摘要
为评估大气沉降对蔬菜中重金属积累的潜在影响,选择非污染和污染2种土壤,分别在工业区、城区和农村等3种大气环境下开展露天与大棚种植对萝卜重金属积累的影响试验。结果表明,土壤是萝卜重金属的重要来源,污染土壤中生长的萝卜铅、镉、汞和砷积累明显高于非污染土壤,但试验区大气环境与种植条件对萝卜地上部分重金属含量也有很大的影响,萝卜地上部分重金属含量工业区>城区>农村,露天种植的萝卜地上部分重金属含量明显高于大棚;大气沉降对大气污染较为严重的工业区萝卜地下部分重金属积累有一定影响,对城区与农村的影响较小。通过清洗方式不能完全清除因大气沉降导致的蔬菜重金属积累,表明由大气沉降的重金属有较高比例已通过蔬菜叶片的气孔进入蔬菜组织内或被蔬菜组织紧密地吸附。研究证实了大气沉降对蔬菜地上部分中镉、铅和汞等重金属积累有直接的作用。
To assess the potential impact of atmospheric deposition on heavy metal accumulation in vegetable crops, several experiments were carried out in three sites at different air pollution levels. The three experiment sites were located in industrial area, urban area and rural area, respectively. For each site, the non-polluted and polluted soils were chosen as experimental soils, pot radish growth experiment was carried out in both open field and greenhouse. The effects of atmospheric deposition on heavy metal accumulation in radish plant were evaluated based on the comparisons of lead （Pb）, cadmium （Cd）, mercury （Hg）, and arsenic （As） concentrations in aboveground and underground parts of radish among three sites or between open field and greenhouse experiments. The results showed that soil was an important source of heavy metals in radish, and the contents of Pb, Cd, Hg and Ar in both aboveground and underground parts of radish in the polluted soil were higher than those in the non-polluted soil. However, the atmospheric environment and plantation conditions had great influences on the content of heavy metals in the aboveground part of radish, and the content of heavy metals in the aboveground part of radish decreased in the order of industrial zone 〉 urban area 〉 rural area. The contents of heavy metals in the aboveground part of radish planted at open field were higher than those planted at the greenhouse. Effects of atmospheric deposition on heavy metal accumulation in the radish from the industrial area with serious air pollution were greater than those from urban and rural areas. The heavy metals were accumulated in the leaves of vegetables because atmospheric deposition could not he completely removed by washing, indicating that a high proportion of heavy metals on the surface of radish leaves deposited by the atmosphere had entered the vegetable tissue through the stomata of the leaves or tightly fixed by vegetables. The results indicated that atmospheric deposition had direct effects on the accumulation of heavy metals such as Cd, Pb and Hg in the aboveground parts of vegetables.
出处
《土壤通报》
CAS
北大核心
2018年第1期184-190,共7页
Chinese Journal of Soil Science
基金
国家重点研发计划专项(2017YFD0800305)
杭州市科技发展计划项目(20170432B23)资助
关键词
大气沉降
萝卜
重金属积累
污染
Atmospheric deposition
Radish
Heavy metal accumulation
Pollution
