Notice of Retraction: Integrated Assessment on Heavy Metal Pollution of CropLand Soils in the Middle Reaches of the Bi River

Abstract

Research on soil pollution and human health caused by mining activities is an important issue in environmental sciences. Assessing standards and methods of cropland soil pollution play important role in reference of results. Taking the croplands of Chichangping village in the Middle Reaches of the Bi River as research area, this paper measures the contents of four kinds of heavy metals (Pb, Zn, Cd, As) through field sampling and laboratory analysis. Evaluates the pollution degree by using the Soil Background Value of both Yunnan Province and China, and the Standard Value of National Soil Environmental Quality (Grade Π) with three assessing methods: the pollution index, the geo-accumulation index and the potential ecological risk index. The results indicate: (1) the cropland soils of Chichangping village are polluted seriously whatever the soil standard value and assessing methods is used. The pollution order is Cd (severe pollution) >; Pb (light-severe pollution) >; Zn (middle-severe pollution) >; As (no pollution). The polluting sources come from the Lanping Lead-Zinc Mine; (2) The pollution degree is higher with the background value of both Yunnan Province and China than the National Soil Environmental Standard (Grade II). The pollution degree is consistent with the background value of both Yunnan Province and China. Therefore, it is more reasonable to use background value as assessing standards in soil environment quality evaluation. (3) Because heavy metals have different toxic to crops, it is necessary to use the advantage of the pollution index and the potential ecological risk index in assessing soil pollution, and to consider both mean and maximum in using the potential ecological risk index in order to a better understanding of heavy metal pollution.