Cd Pb Cu Zn As复合污染对水稻的影响

Compound Pollution of Cd, Pb, Cu, Zn and As on Lowland Rice.

应用田间试验和盆栽试验，研究Ｃｄ、Ｐｂ、Ｃｕ、Ｚｎ、Ａｓ复合污染在草甸棕壤上对水稻产量及元素含量的影响。结果表明，在接近土壤环境质量标准低浓度水平下，水稻发育正常，减产幅度＜１０％，但土壤Ｃｄ、Ｐｂ临界值下降，籽实中Ｃｄ、Ｐｂ、Ｚｎ吸收系数提高，Ｃｄ、Ｐｂ含量超标，低剂量时Ｃｄ超标３７．５％，高剂量时超标１００％，增加了对人体健康潜在危险。主要原因在于５元素间存在协同作用，Ｐｂ、Ｃｕ、Ｚｎ、Ａｓ的存在增加了Ｃｄ的活性与解吸率，使其易迁移，为防止土壤污染增加了困难。

The ecological effects of Cd, Pb, Cu, Zn and As on lowland rice were studied in brown earth in the pot and field experiments. When the dosages of the heavy metals added to the soils were close to the Soil Environmetal Standards, lowland rice grew normally in appearence and its yield decreased by <10%. The causes of decrease in yield were that the soil criteria values of Cd and Pb reduced and the uptake of Cd, Pb and Zn by rice seed increased. The concentrations of Cd and Pb in rice exceeded the Food Health Standards, which posed latent danger to human health. There was a synergistic effect in these five elements. The coexistance of Pb, Cu, Zn and As enhanced the activity and desorption of Cd. So, the concentrations of Cd in seed in low dosage treatment exceeded the standard by 37.5%, while these of Cd in high dosage treatment exceeded by 100%.