兰州市蔬菜基地蔬菜体内As污染及累积效应研究

对兰州市蔬菜基地蔬菜体内As质量比进行方差分析和多重比较.结果表明,同一区域土豆、西红柿、茄子、辣椒、豆角、白菜和大葱体内As质量比之间表现出极显著差异,大葱体内As质量比显著高于其他蔬菜体内As质量比,白菜体内As质量比最低;不同区域相同土豆、西红柿、茄子、辣椒、白菜和大葱体内As质量比之间表现出显著差异.豆角体内As质量比之问没有表现出差异,兰州市七里河区蔬菜基地蔬菜体内As质量比显著高于其他各区蔬菜基地蔬菜体内As质量比,永登县蔬菜基地蔬菜体内As质量比最低.蔬菜体内As质量比与土壤As质量比呈显著正相关性.

As pollution and its cumulative effects on the vegetables growing in vegetable base of Lanzhou City

The purpose of this paper is to present our investigation and analysis of the As content of vegetables and soil in vegetable bases of Lanzhou City, so as to provide a guidance to the pollutionfree vegetable base construction and heavy metal elements pollution control. Analyzing the content of As in the vegetable bodies in the vegetable-growing base of Lanzhou, we have found its noticeably different effects on the growth of potato, tomato, eggplant, capsicum,green bean, cabbage, chive, and so on in the bodies of vegetables in the base of Lanzhou. On the whole, the As content of chive proves significantly higher than in other vegetables while that of cabbage turns out to be the lowest. On the other hand, the As content in the same species of vegetable, such as in the potato, tomato, eggplant,capsicum, cabbage, and chive produced in different regions were found remarkably different whereas that of green bean produced in different regions were found of no difference at al. Our analysis has also found that As content of Qilihe district tends to be significantly higher than that in other districts, with that in Yongdeng county being the lowest. It has also been found that the As content of vegetables and the soil quality proves positively correlated with each other. In addition, while finding from our preliminary study the relevance of heavy metals in the soil and the growth of vegetables, we have also discovered the effect of the heavy metals on the quality change of the soil. The pollution situation around the outskirts of urban areas prove to have brought more seriously contaminated vegetables, while the vegetables produced further away from the outskirts of the urban areas prove less contaminated, with greater effects of heavy metal contamination on the vegetables due to influence of transportation, industrial production and other human activities. As a result of the lag, cumulative and irreversible influence by nature, the contamination of vegetables should be studied on the basis of "focus on anti-control,"combining a number of ways to develop an economical and easy to approach to promoting the management means for effective prevention of heavy metal pollution. For the status in situ of the heavy metal pellutiun of the five districts and the three counties of Lanzhou City, it has been found that measures should be taken by the relevant departments to strictly control the "three wastes" of the industrial emissions and the irrational use of pesticides and chemical fertilizers with heavy metal contents, along with the vegetable bases selected in a clean and less polluted areas.