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1.
居室氡气污染和防治研究   总被引:1,自引:0,他引:1  
论述了氧的性质、室内空气中氡的主要来源以及氡子体的动力学性质,分析了氡的危害及其机理,并提出了室内氧污染的防治措施。  相似文献   

2.
环境氡的来源与防治对策   总被引:11,自引:1,他引:10  
论述了环境氡的来源、危害,着重分析了室内氡的主要来源是地基岩石、土壤,分析了北京市区氡的地质背景和防氡与降氡的一些基本措施  相似文献   

3.
居民住宅和单位用房中氡的来源及有关问题   总被引:1,自引:0,他引:1  
吴慧山  谈成龙 《铀矿地质》1996,12(2):104-110
本文讨论了人类正常生活环境中氡的来源及产生的机制、氡对人体的侵害、以及防氡降氡的某些措施等问题。  相似文献   

4.
空气中氡浓度的预测   总被引:4,自引:0,他引:4  
氡是一种放射性惰性气体,它与肺癌的关系已引起人们的高度重视,世界上许多国家都开展了环境氡的研究工作;氡的母体元素铀、镭在地质环境中的分布与空气中的氡浓度水平有密切关系,通过研究地质环境中铀、镭的分布资料,就能快速定性地评价空气中氡浓度水平.  相似文献   

5.
理想条件下氡及其子体运移规律研究   总被引:2,自引:1,他引:1  
从实验入手,应用高灵敏度,高精度,静态,易于重复观测的CD-1α杯测氡方法,在室内较理想条件下,研究了氡及其子体自身固有的运移规律,主要发现是:氡及其子体比重很大;但在理想空气中,它向上运移能力与向下运移能力相似,甚或超过,而远远大于横向运移能力。其规律是:氡及其子体向上运移的贡献大于45%,向下运移不及45%,扩散作用小于10%。  相似文献   

6.
环境氡平衡因子问题的探讨   总被引:1,自引:0,他引:1  
氡及其子体是人体受辐射危害的重要因素,而平衡因子是评价氡及其子体状态的重要参数之一。现就平衡因子进行了室内和室外的测量,对平衡因子的影响因素作了初步的探讨。  相似文献   

7.
为了解不同地质背景条件室内氡浓度水平,采用脉冲电离室测氡仪AlphaGUARD测量了北京广东不同地质背景典型测点的室内氡浓度,同时对广东某一测点进行了长期的室内氡监测。测量和研究结果表明:地表岩性是影响室内氡浓度高低的重要因素之一。地处花岗岩地区的建筑物内氡浓度高于其他岩性地区的室内氡浓度,广东室内氡水平明显高于北京地区,广东北京花岗岩地区的平均室内氡浓度分别为69.98 Bq/m^3和43.97 Bq/m^3,第四系覆盖地区的平均室内氡浓度分别为43.60 Bq/m^3和35.74 Bq/m^3。民用住宅卧室内的室内氡浓度略高于公共建筑物办公室内的室内氡浓度。因此,结合地质背景研究室内氡的水平与分布对指导开展室内氡调查中确定抽样方案、选择测点及进行区域尺度室内氡评价有重要的实用价值。  相似文献   

8.
氡地质潜势规律研究方法探讨   总被引:6,自引:1,他引:5  
唐莉  朱立 《岩矿测试》1999,18(1):1-6
氡的地质潜势是环境氡研究的重要内容,也是从地质背景出发快速评价氡浓度水平的有效方法,氡析出率是反映氡地质潜势的最好参数,根据放射性元素分布规律,地质背景及放射性元素衰变等,建立了计算氡析出率的理论公式。理论计算结果表明,北京市区氡的地质潜势分为四个不同的区,不同潜势区中室内氡浓度水平发生相应变化。说明通过氡地质潜势规律研究,可以确定室内氡浓度水平潜在高值区。  相似文献   

