上海市浦东新区蔬菜地土壤重金属含量及评价

本文对上海市浦东新区非污灌区4个蔬菜园艺场和2个污灌区土壤中的7种重金属进行总量分析,以国家土壤环境质量二级标准评价其单项和综合污染指数,结果表明:4个蔬菜园艺场各个重金属的两项指数均<1,评价结果均为优良,这4个蔬菜园艺场符合无公害食品生产的土壤环境要求。污灌区9个土壤样的Pb、Cr、As单项污染指数<1,Cd、Cu、Zn、Hg的单项和综合污染指数均>1,尤其是Cd污染最为严重,单项污染指数最高达6.6,综合污染指数4.84;所调查的9个土壤样中33%为中污染,67%为重污染,该污灌区蔬菜地土壤污染主要来源于上世纪70年代应用黄浦江疏浚底泥(吹泥),污水灌溉和乡镇企业的化工污染物扩散。

HEAVY METAL CONTENTS IN AND EVALUATION OF VEGETABLE SOILS IN PUDONG NEW DISTRICT OF SHANGHAI

Concentrations of heavy metals in soils of 4 truck gardens and 2 sewage-irrigated zones in Pudong, Shanghai were determined. Evaluation was made of indexes of single contaminants and combined pollution according to the national standard for evaluation of soil environmental quality. Both values of the 4 gardens were less than 1, indicating that they meet the requirements of soil environment for producing hazard-free food. Nine soil samples collected from the two sewage irrigated regions, the indexes of monomial and synthetical pollution of Pb, Cr and As were less than 1, and of Cd, Cu, Zn and Hg were more than 1, especially those of Cd, the most serious one, which were 6.6 and 4.84, respectively. About 33 % of the 9 soil samples were moderately polluted and 67 % seriously polluted. The cause of the pollution is the application of sewage sludge from the Huangpu River and chemical pollution from village enterprises.