贵州典型汞矿区作物对汞的累积特征及品质差异

为了摸清贵州典型汞矿区作物的受污染状况和汞矿污染对作物品质的影响,采用定点取样和实验室分析相结合的方法研究了贵州典型汞矿区水稻和玉米作物体内的汞累积特征,以及不同汞浓度下的作物品质差异。结果表明:1)汞矿区水稻籽粒的总汞含量为0.14～0.71mg/kg,甲基汞含量为4.85～16.85μg/kg;玉米籽粒中的总汞含量为0.13～0.17mg/kg,甲基汞含量为2.31～3.67μg/kg:总汞含量均高于国家食品安全中的汞限量卫生标准(总汞≤0.02mg/kg)。2)水稻籽粒中的总汞和甲基汞含量普遍高于玉米。3)相关分析表明,不同汞矿区,水稻和玉米中的淀粉和粗蛋白与作物中的汞含量普遍呈负相关,其中,务川汞矿区水稻籽粒中的粗蛋白与总汞和甲基汞含量呈极显著和显著负相关(r=-0.996和-0.972),淀粉与甲基汞含量呈显著负相关(r=-0.964);滥木厂汞矿区玉米籽粒中的粗蛋白与甲基汞含量呈极显著负相关(r=-0.967)。结论:贵州省典型汞矿区的主要粮食作物均受到了不同程度的汞污染,且高浓度的汞含量还影响了作物的物质转化,使水稻和玉米籽粒中的淀粉和粗蛋白含量降低。

Hg Accumulation Characteristics and Quality Differences of Crops in Typical Hg Mining Areas in Guizhou

To investigate mercury accumulation characteristics and the quality difference of rice and maize from Hg mining areas,total mercury(THg),methylmercury(MeHg),protein and amylum were measured in crops samples collected from typical mercury mining areas in Guizhou Province.The results showed that contents of THg and MeHg in rice varied in the ranges of 0.14～0.71 mg/kg and 4.85～16.85 μg/kg respectively.Contents of THg and MeHg in maize varied in the ranges of 0.13～0.17 mg/kg and 2.31～3.67 μg/kg respectively.The THg content in rice and maize was far higher than the national food limited standards.The contents of THg and MeHg in rice were higher than in maize.The correlation analysis showed that the protein and amylum content were normally negatively correlated to the Hg content in crops.The protein content of rice showed significant negative correlation with THg content,and negative correlation with MeHg content,amylum of rice was significantly negatively correlated to MeHg content in Wuchan area.The protein content of maize was significantly negatively correlated to MeHg content in Lanmuchang area.The crops were polluted by Hg in different levels in typical mining areas,substance transformation of crops was affected by high concentrate mercury,which made the contents of protein and amylum decreased in rice and corn.