Bennett J P, Chiriboga E, Coleman J, Waller D M
Biological Resources Division, US Geological Survey, Institute for Environmental Studies, University of Wisconsin, Madison 53705, USA.
Sci Total Environ. 2000 Feb 10;246(2-3):261-9. doi: 10.1016/s0048-9697(99)00464-7.
Wild rice grain samples from various parts of the world have been found to have elevated concentrations of heavy metals, raising concern for potential effects on human health. It was hypothesized that wild rice from north-central Wisconsin could potentially have elevated concentrations of some heavy metals because of possible exposure to these elements from the atmosphere or from water and sediments. In addition, no studies of heavy metals in wild rice from Wisconsin had been performed, and a baseline study was needed for future comparisons. Wild rice plants were collected from four areas in Bayfield, Forest, Langlade, Oneida, Sawyer and Wood Counties in September, 1997 and 1998 and divided into four plant parts for elemental analyses: roots, stems, leaves and seeds. A total of 194 samples from 51 plants were analyzed across the localities, with an average of 49 samples per part depending on the element. Samples were cleaned of soil, wet digested, and analyzed by ICP for Ag, As, Cd, Cr, Cu, Hg, Mg, Pb, Se and Zn. Roots contained the highest concentrations of Ag, As, Cd, Cr, Hg, Pb, and Se. Copper was highest in both roots and seeds, while Zn was highest just in seeds. Magnesium was highest in leaves. Seed baseline ranges for the 10 elements were established using the 95% confidence intervals of the medians. Wild rice plants from northern Wisconsin had normal levels of the nutritional elements Cu, Mg and Zn in the seeds. Silver, Cd, Hg, Cr, and Se were very low in concentration or within normal limits for food plants. Arsenic and Pb, however, were elevated and could pose a problem for human health. The pathway for As, Hg and Pb to the plants could be atmospheric.
世界各地的野生稻样本被发现重金属含量升高，这引发了对其对人类健康潜在影响的担忧。据推测，威斯康星州中北部的野生稻可能因大气、水和沉积物中的某些元素暴露而含有较高浓度的重金属。此外，此前尚未对威斯康星州野生稻中的重金属进行研究，因此需要进行基线研究以供未来比较。1997年9月和1998年9月，从贝菲尔德、森林、朗格拉德、奥奈达、索耶及伍德县的四个地区采集了野生稻植株，并将其分为根、茎、叶和种子四个植物部分进行元素分析。对各地51株植物共194个样本进行了分析，根据元素不同，每个部分平均有49个样本。样本经清洗去除泥土后进行湿法消解，并用电感耦合等离子体质谱仪（ICP）分析银、砷、镉、铬、铜、汞、镁、铅、硒和锌。根中银、砷、镉、铬、汞、铅和硒的含量最高。铜在根和种子中的含量最高，而锌仅在种子中的含量最高。镁在叶中的含量最高。利用中位数的95%置信区间确定了这10种元素种子的基线范围。威斯康星州北部的野生稻种子中营养元素铜、镁和锌的含量正常。银、镉、汞、铬和硒的浓度很低或在食用植物的正常范围内。然而，砷和铅的含量升高，可能对人类健康构成问题。砷、汞和铅进入植物的途径可能是通过大气。
