广东省温泉宾馆室内氡来源分析

利用RAD7便携式测氡仪和NR-67A型连续测氡仪测量了广东省一些温泉宾馆室内外氡浓度。从无人入住的宾馆房间内氡浓度的变化来看，土壤氡的渗入是底层房间氡的主要来源。当在浴室内使用温泉水洗浴时，客房内平均氡浓度水平比没有用温泉水时高出10．9％～813％，浴室内氡浓度比没有用温泉水洗浴时高出13．8％～489％。宾馆室内使用温泉水有较高的氡转换系数。某些宾馆室内氡浓度超标。可能对宾馆工作人员造成潜在健康危害，应采取一些管理措施或技术手段降低其暴露水平。     

广东花岗岩类温泉水-汽转化过程中氡浓度的变化及其危害

广东省是我国温泉出露最多的省份之一。在温泉附近建立温泉宾馆,是利用温泉资源大力发展本地旅游业的有效途径之一。本文利用新型NR 667A连续测氡仪测量了广东省4处温泉宾馆室内外空气中氡浓度以及室内温泉水氡浓度。温泉水氡浓度变化范围为53 4～292 5Bq L,室外氡浓度范围是17～48Bq m3,而客房内平均氡浓度水平比没有用温泉水时高出10 9%～813%,浴室内氡浓度比没有用温泉水洗浴时高出13 8%～516%。在宾馆室内使用温泉水有较高的氡转换系数。某些宾馆室内氡浓度超标,可能对宾馆工作人员造成潜在健康危害,应采取一些管理措施或技术手段降低其暴露时间或程度。     

四平市区土壤中氡的分布规律

在国内对测量天然条件下城市土壤中氡还为数不多的情况下，利用静态活性炭吸附法，对四平市区土壤中氡进行了测量，分析了四平土壤中氡的分布规律。区内土壤中氡浓度的变化范围为0.1-46.7Bq/l，个别点测值高出世界土壤中氡浓度平均值（7.4Bq/l)的8．6倍。根据土壤中镭的含量计算了空气中氡的变化规律，在距地表1m高的空气中氡浓度平均值为3.54Bq/l，此值在世界正常值范围（1－10Bq/l)内。     

北京广东典型地区室内氡气浓度与地质背景关系

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。     

土壤氡浓度日变化影响因素研究

地表壤氡可以反映地下深部的水文、地质、矿产、热源等信息,但土壤氡浓度有年变和日变的特点。为了研究土壤氡浓度日变化规律及其影响因素,采用α能谱测氡仪对土壤氡进行连续测量。结果表明:土壤氡浓度呈单峰型日变化特征,最大值出现在19:00~22:00,最小值出现在11:00~14:00,土壤温度是影响土壤氡浓度的关键因子,土壤氡浓度与土壤温度呈正相关。降雨对土壤氡浓度有显著的影响,降雨后土壤氡浓度出现双峰型日变化特征,其变化与土壤湿度和空气温度等气象因素有关。     

台山市某地块环境放射性水平研究

本主要测量了广东省台山市某地块的现场地面γ强度、空气氡浓度、土壤氡浓度、水中氡浓度，以及水中微量元素。结果表明，测区内大部分区域地面γ强度为256．1－522nGy/h，个别地段的地面γ强度大于522nGy/h；测区内水中氡浓度一般为0．28－5．31kBq/m^3，个别大于10kBq/m^3，测区内土壤中氡浓度较高，分析表明，测区内地面γ强度和氡浓度偏高的原因除了与地质因素有关外，还与地形等因素有关，最后对该地块放射性水平作出综合评价，提出相应的防护措施。     

小型氡室氡浓度准确性影响因素的探讨

小型氡室是一种综合测氡仪器的标定装置,适合目前各种测氡仪器的标定。湿度、温度、闪烁探测器的漏计现象等因素影响氡室内氡浓度。湿度影响着气溶胶的密度,湿度越大,气溶胶的密度也越大,导致探测器探测的计数也变大;温度增加,分子的扩散系数随着增加,使镭源释放的氡量增加,导致氡浓度变大;闪烁体的发光衰减时间较长,测量大活度样品时,会出现漏计现象。对应不同的影响因素采取了相应的修正措施。     

乌鲁木齐某实验楼室内氡浓度测量及影响因素分析

对乌鲁木齐某实验楼室内氡浓度的测量结果表明,该实验楼室内氡浓度在39～137 Bq/m3,平均76.1 Bq/m3,吸入氡及其子体对相关人员的年均有效剂量为0.51～0.68 mSV,平均值为0.57 mSV,高于乌鲁木齐平均水平,推测与研究区活动断层出露有关。分析数据显示,研究区地下土体扩散氡对一层室内氡浓度影响较大,导致一层室内氡浓度较高,且室内氡浓度在一定程度上受到房屋朝向影响。并结合影响因素,有针对性的提出了预防和降低室内氡浓度的措施。     

