江苏省土壤重金属分布特征与污染源初步研究

A preliminary study of the distribution and pollution source of heavy metals in soils of Jiangsu Province

以24186个表层土壤(0～20cm)和6127个深层土壤(150～200cm)样品之Cd、Hg、Pb、As等含量数据为基础,研究了江苏全省土壤环境的重金属分布与主要污染特征。结果表明,全省自然土壤环境与人为活动土壤环境的重金属元素分布都不均匀,但人为活动土壤环境中的不均衡程度远高于自然土壤环境;全省农田中有1.02%的土壤受到Cd、Hg、Pb等8种重金属的严重污染,苏州市、无锡市土壤环境被重金属污染的程度相对严重;工业化、城市化进程中的人为活动及自然地质作用都是引起江苏局部土壤重金属污染的重要原因,自然成因的重金属污染土壤多呈面状、多元素、低强度、双层污染等特点,从而与人为成因的重金属污染土壤有所区别。

Based on data of 24186 topsoil （0-20 cm in depth） and 6127 deep soil （150-200 cm in depth） samples from whole Jiangsu which contain such elements as Cd, Hg, Pb, As, Cu, Zn, Cr, and Ni, the authors studied the distribution and pollution characteristics of heavy metals in soils by analyzing their spatial variation and pollution source. Some conclusions have been reached： First, the spatial distribution of heavy metal elements is relatively uneven within natural environmental softs and anthropogenic environmental softs of Jiangsu, and the nonuniformity in anthropogenic environmental soils is higher than that in natural environmental soils. Second, a part of farmland soils （1.02% or so） has been badly polluted by some heavy metal elements such as Cd, Hg and Pb, and the pollution from Suzhou and Wuxi is the most severe in all soils of Jiangsu Province. Third, human activities in the industrialization and expansion of cities and some natural geological processes with the formation of parent soil are both important factors responsible for local pollution of heavy metals, and there exist obvious differences between man-made pollution and natural pollution in soils. It is thus held that natural pollution of heavy metals is characterized by planar, polymetallic and double-layer soil pollution with relatively low concentration, whereas things are quite different for man-made pollution.