Puffing on Polonium By ROBERT N. PROCTOR NYTimes

[Demeter]

http://www.nytimes.com/2006/12/01/opinion/01proctor.html?_r=5&oref=slogin&oref=slogin&oref=slogin&oref=slogin&oref=login



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December 1, 2006
Op-Ed Contributor
Puffing on Polonium
By ROBERT N. PROCTOR
Stanford, Calif.

WHEN the former K.G.B. agent Alexander V. Litvinenko was found to have been poisoned by radioactive polonium 210 last week, there was one group that must have been particularly horrified: the tobacco industry.

The industry has been aware at least since the 1960s that cigarettes contain significant levels of polonium. Exactly how it gets into tobacco is not entirely understood, but uranium “daughter products” naturally present in soils seem to be selectively absorbed by the tobacco plant, where they decay into radioactive polonium. High-phosphate fertilizers may worsen the problem, since uranium tends to associate with phosphates. In 1975, Philip Morris scientists wondered whether the secret to tobacco growers’ longevity in the Caucasus might be that farmers there avoided phosphate fertilizers.

How much polonium is in tobacco? In 1968, the American Tobacco Company began a secret research effort to find out. Using precision analytic techniques, the researchers found that smokers inhale an average of about .04 picocuries of polonium 210 per cigarette. The company also found, no doubt to its dismay, that the filters being considered to help trap the isotope were not terribly effective. (Disclosure: I’ve served as a witness in litigation against the tobacco industry.)

A fraction of a trillionth of a curie (a unit of radiation named for polonium’s discoverers, Marie and Pierre Curie) may not sound like much, but remember that we’re talking about a powerful radionuclide disgorging alpha particles — the most dangerous kind when it comes to lung cancer — at a much higher rate even than the plutonium used in the bomb dropped on Nagasaki. Polonium 210 has a half life of about 138 days, making it thousands of times more radioactive than the nuclear fuels used in early atomic bombs.

We should also recall that people smoke a lot of cigarettes — about 5.7 trillion worldwide every year, enough to make a continuous chain from the earth to the sun and back, with enough left over for a few side-trips to Mars. If .04 picocuries of polonium are inhaled with every cigarette, about a quarter of a curie of one of the world’s most radioactive poisons is inhaled along with the tar, nicotine and cyanide of all the world’s cigarettes smoked each year. Pack-and-a-half smokers are dosed to the tune of about 300 chest X-rays....

Robert N. Proctor is a professor of the history of science at Stanford University.

[wtmusic]

1. We needed another reason why smoking causes cancer?

Amazing.

:wow:

[Mojorabbit]

2. I wonder why smoker's hair does not fall out

I read where polonium cannot be absorbed from the skin. Is there a barrier or semi barrier in the lungs to prevent major poisoning since so little is needed to kill when taken by mouth?

[muriel_volestrangler]

3. But consider how little there is in a cigarette

0.04 picocuries inhaled per cigarette. The activity of polonium 210 is 4500 curies per gram, so that's 0.000009 picograms of polonium from one cigarette. The maximum safe body burden of polonium is 7 picograms, which would be absorbed from 787,500 cigarettes. That's 40 a day for 54 years - but, from the second link, "polonium is only slowly excreted – it has a biological half life of around a month" - so the polonium is gradually eliminated from the body. There will be a steady state where the intake from cigarettes balances the excretion, but it will be way below the 7 picogram level.