Contents and Distribution of Pb, Cd and As in Chinese Tobacco Leaves

The contents and distribution of Pb, Cd and As in 497 flue-cured and 17 burley tobacco leaf samples collected from major tobacco production regions of China in 2004 were studied. The results suggested that in most flue-cured tobacco samples, the contents of Pb and Cd were less than 4mg/kg, and the content of As was less than 0.5mg/kg; and Pb and Cd might be the main heavy metals in flue-cured tobacco in China. Burley tobacco has higher Pb and Cd contents than flue-cured tobacco does, while the content of As is higher in flue-cured tobacco; the major factors which influence the accumulation of Pb, Cd and As in tobacco are environment and the background values of these elements in soil, the influence of tobacco cultivar is negligible. Significant differences in Pb, Cd and As contents were observed between samples from different regions, it suggested that the three elements were regionally distributed markedly for Pb and Cd, and less visible for As.