Polonium-210 is an alpha emitter that has a half-life of 138.376 days. A milligram of 210Po emits as many alpha particles as 5 grams of radium. A few curies (1 curie equals 37 gigabecquerels) of 210Po emit a blue glow which is caused by excitation of surrounding air.
A single gram of 210Po generates 140 watts of power.[12] Because it emits many alpha particles, which are stopped within a very short distance in dense media and release their energy, 210Po has been used as a lightweight heat source to power thermoelectric cells in artificial satellites. A 210Po heat source was also used in each of the Lunokhod rovers deployed on the surface of the Moon, to keep their internal components warm during the lunar nights. Some anti-static brushes contain up to 500 microcuries of 210Po as a source of charged particles for neutralizing static electricity in materials like photographic film.[13].
Another use of Polonium-210 has come to light recently is its effectiveness as a radioactive poison. Former KGB spy Alexander Litvinenko was poisoned with Polonium-210, probably on November 1, 2006, resulting in his death on November 23, 2006.
Polonium is an extremely toxic element: highly radioactive and chemically toxic, it is very difficult to handle safely.
Weight-for-weight, its toxicity is around 109 times greater than hydrogen cyanide. Even in microgram amounts, handling 210Po is extremely dangerous, requiring specialized equipment and strict handling procedures. Alpha particles emitted by polonium will damage organic tissue easily if polonium is ingested, inhaled, or absorbed (though they do not penetrate the epidermis and hence are not hazardous if the polonium is outside the body).
The lethal dose (LD50) for acute radiation exposure is generally about 4 Sv [21]. One Bq of 210Po (i.e., an amount that produces one decay per second) causes a radiation dose of 0.51 µSv if ingested, and 2.5 µSv if inhaled [22]. Since 210Po has an activity of 166 TBq per gram[22], a fatal 4-Sv dose can be caused by ingesting 8 MBq (200 microcurie), about 50 nanograms (ng), or inhaling 1.6 MBq (40 microcurie), about 10 ng.
One gram of 210Po could thus in theory poison 100 million people.http://en.wikipedia.org/wiki/Polonium![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}