【摘要】 上海市大金山岛由于自然地理隔离的因素,受到人为侵扰较少,是上海市最大的乡土植物基因库。然而,重金属等污染物通过大气传输,在土壤中富集,造成土壤污染。本文对大金山岛土壤铅(Pb)、镉(Cd)、铜(Cu)、锌(Zn)浓度进行测定,以上海城市绿地土壤为对照,对比2012年大金山岛土壤测定结果进行对比分析。结果表明:(1)大金山岛土壤Pb、Cd、Cu、Zn浓度分别为36.2±10.3、0.9±0.5、52.1±63.7、91.0±62.2 mg/kg,Cd、Cu和Zn浓度显著低于城市绿地,但是Pb浓度显著高于城市绿地;与2012年相比,大金山岛土壤Pb、Cd和Cu浓度分别提高32.1%、350%和141%,Zn浓度降低6.5%;对比我国《土壤环境质量标准》一级标准,大金山岛土壤Pb、Cd、Cu、Zn超标率分别为50.0%、91.7%、76.2%和34.5%。(2)大金山岛土壤Pb、Cd、Cu、Zn浓度之间具有显著的正相关关系,但是时间变化规律不一致;土壤重金属的空间分布特征与潜在污染来源方向不符,西北部浓度较低而中部较高。(3) 2012年至2017年,大金山岛土壤总体污染水平从轻微生态危害程度上升到中等生态危害程度,主要污染物种为Cd。大金山岛Cd的污染加剧情况急需引起相关海洋及其岛屿生态与环境保护部门的重视,也需要进一步的治理措施加以防治。更多还原

【Abstract】 As an uninhabited island,Dajinshan island is not directly disturbed by human activities,but it has the potential of being affected by atmospheric deposition.In order to quantify the effect of human activities on soil changes in Dajinshan island,the concentrations of lead(Pb),cadmium(Cd),copper(Cu),zinc(Zn) and relevant physio-chemical properties of soil,were determined in 2017.The properties of urban greening soil and the values determined in 2012 were used as comparison.The results showed that:(1) The soil concentrations of Pb,Cd,Cu and Zn in Dajinshan island were 36.2±10.3,0.9±0.5,52.1±63.7 and 91.0±62.2 mg/kg,respectively.The concentrations of Cd,Cu and Zn were significantly lower than the values of urban green land but the concentration of Pb was significantly higher.Compared to the values determined in 2012,the concentrations of Pb,Cd and Cu were 32.1%,350% and 141% higher,respectively,but the concentration of Zn was 6.5% lower.Compared to the environmental quality standard for soils(GB 15618—1995),the percentages of exceedance for Pb,Cd,Cu and Zn were 50.0%,91.7%,76.2% and 34.5%,respectively.(2) The concentrations of heavy metals were positively correlated,but their temporal patterns were different.The spacial distribution of heavy metals were inconsistent with the direction of the potential emission source.(3) The potential ecological risk of heavy metal in Dajinshan island has increased from low level in 2012 to moderate level in 2017.Cd showed the highest potential ecological risk.更多还原