皖北煤矿区农田土壤-小麦中重金属分布特征 及健康风险评价

为了研究矿区农田土壤-小麦中重金属分布及农作物中重金属的迁移特征,以皖北恒源煤矿为研究对象,在矿区范围内采集了16个农田土壤和对应的小麦样品进行测试分析,应用内梅罗指数法评价了矿区内农田土壤重金属的污染状况,采用回归模型分析研究土壤根系、根系茎籽粒中重金属的迁移转化,并利用靶标危害系数法评价了小麦籽粒中重金属对人身健康的影响。研究结果表明:研究区农田土壤中的Cu、Zn、Mn、Pb、Hg、Cd、As、Cr和Ni等8种重金属元素含量低;小麦籽粒中重金属含量也未超出标准限量值;在小麦根、茎、籽粒等器官中,Mn、Pb、Cd、As、Cr和Ni在小麦根部含量最大,Hg较多地分布在小麦的茎中,Zn和Cu更易向上迁移至小麦的籽粒中;小麦籽粒中的Pb、Hg、Cd、As和Cr等重金属的单一重金属元素的靶标危害系数THQ和多种重金属元素的复合危害系数TTHQ均小于1。

Distribution characteristics and health risk assessment of heavy metals in farmland soil and wheat in coal mining area of Northern Anhui

In order to study the distribution of heavy metals in farmland soil and wheat and the migration characteristics of heavy metals in crops,the Hengyuan Coal Mine in Northern Anhui was taken as the research object,16 farmland soil and corresponding wheat samples collected in the mining area were tested and analyzed,and the pollution state of heavy metals in farmland soil in the mining area was evaluated by Nemerow index method.The migration and transformation of heavy metals in soil-root system and root-stem-seed were studied by regression model,and the impact of heavy metals in wheat grains on human health was evaluated by target hazard coefficient method.The results showed that the content of nine kinds of heavy metal elements in farmland soil in the study area was low,including Cu,Zn,Mn,Pb,Hg,Cd,As,Cr and Ni;heavy metal content in wheat grains did not exceed the standard limit value;the contents of Mn,Pb,Cd,As,Cr and Ni were the highest in the roots,Hg was more distributed in the stems of wheat,and Zn and Cu were more likely to migrate up to the wheat seeds;THQ and TTHQ of heavy metals in wheat grains such as Hg,Cd,As and Cr were all less than 1.