五大连池氡矿泉水中氡含量特征分析

本文对五大连池地区氡矿泉水中氡含量进行了等级划分,并讨论了不同浓度氡矿泉水对应的医疗效果、使用方法及危害性。     

氡测量方法与标准氡室综述

本文介绍了常用的氡测量方法和测氡仪器,对氡测量技术进行了较详细分析,为选择适宜的方法进行氡浓度监测提供了参考。标准氡室的研制为各种测氡仪器的刻度和量值溯源性提供了技术支撑,保证了测量结果的准确可靠,文章简要介绍了国内外标准氡室的发展状况。     

氡可致癌

The New England Journal ofMedicine的评论指出,氡这种由土壤、石头及许多建筑材料里放出的放射性气体,可能在不吸烟者中造成了1万名肺癌患者的死亡。这篇评论是在对富氡环境中工作的矿工肺癌患者进行研究后写的。氡常聚集在地下,在通风情况不好的房间及建筑物的地下室也可发现。它在户外空气中会迅速地冲淡。可以推测,在导致肺癌的诸因素中,氡     

人类首次精确测量低浓度氡

正自然界中的放射性惰性气体氡无色、无味、无嗅,但是大剂量高浓度的氡却是致命的。高剂量的辐射主要存在于由花岗岩组成的底土中。同样,它也存在于建筑材料中。长久以来,人们已经了解高浓度的氡可以导致肺癌。然而,科学家现在认为低浓度的氡也有致病的危险,并增加了氡辐射效应的等级划分。氡     

室内空气中氡的防护

介绍了氡的产生和特性,阐述了室内氡的来源,介绍了室内氡浓度的测量方法,由此总结了降低室内氡浓度的一些控制措施,以期创造健康的室内环境.     

地下工程中氡的来源与检测方法

在重庆,存在大量的地下工程,如人防工程,地下商场等,但至今没有发现对其中氡浓度进行检测的报道.本文介绍了地下工程中氡的来源,综述了当前使用的氡的检测方法,认为现在广泛使用于普通室内氡检测的方法需进一步改进才能应用于地下工程中氡的检测.     

中型氡室温湿度智能控制系统设计

氡室可以对广泛使用的各种测氡仪器进行刻度、性能测试,并进行氡的控制实验。国家有关标准规定,氡室的温度应该在-5℃到＋40℃内可控,在测氡仪的标定过程中应使用常温标定,并且湿度要满足一定的要求。依照校准规定,本文研究设计了一种中小型氡室温湿度智能控制系统方案,详细阐述了AVR单片机与温湿度传感器、氡室制冷系统和除湿系统等部件接口实现的软、硬件技术要点。通过理论计算对设计方案进行分析,结果表明是可行的。控制系统既可以独立完成对氡室温湿度的监控,也可以通过RS-232C接口与PC机通信,组成基于PC机的集成控制系统。     

氡室与液体氡源校准氡钍分析仪比对

本文分别使用氡室和液体氡源对氡钍分析仪进行校准,介绍氡室和液体氡源的原理和校准方法,对校准的方法、过程、结果进行分析和探讨。     

浅谈活性炭盒法对室内空气中氡浓度的测量

研究了活性炭盒法测定室内空气中氡浓度的影响因素,考察了采样时间、平衡时间、样品测量时间等对空气中氡浓度的影响。     

铀矿石氡的释放实验研究

采用恒温恒湿箱控制实验温湿度,利用伽玛能谱仪测量不同温度和不同湿度条件下氡的释放量,分析了温湿度对铀矿石氡释放的影响。结果表明,在湿度为60%、70%和80%条件下,氡的释放量随温度升高而增大,呈近似正指数函数关系;在温度为20℃和30℃时,湿度对氡释放的影响不大;40℃以上,湿度对氡释放的影响比较明显,说明湿度对铀矿石氡的释放影响比较复杂,其规律性不明显。     

Radon programme: presence and future

An overview of radon programme experience is presented. The paper summarises broad topics concerning radon issue: philosophy of radon policy, radon measurements strategies with respect to indoor radon variation, progress in radon measurement of an individual house (radon diagnosis), national programmes, the role of preventive measures and interventions with respect to existing and future exposure and knowledge of radon risk, problems of remediation strategies, radon mapping process and sense of delineation of radon prone areas, public awareness on radon issue and publicity campaign. Some research activities are proposed aiming at effective solutions for radon issues in the future.     

Radon in soil gas--investigation and data standardisation at radon reference sites, Czech Republic

Radon risk mapping at building sites in the Czech Republic indicate an advisable level of protection of buildings against the penetration of radon from the geological basement. Various techniques and instruments are used for the measurement of radon in soil gas. A national radon chamber and three radon reference sites in Central Bohemia enable radon data standardisation. Tests of field radon measurements and the reported radon activity concentration in soil gas at the reference sites are based on comparisons with other organisations and with a database of reference site measurements. The radon reference sites have been used for various investigations of radon in soil gas during the period 2000-07.     

Variation of soil radon concentrations in southern Ontario

Radon has been identified as the second leading cause of lung cancer after tobacco smoking. Information on indoor radon concentrations is required to assess the lung cancer burden due to radon exposure. However, radon data in highly populated southern Ontario are very limited. Since radon in soil is believed to be the main source of radon in homes, measurements of soil gas radon concentrations can be used to estimate variations in radon potential of indoor environments. This study reports a transect survey of natural background variation in soil radon levels across southern Ontario. The results indicate that radon risk could be high in some areas of southern Ontario.     

