Lots of technical details from Wikipedia:
Polonium is a highly radioactive and toxic element and is dangerous to handle. Even in milligram or microgram amounts, handling polonium-210 is very dangerous and requires special equipment used with strict procedures. Direct damage occurs from energy absorption into tissues from alpha particles.
The maximum allowable body burden for ingested polonium is only 1100 becquerels (0.03 microcurie), which is equivalent to a particle weighing only 6.8 × 10-12 gram. Weight for weight polonium is approximately 2.5 × 1011 times as toxic as hydrocyanic acid. The maximum permissible concentration for airborne soluble polonium compounds is about 7,500 Bq/m3 (2 × 10-11 µCi/cm3).
Polonium has been found in tobacco smoke from tobacco leaves grown at some specific places, as a contaminant [3] [4] and in uranium ores.
GlobalSecurity.org has a writeup on the element’s history:
Marie and Pierre Curie discovered the radioactive elements radium and polonium. Before this discovery, uranium and thorium were the only known radioactive elements. While studying uranium minerals. Marie Curie noticed two minerals were much more radioactive than uranium itself. She and her husband, Pierre, chemically separated the compounds in the minerals and found a substance 400 times more radioactive than uranium. Marie named this substance polonium, after her native country of Poland.
Polonium can be handled relatively safely but is quite dangerous if ingested. That makes it a pretty effective poison:
Trackback this Post:Because of their large size, alpha particles have minimal penetration ability and are easily stopped by most materials. For example, the epidermal layer of the human skin is 250-300um thick. The penetrating range of the alpha particle is only 40um in this external dead tissue, so they do not have enough force to penetrate into the live tissues inside the body. Alpha sources are only harmful when ingested or when the internal live human tissue is exposed to them. Because the polonium-210 is encapsulated, no workers in the manufacturing environment are required to take any additional safety measures while working with alpha sources. The design of the equipment employing alpha sources prevents prolonged direct contact between the sources and personnel.
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November 25th, 2006 at 2:28 pm
What I find very interesting is that nobody in the press or blogs seems yet to have connected the poison to one of its main uses — triggers for thermonuclear weapons. Was there a message in the choice of poison? Is somebody making enough Po-210 to be very, very dangerous? Is it irony from defunct Soviet nuclear weapons? Coincidence?
November 27th, 2006 at 10:27 am
All a bit of an attempt to capitalise on an unfortunate accident… looks like Litvinenko’s Micro Nuclear Battery - which probably powered a transmitter - had ruptured, releasing the Polonium 210 into his body.
So the BBC report in which an unamed source at the hospital had revealed that 3 dense objects had shown up on an x-ray of his body, and that one of these objects had appeared to have been ruptured, was correct.
Therefore the police are not treating this as a ‘murder’, only as a ’suspicious death’. The rest of the unfounded rumour mongering is just anti Putin PR.
December 2nd, 2006 at 12:58 am
Is polonium itself poisonous, or is it the radioactivity?
December 5th, 2006 at 4:04 pm
Does anyone know, or know where to find, the maximum permissible concentration of PARTICULATE Po-210, i.e Bequerels per cubic metre or microcuries per cubic centimetre?
December 7th, 2006 at 8:14 pm
Hi. I work at American Elements. Thought you might be interested in its website as a resource in your Sci/Tech links. In addition to Polonium info, the conmpany manufactures Isotopes and Nanomaterials, so you can see information and applications on all the elemental isotopes, as well as, nanoparticles, fuel cell materials, solar energy materials, etc. Cheers!