Geogenic distribution and baseline concentrations of Cu and Zn in surficial soil of Guiyang, China

摘要

This paper describes the environmentally geochemical characteristics of heavy metal pollutants such as Cu and Zn in the surficial soil of Guiyang, the capital city of Guizhou Province. The baseline concentrations of heavy metals in soil and the geochemical norms have been established to distinguish natural or artificial influence on the environment. Using the statistically analytical methods, we have established the baseline of Cu in Guiyang (18.8 mg/kg) and the soil (over 68.4 mg/kg) may suffer Cu contamination. The data of Zn are 46.3 mg/kg and 112.0 mg/kg. Geoaccumulation index analysis indicated that the surficial soil that has suffered non-pollution to mid-pollution of Cu accounts for 38%, 38%, and 22% for mid-pollution, and only 2% between mid-pollution to severe pollution. Surficial soil that has suffered non-pollution to mid-pollution of Zn accounts for 41%, 50%, and 7% for mid-pollution, and only 2% between mid-pollution to severe pollution. The maximal degree of Cu contamination is 5.09 in the surficial soil of Guiyang. Surficial soil that has not suffered Cu pollution accounts for 53.2%. The total pollution degree of Cu is slightly over zero. So the surficial soil of Guiyang has suffered slight Cu pollution. The maximum value of Zn contamination degree is 2.85 in the surficial soil of Guiyang. 77.8% of the surficial soil has not yet suffered any Zn pollution. The total pollution degree of Zn is less than zero. So the surficial soil in Guiyang is free from pollution of Zn.