上海城郊农田土壤锑含量分布及生态风险

Distribution characteristics and potential ecological risk assessment of antimony in urban suburb farmland soil

采集了上海城郊34块农田的不同深度土壤样品共计443个,测定了锑含量,并用单因子污染指数和潜在生态风险指数进行评价。结果表明,上海城郊农田土壤中锑浓度平均值低于上海土壤环境背景值(0.75 mg/kg),随深度加深而逐渐降低,表层土壤锑平均质量浓度为0.55 mg/kg,超背景值比例为24.11%,中层和深层土壤超背景值比例分别只有9.09%、0.91%。近郊农田的土壤锑含量总体高于远郊,近郊和远郊的单因子污染指数分别为1.14、0.70,分属轻度污染和尚清洁;潜在生态风险指数分别为5.99、3.68,均属轻微风险。近郊农田受城市化进程影响较大,农用地破碎化程度较高,特别是宝山区和嘉定区值得进一步关注。

34 farmlands in Shanghai suburb were chosen to evaluate and 443 soil samples were collected.Then,antimony(Sb)was determined and evaluated using single-factor pollution index and potential ecological risk index.Results showed that the average content of Sb in the study area was lower than the background of soil in Shanghai(0.75 mg/kg).The content of soil Sb gradually declined with the soil depth.The average mass concentration of Sb in the surface soil was 0.55 mg/kg and 24.11%of the samples exceeded the background,while only 9.09%and 0.91%in the middle soil and ground soil exceeded.Sb in the suburb soil was higher than that in the outer suburb.The single-factor pollution index of suburb and outer suburb were 1.14 and 0.70,belonging to slight pollution level and still clean level,respectively.The potential ecological risk index were 5.99 and 3.68,respectively,both belonging to slight risk level.Suburb farmlands were greatly affected by urbanization and had a high degree of fragmentation,especially Baoshan District and Jiading District deserving further attention.