农用地土壤重金属分布特征与污染分析

Distribution Characteristics and Pollution Analysis of Soil Heavy Metals in Agricultural Land

为探讨国内农用地土壤环境污染问题,本文利用已经公开发表的文献数据,借助环境污染指数(PI)、Nemerow综合污染指数、单因素方差分析等方法,对农用地土壤Cr、Cu、Cd、Pb、Zn5种重金属分布特征和污染状况进行分析.结果表明:(1)我国农用地(样地)土壤重金属含量分布特征存在空间分布及种植类型等方面的差异,重金属含量平均值均在国家农用地土壤风险筛选值最高允许浓度标准限定之内.(2)基于区域土壤环境背景值的污染状况分析表明,研究区农用地(样地)土壤出现不同程度的污染现象;基于国家农用地土壤风险筛选值的污染状况分析表明,研究区仅个别农用地(样地)土壤Cd出现污染,Cr、Cu、Pb、Zn未达到污染水平,不同区域农用地(样地)土壤综合污染指数大小依次为:华中>西南>华南>华东>西北>东北>华北,不同种植区农用地(样地)土壤综合污染指数大小依次为:蔬菜种植区>果园>粮食作物种植区>药材园>其他园>茶园.

In order to discuss the soil environmental pollution of agricultural land in China, the distribution characteristics and pollution status of the five heavy metals Cr, Cu, Cd, Pb and Zn in the soil of agricultural land were analyzed by using the published literature data and the methods of environmental pollution index(PI),Nemerow comprehensive pollution index and single-factor analysis of variance. The results showed that:(1) The distribution characteristics of heavy metal content in soil of agricultural land(sample land) in China were different in spatial distribution and planting types, and the mean value of heavy metal content was within the limit of the maximum allowable concentration standard of soil risk screening value of national agricultural land.(2) Analysis of soil pollution status based on the regional soil environmental background value showed that the agricultural land(sample land) in the study area had different degrees of soil pollution;The pollution status analysis based on the soil risk screening value of national agricultural land showed that only a few agricultural land(sample land) in the study area had soil Cd pollution, while Cr, Cu, Pb and Zn did not reach the pollution level. The comprehensive soil pollution index of agricultural land(sample land) in different regions was: in Central China>Southwest China>South China>East China>Northwest China>Northeast China>North China, the comprehensive soil pollution index of agricultural land(sample land) in different planting areas was in the order of: vegetable planting area>orchard>grain crop planting area>medicinal herb garden>other garden>tea garden.