Tobacco companies knew for decades that cigarette smoke was radioactive and potentially carcinogenic but kept the information from the public, according to a new study.
The tobacco industry began investigations into the possible effects of radioactive particles, identified as polonium-210, as early as the 1960s, says the study by UCLA researchers who analyzed dozens of previously unexamined documents.
"I've not seen a document before that's specifically cited the industry's own internal research finding that sufficient levels of polonium-210 can cause cancer," says Matt Myers of the Campaign for Tobacco-Free Kids.
This week, the Food and Drug Administration began requiring tobacco companies to disclose details about new products and changes to existing ones.
"We used to think that only the chemicals in the cigarettes were causing lung cancer," said Hrayr S. Karagueuzian, lead author of the study published in the peer-reviewed journal Nicotine & Tobacco Research.
Now, he said, the industry's own research shows that polonium-210, absorbed by tobacco leaves and inhaled by smokers, is dangerous. He said UCLA researchers found that the radioactivity could cause 120 to 138 deaths for every 1,000 regular smokers over a 25-year period.
David Sutton, spokesman for Philip Morris USA, said the company does not add polonium-210 to its products. He said it's a "naturally occurring element in the air" and has been widely discussed by the public health community for years.
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