Tobacco companies have covered up for 40 years the fact that cigarette smoke contains a dangerous radioactive substance that exposes heavy smokers to the radiation equivalent of having 300 chest X-rays a year.
Internal company records reveal that cigarette manufacturers knew that tobacco contained polonium-210 but avoided drawing public attention to the fact for fear of “waking a sleeping giant”.
Polonium-210 emits alpha radiation estimated to cause about 11,700 lung cancer deaths each year worldwide. Russian dissident and writer Alexander Litvinenko died after being poisoned with polonium-210 in 2006.
The polonium-210 in tobacco plants comes from high-phosphate fertilisers used on crops. The fertiliser is manufactured from rocks that contain radioisotopes such as polonium-210 (PO-210).
The radioactive substance is absorbed through the plant’s roots and deposited on its leaves.
People who smoke one-and-a-half packets of cigarettes a day are exposed to as much radiation as they would receive from 300 chest X-rays a year, according to research.
New health warning labels such as “Cigarettes are a major source of radiation exposure” have been urged by the authors of a study published in this month’s American Journal of Public Health.
“This wording would capitalise on public concern over radiation exposure and increase the impact of cigarette warning labels,” the Mayo Clinic and Stanford University authors say.
Quit Victoria executive director Fiona Sharkie said Australian tobacco companies were not legally obliged to reveal the levels of chemicals contained in cigarettes. This made it difficult to know exactly how damaging PO-210 was and meant it was impossible to know what effect it had on other poisons contained in cigarettes.
“It (PO-210) is obviously highly toxic and we applaud any efforts to publicise the dangers,” she said. “But the industry needs to be better regulated before we can support specific warnings.”
Inhalation tests have shown that PO-210 is a cause of lung cancer in animals. It has also been estimated to be responsible for 1% of all US lung cancers, or 1600 deaths a year.
The US authors analysed 1500 internal tobacco company documents, finding that tobacco companies conducted scientific studies on removing polonium-210 from cigarettes but were unable to do so. “Documents show that the major transnational cigarette manufacturers managed the potential public relations problem of PO-210 in cigarettes by avoiding any public attention to the issue.”
Philip Morris even decided not to publish internal research on polonium-210 which was more favourable to the tobacco industry than previous studies for fear of heightening public awareness of PO-210.
Urging his boss not to publish the results, one scientist wrote: “It has the potential of waking a sleeping giant.” Tobacco company lawyers played a key role in suppressing information about the research to protect the companies from litigation.
The journal authors, led by Monique Muggli, of the nicotine research program at the Mayo Clinic, say: “The internal debate, carried on for the better part of a decade, involved most cigarette manufacturers and pitted tobacco researchers against tobacco lawyers. The lawyers prevailed.
“Internal Philip Morris documents suggest that as long as the company could avoid having knowledge of biologically significant levels of PO-210 in its products, it could ignore PO-210 as a possible cause of lung cancer.”
Source: William Birnbauer, Theage.com.au