重庆市南川区东部水稻根系土重金属含量特征与来源

对重庆市南川区东部地区水稻土壤中As等7种元素进行采样监测，采用加权综合指数等方法对土壤环境质量进行评价，并对土壤重金属来源进行解析。结果表明，土壤中重金属Hg、Cr、Cu、Pb和Zn等元素均未超过国家农用地土壤标准筛选值，As和Cd分别有1和5个样品超标，总体呈重污染状态及中等危害生态风险，Cd为最主要的生态风险因子。土壤中Cr、Cu、Pb、Zn和As重金属主要来源于成土母质，Hg主要来源于铝冶炼，Cd受成土母质和农业活动共同控制。 

Characteristics and Source of Heavy Metal Contents in Rice Root Soils in Eastern Nanchuan District of Chongqing City

Seven kinds of elements such as As in rice soil in the eastern part of Nanchuan district of Chongqing were sampled and monitored.Soil environmental quality was evaluated by weighted composite index and sources of heavy metals in soil were analyzed.Results showed that contents of heavy metals such as Hg，Cr，Cu，Pb and Zn in the soil did not exceed national standard for soil use of agricultural land.One and five samples of As and Cd exceeded the standard，and overall situation was heavy pollution and medium-risk ecological risk.Cd was the most important ecological risk factor.Heavy metals of Cr，Cu，Pb，Zn and As in the soil were mainly derived from parent material，and Hg was mainly derived from aluminum smelting，Cd was jointly controlled by parent material and agricultural activities.