Agronomic Factors Affecting Polonium-210 and Lead-210 Levels in Tobacco. II. Varieties and Curing Methods
1968
Tso, T. C. | Carr, J. M. | Ferri, E. S. | Baratta, E. J.
Tobacco seedlings accumulated Pb²¹⁰ and Po²¹⁰ to a concentration much higher than that found in the soil. The levels of these radioelements decreased as the plants grew. Only minor differences were observed in harvested leaves of two flue-cured varieties — ‘Coker 319’ and ‘Virginia Bright Leaf.’ The Pb²¹⁰ and Po²¹⁰ content in the seeds arc in much lower levels than those in the respective leaves produced from the same plant. Neither of the two methods of flue-curing — a closed system with wood or an open system with kerosene — resulted in significant differences in radioisotope levels of cured leaf. Pb²¹⁰ and Po²¹⁰, if present in the combustion products of wood, were trapped in or exhausted through the flue pipes and were not deposited on the tobacco. Kerosene, because it contains little radioactivity, would not contribute much to the Pb²¹⁰ and Po²¹⁰ level of cured leaf when fnlly exposed to products of combustion in an open system.
显示更多 [+] 显示较少 [-]