氡与室内空气环境

氡是一种放射性气体，在室内空气中广泛存在，并对人体造成极大伤害，因此倍受人们关注。本文主要介绍室内空气中氡的特性，来源，健康影响和防治措施。     

兰州市绿色建筑室内空气氡污染研究

为了解寒旱地区甘肃省兰州市绿色居住建筑室内空气氡(Rn)活度浓度的变化特性,对兰州市某一星级绿色居住建筑进行长期检测,确定绿色居住建筑室内空气氡活度浓度水平及影响因素。检测结果表明:同一房间不同功能区氡活度浓度表现为卧室厨房客厅,户型为四室两厅三室两厅;随着楼层增高,室内空气氡活度浓度降低,室外氡活度浓度低于室内;新风系统运行可有效降低室内空气氡活度浓度;室内装饰装修材料的引入,极大增加了室内空气氡活度浓度;兰州市市民人体年有效照射剂量处于安全水平。这些研究成果为寒旱地区室内空气氡污染评价提供了科学依据。     

室内放射性物质氡的来源、危害与控制

阐述氡对人体的危害;室内空气氡主要来源(岩石土壤、建材、燃气、地热水等);室内氢的防治方法(通风排气、应用空气清新器、吊扇电扇、室内装修);室内氡的控制标准与检测方法.     

民用建筑工程室内空气中氡浓度检测方法探讨

通过对有关测氡仪在标准氡室检测数据的分析,对室内空气中氡浓度的测试方法进行了探讨。     

室内空气污染主要来源与防治对策分析

室内环境质量的优劣直接影响到人们身体的健康。随着人们物质生活水平的提高,对室内空气质量的要求也在逐步提高。在分析现阶段室内空气污染状况的基础上,对室内空气污染中甲醛、氨、氡、苯和TVOC的成因及对人体健康的危害进行了分析,从装修、施工、入住等方面提出了相应的防治措施,并通过检测工作来进行室内空气污染评估与控制。     

氡和室内氡浓度检测

1氡的基本性质 　　室内空气污染引起的建筑物综合症已经被广泛关注,人们知道甲醛、氨、苯是常见的室内空气污染物,而对无色无味的氡却知之甚少.……     

装潢造成的室内空气污染及其危害

室内空气污染物按照国家标准和EN欧洲相关环保标准主要控制甲醛、苯、氨、总挥发性有机物TVOC、氡五项指标.生活中来自不同物体散发的污染物不同,危害也不同.     

室内装修空气污染现状与防治措施

对室内装修中甲醛、苯、氨、TVOCs、氡五种常见的污染物进行了介绍,分别研究了各种污染物的来源及危害,提出了树立绿色装修理念、保持通风、控制新家具数量、绿色植物净化处理等防治措施,以期从源头上削减和控制室内空气污染。     

氡和室内氡浓度检测

1氡的基本性质室内空气污染引起的建筑物综合症已经被广泛关注,人们知道甲醛、氨、苯是常见的室内空气污染物,而对无色无味的氡却知之甚少。氡的原子序数是86,是元素周期表中第六周期的零族元素,其相对原子质量为222.0,是气体中最重的一个元素,但无色无味,能溶于水。氡是一种放射性元素,是铀系核素衰变的中间产物,氡元素有几种同位素:氡一222、氡一218、氡一220,分别来自不同的镭同位素:镭一226、镭一224、镭一223,而镭同位素分别有铀一238(半衰期4.49x109年)、钍一232(半衰期1.39X1010年)、铀一235(半衰期7.13X108年)衰变形成。几种氡同位…     

我国第一部《室内空气质量标准》实施

由国家质量监督检验检疫局、国家环保总局、卫生部制定的我国第一部《室内空气质量标准》于2003年3月1日正式实施。《标准》为消费者解决自己的污染难题提供了有力武器。　　据悉，《标准》引入室内空气质量概念，明确提出了“室内空气应无毒、无害、无异常嗅味”的要求。其中规定的控制项目不仅有化学性污染，还有物理性、生物性和放射性污染。化学性污染物质中不仅有人们熟悉的甲醛、苯、氨、氡等污染物质，还有可吸入颗粒物、二氧化碳、二氧化硫等13项化学性污染物质。《标准》结合了我国的实际情况，既考虑到发达地区和城市建筑中的…     

室内氡污染的危害及防治

简要介绍了氡的产生和氡污染的来源以及室内氡浓度的影响因素,结合氡的物理化学性质分析了室内氡污染对人体健康的危害,并针对室内氡污染的来源具体阐述了室内氡污染的控制措施和治理方法,以期创造健康的室内环境。     

地下空间氡的产生机理及通风控制

本文建立了土壤和建材的氡析出模型,在充分考虑各个影响因素的前提下,推导出了土壤和建材的表面析氡率公式,并依据此公式,进而推导出了室内氡浓度与通风换气效率的关系式。应用以上公式,对一典型的地下空间模型进行了计算,结果表明:地下空间氡的主要来源是土壤氡气的逸出,约占总析氡量的70豫～90豫;在较高的氡浓度状态下,室内氡浓度对通风十分敏感,增大地下空间的通风换气率,会使空气氡浓度大幅度的降低。因此,若按照地下空间的标准新风量进行设计,控制室内氡水平在400Bq/m3以内是很容易的,但是若要控制室内氡水平在200Bq/m3以内,则至少需要25.2m3/h的人均新风量,考虑新风不能得到完全利用,所需引入的室外新风量至少为31.5m3/h(以地下商场为例)。     

Influence of ventilation on indoor radon level

Detailed radon measurements were conducted at different residential units in Hong Kong in winter time when air-conditioners were off and also in summer time when air-conditioners were on. Ventilation rates were measured concurrently to investigate the influence of ventilation on indoor radon level. The ratio of indoor radon level to outdoor radon level was plotted against ventilation rate, and it was found that a critical value existed after which the indoor radon level could be considered identical to the outdoor level. This result is important for use in ventilation design to reduce indoor radon pollution.     

空调室内氡及粒子污染的传播及其数值模拟

室内氡(含氡子体)污染的传播与粒子(悬浮颗粒)污染在室内的传播过程相关,通风空调气流对氡及粒子污染的传播影响很大。本文详细阐述了室内氡和粒子的来源和特点、氡及其子体在空气中的传播机理以及除去方法,分析了通风空调系统对室内氡及子体传输的影响、以及氡在空气中迁移的动力学模型,分析比较了通风室内氡及粒子污染物迁移沉降过程的数值模拟方法,提出了空调气流环境下氡及粒子污染传播及其数值模拟中的关键问题。     

Variation in residential radon levels in new Danish homes

Radon‐222 gas arises from the radioactive decay of radium‐226 and has a half‐life of 3.8 days. This gas percolates up through soil into buildings, and if it is not evacuated, there can be much higher exposure levels indoors than outdoors, which is where human exposure occurs. Radon exposure is classified as a human carcinogen, and new Danish homes must be constructed to ensure indoor radon levels below 100 Bq/m³. Our purpose was to assess how well 200 newly constructed single detached homes perform according to building regulations pertaining to radon and identify the association between indoor radon in these homes and municipality, home age, floor area, floor level, basement, and outer wall and roof construction. Median (5–95 percentile) indoor radon levels were 36.8 (9.0–118) Bq/m³, but indoor radon exceeded 100 Bq/m³ in 14 of these new homes. The investigated variables explained nine percent of the variation in indoor radon levels, and although associations were positive, none of these were statistically significant. In this study, radon levels were generally low, but we found that 14 (7%) of the 200 new homes had indoor radon levels over 100 Bq/m³. More work is needed to determine the determinants of indoor radon.     

