In 40 years Tobacco Companies have found that cigarette smoke contains a dangerous radioactive substance that exposes heavy smokers to the radiation equivalent of having 300 chest X-rays a year.
Researchers showed in a study 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 is a very dangerous because it emits alpha radiation which can cause about 11,700 lung cancer deaths each year worldwide. In 2006 Alexander Litvinenko, a Russian writer, died after being poisoned with polonium-210.
The polonium-210 in tobacco plants comes from high-phosphate fertilizers used on crops. The fertilizer is manufactured from rocks that contain radioisotopes such as poloniu-m-210.
Researchers found that 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. 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. Researchers are sure that PO-210 is obviously highly toxic and they will approve any efforts to publicize it danger.
They added: "But the industry needs to be better regulated before we can support specific warnings."
Researchers found a lot of arguments for to proof that PO-210 is very dangerous for people’s health. After an inhalation tests they 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 analyzed 1500 internal tobacco company documents, finding that tobacco companies conducted scientific studies on removing polonium-210 from cigarettes but were unable to do so.
Philip Morris even decided not to publish internal research on polonium-210 which was more favorable 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.