Source of Lead-210 and Polonium-210 in Tobacco

Abstract

Test plants were grown within a chamber enriched with radon-222 in the atmosphere, in tobacco fields with different sources of phosphate-containing fertilizer, and in culture containing lead-210 in the nutrient solution. Harvested leaves were subjected to three curing conditions. The major portion of the lead-210 in the plant was probably absorbed through the roots. Airborne radon 222 and its daughters contributed much less to the plant's content of lead-210 and of polonium-210. The stage of leaf development and the methods used to cure the leaf affected the final amount of polonium-210 in tobacco leaf.

210Po and 210Pb Activity Concentrations in Cigarettes Produced in Vietnam and Their Estimated Dose Contribution Due to Smoking

“…Besides the natural source of 210 Po and 210 Pb in soils, the amount of these isotopes can be increased by fertilizers, especially the one containing phosphate. The activity of 210 Po in the commercial fertilizer which contained phosphate was 6.5 times higher than that of the specially mixed one [2]. On the other hand, vegatation is also contaminated by 210 Po and 210 Pb as a result of 222 Rn deposition from the atmosphere prepitation, and the sticky surface of tobacco leaves is a good condition for 210 Po and 210 Pb to deposit on.…”

“…On the other hand, vegatation is also contaminated by 210 Po and 210 Pb as a result of 222 Rn deposition from the atmosphere prepitation, and the sticky surface of tobacco leaves is a good condition for 210 Po and 210 Pb to deposit on. The 210 Po concentration in tobacco plants grown in the greenhouse whose 222 Rn concentration was maintained at approximately 500 times greater than in the normal atmosphere was as twice as the plants grown normally [2]. During tobacco combustion, 210 Po and 210 Pb in cigarette smoke are taken into human body.…”

“…Besides, the presence of 210 Pb in tobacco is also of interest because it is a long-lived precursor (22.3 years) that supports the radioisotope 210 Po [1]. 210 Po and 210 Pb are absorbed into tobacco plant mostly in two ways: the first one is the direct uptake of the roots from soils and the other one is the deposition from the atmosphere on the leaves [1], [2], [3]. Besides the natural source of 210 Po and 210 Pb in soils, the amount of these isotopes can be increased by fertilizers, especially the one containing phosphate.…”

“…Alpha particles emitted from 210 Po ionize surrounding tissues and also caused damaging internal exposure. As a result, smoking cigarette increases the risk of causing lung cancer, heart attack, mental illness, et cetera [1], [2], [3]. Many investigations about 210 Po and 210 Pb concentrations in cigarettes have been carried out in Brazil, Poland, Hungary and so on.…”

“…Many investigations about 210 Po and 210 Pb concentrations in cigarettes have been carried out in Brazil, Poland, Hungary and so on. Most of them indicated the harm of 210 Po to smokers' health because of the rather high concentrations of 210 Po in cigarettes and also the effective dose from 210 Po and 210 Pb in cigarette smoke [1], [2], [3]. Therefore, an investigation of these two radioisotopes in eighteen brands of cigarette produced in Vietnam via radiochemical separation and spontaneous deposition of polonium on copper discs has been made.…”