Polonium-210: All you need to know about the poison that killed Sunanda Pushkar

It’s official. The Delhi police has confirmed that Sunanda Pushkar, the late wife of Congress leader and Thiruvananthapuram MP Shashi Tharoor was poisoned to death on 17 January 2014. The autopsy report also refers to Polonium-210, a highly hazardous poison that might have been used to kill Sunanda.

But what exactly is this  Polonium-210 and where does it come from?

According to Chemistry World , the journal published by the Royal Society of Chemistry, the silver-coloured metal was discovered by Marie and Pierre Curie in 1897 and is usually found in uranium ores. This polonium is the source of Polonium-210, or Po-210, which “is one of 25 radioactive isotopes of polonium - it decays to lead by alpha particle emission, with a half life of 138 days.”

Po-210 has been used earlier for killing  humans.

Swiss scientists doubt that former Palestine president Yasser Arafat was killed after he was poisoned by Po-210. According to a 108-page report prepared by experts and scientists at Lausanne University Hospital’s Institute of Radiation Physics in Switzerland, the role of P-210 was more or less established in the death of Arafat. The report, which is available with Al Jazeera , said that Swiss scientists found that “the results moderately support the proposition that the death was the result of poisoning with polonium-210”.

On 23 November 2006, a former Russian agent Alexander Litvinenko died in London after he was poisoned by Po-210. It was alleged that two Russians had put Po-210 into the coffee that Litvinenko drank. The fatality of Po-210 can well be imagined with how United Nuclear, a firm that deals scientific equipment and nuclear supplies, described the poison : “An incredibly toxic and powerful Alpha radiation emitter, Po-210 is just about the last thing you’d ever want in your coffee. Come to think of it, it is the last thing you’d ever want in your coffee.”

Following Litvinenko’s death, a report in The Guardian said that Po-210 is extremely hard to detect.

“It is extremely hard to detect. Scientists only identified it in Litvinenko hours before his death. A former FSB officer, and teetotaller, Litvinenko was a fitness fanatic. Doctors say it was only because he was in such good shape that he lasted so long. If he had died sooner, the cause of death would probably never have been uncovered."— The Guardian report had said .

Po-210 is a rare and highly radioactive isotope that is not easily available. According to Chemistry World, unless one has “access to a nuclear facility”, it is difficult to collect the material. The production of Po-210 is extremely low globally as well. “Around 100 grams a year of Po-210 are manufactured worldwide in nuclear reactors, by bombarding bismuth-209 with neutrons,” the Chemistry World said .

As a deadly killer, Po-210 is convenient because a very tiny amount is sufficient to snuff out life from someone. “A microgram of Po-210, which is no larger than a speck of dust, would certainly deliver a fatal dose of radiation,” the Chemistry World said.

“Polonium is only slowly excreted - it has a biological half life of around a month - and this ensures its alpha particles continue to wreak havoc once inside the body. One likely method of administration would be as a soluble salt (citrate or nitrate, for example) added to the victim’s food or drink. Once ingested, polonium is rapidly distributed around the body, leaving a trail of reactive radicals in its wake as it steals electrons from any molecule it encounters. Low-level DNA damage from radiation can cause genetic changes that affect cell replication, whereas more severe damage may force the cell to self destruct by apoptosis."— the Chemistry World said .

What makes Po-210 even more dangerous is that it can be transported easily. “… it can be safely carried in glass vials and will not set off radiation detectors at airports”, The Guardian said .

The killer capacity of Po-210 was established  in 1956 when Irène Joliot-Curie, the daughter of the metal’s discoverer Marie, died of leukaemia following accidental expose to polonium.