缅甸拉泰-其培河段恩梅开江断裂带氡气测量

利用测量土壤中氡气异常来确定隐伏断裂的几何学特征。在缅甸拉泰—其培河段布置的四条测氡剖面中,氡气异常明显,拉泰-芒童段异常值约为本底值的3～8倍,芒童以南部分异常值比本底值高100倍,表明芒童以南地段活动性较强。氡气测量结果很好地控制了恩梅开江断裂在覆盖层之下的延伸展布方向。地表开挖及平硐揭露,很好地验证了测氡结果所推测的断层几何学特征。因此,测定土壤中氡气异常来寻找隐伏断裂的方法是可行的。     

土壤中氡浓度检测及其影响因素

综合相关文献研究,通过工程实例介绍土壤中氡气浓度的检测方法,对检测结果进行统计学分析,根据分析结果探讨不同土壤中氡浓度差异及其影响因素。结果显示:土壤孔隙度是影响土壤中氡气浓度的关键因素。不同类型的表层土壤,孔隙度不同,所含氡气浓度也不同。当表层土壤为房渣土、填土时,土质夯实,孔隙率低,氡浓度含量较低;表层土壤为粉土、粉质粘土时,土质较均匀,土层较疏松,孔隙度略大,土壤氡浓度大于前者;表层土壤为粉砂、细砂时,土层更为疏松,土壤中孔隙度再次增大,氡在土壤中有大量的存储空间,所含的氡浓度最大。因此,土壤的孔隙度大小影响氡从地下向地表渗透析出的难易程度,孔隙度越大氡越容易渗透其中,浓度就越高。     

环境中氡及其子体的危害与控制

简要回顾氡致肺癌的长时间认识过程和研究历史,简述了当年铀矿工人和矿工吸入氡及其子体与肺癌发病率的关系,指出环境中氡的危害。重点讨论了国内外室内氡和地下建筑物中氡浓度分布及其来源,从而启发人们研究环境中氡的地质来源以及控制室内氡水平的基本措施;进一步阐述了我国室内氡研究的成果和需要进一步研究的问题。     

A search for correlation between seismicity and radon anomaly in hot springs

Measurements of radon contents of the exholved gas emanating from several hot water springs along the Western Coast of India are reported here. Concentration of radon in gas phase of individual springs varied in general, directly with the surface temperature of the water emerging from the respective springs, and showed little variation with time. Radon measurements were carried out continuously for about two years at two hot springs located at Ganeshpuri and Sathivali in the coastal area of Northern Maharashtra. The distant tremors did not cause any variation in the radon content. There was no marked local seismic activity during the period of observations, and the levels of radon stayed essentially constant. The measurements were also carried out at a hot spring in Assam, for about 8 months. These also did not show any significant variation; this period too lacked any marked local seismicity.     

Indoor radon concentrations in relation to geology in Slovenia

For this study 330 instantaneous indoor radon concentrations were selected from the database assembled during the Slovenian National Radon Programme. A relationship was found between indoor radon concentrations, rock type, tectonic faults and age of buildings. Indoor radon concentrations were elevated in buildings that were older than 50 years and in those with a fault under foundations. When these data were eliminated, elevated indoor radon levels were found only in buildings built on limestone. Our conclusions were confirmed by using the machine learning methods: clustering and multiple regression.     

Some measurements of radon in south west England

Summary A survey of radon in soil gas emissions was carried out in the Carnmenellis area of Cornwall to establish the location and extent of any major radon gas concentrations. Measurements of soil radon gas levels showed considerable variation. Radon emission variation with respect to atmospheric pressure was monitored but results showed no correlation between the variables. A survey of schools in the region with high indoor radon concentrations was carried out for comparison with the results of the main survey. A good correlation was found between the two surveys, suggesting that broad-based radon hazard mapping on a local scale may be feasible.     

The indoor radon problem: Studies in the Albuquerque,New Mexico area

Radon buildup in homes is now recognized throughout the world as a potentially major health hazard. The U.S. Nuclear Regulatory Commission and the U.S. Environmental Protection Agency estimate 8,000–30,000 fatalities per year in the United States due to indoor radon. The Albuquerque, New Mexico area was chosen for study because it is representative of metropolitan areas in the southwestern United States where slightly uraniferous source rocks (Sandia granite) have provided the very immature soil for much of the area. The granite contains 4.7 ppm U, and limestone capping the granite 5.7 ppm U. Soils in the area average 4.24 ppm U, and Th/U ratios average 3.2. These data suggest some removal of U from the source rocks, but fixation of the U in the soils (that is, as opposed to widespread removal of the U by solution), thus providing a ready source for soil radon. A pilot study of soil radon in the area in winter of 1983–1984 shows high values, 180 pCi/l, relative to the U.S. average (about 100 pCi/l). In the winter of 1986–1987, 180 dwellings were surveyed for their indoor radon levels, including 20 that had been surveyed in summer of 1986. Twenty-eight percent of those in the winter study yielded indoor radon above the EPA suggested maximum permissible level of 4 pCi/l air, well above the EPA estimate of 10–15 dwellings for the U.S. The indoor radon levels show positive correlation with closeness to the Sandia Mountains, to soil radon, to excess insulation, to homes with solar capacities, and other factors. Building materials may provide a very minor source of some indoor radon. Summer readings are lower than winter readings except when the houses possess refrigerated air conditioning.     

Radon variations in an active landslide zone along the Pindar River, in Chamoli District, Garhwal Lesser Himalaya, India

Radon measurements were made in the soil and spring/seepage water in and around an active landslide located along the Pindar river in the Chamoli District of Uttaranchal in Garhwal Lesser Himalaya, to understand the application of radon in geological disasters. The landslide is a compound slide i.e. a slump in the crown portion, and debris slide and fall in the lower part. The bedrock consists of gneisses and schists of the Saryu Formation of the Almora Group of Precambrian age. The presence of several small slump scars and debris slide/fall scars along the length of the slide indicates continuous downward movement. The radon concentrations in the present study are much lower in comparison to values reported from other regions. However, the present radon data show relative variation in the slide zone. The concentration of radon measured in landslide zones varies from 3.1 Bq/l to 18.4 Bq/l in spring water and from 2.3 kBq/m³ to 12.2 kBq/m³ in the soil gas of the debris. Along the section of the slide, the radon values in water and soil are slightly higher in the upper slopes i.e. toward the crown portion of the landslide as compared to the distal portion. The relatively low concentration of radon both in soil gas and water in the toe portion of the landslide may be due to the high porosity of the debris, which does not allow radon to accumulate in the soil and water, whereas, towards the crown portion, the high frequency of fractures increases the surface area due to particle size reduction, and the near absence of debris enhances the radon emanation in soil.     

Radon distributions in the Hail Region of Northern Saudi Arabia

Indoor radon measurements were carried out in a total of 420 dwellings and 17 schools in Hail region of Saudi Arabia, using NTDs based radon dosimeters. The duration of the measurements was one year, from April 2008 to April 2009. The indoor radon concentrations varied from 4 to 513 Bq/m³ with an overall average of 45 Bq/m³ for all surveyed dwellings. These passive measurements were confirmed by the active measurements. The anomalous concentrations above 200 Bq/m³ were observed in 13 dwellings, representing 3.1 % of the total surveyed dwellings. In Inbowan village alone, it was found that 7.6 % of the dwellings have indoor radon concentration above 200 Bq/m³. The highest average indoor radon concentration of 64 Bq/m³ was found in Inbowan village while the lowest average of 24 Bq/m³ was found in Majasah village. The city of Hail showed an average indoor radon concentration of 49 Bq/m³. The average indoor radon concentration in one area located at the edge of the Aja Mountain in Hail city was 111 Bq/m³. The elevated indoor radon concentrations in many dwellings in the Hail region, prompted us to measure outdoor ground radon in such locations using gas monitor. It was found that radon concentrations at a depth of 0.5 m varied significantly from place to place ranging from 1.2 to 177 kBq/m³. The outdoor radon concentrations are generally correlated with the indoor radon measurements. Radon exhalations from construction materials and soil samples from the Hail region were also measured. It was found that radon exhalations from soil samples are higher than that of construction materials by a factor of at least 3 and reaching up to 11. These results indicate that soil is the main source of indoor radon. Geological interpretations of the results are also given.     

济南平阴氡温泉水化学成分与同位素特征研究

在系统的分析济南平阴氡温泉水化学成分和同位素特征的基础上,结合当地地形和水文条件,研究了氡温泉水的起源和形成年龄,结果显示:济南平阴氡温泉水温为28.3℃,pH值为中性,水化学类型为Cl·SO4-Na·Ca型,富含氡、锶、氟、锂、溴、偏硅酸、偏硼酸等微量元素,且含量均符合理(医)疗热矿泉水水质标准,其中氡含量特别高是该温泉的一个显著特点。氡温泉水的同位素测定资料显示,平阴氡温泉热水起源于大气降水,用氚及14C法估算出的氡温泉水的表观年龄在15.81±2.17 ka。     

Radon in Himalayan springs: a geohydrological control

 This paper presents the results of radon measurements in springs of the Himalayan region by using radon emanometry technique. The radon was measured in different springs, draining from different geohydrological setups, and from stream water in order to find the geohydrological control over radon concentration in groundwater emanating in the form of spring. The radon values were found to vary from 0.4 Bq/l to 887 Bq/l, being observed lowest for a turbulent stream and highest for the spring. The radon values were recorded highest in the springs draining through gneiss, granite, mylonite, etc. Radon concentrations have been related with four spring types viz. fracture-joint related spring, fault-lineament related spring, fluvial related spring and colluvial related spring, showing geohydrological characteristics of the rocks through which they are emanating. The high radon concentration in fracture-joint and fault-lineament spring is related to increased ratio of rock surface area to water volume and uranium mineralisation in the shear zones present in the close vicinity of fault and thrust. The low concentration of radon in fluvial and colluvial springs is possibly because of high transmissivity and turbulent flow within such deposits leading to natural de-emanation of gases. Received: 6 January 1998 · Accepted 11 May 1999