Po-210 AND Pb-210 ACTIVITY IN CHINESE CIGARETTES

The radon decay products lead-210 (Pb-210) and polonium-210 (Po-210) are known components of tobacco. China is the world's largest producer and consumer of cigarettes, yet no comprehensive published reports of the Pb-210 and Po-210 activity concentrations in Chinese cigarettes are available. Twelve brands of cigarettes that were commonly smoked within a group of 184 Chinese smokers were selected for Ph-210 and Po-210 activity analysis. For each brand, the tobacco from two cigarettes was isolated, dried, weighed, spiked with a (209)po tracer for yield, and digested with concentrated HNO3, followed by HCl. The polonium in each digested solution was spontaneously deposited onto a nickel disc. The polonium activity was then counted rising alpha spectroscopy. The mean (range) Po-210 activity for all brands was 23 (18-29) mBq cig(-1). The state of radioactive equilibrium between (210)To and Pb-210 in each cigarette was verified in three brands of cigarettes. Cigarettes from two brands were smoked on a machine in order to estimate the fraction of Pb-210 and Po-210 inhaled. An average of 8% of the Pb-210 and 13% of the Po-210 in the tobacco of the cigarettes was transferred to the mainstream smoke. It is thus estimated that a person smoking 20 of these cigarettes per day in China would inhale a mean (range) of 37 (29-46) mBq d(-1) of Pb-210 and 60 (47-75) mBq d(-1) of Po-210. Cigarette smoking in China may therefore be a large source of a person's daily intake of Pb-210 and Po-210.Environmental SciencesPublic, Environmental & Occupational HealthNuclear Science & TechnologyRadiology, Nuclear Medicine & Medical ImagingSCI(E)9ARTICLE5543-5499