紙巻たばこに含まれる安定同位体セシウムの煙中移行

抄録

While airborne emission of radioactive cesium (Cs) from contaminated biomass by fire has been studied, only few data is publicly available with regard to the transfer of Cs in tobacco leaf to tobacco smoke. The purpose of this study was to investigate the fate of Cs during cigarette smoking, utilizing stable cesium isotope (¹³³Cs) which is naturally contained in tobacco leaf. In order to calculate the transfer rate, mainstream and sidestream smoke from four brand styles of commercial cigarettes were collected with a machine-smoking method. Ash and butts from the smoked cigarettes of two out of the four brand styles were also collected for the estimation of mass balance. After digestion, those collected samples were analyzed with ICP-MS to determine the amount of ¹³³Cs, and the amounts were compared with the original concentration in the cigarettes examined. The transfer rates of ¹³³Cs into the mainstream smoke were proportional to the tar-level of each cigarette, whereas those into sidestream smoke were almost similar among the brand styles investigated. The maximum transfer rates into mainstream and sidestream smoke were 0.35% and 0.57%, respectively, and almost all ¹³³Cs in tobacco was retained in ash and cigarette butts.