Po210

Polonium-210 (210Po) is a radioactive isotope of the element polonium, with atomic number 84 and mass number 210. It is produced in nuclear reactors by neutron irradiation of bismuth-209 and then chemically separated. 210Po decays by alpha emission to stable lead-206, with a half-life of about 138.4 days. It has a very high specific activity, approximately 166 terabecquerels per gram, making even minute quantities extremely hazardous.

The decay involves alpha particles with an energy of about 5.3 MeV. External exposure is limited by the short range of alpha radiation, but ingestion or inhalation can deliver a large internal dose and cause severe organ damage. Because of its radiotoxicity, handling 210Po requires strict radiological controls, containment, and licensing.

Historically notable uses include as a neutron initiator in implosion-type nuclear weapons, notably the polonium-beryllium “urchin” initiator used in several Fat Man-type devices. In civilian applications, 210Po has been employed in static eliminators to remove electrostatic charges in printers and other equipment, though safety concerns and regulatory controls have reduced such uses.

Occurrence and production are tightly regulated. 210Po occurs only in trace amounts in uranium ores and is predominantly produced artificially in reactors. Due to its extreme radiological hazard and potential for misuse, polonium-210 is subject to strict international controls and monitoring. A high-profile poisoning involving Po-210 occurred in 2006, when former Russian agent Alexander Litvinenko died from radiation poisoning after exposure to the isotope, highlighting its notoriety and security concerns.