The real-life spy thriller surrounding the poisoning of Russian defector Alexander Litvinenko makes the apparent poison, radioactive polonium-210, sound like a supersecret killer ingredient. It's rare to find it in lethal concentrations, to be sure - but actually not so rare to find it in everyday life.
In minute quantities, polonium-210 has been used over the years to spark up spark plugs and banish static cling. Polonium is one of the carcinogens in tobacco smoke, and you can buy a smidgen of it over the Internet at $69 a pop, as more than one news report has noted. Heck, there's even radioactive polonium in plain old dirt.
"It's present in all of us, in trace amounts - say, in nanocuries," said Keith Eckerman, a senior research scientist at Oak Ridge National Laboratory.
The amount is key. We might notice no ill results from billionths of a curie (which serves as a measure of activity). In contrast, Litvinenko is thought to have been exposed to something around 5 millicuries (thousandths of a curie), said Kelly Classic, associate editor for media relations at the Health Physics Society.
That's a minute amount - a speck of polonium that active would weigh less than a millionth of a gram, according to the Health Physics Society's information sheet on polonium (PDF file). But getting that much polonium together would probably require going to the source, which usually involves a nuclear reactor. This is why investigators are thinking the hit on Litvinenko was a high-level spy-vs.-spy job.
The amounts used in industrial applications - yes, including those $69 polonium samples, which are typically used to calibrate radiation detection devices - are far more minute: a speck of a speck of a speck.
Polonium is notable among radioactive substances because its radioactivity comes exclusively in the form of alpha particles - positively charged clumps comprising two protons and two neutrons. Such radiation poses a negligible external hazard, because it penetrates only a few cells deep. That's why it's useful for calibrating radiation detectors, Eckerman said.
But if enough polonium-210 is ingested or breathed in, it causes big trouble - as the death of Alexander Litvinenko has demonstrated. Within days, the spy-turned-whistleblower succumbed to radiation poisoning.
So should the authorities shut down the $69 polonium operation? Hardly.
The radioactive samples that United Nuclear is selling over its Web site are encased in disks of inert material, or planchettes, as a safety measure, and thus aren't considered all that hazardous, Eckerman told me. "It's physically bound to that substrate, so it's not possible to mechanically remove it," he said. "You'd have to dissolve the whole planchette."
United Nuclear does have an extra measure of intrigue because it was founded by Bob Lazar, who has claimed that he helped the U.S. government reverse-engineer alien UFO technology. But even if Lazar is a "UFO nut," there doesn't seem to be much mystery surrounding United Nuclear's scientific supply operation.
Polonium-210 also is contained within protective sheathing in the modern-day materials and devices used to cancel out static electricity - which would again make it difficult to turn the tiny radioactive mini-specks into something dangerous. "You would have to break the device open and scrape off the polonium," Classic told me.
Even if you could somehow isolate the polonium from hundreds of $69 disks, or thousands of static-neutralizing brushes, you wouldn't have nearly enough to create the Litvinenko effect. Theoretically, the best you might be able to do is elevate a person's cancer risk, years down the line.
The fact that polonium-210 isn't as well-known as plutonium or uranium is probably a big factor behind the interest in an incident that is sounding more and more like a "science-fiction spy thriller," Classic said.
"They happen to be using something that most of the population hasn't heard about before," she observed, "which makes it even more mysterious."