Abstract:
In order to explore the distribution characteristics of Cd pollution in cultivated land soil in karst areas, 2503 samples were collected from the topsoil of cultivated land in Wudang District, so as to measure the mass fraction and pH value of Cd. Statistical methods and geo-statistical theory were used to analyze the measured data. The present situation of pollution in cultivated land soil in this area was evaluated by using pollution index of Cd, soil comprehensive pollution accumulation index and comprehensive potential ecological hazards of Cd. The principal component analysis method was used to explore the source of pollution. The results show that: ① The average value of the measured mass fraction of Cd in the whole region is 0.426 mg·kg
−1, which exceeds the national soil heavy metal pollution screening value (0.400 mg·kg
−1), but does not exceed the background value of Guizhou Province (0.659 mg·kg
−1); ② The results of the regional comprehensive pollution index of Cd demonstrate a mild pollution grade; the soil comprehensive pollution accumulation index is evaluated as a safety grade; and the environmental threat of Cd is a mild ecological hazard; ③ Natural soil parent material is the main source of Cd in the study area, and some high pollution points are greatly caused by human activities.