大气沉降对水稻各器官铅镉汞砷积累的影响

为了解大气沉降对水稻中重金属积累的可能影响,选择非污染和污染2种土壤,分别在工业区和农村等2种大气环境下开展露天种植与大棚种植对水稻各器官重金属积累的影响试验。结果表明,水稻中积累的重金属主要来自土壤,其各器官中铅、镉、汞和砷的积累量在污染土壤中明显高于非污染土壤;但试验区大气环境与种植条件对水稻茎叶和谷壳中重金属含量也有较大的影响,工业区生长的水稻茎叶和谷壳中重金属含量高于农村,露天种植的水稻茎叶和谷壳重金属含量高于大棚种植。工业区与农村之间、露天种植与大棚种植之间水稻根系和糙米中重金属含量差异不明显,说明大气污染对糙米中重金属的积累无显著的作用。

Effects of Atmospheric Deposition on the Accumulation of Pb,Cd, Hg and As in Rice Plant Organs

To assess the potential impact of atmospheric deposition on heavy metal accumulation in rice plant, several experiments were carried out in two sites with different air pollution levels. The two experiment sites were located in industrial area and rural area, respectively. For each site, non-polluted and a polluted soils were collected as experimental materials, pot rice growth experiments were carried out in both outdoor and greenhouse. The effects of atmospheric deposition on heavy metal accumulation in different organs of rice plant were evaluated based on the comparison of Pb, Cd, Hg, and As concentration between the two sites or between outdoor and greenhouse experiments. The results showed that soil was an important source of heavy metals in rice plant, and the contents of lead, cadmium, mercury and arsenic in different organs of rice plant from the polluted soil were higher than those in the non-polluted soil. The atmospheric environment and plantation condition had a great influence on the content of heavy metals in the stem and leaf and husk of rice plant, and the content of heavy metals in the stem and leaf and husk of rice plant in the industrial zone was greater than that of rural area. The content of heavy metals in the stem and leaf and husk of rice plant in open field was higher than that in the greenhouse. No significant difference was observed in Pb, Cd, Hg, and As concentration of roots and brown rice between industrial zone and rural area, or between outdoor and greenhouse experiments, indicating that air pollution had no significantly direct effect on the accumulation of heavy metals in brown rice.