Research on the Linear Comprehensive Evaluation Model of Heavy Metals in Tobacco Leaf

Due to the limited standard of heavy metal on tobacco was not released, both at home and abroad, for producing heavy metal-low risk cigarettes through controlling the raw material procurement and leaf group formula, the heavy metal level in tobacco leaf should be quantitatively characterized among regions. The heavy metal content of Cr, Ni, As, Cd, Se, Hg, and Pb in 1 200 samples of tobacco leaves from 114 counties of 12 provinces was determined by the method of ICP-MS. Based on comprehensive evaluation model of index sum, four comprehensive evaluation indexes (CEIs) was determined, and their regiospecificity was compared by statistical parameters. A map of ArcGIS geostatistic distribution was drew, and the reason to its spatial distribution was analyzed. Results indicated that:(1) The four CEIs were generally notably consistent, but the CEI, composed by range transformation method and analytic hierarchy process (Tdc), presented optimal specificity because of itself characteristics. (2) The Tdc-ArcGIS geostatistic analysis indicated that some eastern provincesthe provinces of Shandong, Anhui, Jiangxi and Fujian(except Songxi Nanping) showed a relatively low comprehensive level of heavy metal in tobacco leaf (CLHMT), but some central and south provinces (the provinces of Chongqing, Guizhou, Hunan, Guangxi and Yunnan) were relatively high, especially Hunan and Yunnan provinces. (3) The CLHMT had a big regional difference, and its distribution was consistent with our country's metal mine, mining and other industrial and agricultural pollution of heavy metal may be an important factor to lead to a higher CLHMT. (4) The map of geostatistic distribution and the Tdc data can be used as qualitative and quantitative judgment formula for cigarette industrial enterprise in raw materials procurement and leaf group formula.