铅锌矿区附近大气沉降对蔬菜中重金属积累的影响

Effect of atmospheric deposition on heavy metal accumulation in vegetable crop near a lead-zinc smelt mine

为了解大气污染环境下大气沉降对农作物重金属积累的影响,选择离某一铅锌矿区不同距离的3个具有不同大气沉降强度的试验点,采用覆膜和露天对比研究3种不同重金属污染土壤上和水培条件下生长的大白菜(Brassicacampestris ssp.Pekinensis)中重金属的积累状况.结果表明,大气污染强度和土壤污染强度对大白菜地上部分重金属积累均有明显的影响.土培试验中露天条件下生长的大白菜地上部分重金属元素Cd、Pb、Hg、Zn和Cu的浓度比覆膜条件下平均高152.63%、129.52%、90.64%、10.01%和0.44%;水培试验的相应值分别为342.83%、476.20%、257.58%、12.00%和8.33%.铅锌矿区附近大气沉降对大白菜地上部分Cd、Pb和Hg等重金属积累有直接的作用.

Several pot experiments were done to test the contribution of soil pollution and atmospheric deposition to heavy metal accumulation in Chinese cabbage （Brassica campestris ssp. Pekinensis） in order to understand the effects of atmospheric deposition on heavy metal accumulation in the vegetable. The experiments were carried out in three sites with different heavy metal intensity of atmospheric deposition, which were 100, 500, and 1 000 m away from a lead-zinc smelt mine, respectively. Both hydroponic and soil pot culture experiments at each experimental site were conducted under the conditions of open air and plastic film cover. The results showed that both intensities of soil and atmospheric heavy metal pollution had significant effects on heavy metal accumulation in above-ground part of the vegetable. For soil pot culture experiment, the accumulations of Cd, Pb, Hg, Zn and Cu in above-ground part of the vegetable under the open air condition were 152. 63%, 129.52%, 90.64% , 10.01% and 0.44 % higher than those under the plastic film cover condition. For hydroponic pot culture experiment, the accumulations of Cd, Pb, Hg, Zn, and Cu in above-ground part of the vegetable under the open air condition were 342.83%, 476.20%, 257.58%, 12.00% and 8. 33% higher than those under the plastic film cover condition. It is suggested that atmospheric deposition has direct effect on the accumulations of Cd, Pb and Hg in above-ground part of the vegetable.