A Study of the Differences in Heavy Metal Distributions in Different Types of Farmland in a Mining Area

To investigate the effects of different types of land use and soil depths on the distributions of heavy metals in the soil in mining areas, heavy metals in different soil layers of five types of agricultural land in the Tongguan gold mining area were studied. The results revealed that the land use type had a greater impact than soil layers on the distribution of heavy metals in the soil. Among the five types of agricultural land examined, the risk values were only exceeded for the heavy metals lead(Pb) and mercury(Hg) in the pepper field, indicating combined pollution of Pb and Hg. Furthermore, some of the heavy metals, such as Pb, zinc(Zn), cadmium(Cd) and Hg, were highly significantly and positively correlated with each other. The pepper field should be monitored to prevent pollution from other heavy metals.