Polonium-210

Its extreme toxicity is attributed to intense radioactivity, mostly due to alpha particles, which easily cause radiation damage, including cancer in surrounding tissue.

Further discoveries and the concept of isotopes, first proposed in 1913 by Frederick Soddy, firmly placed 210Po as the penultimate step in the uranium series.

[4] In the 1950s, scientists of the United States Atomic Energy Commission at Mound Laboratories, Ohio explored the possibility of using 210Po in radioisotope thermoelectric generators (RTGs) as a heat source to power satellites.

[5] Polonium-210 was used to kill Russian dissident and ex-FSB officer Alexander V. Litvinenko in 2006,[6][7] and was suspected as a possible cause of Yasser Arafat's death, following exhumation and analysis of his corpse in 2012–2013.

This results in a buildup of lead and bismuth, and ensures that heavier elements such as thorium and uranium are only produced in the much faster r-process.

[13] Through this method, approximately 8 grams (0.28 oz) of 210Po are produced in Russia and shipped to the United States every month for commercial applications.

[4] By irradiating certain bismuth salts containing light element nuclei such as beryllium, a cascading (α,n) reaction can also be induced to produce 210Po in large quantities.

[15] 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 in each of the Lunokhod rovers deployed on the surface of the Moon, to keep their internal components warm during the lunar nights.

[16] Some anti-static brushes, used for neutralizing static electricity on materials like photographic film, contain a few microcuries of 210Po as a source of charged particles.

[4][23] Elevated concentrations of 210Po in tobacco were documented as early as 1964, and cigarette smokers were thus found to be exposed to considerably greater doses of radiation from 210Po and its parent 210Pb.

[25] Heavy smokers may be exposed to the same amount of radiation (estimates vary from 100 µSv[19] to 160 mSv[26] per year) as individuals in Poland were from Chernobyl fallout traveling from Ukraine.

The decay chain of uranium-238 , known as the uranium series or radium series, of which polonium-210 is a member
Schematic of the final steps of the s-process . The red path represents the sequence of neutron captures; blue and cyan arrows represent beta decay , and the green arrow represents the alpha decay of 210 Po. It is the short half-lives of 210 Bi and 210 Po that prevent the formation of heavier elements, instead resulting in a cycle of four neutron captures, two beta decays, and an alpha decay.