| heal.abstract |
The root uptake of Caesium (134Cs) and its subsequent distribution into the shoots, flowers and leaves, as well as the direct deposition of 134Cs on these parts of the plant, were studied in pot experiments, using three tobacco plant varieties (McNair, Kaba Koulac and Katerinis) that are widely cultivated in Greece. The vertical migration of 134Cs into the soil and the quantity of this element contained in the smoke of burning radio-polluted leaves were also studied. For the root uptake of 134Cs, a significant varietal difference was observed, both in calculated Transfer Factor (TF) and in distribution of 134Cs in the different plant parts. A variety dependent difference in 134Cs content was also measured for foliar uptake (direct deposition). It was observed that the main quantity of 134Cs was absorbed or intercepted by the lower leaves of the plants, compared to the quantity absorbed or intercepted by the other plant parts (sterns, upper leaves and flowers). During the two-month period of tobacco cultivation, the wet-deposed 134Cs was contained in the upper five centimeters of soil, while no radionuclide migration was detected in dry deposition. Finally, the amount of 134Cs detected in the smoke was measured to be less than 1% of the total amount in the ashes of the leaves. |
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