Relationship Characteristics and Risk Assessment of Heavy Metal Contents in Soil Aggregates and in Crops Around a Typical Pb-Zn Mining Area

The threat that heavy metals in soil aggregates pose to the ecological environment is an issue that should not be neglected. In order to determine the relationship between heavy metals in soil aggregates and those in crops, and to study the potential risk of heavy metals in soil aggregates, a portion of arable land in the Caiyuanhe lead-zinc mining area, which belongs to the section of Mapo lead-zinc mining in Duyun City, Guizhou province, was selected as the study area. The soil sample was collected from the cultivated layer (0-20 cm), and all crops were classified as leaf crops, fruit crops, and grain crops. The various sizes of soil aggregates sieved were>2, 1-2, 0.5-1, 0.25-0.5, 0.053-0.25, and0.53-0.25 mm>0.5-1 mm>2 mm>0.053 mm; ② the enrichment capacity of all the crops included in the study was Cd>Zn>Pb; ③ the Pearson correlation analysis suggested that grain crops could enrich and transfer Pb in soil aggregates of different size, and the Zn in grains mainly originated from soil aggregates with a size of>1 mm; ④ it was also found that soil aggregates of a smaller size presented a greater total potential ecological risk. The order of ecological risk of heavy metals in soil aggregates of the same size was Cd>Pb>Zn. Moreover, the Pb in leaf crops and fruit crops poses a great health risk to children in the study area. © 2021, Science Press. All right reserved.