NEW YORK: If substantial amount of Polonium 210 were used to poison Alexander Litvinenko, the former Russian spy who died in London on Thursday, whoever did it presumably had access to a high-level nuclear laboratory and put himself at some risk carrying out the assassination.
Polonium 210 is highly radioactive and very toxic. By weight, it is about 250 million times as toxic as cyanide, so a particle smaller than a dust mote could be fatal, the New York Times reported.
There is no antidote, and handling it in a laboratory requires special equipment. But to be fatal, it must be swallowed, breathed in or injected; the alpha particles it produces cannot penetrate the skin.
So it could theoretically be carried safely in a glass vial or paper envelope and sprinkled into food or drink by a killer willing to take the chance that he did not accidentally breathe it in or swallow it, the report said.
"This is wild," said Dr F Lee Cantrell, a toxicologist and director of the San Diego division of the California Poison Control System said. "To my knowledge, it is never been employed as a poison before. And it is such an obscure thing. It is not easy to get. That is going to be something like the KGB would have it in some secret facility or something."
In a quick search of medical journals, he could only find one article describing the deliberate use of a radioactive poison to kill. It was from 1994, he said, published but he could not read the details because it was in Russian.
Polonium is extremely rare in nature. Named by its discoverer, Marie Curie, after her native Poland, it occurs in trace amounts in uranium ore and has been found in minute quantities in plants like tobacco, as well as in humans who ate caribou that ate lichens growing near a uranium mine.
But making the "significant quantities" described in Litvinenko's body by the British Health Protection Agency would require a nuclear reactor that could bombard the element bismuth with neutrons, the report said.
"To most chemists, this is astonishing," said Dr Andrea Sella, a lecturer in inorganic chemistry at London's University College.
"This is not available commercially. This is not the kind of weapon that any kind of amateur could construct," he said adding "it would require real resources to do it."
Robert C Whitcomb Jr, a health physicist for the Centers for Disease Control and Prevention, said polonium has industrial uses and could be produced in commercial, university or government reactors.
Polonium 210 does its damage by emitting alpha particles, which have enough energy to tear apart the genetic machinery of cells, killing them outright or causing them to mutate into tumor-producing forms. It gives off 5,000 times more alpha particles than the same amount of radium does.
Alpha-emitters are not picked up by normal radiation-detection devices, a British expert said, so it would be relatively easy to take across a border.