稀土农用对环境的影响

稀土在我国工业、农业应用中已有几十年的历史,人们对稀土在农作物上的增长作用及机理已逐渐了解,其在农用上的应用也越来越广泛,对环境的影响亦逐渐引起人们的关注。文章从稀土元素在环境中的含量、毒性特点、辐射水平、残留量等方面分析讨论了稀土农用对环境的影响。现有研究结果表明:稀土微肥在现行施用量的条件下,对人体健康是安全的,不会对环境、水体、农田生态环境造成污染。     

Concentrations of long-lived artificial radionuclides in the moss-lichen cover of mountain plant communities

Specific features of⁹⁰Sr and¹³⁷Cs accumulation in individual lichen species and in the moss-lichen cover of plant communities were studied in some mountain ranges of the Polar and Northern Urals. The results showed that the amounts of radionuclides in lichens and mosses of mountain plant communities are at the level characteristic of the moss-lichen cover of flat ecosystems, and their accumulation depends on⁹⁰Sr and¹³⁷Cs input with the global radioactive fallout. The radionuclide contents in lichens and mosses sampled from different mountain rocks, slopes, and elevations fluctuate around this level. The differences depend both on the structural and functional properties of plants and on the climatic and ecological features of their environment.     

THE NEED FOR A COMPREHENSIVE APPROACH IN THE MANAGEMENT OF ENVIRONMENTAL RESOURCES1

ABSTRACT Environmental resources can be managed properly only by adopting a comprehensive approach. The whole environment must be considered as a single system, and prior to any action, all types of environmental impacts caused by it should be studied in detail. This paper underlines the close relationship between different environmental problems, analyzes existing management patterns, and proposes new alternatives whenever applicable. The different constraints, which have to be considered in the decision-making process while developing a plan, are also discussed. It is concluded that efforts neglecting the interaction among different aspects of the environment do not upgrade the quality of water, air, and land to any appreciable degree.     

四川卧龙热矿水的化学

矿泉水是一个十分复杂的物理化学体系。本文从无机地球化学和化学热力学的角度出发,讨论了卧龙饮用天然热矿水的硅、锶、氡、碳酸盐化学和稳定同位素特征。为该矿水水文地球化学、环境化学和生物化学等方面的进一步研究提供了化学基础资料。     

天然放射性物质及环境问题

天然放射性物质（ｎａｔｕｒａｌｌｙｏｃｃｕｒｒｉｎｇｒａｄｉｏａｃｔｉｖｅｍａｔｅｒｉａｌｓ，简称ＮＯＲＭ）广泛存在于地层中，当石油或天然气从地下开采出来时，痕量的天然放射性核素如镭、氧等也随之采出，并分别集中于管道及设备的垢层或天然气加工装置的内壁薄膜上。文章在对外文资料调研的基础上，将ＮＯＲＭ的有关知识、存在场所、对人体潜在的危害途径及有关辐射防护方法进行了介绍。     

关注室内放射性环境污染 保护公众健康

室内的各种放射性环境污染影响人类健康，本文通过对各种室内放射性环境污染的简要评述，让人们对室内放射性环境污染有科学认识，并提出一些对策。     

柳州地区建筑材料放射性水平及其致居民剂量

本文采用全国统一方法,检测了广西柳州地区常用建材中~(226)Ra、~(232)Th、~(40)K的比活度.以煤灰砖最高,石灰石最低。比活度依次为煤灰砖>粘土砖≈土壤>水泥>灰砂砖>混凝土制品>石灰石.经估算,煤灰砖致居民的有效剂量当量较大,为3.98mSv·a~(-1);其它各种建材致居民的有效剂量当量在0.23—1.01mSv·a~(-1)之间,低于、等于或略高于本底.     

放射性气溶胶的净化

介绍了放射性气溶胶的国内外研究现状,包括放射性气溶胶的特性、净化技术、净化效果测定和评价等方面的研究现状.针对放射性气溶胶组分、粒径分布的研究,为放射性气溶胶收集效率的研究提供理论支撑.结合净化技术的发展现状,使净化技术在放射性气溶胶领域的工程应用中得到优化,更有效地减少放射性气溶胶对人类及环境的危害.     

铀矿井排风口尾气对周边农田土壤放射性污染的预测

铀矿井尾气排风口周围土壤中放射性物质的累积性污染不容忽视,但目前处于监测和积累数据阶段.在对指数平滑法综合应用分析研究的基础上,根据某铀矿井排风口周边某一农田土壤中近10 a的铀(238U)质量比监测数据建立了指数平滑预测模型,对土壤放射性铀(238U)污染进行预测,并对预测结果进行了深入分析,精度达75%以上.预测结果表明,采用指数平滑法建立土壤放射性污染预测模型是可行的,具有一定的应用价值.铀矿井排风口尾气对周边土壤的放射性累积性污染呈逐年递增趋势,迫切需要采取一些切实可行的控制措施.     

Analysis of Local Dandelion (Taraxacum officinales.l.) Cenopopulations from Radioactively Contaminated Zones

Local dandelion (Taraxacum officinales.l.) populations were studied in the areas of the Eastern Ural Radioactive Trace and the floodplain of the Techa River in its upper reaches. In impact plots, the density of soil and plant cover contamination with ⁹⁰Sr and ¹³⁷Cs exceeded the background level by factors of 13–440 and 2–500, respectively; the radiation load exceeded the background level by factors of 1.5 to 45. The seed progeny of plants from these plots was characterized by a high proportion of abnormal seedlings and an increased level of chromosome aberrations in meristem cells. In some years, variation in the seedling viability, growth rate, and developmental rate in these plots exceeded the reaction norm of plants from the background plot, demonstrating both stimulation and inhibition of growth processes. The response of seeds to acute irradiation at high challenging doses varied depending on the level of background radiation in the plots.