A major environmental issue is heavy metal contamination in the soil and water. The accumulation of heavy metals in soil, water and plant biomass has been extensively documented in Vietnam. Growing crops in polluted areas can inhibit tissue growth and accumulation of heavy metals, resulting in potential risks to human health. In this paper, both in pots and field experiments, the effect of heavy metal contamination on plant growth and the accumulation of Cu, Pb and Zn in lettuce (Lactuca sativa L.) were evaluated. The accumulation of heavy metals in the roots and leaves of lettuce makes a big difference. The heavy metal content in the roots is much higher, typically 1.5 to 2 times higher, than that accumulated in the leaves. Lettuce plants often have a higher cumulative heavy metal coefficient from soil to roots than that from roots to leaves. The highest cumulative coefficient is always Zn, followed by Cu and Pb. Good results have also been demonstrated by the use of organic and inorganic modifications such as phosphate fertiliser, lime, and sawdust to reduce heavy metal absorption in lettuce plants. The tendency of the lettuce plant to accumulate more Zn than Cu and Pb. More effects were found in all experiments with phosphate fertiliser, lime and sawdust added to reduce the accumulation of Cu, Pb and Zn in lettuce. However, in order to reduce Cu, Pb and Zn absorption by lettuce, particularly for Cu and Pb, the application of lime and phosphate fertiliser is more effective than sawdust.
Author (s) Details
Prof. Dr. Nguyen Xuan Cu VNU-University of Science, Vietnam National University-Hanoi,334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam.