绵阳市主要蔬菜基地土壤重金属污染特征与评价

On Heavy Metal Contamination Characteristics of Vegetable Base and Their Assessment at Mianyang

采用地球化学元素背景值与绵阳浅层土壤元素背景值,按照地积累指数法与土壤重金属元素污染评价标准,对绵阳市主要蔬菜基地土壤重金属污染进行评价.结果表明:采用不同背景值得到相似的评价结果,研究区九岭镇蔬菜基地Zn为轻度污染,主要来自人为活动直接贡献;Cd为轻度污染,考虑为人为直接活动以外贡献;金峰镇蔬菜基地Cr、Cd为警戒水平,主要来自人为活动以外贡献;刘营镇蔬菜基地Zn、Cr为警戒水平,部分地区Cd为警戒-轻度污染,主要来自人为活动以外贡献.

This article uses the index of geo -accumulation and soil heavy metal contamination evaluation standard,and index of geo-accumulation and shallow soil element background values of Mianyang to evaluate the heavy metal contamination of the major vegetable base in Mianyang. The results showed that：Using different background values leads to similar evaluation results,so the Zn of vegetable base in the study area,Jiuling Town, is lightly polluted resulted from contribution of human activities,Cd from outside man-made factors. Cr,Cd of vegetable base at Jingfeng Town belong to the alert level and the pollution is from outside man-made factors. Cr of vegetable base at Liuying Town is involved in alert level,and the parts of Zone Cd are alert-light pollution from outside man -made factors. Research shows that human activities and environment pollution affect heavy metal contamination in the studied area.