中文摘要：

就当前各方对土壤污染概念认识的差别进行了讨论，提出以土壤环境背景值、土壤环境质量第二级标准值和土壤污染临界值作为区域和场地土壤污染评价的3类指标的建议。3类指标的取值及含义为：（1）土壤环境背景值上限值：采用当地数值。这是揭示当前土壤是否有污染物进入的临界点，是保持当前土壤良好状态的目标值。若土壤中化学物质含量高于此值，则要警惕，要找出和控制污染源，防止污染物继续进入，以保护土壤环境质量。（2）土壤环境质量标准：采用通用的GB15618第二级标准值。这是初步判断和识别当地土壤是否受污染的筛选值。若化学物质含量低于此值，说明土壤未受污染，不须进行深入调研；若高于此值，则土壤可能受污染，但要依据深入调研或风险评估而定。（3）土壤污染临界值：通过对当地土壤污染的风险评估，得出土壤污染临界值。这是揭示土壤是否受污染的阈值。若化学物质含量高于此值，说明土壤已受污染，应研究提出修复污染土壤与控制污染源的方案。

英文摘要：

Three guidelines are set forth for evaluation of soil contamination at the scale of a region or a specific site in view of ambiguity of the definition for soil contamination at present. The three guidelines, mainly based on chemical levels, are upper limit of soil environmental background ,Grade II criteria of the national soil environmental quality standard （GB 15618 ） and threshoM value of soil contamination. The upper limit of soil environmental background ,which corresponds to the local soil environmental background, is a critical value for discriminating between pedogenic source and anthropogenic inputs of chemicals as well as a target value for protecting the soil environment. If a chemical would be higher than this upper limit, measures should be undertaken in exploration and control of its potential anthropegenic sources in order to protect the soil quality from further impact of these sources. The soil environmental quality standard,which is equivalent to Grade II criteria of the national soil environment quality standard,is a screening level for distinguishing uncontaminated soils from contaminated soils preliminarily. If the level of a chemical in the soil is lower than this standard,it indicates that the soil is not contaminated. Otherwise,the soil might be contaminated potentially and further investigation and/or risk assessments of the eco-environment and human health should be recommended. The threshold value of soil contamination, which could be acquired through risk assessment of the problem soil, is a critical value for determining whether the soil is contaminated or not. Beyond this value, the soil is contaminated and countermeasures should be undertaken to control the pollutant sources and remedy the contaminated soil.