摘要：我国土壤污染情况已不容忽视，其中以重金属污染问题最为突出。重金属在土壤中不能被降解，可通过食物链进入人体。当重金属在人体内积累到一定程度时，可对人体健康造成危害。

本文以江苏省镇江市丹徒区312国道旁菜地土壤及其中蔬菜为研究对象，共设置了五个采样点。此次实验通过酸消解法使土壤及蔬菜中的重金属溶出，采用原子吸收火焰法分别测定30个样品中的镉、铬、铅、锌、铜。通过参考《土壤环境质量标准》、

《江苏省土壤元素地球化学基准值》、《食品中污染物限量》、《食品中铜限量卫生标准》和《食品中锌限量卫生标准》，用单因子指数法和内梅罗综合污染指数法对样品的污染水平进行评价。

调查研究结果表明，在利用单因子指数进行评价时，五个采样点土壤的镉元素超标相对严重；除采样点1以外，其余采样点的锌元素轻微超过国家规定的限值；土壤中铬、铅、锌和铜元素未超过国家限值；蔬菜中所测重金属元素铬、铅明显超过国家限值。当采用内梅罗综合污染指数进行综合评价时，所有土壤及蔬菜样品中的重金属含量均严重超标。若长期食用该地区的蔬菜，人体健康可能受到损害。

关键词：土壤；蔬菜；重金属元素；污染

Abstract：China's soil pollution situation can not be ignored, of which the most prominent problem of heavy metal pollution. Heavy metals can not be degraded in the soil and can enter the body through the food chain.

Five sampling points were set up in vegetable field in the area of 312 National Road, Dantu District, Zhenjiang City, Jiangsu Province, in which the soil and vegetables were studied. In this experiment, heavy metals in soil and vegetables were extracted by acid digestion method. Cadmium, chromium, lead, zinc and copper in 30 samples were determined by Atomic Absorption Spectroscopy method. By referring to the "Environmental quality standard for soils ", "Geochemical baseline values of elements in soil of Jiangsu Province ", "Maximum levels of contaminants in foods ",  "Tolerance limit of copper in foods ", "Tolerance limit of zinc in foods", the single factor index and the Nemero comprehensive pollution index were used for evaluating the pollution level of the samples.

The results showed that the cadmium pollution in the five sampling sites  was relatively severe when the single factor index is used. In addition to the sampling point 1, the zinc content of the remaining sampling points was slightly higher than the national limit. Lead, zinc and copper elements did not exceed the national limit; vegetable samples of heavy metal elements in chromium, lead significantly surpassed  the  national limit. When the Nemero comprehensive pollution index was used, the contents of heavy metals in all soil and vegetable samples were seriously exceeded. If the residents eat vegetables in the region for a long term, their health may be damaged.

Keywords: soils; vegetables; heavy metal elements; pollution.

目录

第一章绪 论 1

1.1概述 1

1.2土壤及蔬菜中重金属的污染来源、特点和危害 2

1.2.1土壤及蔬菜中重金属的主要污染来源 2

1.2.2重金属污染特点 3

1.2.3土壤及蔬菜重金属污染的危害 4

1.3重金属的检测方法 5

1.3.1紫外-可见分光光度法（UV） 5

1.3.2原子吸收光谱法（AAS）