轻度砷污染耕地中作物重金属富集特征分析OA

To investigate the enrichment characteristics of heavy metals in crops grown in mildly arsenic(As)-contaminated cultivated soils,this study,the contents of Cd,Hg,As,Pb,Cr,Cu,Zn,and Ni in the topsoil,as well as the contents of Cd,Hg,As,Pb,and Cr in the edible parts of major crops(wheat,rice,lotus root,garlic,and soybean)in Shandong province were measured.The geo-accumulation index,bioconcentration factor,and correlation analysis were employed to assess soil heavy metal contamination and the contents and enrichment characteristics of the heavy metal in crops.The results showed that the exceedance rate of As content in the soil was 12.5％,while the contents of Cd,Hg,Pb,Cr,Cu,Zn,and Ni were all below the corresponding risk thresholds.The average contents of Cd,Hg,As,Pb,Cu,Zn,and Ni were 1.08,1.39,1.46,1.31,1.11,1.18,and 1.38 times of their respective soil background values,respectively.The geo-accumulation index evaluation indicated that Pb,Cr,Cu,and Zn exhibited no contamination at most sampling sites,Cd,Hg,and Ni exhibited mild to moderate contamination at most sampling sites,and As exhibited moderate contamination at most sampling sites.The contents of Cd,Hg,As,Pb,and Cr in the edible parts of all crops were below the permissible limits of food safety standards.Correlation analysis revealed that Cd and Pb contents showed an extremely significantly positive correlation in garlic,lotus root,and soybean,while As and Cr contents showed an extremely significantly positive correlation in garlic,soybean,wheat,and rice.Enrichment characteristic analysis demonstrated that lotus root,rice,and soybean had low enrichment capacities for Hg,and the enrichment capacity of lotus root for Cd,Pb,and Cr was much lower than that of the other crops.Correlation analysis between the heavy metal contents in the edible parts of crops and those in the soil revealed that the contents of Hg,As,Pb,and Cr in wheat,the contents of As and Pb in garlic,and the content of As in soybean were significantly or extremely significantly correlated with their corresponding heavy metal contents in the soil.In conclusion,the heavy metal contamination level in the cultivated soil was low,enabling the safe production of agricultural products.