长江流域(安徽段)土壤-作物系统重金属污染特征及健康风险评价

为研究长江流域安徽段土壤-作物系统重金属的污染特征及健康风险，采集了水稻和小麦及其根系土样品338组，测定了8种重金属含量，采用污染指数法、潜在生态危害、多元统计分析和健康风险进行评价.结果表明，水稻根系土和小麦根系土重金属含量均超过江淮流域背景，根系土Cd、 Cu、 Cr和Ni具有明显的积累效应，水稻根系土较小麦土污染严重；潜在生态风险为轻微-中等风险等级，主要来源于Cd和Hg元素.多元统计分析显示Cu、 Pb、 Zn和Cd为工业源和农业源，Cr、 Ni为自然源，As和Hg为农业源.水稻对重金属的吸收富集强度依次分别为：Cd>Zn>Cu>Hg>Ni>As>Cr=Pb,小麦对重金属的吸收富集强度依次分别为：Zn>Cd>Cu>Hg>Ni>As=Pb>Cr;根系土重金属健康风险评估结果显示儿童更易受到重金属污染威胁，经口摄入是发生非致癌风险的主要暴露途径.非致癌风险评价表明小麦根系土对儿童具有一定的非致癌风险，但不存在致癌风险.摄入水稻和小麦对成人和儿童均有一定程度的非致癌风险和不可接受的致癌风险.

Heavy Metal Pollution Characteristics and Health Risk Assessment of Soil-crops System in Anhui Section of the Yangtze River Basin

In order to explore the pollution characteristics and health risks of heavy metals in a soil-crop system in the Anhui section of the Yangtze River basin, a total of 338 groups of soil samples from rice, wheat, and their roots were collected, and the contents of eight types of heavy metals were determined. Additionally, the pollution index method, potential ecological hazard, multivariate statistical analysis, and health risk were used to evaluate the heavy metal content in rice and wheat root soil. The results showed that Cd, Cu, Cr, and Ni in the soil had an obvious accumulation effect, and the pollution of rice root soil was more serious than that of wheat soil. The potential ecological risk was mild to moderate, which mainly came from the elements Cd and Hg. Multivariate statistical analysis showed that Cu, Pb, Zn, and Cd were industrial sources and agricultural sources; Cr and Ni were natural sources; and As and Hg were agricultural sources. The absorption and enrichment intensity of heavy metals by rice was in the order of Cd>Zn>Cu>Hg>Ni>As>Cr=Pb, and those in wheat were ordered as Zn>Cd>Cu>Hg>Ni>As=Pb>Cr. The root soil heavy metal health risk assessment indicated that oral intake was the main exposure route of non-carcinogenic risk, and children were more vulnerable to heavy metal pollution. Non-carcinogenic risk assessment showed that wheat root soil posed non-carcinogenic risk to children but no carcinogenic risk. Intake of rice and wheat had some degree of non-carcinogenic risk and unacceptable carcinogenic risk for both adults and children.