[Corresponding analysis on rice grain heavy metal pollution in Fujian province]

By the methods of environmental statistics and corresponding analysis, this paper collected 38 early and late rice grain samples from the middle, southern, northern, western and eastern parts of Fujian Province to detect their Hg, As, Cr, Cd and Pb contents, and to search for the main factors resulting in the difference of rice cropping type in different regions, aiming at further understanding the relationships between heavy metal pollution and rice cropping type. The results showed that among the test heavy metals in grain, Pb had the highest percentage (100%) beyond the standard level, followed by Hg (78.95%), Cd (50.5%) and Cu (2.63%), while As did not surpass the standard level. It therefore could be concluded that Pb and Cd were the main factors resulting in the difference of rice cropping type in different regions. The results also showed that 38 rice grain samples could be clustered into 7 groups, indicating that different rice cropping types would significantly cause different degrees of heavy metal pollution, which suggested that the best way in controlling and preventing rice grain heavy metal pollution could be the approach of combining site-controlling with variety selection, based on the situation of different regions and rice cropping systems.