THE trail of clues in the mysterious death of Alexander V. Litvinenko may lead to Moscow, as the former spy claimed on his deathbed. But solving the nuclear whodunit may prove harder than Scotland Yard and many scientists at first anticipated.The complicating factor is the relative ubiquity of polonium 210, the highly radioactive substance found in Mr. LitvinenkoÂ’s body and now in high levels in the body of an Italian associate, who has been hospitalized in London. Experts initially called it quite rare, with some claiming that only the Kremlin had the wherewithal to administer a lethal dose. But public and private inquiries have shown that it proliferated quite widely during the nuclear era, of late as an industrial commodity.
“You can get it all over the place,” said William Happer, a physicist at Princeton who has advised the United States government on nuclear forensics. “And it’s a terrible way to go.”