Indoor Radon Concentrations In Homes Of Sichuan Residents And The Dose To The Population Exposed To Radon And Its Daughters

This paper presents the results of indoor radon surveys in the Sichuan province of China. The indoor radon concentrations found using scintillation or the two-filter method, ranged from 1.0 Bqm^?3 to 170.2 Bqm^?3. The arithmetic mean concentrations of indoor radon and its progeny were 17.8 Bqm^?3 and 10.8 Bqm^?3 EER (2.9 m WL), respectively. A seasonal pattern of the maximum in winter and the minimum in summer was observed for radon and its progeny concentrations. The annual effective dose equivalent resulting from indoor and outdoor inhalation of radon progeny totalled 0.93 mSv. Of the 109 million people living in Sichuan, 3000-6800 may die annually from lung cancer induced by the inhalation of radon progeny.     

广州市室内氡浓度调查报告

我公司于2008～2009年承担了全国室内氡调查项目中广州地区的调查工作。本次调查中,按全国室内氡浓度调查方案的要求,按行政区、人口分布、建筑物和种类等分布了采样点,共布了146个采样盒,回收了135个。结果表明,广州市室内氡平均浓度为32.70Bq/m3,最大值156Bq/m3,最小值4Bq/m3。这次全国10个城市室内氡浓度调查结果的均值为34.9Bq/m3。在广州室内氡调查结果比较低的主要原因是人们长期开窗通风的生活习惯。与工程验收检测的氡浓度相差甚远,主要的原因是检测时的状态不同。     

Radon and Natural Ventilation in Newer Danish Single-Family Houses

Abstract To investigate the effect of ventilation on indoor radon (²²²Rn), simultaneous measurements of radon concentrations and air change rates were made in 117 Danish naturally ventilated slab-on-grade houses built during the period 1984–1989. Radon measurements (based on CR-39 alpha-track detectors) and air change rate measurements (based on the perfluorocarbon tracer technique; PFT) were in the ranges 12–620 Bq m^?3 and 0.16?0.96 h^?1, respectively. Estimates of radon entry rates on the basis of such time-averaged results are presented and the associated uncertainty is discussed. It was found that differences in radon concentrations from one house to another are primarily caused by differences in radon entry rates whereas differences in air change rates are much less important (accounting for only 80,0% of the house-to-house variation). In spite of the large house-to-house variability of radon entry rates it was demonstrated, however, that natural ventilation does have a significant effect on the indoor radon concentration. Most importantly, it was found that the group of houses with an air change rate above the required level of 0.5 h^?1 on average had an indoor radon concentration that was only 50% (0.5±0.1) of that of the group of houses with air change rates below 0.5 h^?1. The reducing effect of increased natural ventilation on the indoor radon concentration was found to be due mainly to dilution of indoor air. No effect could be seen regarding reduced radon entry rates.     

Characterizing the sources,range, and environmental influences of radon 222 and its decay products

Recent results from our group directly assist efforts to identify and control excessive concentrations of radon 222 and its decay products in residential environments. We have demonstrated directly the importance of pressure-induced flow of soil gas for transport of radon from the ground into houses. Analysis of available information from measurements of concentrations in U.S. homes has resulted in a quantitative appreciation of the distribution of indoor levels, including the degree of dependence on geographic location. Experiments on the effectiveness of air cleaning devices for removal of particles and radon decay products indicate the potential and limitations of this approach to control.     

Indoor radon concentrations caused by construction materials in 23 workplaces

The aim of this study was to compare the measured and the calculated concentrations of indoor radon caused by building materials at 23 workplaces. The measured concentrations of radon were clearly higher than the calculated radon concentrations from the building materials, which indicated that the main source of indoor radon was the soil under and around the buildings. The highest means of continuously (933 Bq m(-3)) and integrated (169 Bq m(-3)) measured and calculated (from 70 to 169 Bq m(-3)) concentrations of radon were found in hillside locations. On the other hand, the median (27 and 43 Bq m(-3)) and maximum (626 and 1002 Bq m(-3)) values of calculated indoor radon concentrations exhaled from construction materials were the highest at the ground level places. On average, only 7-19% of the radon seemed to originate from the construction materials.