Distribution of Polonium-210 in the Human Lung

Abstract

210Po was measured in the tracheobronchial tree and parenchyma of cigarette smokers and nonsmokers to determine whether this .alpha. emitter is retained in smokers. The ratio of 210Po concentration in the tracheobronchial tree (T) to that in the lung parenchyma (P) in nonsmokers is T/P = 2.7 .+-. 0.5. The ratio in smokers is T/P = 1.1 .+-. 0.2. The difference in these ratios can be related to retention of 210Po or its 210Pb precursor in the parenchymal tissue. About 5 pCi deposited and retained on alveolar surfaces and an average excess of 0.3 pCi 210Po retained on the tracheobronchial tree is estimated for smokers. Measurements in ex-smokers result in a ratio (T/P) = 0.8 .+-. 0.4, possibly related to long-term retention of deposited 210Pb in alveolar tissue. [This study is relevant to lung cancer etiology.].