连云港市典型蔬菜基地土壤中重金属和有机氯污染调查与评价

摘要

对连云港市3个典型蔬菜基地土壤中汞、铅等金属元素以及六六六、DDT和 BaP 等20种污染因子进行了调查，采用单因子污染指数、内梅罗污染指数及综合污染指数等相结合的方法进行了评价。结果表明，部分点位 Pb 和 DDT等含量超标，蔬菜基地土壤环境质量处于尚清洁或污染状态，已不能满足食用农产品生产的需求。大部分点位重金属含量高于江苏和全国黄棕壤土壤环境自然背景值，其中 Cd、Zn比背景值高近一倍，已经达到污染警戒水平，需查明 Hg、Cd、Zn、有机氯等污染来源。土壤中有机质含量较低，达到很缺乏级别。%Soil samples collected from three typical vegetable bases in Lianyungang were analyzed to determine concentrations of 20 kinds of pollutants,such as heavy metals,Organochlorine Pesticides and benzo(a)pyrene.Single pollution index,Nemerow index and comprehensive pollution index for different pollutants were calculated.The results showed that pollution indexes of Pb and DDT were higher than standard concentration,leading to a 'polluted'level for the vegetable bases investigated,indicating that the quality of soil could not meet the demand for vegetables.Concentrations of heavy metal at most sites were higher than background values. Cd,Zn levels were nearly twice as high as the background values,leading to an 'alarming'level.Pollution sources of Hg,Cd,Zn and organic chlorine should be identified.Organic matter content of the soil were very low,belong to 'lacking'levels.