江西某蔬菜基地土壤重金属污染现状

根据表层土、深层土的采样研究资料,获取了江西某蔬菜基地的土壤主要重金属元素基准值,分析了5种重金属元素在该区表层土中的分布、分配及相关特点,分析了元素的迁移特征。对该蔬菜基地的土壤重金属污染现状作了初步评价,并提出了合理调整的相关建议。研究发现,该蔬菜基地表层土(耕作土层)中Cd、Hg、Pb存在明显的积聚现象。局部地段土壤中已超出了农业部颁发的无公害蔬菜产地以及绿色食品产地土壤环境质量标准,成了"不安全生产区"。同时发现区内重金属含量本底值并不高,重金属的污染积蓄主要与人类生产活动有关,可能来源于长期不合理的施肥与喷药。

THE PRESENT SITUATION OF SOIL HEAVY METAL POLLUTION IN A VEGETABLE BASE OF JIANGXI PROVINCE

Based on sampling data from soil of deep and top layers,the authors obtained the standard contents of main heavy metallic elements in soil of a vegetable base in Jiangxi Province,analyzed the distribution and relevant characteristics of five heavy metallic elements in top soil of this base,and probed into the migration features of these elements.According to related laws and decrees issued by the Ministry of Agriculture,this paper preliminarily evaluated the present situation of soil heavy metal pollution in this base and put forward the proposal that the scope of this vegetable base should be reasonably regulated.The research reveals that there exists obvious accumulation of Cd,Hg and Pb in top soil(farming layer) of this vegetable base.Some areas have become "safeless production places" with the Cd,Hg and Pb contents of soil in excess of the Environment Quality Standard for Harmless Food Production Places stipulated by the Ministry of Agriculture.It is found that the original contents of heavy metallic elements in soil are not high,that the accumulation of heavy metallic pollution results mainly from the productive activity of mankind,i.e.,from the prolonged unreasonable application of fertilizer and pesticide.