basic qualities, where 
and why it is produced and how it destroys human tissue. In an 
interview with National Interest online editor, Ximena Ortiz, 
Turekian also says that the decision to look for polonium as a source 
of the poisoning required a high-degree of sophistication and 
possibly some prior knowledge.

NIo: Could you explain what polonium is?

KKT: First of all, the basic chemistry of polonium: It's everywhere 
naturally. Polonium-210 occurs in anything that has uranium, but the 
levels are very, very low.

During the development of the atomic bomb, what was needed was an 
initiator, something that would get the uranium-235 to start 
fissioning. They developed a way of manufacturing polonium-210 
artificially with bismuth-209. They took that polonium and combined 
it with beryllium. This emits neutrons at just the right energy to 
initiate a nuclear reaction. That's still the major use of 
polonium-210 now.

When polonium-210 was fabricated in such large quantities-they would 
actually machine it and make shapes, and things like that-they also 
started using it for reactors in satellites. So there is that use to 
it as well.

Anyhow, wherever there is a nuclear arsenal, there's polonium-210. It 
has a half-life of 138 days, which means if you start with ten grams, 
in 138 days it will be down to five grams and in another 138 days it 
will be down to 2.5. It will be effectively gone in three and a half 
years. So they have to keep manufacturing it.

NIo: Do all nuclear states manufacture polonium?

KKT: Everyone uses polonium-210. People quickly realized they needed 
an initiator, and polonium-210 is the initiator of choice for a lot 
of reasons.

NIo: Does it make a difference if you manufacture a uranium bomb 
versus a plutonium bomb?

KKT: All of them need something to provide neutrons to initiate the reaction.

NIo: Would civilian nuclear reactors also use polonium?

KKT: My guess is that polonium-210 is not necessary for a nuclear 
reactor for energy production, though I'm not an expert in that area. 
It's actually manufactured from bismuth in nuclear reactors. Whereas 
bombs in their compact state-with a core of plutonium-210 and 
beryllium-are dependent on it.

NIo: So you wouldn't be producing it if you're not producing a bomb?

KKT: Probably not.

NIo: Once you obtained polonium-210, how would you use it as a poison?

KKT: Polonium-210 is called an alpha emitter. Alpha is essentially a 
helium atom stripped of all its electrons, and it comes out with a 
tremendous amount of energy. It does not have a long range, however; 
you can put a piece of paper over it and it stops the particles. They 
do a lot of damage close up, but they don't go great distances. You 
could carry it around in a box, and no one would know you had any by 
the radiation. It would get warm if you had a lot of it, but no one 
could detect it if you had a vial surrounded by sawdust.

That's also the source of its hazards. Being an alpha emitter, with 
these very energetic, charged particles, if it bombards tissue it 
destroys the tissue, or causes it to mutate. People have been 
studying that for quite awhile, for a lot of reasons including the 
hazards of second-hand smoke. It has an interesting history. A 
massive dose of alpha particles next to human tissue would cause 
damage that could lead to sickness and death.

NIo: How could one use it as a poison without hurting themselves?

KKT: Remember the rays aren't like X-rays or gamma rays that 
penetrate a great distance. This stuff, the radiation isn't going to 
go beyond the cardboard box. It's easy to handle as long as there's a 
container.

NIo: What about removing it, how would you poison another person? 
Would you put it into food?

KKT: Well, you could put it into food. It would act like a small 
explosion in the cells, and that's where the damage is done. It could 
also be inhaled, but I don't think that's what you would do to 
someone else. You're not going to use an aerosol spray in the air 
you're breathing.

NIo: How would you go about exposing the food to the polonium?

KKT: I'm not really a chef. You don't need a whole lot of it, though; 
adding it to food in some way or another need not be obvious or 
ostentatious.

NIo: It still seems like such an exotic property to choose, though.

KKT: Well, there's plenty of polonium-210 available-any place there's 
a bomb maintenance facility-and it's always manufactured. It is a 
sophisticated thing to know that polonium-210 is dangerous, but 
that's been known because it did a lot of harm to people throughout 
the Manhattan Project.

Beyond that, I have no idea. I was surprised that somebody was clever 
enough to look for polonium-210 during the investigation. If you were 
looking for alpha emitters, there is a diagnostic energy for 
polonium-210 no one would mistake. But the act of looking into that 
shows some insight into what might have been used, and I have no idea 
how they got that insight. Maybe they knew something about this 
person or the people he hung around with.