9.
本文从战略角度出发考虑了社会生活用房中氡的测量和减少氡对人体作用的问题;讨论了住宅中氡的测量,氡的来源,以及氡浓度变化的原因和若干防氡措施等。  相似文献   

10.
地球上所有生物都受到天然辐射和人为辐射的照射 ,天然辐射是主要来源。在人类所受到的天然辐射照射中一半以上来自放射性气体氡及其子体的贡献 (联合国原子能效应委员会 ,2 0 0 0 )。氡及其子体是诱发肺癌的主要因素之一 ,已被世界卫生组织 (WHO)列入室内致癌物质。因此 ,氡危害预测及新的环境辐射现场检测技术自 2 0世纪 80年代以来一直是热点研究课题。我“辐射与环境实验室”自 1995年以来取得如下主要成果 :1 建立了自然环境中大地大气氡交换理论模型在某些花岗岩或构造断裂带等潜在土壤氡高浓度区 ,室内积累的高氡浓度将对公众健…  相似文献   

11.
The incidence of lung cancer in the Gejiu area of Yunnan Province ranks the first in the world.The radon level(indoor,soil) was measured in the Gejiu area by the SSNTD method from 1990 to 1996,The result indicates an extensive high-level of indoor radon in that area though U and Th are lower in local limestones,The indoor radon level of houses located in the geologic fault zone is 6 times high that 2km far from the fault zone.The reason probably is that the radon level of soil in the fault is 6-8 times high that 1 km far from the faults.our data indicate that a lower range of radon levels,0-100Bq.m^-3,exists in healthy families.However,a higher radon level,over 800 Bq.m^-3,is often found corresponding to that of cancer patients‘ homes(the house-owners are suffering from either lung cancer or leukaemia or liver cancer),Obviously,an increase in lung cancer incidence follows an increase in indoor radon level,The risk of cancer induced by indoor radon is no longer an inference,but a fact.  相似文献   

12.
Radon and its progenies have been ranked second of being responsible for lung cancer in humans. Hong Kong has four major groups of uranium-rich plutonic and volcanic rocks and is suffering from radon emanated therefrom. However, there is a lack of radon potential maps in Hong Kong to resolve the spatial distribution of radon-prone areas. A ten-point radon potential system was developed in Germany (2005) to predict radon potential using both the in situ geogenic and geographic parameters under hierarchical ranking. Primarily, the ten-point system requires the desk study of the geological environment of sampling sites, which has an advantage of saving resources and manpower in extensive radon potential mapping over the traditional soil radon concentration sampling method. This paper presents a trial of radon potential mapping in Hong Kong to further verify the system. Despite some slight departures, the system demonstrates an acceptable correlation with soil radon concentrations (R 2 = 0.62–0.66) from 768 samples of mainly intermediate radon potential. Hong Kong has a mean soil radon concentrations of 58.9 kBqm?3, while the radon potential from the ten-point system achieves an average of 4.93 out of 10 over the territory. The vicinity of fault zone showed high soil radon concentrations and potentials, which were conducive to uranium enrichment and rapid soil-gas diffusion near faults. High uranium-238 content in soil was found to cause high soil radon concentration with a large R 2, 0.84. The Jurassic granite and volcanic crystal tuff cover more than 85 % of the whole Hong Kong area, and they show relatively high radon concentrations (Geometric mean 83 and 49 kBqm?3, respectively) which are associated with their high uranium contents (Geometric mean 234 and 197 Bqkg?1, respectively). While indoor radon concentration is an important factor for radon risk assessment, this study has not considered the correlation between indoor radon concentration and radon potential. The reason is that almost all buildings in Hong Kong are high-rise buildings where indoor radon concentrations are governed only by the radium content in the building materials and the ventilation conditions.  相似文献   

13.
Groundwater constitutes the major source of utility water in Ekiti State with the majority of the population depending on groundwater for drinking and other household uses. Soil in the area is commonly used as a component of building materials, which may produce radon in the indoor environment. Excessive concentrations of radon in water and soil can cause radiological health risks to human as witnessed by the increased cases of lung cancer among non-smokers in Nigeria, which may be traceable to the ingestion and inhalation 222Rn in drinking water and indoor air. In the present study, comparative in situ measurements of radon in groundwater and soil gas were carried out at one hundred selected locations across the Ekiti State in southwest Nigeria, using a RAD7 radon detector to generate a radon distribution map and to estimate radiation hazards due to radon. The concentrations of radon in groundwater ranged from 0.9 to 472 Bq L?1 with a mean of 34.7?±?4.4 Bq L?1, while those of soil gas ranged from 0.1 to 315 kBq L?1 with a mean of 38.9?±?1.4 kBq L?1. The total annual effective dose due to inhalation and ingestion of radon in groundwater amounted to 94.7 µSv year?1, which is lower than the reference dose of 100 µSv year?1 recommended by the World Health Organization (WHO). The radon map generated for groundwater and soil gas identified three distinct areas with radon levels ranging from low to high. The results of this study show that some locations (Emure, Gbonyin, Ijero and Ikole) show mean total annual effective doses which are higher than the recommended limit. It can then be inferred that the groundwater samples pose significant radiological hazards to the population and that the noticed increase in lung cancer cases may be attributed to the consumption of groundwater in the area.  相似文献   

14.
崔霖沛 《地质论评》1994,40(2):157-164
氡气灾害是一种广泛分布的地质灾害。室内氡气浓度偏高会使居民患肺癌的几率增高,而室内氡气主要来自房屋地基所在的地质单元。笔者在美国犹他大学研究所工作期是,研究了瑞丁普朗花岗片麻岩带近地表氡的浓度与铀含量的关系以及铀的分布与居民癌症死亡率之间的相关关系。铀的区域性分布是利用航空伽马能谱测量资料求得的,说明利用航空伽马能谱测量资料开展氡气灾害区域评价的可能性。文中还举例说明氡气调查在制定建设规划方面的作  相似文献   

15.
It has been established that radon and its airborne decay products can present serious radiation hazards. A long term exposure to high concentration of radon causes lung cancer. Besides, it is also known that out of the total radiation dose received from natural and man-made sources, 60% of the dose is due to radon and its progeny. Taking this into account, an attempt has been made to estimate radon concentration in dwellings in and around Guwahati using aluminium dosimeter cups with CR-39 plastic detectors. Results of preliminary investigation presented in this paper show that the mean concentration is 21.31 Bq m − 3.  相似文献   

16.
Analysis of one year measurements of in situ radon (222Rn) and its progenies along with surface air temperature, relative humidity and pressure near to the Earth’s surface has been carried out for the first time at the National Atmospheric Research Laboratory (NARL, 13.5°N and 79.2°E) located in a rural site in Gadanki, south India. The dataset was analysed to understand the behaviour of radon in relation to the surface air temperature and relative humidity at a rural site. It was observed that over a period of the 24 hours in a day, the activity of radon and its progenies reaches a peak in the morning hours followed by a remarkable decrease in the afternoon hours. Relatively, a higher concentration of radon was observed at NARL during fair weather days, and this can be attributed to the presence of rocky hills and dense vegetation surrounding the site. The high negative correlation between surface air temperature and activity of radon (R = – 0.70, on an annual scale) suggests that dynamical removal of radon due to increased vertical mixing is one of the most important controlling processes of the radon accumulation in the atmospheric surface layer. The annual averaged activity of radon was found to be 12.01±0.66 Bq m?3 and 4.25±0.18 Bq m?3 for its progenies, in the study period.  相似文献   

17.
Attempts to predict which geographic areas should be associated with a high percentage of homes with unusually high indoor radon levels have been based on estimates of soil radon and soil permeability for geological units. In northern Virginia and southern Maryland, it appears that predictions of indoor radon based on estimates of homesite soil radon and soil permeability are very useful.  相似文献   

18.
Relationship between radon concentrations in indoor air and in soil gas   总被引:3,自引:0,他引:3  
In the Ljubljana region, 53 schools were selected for measurements of radon concentrations in soil gas close to a school building, and indoor radon concentrations in one of the ground-floor classrooms of each building. The aim was to establish a relationship between radon concentrations in indoor air and in soil gas from the ground on which the building is situated. Soil gas radon concentrations between 2 and 14 kBqm-3 were found. Indoor radon concentrations ranged from 20 to 1,440 Bqm-3, with seven values exceeding 200 Bqm-3. It is concluded that good quality of the construction elements ensure low indoor radon concentration, regardless of high soil gas radon level.  相似文献   

19.
居室氡的影响因素及分布特点   总被引:9,自引:1,他引:9  
氡是天然放射性系列铀系中唯一的气态元素,它对人体健康的影响尤其是氡与肺癌的关系已引起人们的高度重视,已成为环境保护研究的一个重要对象.本文就地壳中放射性元素的分布规律及氡的迁移进行介绍,并着重讨论了居室氡的影响因素,以期利于今后氡危害防治工作的进行.  相似文献   

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