SCIENCE
Polinium Ploy (Part 2)
By Dr Rizwana Rahim
Chicago, IL

Polonium (Po) is the first element discovered in 1899 by Marie and Pierre Curie, both future Nobelists.
Po is a silvery metal (At. No. 84, At. Wt. 209), readily soluble in dilute acids but only slightly in alkalis. It is 2.5 x 10^11-times more toxic than hydrogen cyanide. It is present in nature but in extremely low abundance in the environment, including as a contaminant in tobacco, in the soil (about one-trillionth of a curie/g), in air (produced by radon-22 gas decay) and in Uranium ores (about 1 mg/ton of Uranium-238 ore).
According to Argonne National Labs, Po has about 25 radioisotopes, more than any other element. Po-210 has a half-life of 138 days (i.e., it takes 138 days to reduce the original amount in half. Po-210 decays to lead (Pb) isotope-206, by the emission of alpha particles. Exposure to it from external sources can be easily blocked, but not when it is within the body. One mg Po-210 emits as much alpha particles as 5 g of Radium-226. Other radioisotopes of Po with significant half-life include Po-208 and Po-209. Commercially, Po-210 (At. No. 84) is not easy to produce. Very small quantities of it are produced by neutron bombardment of Bismuth (Bi-209; At. No. 83). Decay of Po-210 generates enormous heat (one-half gram of it generating 900 degree F or, 500 degree C) and for this reason it is used a heat source in space satellites and lunar rovers in cold lunar environs. It is also used in ceramic micro-beads and chemical ionization devices as static removers; production of DVD, computer chips, etc., all require static-free environments. If the microbeads are accidentally ingested, the beads and thus the radioactivity are not likely to remain in the body for long.

210 Po-210 is very lethal, only if inhaled or ingested. As it decays fairly rapidly (138, half-life), its alpha radiation emissions cause enormous internal damage. One gram of Po-210 can deliver up to 1 million lethal doses. Since alpha particles strongly react with matter, a thin film oil/liquid, or a layer of dead skin cells on one’s body can be effective protection against Alpha-emission. Because of this, Henry Kelly (Federation of American Scientists) says that, once produced and obtained, Po-210 can be easily transported. But, without nuclear reactors, it seems nearly impossible to produce Po-210. And, to extract sufficient amount of Po-210 from static removers and other Po-210 containing devices would require buying excessive number of these devices, which is not going to go unnoticed. For these reasons, Steve Fetter of University of Maryland doesn’t think Po-210 would be effective as a weapon of mass destruction, and he offers this scenario: if a Po-210 device is dropped on a sidewalk, the contamination will surely be great but no exposure problem “unless you go lick the sidewalk.”
Once Po-210 is ingested, inhaled or absorbed by the body otherwise, it is distributed widely via blood, and the whole body would be exposed to the damage it would cause. Through blood, spleen, liver and kidney could each get 10% of the intake, the rest (70%) distributed in the entire body. Alpha-particles would destroy DNA, most cellular functions and eventually the organs. About one-tenth of a microgram is considered enough to kill a human being.
Al Keane, an Argonne biophysicist who specializes in radiation-caused biological effects, thinks that by scanning his body with gamma-ray detector, it should be possible to work out the Po-210 dosage Litvinenko had received. In addition to alpha-particles, Po-210 also emits gamma rays (one gamma particle per 100,000 alpha-particles). While alpha particles in the body cannot be detected outside (alpha-emissions cannot penetrate the skin), gamma rays CAN be detected, which would help calculate how much Po-210 did Litvinenko receive.
Though Po-210 was found on the surfaces of places Litvinenko (and other-contaminated persons) visited, P-210 exposure to anyone else would be negligible, unless, e.g., Po-210 from their fingers which may have touched a contaminated surface is transferred to mouth or nose.
In addition, various rumors were circulating about Litvinenko himself that: he was involved in blackmail attempts, threatening to make public highly confidential information he claimed he had from KGB files; he was a supoorter/sympathizer of Chechen rebels and was himself involved in making a dirty bomb; he converted to Islam while he was bed-ridden (which is why, before burial in Highgate Cemetery, some people say, there was a memorial service for him in a London mosque).
In any case, the face of a hair-less, totally emaciated face of Livinenko on his deathbed has been etched on our memory, and we wonder if the KGB of the Cold War days has been resurrected as we go into 2007.


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Editor: Akhtar M. Faruqui
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