贵州草海耕地土壤重金属污染特征及安全评价

Characteristics and Safety Evaluation of Farmland Soil Polluted by Heavy Metals in Caohai of Guizhou

目前对贵州威宁县草海生态区重金属污染状况的研究还很少,为更好的促进草海生态区环境的可持续发展,了解草海生态区土壤重金属的污染状况,本文对草海生态区主要农业区耕地土壤样品进行了分析和测定,依据国家《土壤环境质量标准》(GB15618-1995)二级标准作为评价标准,分析了对土壤环境及人体危害较大的Cd、Cr、Hg、Pb、As、Zn等重金属元素的累积和污染程度。结果表明:草海生态区耕地土壤的重金属含量差异较大;土壤污染综合评价值范围在1.79～2.71之间,综合指数为2.12,处于中度污染状态。其中东山村、民族村、大马城村、银龙村和西海村等5个村处于中度污染级别,白马村、郑家营村和出水口等3个村处于轻度污染级别;Cd和Hg的累积污染程度较高,主要可能是由于长期进行不合理土法炼锌所致。

The research was few for heavy metal pollution in Caohai ecological zone of Weining County in Guizhou province. Cultivated soil samples were analyzed and determined in the major agricultural areas of the above men- tioned zone in order to better promote sustainable development of environment and understand the soil pollution by heavy metals in this area. Analysis of the accumulation and pollution of Cd, Cr, Hg, Pb, As and Zn to the soil en- vironment and human beings was made, by contrast with the national standard II of ＂soil environmental quality standards＂ （GB15618-1995）. The results showed that the farmland soil heavy metal pollution was different in Cao- hai ecological zone. The comprehensive evaluation values of soil pollution range from 1.79 to 2.71, with the com- posite index of 2.12, in moderately polluted situation. Five villages were in at a moderate polluted level and three villages were at a low level. The accumulated pollution of Cd and Hg were higher, mainly caused by zinc smelting in a long time.