The radiation dose from radium and polonium found naturally in tobacco leaves can be a thousand times more than that from the caesium-137 soaked up by the leaves from the Chernobyl nuclear accident area, a Greek researcher has said.
Constantin Papastefanou from the Aristotle University of Thessaloniki in Greece measured radioactivity in tobacco leaves from across the country and calculated the average radiation dose that would be received by people smoking 30 cigarettes a day.
He found that the dose from natural radionuclides was 251 microsieverts a year, compared with 0.199 from Chernobyl fallout in the leaves.
According to Papastefanou, though the radiation dose from smoking is only 10 per cent of the average dose anyone would receive from all natural sources, it is an increased risk.
"Many scientists believe that cancer deaths among smokers are due to the radioactive content of tobacco leaves and not to nicotine and tar," said Papastefanou.
The findings appear in the journal Radiation Protection Dosimetry, reports New Scientist.