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| Heavy metal pollution characteristics and assessment of rice grain from a typical high risk area of Changshu City, Jiangsu Province. |
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Abstract In order to concern about safety of food from Yangtze River Delta, one of rapidly developing regions in China, 155 rice grain samples were collected from high risk area in 10 towns of Changshu City in South Jiangsu in 2005. Analysis methods of ICP-AES and HG-AFS were used to determine content of Cd, Cr, Cu, Pb, Zn, Ni, Hg and As in rice flesh and hull samples. According to relative national standards of China and human health risk assessment, pollution and safety of rice flesh and hull in study area were evaluated. There was an identity between the sequence of heavy metals in rice flesh and hull of 10 study towns, and the distribution characteristics of some metals in rice flesh and hull of these towns were different. Some heavy metals in rice flesh were correlated with them in hull, especially Cu, Zn and Ni. Pb, Hg, As and Cd in some rice flesh were above the national standards when evaluated with single factor index method. Pb exceeded the standard seriously by 29.7%, followed with Hg (20.6%). As and Pb in some hull were above the national standards, they exceeded their standards by 3.2% and 1.3%, respectively. The composite pollution indexes of rice flesh ranged from 0.30 to 3.50, and 28.4% of them were contaminated with metals. The highest arithmetical mean composite pollution index (1.42) was found in Xingang town, which could be categorized as light pollution. However, other towns could be regarded as no pollution from the means of them. The composite pollution indexes of hull ranged from 0.15 to 2.46, and 3.2% of them were polluted. From the means all towns were in security. Results of exposure risk assessment for the rice flesh suggesting that rice grown in Changshu posed Cu and Zn potential risk to food safety and rice from some towns possessed Pb potential risk.
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Received: 29 July 2008
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