Saturday, July 7, 2012

Polonium: The best and worst poison

So, while up in New York, I picked up The Poisoner's Handbook from The Strand. The subtitle is 'Murder and the Birth of Forensic Medicine in Jazz Age New York'. I loved it. It's a murder mystery with heavy doses of history, politics, and science. I'll give it one of the best compliments I can give a book: it reminded me of Rising Tide (one of my favorite books of all time).

Poisoning has always sort of been a "coward's weapon" (killing in secret without the chance of glory, like open battle). The 'Hassassins' terrorized the Middle East, until their downfall in the 14th Century. Poisoning has slowly been dying off due to advances in medicine and science. Doctors can cure a myriad of poisons and forensic scientists can extract tell-tale clues of poisoning, leaving the assassin (and those that order the hit) vulnerable to retaliation.

Except for 1 obscure poison: Polonium. It looks to be more in use than we realize. There's the famous Litvinenko poisoning case in 2006, but it looks like there is at least one more from 2004:

Excellent report about the possible (probable?) use of polonium to assassinate a head of state. I definitely recommend the second half of the video where they go through how they investigated. Great work.

Why is polonium such a great poison? Well, for background, I'll highlight the brain teaser about the 4 radioactive cookies. Polonium is an alpha-emitter. You can hold it in your hand and be perfectly safe. You can have a vial of water with enough polonium to kill dozens and have it just sit there and it won't be easily detected and won't harm a potential assassin, but you sprinkle it in, say, the target's tea or on the target's sushi and they ingest it, they'll die a slow, painful death over 3 weeks and doctor's won't be able to figure it out or cure it...

...Except if you have a radiochemist specifically looking for polonium. Then, even sub-milligram quantities of polonium can be revealed and analyzed. You see, during the early stages of the Manhattan Project, scientists knew plutonium could also be useful to make a bomb and would be much easier to manufacture than Uranium-235.

Years before, chemists had developed a branch of analysis called microchemistry which could handle tiny amounts of chemicals weighing as little as 0.001 gram. But not even such a tiny bit of plutonium was available. So the chemists at the University of Chicago under Glenn Seaborg began in April, 1942, to develop a new method which could handle chemicals which weighed no more than 500 micrograms (1 microgram equals one-millionth of a gram) or about 1/5000 the weight of a single dime. ... This method is known as ultra-microchemistry.

From the data Seabourg's team extracted, engineers were able to then refine designs of nuclear reactors and bomb components months before usable quantities (kilograms) of plutonium were available.

Moving from plutonium to back to polonium, very small amounts of polonium can be extracted very far after the subject is poisoned. It's like a heavy metal; it persists and doesn't break down. It will radioactively decay, but you can still track the 'daughter-products' and that breakdown allows you to even track when the polonium was created. With a large enough sample, from tracking the isotopes of the polonium, a good radiochemist can even tell you which reactor made the polonium. All of these factors make it a very BAD poison to choose.

1 comment:

rcs said...

A polonium-laced salt shaker is one of the clues that leads Russian detective Arkady Renko to the Chernobyl Exclusion Zone in Martin Cruz Smith's Wolves Eat Dogs. Good summer reading.