Comparison of urinary excretion of radon from the human body before and after radon bath therapy

Theoretically, the human body absorbs radon through the lungs and the skin and excretes it through the lungs and the excretory organs during radon bath therapy. To check this theory, the radon concentrations in urine samples were compared before and after radon bath therapy. During the therapy, the geometric mean (GM) and the geometric standard deviation of the radon concentration in air and in the bath water were 979 Bq m(-3), 1.58 and 73.6 Bq dm(-3), 1.1, respectively. Since radon was detected in each urine sample (GM around 3.0 Bq dm(-3)), urinary excretion of radon was confirmed. The results of this study can neither reject nor confirm the hypothesis of radon absorption through the skin. A 15 times higher increment of inhaled radon level did not cause significant changes in radon of urine samples.     

Effect of soil parameters on radon entry into a building by means of the transrad numerical model

High indoor radon concentration means an increased risk of developing lung cancer. When high radon levels are present in a dwelling, the major source is normally the soil. Therefore, it is useful to know the radon concentration field in the soil underneath a building. A steady-state two-dimensional radon transport model has been used to calculate the effect of a reference building on the soil radon concentration, and the influence of soil parameters on radon entry through a single crack in the basement. Both advective and diffusive flows are considered. Away from the building, the well-known undisturbed soil radon concentration profile has been obtained, while under the house the radon level is increased. A variability analysis around the reference site has shown that the most relevant soil parameters on the radon flux at the top of the crack are, in this case, effective diffusion coefficient, soil gas-permeability and deep soil radon concentration.     

氡室建标中几个技术问题的解决办法

标准氡室在氡浓度量值溯源和传递中起着重要作用。为了保证测氡仪量值统一、准确可靠,建立了测氡仪检定装置。针对在建立标准过程中出现的流气式氡源泄漏、氡室实验累积氡浓度值与理论值不一致和液体镭源结晶等问题,重点研究多重密封、改造洗气管路、优化洗气模式及多重过滤等技术方法,并建立氡室累积氡浓度经验曲线和质量管理措施等。按照新建立的实验方法和实验流程,氡室实验调节氡浓度和理论累积氡浓度相对偏差在±3.8%以内,液体镭源长期稳定性在0.7%以内,符合氡室建标的计量性能要求。     

Soil radon measurements in the Canadian cities

Radon has been identified as the second leading cause of lung cancer after tobacco smoking. Information on indoor radon concentrations is required to assess the lung cancer burden due to radon exposure. Since radon in soil is believed to be the main source of radon in homes, measurements of soil gas radon concentrations can be used to estimate variations in radon potential of indoor environments. This study reports surveys of natural background variation in soil radon levels in four cities, Montreal, Gatineau, Kingston and the largest Canadian city of Toronto. A total of 212 sites were surveyed. The average soil gas radon concentrations varied significantly from site to site, and ranged from below detection limit to 157 kBq m(-3). For each site, the soil radon potential (SRP) index was determined with the average soil radon concentration and average soil permeability measured. The average SRP indexes are 20±16, 12±11, 8±9 and 12±10 for Montreal, Gatineau, Kingston and Toronto, respectively. The results provide additional data for the validation of an association between indoor and soil radon potentials and for the development of radon potential map of Canada.     

氡测量仪检定/校准装置的研制

为建立氡测量的计量标准,研制以多功能的标准氡室为核心的氡测量仪检定/校准装置。采用氡浓度动态稳定技术以实现氡浓度的自动调控;设计用夹胶钢化玻璃制作氡室以减少箱体对氡的吸附,并具有良好的保温效果;设计制作温湿度调控系统和气溶胶发生与采集装置,实现氡子体放射性气溶胶的检测功能。装置氡室体积为4m3,氡浓度测量范围为370～20000Bq/m3,氡浓度值测量结果的相对扩展不确定度不超过5.8%,可用于测氡仪器的检定校准和氡子体放射性气溶胶的实验研究。     

The US radon problem, policy, program and industry: achievements, challenges and strategies

US radon research, policy and programs have stalled since their start in the late 1980s and early 1990s. In 2005, more homes had radon above the US Environmental Protection Agency (EPA) Reference Level than anytime in history since more homes were added to the housing stock that had indoor radon concentrations exceeding 150 Bq m(-3) than had been mitigated. Funding for the US radon program has declined two-thirds from 1997 to 2007. Despite impressive goals for radon reduction, EPA lacks sound progress indicators especially in new construction radon control systems. School radon reduction has been at a standstill since the early 1990s. There has been no significant radon risk reduction in low-income sectors of the population. There is need for effective partnerships between the public and private sectors of the US radon professional communities as well as with the international programs and professionals.     

氡析出率测量中的218Po非平衡修正

通过对传统的累积法测量氡析出率模型实验验证,发现得到的氡析出率明显偏低。对测氡仪器的工作原理与集氡罩中氡的浓度变化规律进行分析,发现是由于被测介质表面析出的氡不断进入集氡罩,218Po与氡没有平衡,造成测量的氡浓度明显偏低。通过非平衡修正得到了修正后的氡析出率测量理论模型。利用修正后的该模型得到的介质表面氡析出率与参考值符合得较好,误差小于7%。此外比较优值函数的取值也可发现:修正后的理论模型优值函数的取值小于传统模型,这表明修正后的理论模型更符合实际,该理论模型可应用于氡析出率仪的研制与改进。