北京市小麦籽粒的重金属含量及其健康风险分析

Concentrations and risk of heavy metals in grain of wheat grown in Beijing

为评价北京市小麦重金属含量及其健康风险,采集北京市现有小麦种植区土壤和小麦籽粒对应样品68份,分析其重金属含量,并估算消费导致重金属摄入量。结果表明:北京市麦地土壤重金属As、Cd、Cr、Cu、Ni、Pb和Zn的平均值分别为7.46、0.165、37.8、20.3、24.2、14.3和70.1mg/kg,处于比较清洁水平。这说明小麦种植这种土地利用方式并不会导致土壤重金属升高。小麦籽粒中重金属含量,除Cr与食品卫生标准限值没有显著性差异外,其他元素均显著低于相应标准限值。普通人群通过小麦制品消费,As、Cd、Cr、Cu、Ni、Pb和Zn的摄入量分别为0.005、0.004、0.136、0.994、0.041、0.024、4.75mg/人.d。北京小麦种植的主要4个区中,顺义产小麦的Cr、Cu、Ni和Pb导致的重金属摄入量高于其他3个区,房山产小麦导致的重金属摄入量最低。对于普通人群而言,通过小麦和蔬菜摄入重金属没有明显风险。

Soil and wheat samples in wheat-planted area in Beijing were collected for assessing the concentration and health risk of heavy metals.The results show that the average concentrations of As,Cd,Cr,Cu,Ni,Pb and Zn in the soils from wheat fields are 7.4,0.165,37.8,20.3,24.2,14.3 and 70.1 mg/kg,respectively,which are lower than the baseline concentration of soil from Beijing.It shows that planting wheat did not definitely increase the concentrations of heavy metals in soil.The average concentrations of As,Cd,Cr,Cu,Ni,Pb and Zn in wheat are 0.032,0.031,0.967,7.05,0.293,0.17 and 33.7 mg/kg,respectively.The concentrations of As,Cd,Cu,Ni,Pb and Zn are significantly less than the maximum levels of Food Hygiene Standards of China,and there is no significant difference between Cr concentration in wheat and the maximum Cr level of Food Hygiene Standards.Among the heavy metals,the accumulating ability of wheat for Zn is the best and that of As is the weakest.The average intake rates of As,Cd,Cr,Cu,Ni,Pb and Zn from wheat for people lived in Beijing are 0.005,0.004,0.136,0.994,0.041,0.024 and 4.75 mg/（person day） and there is no significant risk caused by heavy metals intake for common residents in Beijing from staple and vegetables according to the average concentrations of metals and the average consumption.Among the districts of Shunyi,Fangshan,Daxing and Tongzhou,the largest wheat planted areas in Beijing,the average intake rates of Cr,Cu,Ni and Pb in wheat from Shunyi District are higher than those from the other three districts,while the average heavy metal intake rate of wheat from Fangshan is the lowest.