中国环境水氚浓度及其变化

目的 研究90年代初我国环境水氚浓度的水平,分布和变化,建立我国第一个核电站商业运行前环境氚数据库,方法 在全国25个省、市、自治区和香港特区采集水蒸气水,降水,江、河水、湖、库水,自来水,井水,泉水,海水等8类水体1547个有代表性水样品,用国标推荐的方法进行样品处理,制备,用低本底液体闪烁谱仪做水氚测量,用MSOffice建立氚数据库和进行数据处理,用趋势拟合分析求解各类水体氚浓度的经、纬度和时间变化关系。结果 确定了我国第一个核电站商业运行前各类水体氚浓度代表值,给出了各类水体氚浓度的经、纬度时间变化趋势。结论 各类水体氚浓度随纬度和经度线性变化,随时间指数变化,90年代初多种水体氚浓度接近天然氚水平,但空气水蒸气水,降水和泉水氚浓度呈现缓慢升高趋势,应加强核电站氚释放的监测。     

我国食物和环境氚所致居民剂量

目的：研究90年代初我国第一人核电站商业运行前我国居民经食物,饮水和空气途径的年氚摄入量和氚致待有积有效剂量。方法：根据我国食物和环境氚调查的氚浓度数据。我国居民空气、饮水和食物摄入量数据和ICRP72号出版物推荐的剂量系数,用MSOffice软件进行计算和归因分析。结果：计算了氚致列我国各地区成年,少年,幼儿组经诸途径的年氚摄入量和待积有效剂量。我国成人,少年和幼儿平均每年的氚摄入量分别为16200,11600和8040Bq/a,氚致待积有效剂量分别为0．53,0．52和0．75μSv/a。结论：我国氚致居民剂量的主要来源是食物,特别是食物中的有机结合氚,食物氚致剂量对3个年龄组平均约占87％。     

中国食物和环境氚数据库的建立

20世纪90年代初期，受卫生部委托，在我国25个省、市、自治区和香港特区等较大范围内开展了一次较为系统的食物和环境氚水平监测及其所致居民剂量研究。本次研究获得的数据可作为我国氚环境的背景值。因此，创建中国食物和环境氚数据库，会对今后深入开展环境和食物中氚的监测及其生物效应的研究起到参考、借鉴的重要作用。     

上海市环境氚调查与所致居民剂量估算

目的：为了解上海市的环境氚含量及其由此所致居民剂量，从１９８８年～１９９３年取不同的环境样品进行了氚含量的测量。方法：用液体闪烁法测量氚。结果：发现上海市环境水和食品氚含量为一般本底水平。其中自来水和地表水氚浓度分别是１．１９Ｂｑ·Ｌ－１和１．５４Ｂｑ·Ｌ－１，且枯水期地表水氚浓度明显高于丰水期（Ｐ＜０．０５）。空气氚和雨水氚浓度均值是０．６３Ｂｑ·ｍ－３和３．６９Ｂｑ·Ｌ－１，季节变化规律不明显。食品游离水氚和有机结合氚含量均值分别是４．１１Ｂｑ·Ｌ－１和２８．４４Ｂｑ·Ｌ－１，ＳＡＲ值是６．９２。上海地区居民的待积有效剂量当量为０．２４μＳｖ，剂量的５０％是来自食品。结论：上海环境氚含量属一般本底水平，对居民身体不构成危害。     

我国部分城市地下水饮用水氡含量及剂量贡献研究

目的 初步调查我国典型城市地下水饮用水氡水平和分布特征,估算生活用水地下水氡释放所致居民有效剂量。方法 选择北京、内蒙古、宁夏、陕西、河南、辽宁和黑龙江共7个省(自治区、直辖市)的12个典型城市,采集市政地下水供水共73个水样,采用连续测氡仪水氡测量装置测量水氡含量,估算生活用水地下水氡释放所致居民有效剂量。结果 7个省(直辖市)12个城市的地下水饮用水氡含量均值为11.8 Bq/L,范围为1.0~63.8 Bq/L,有37%的样品氡含量超过了美国环境保护部(EPA)推荐的饮用水氡浓度限值11.1 Bq/L。全部样品氡含量低于世界卫生组织(WHO)建议的公共饮用水氡浓度参考水平100 Bq/L。生活用水地下水氡释放所致居民年有效剂量均值为29 μSv(2.4~160 μSv)。结论 通常情况下,生活用水地下水氡释放对居民的剂量份额较低,可以忽略。但是,在一些花岗岩地区,生活用水过程地下水氡释放所致居民的剂量贡献应该引起重视。     

康奈尔健康量表评价飞行学员精神健康状况的前瞻性研究

采用康奈尔健康量表（CMI）对1273名飞行学员的精神健康状况进行了为期两年的前瞻性调查。结果显示，CMI总分及各部分得分均数逐年下降；低分组段人数逐年增多；得分高于精神障碍筛查标准（CMI总分≥30分，M～R分≥10分）者分别为2．3％（1991年）、1．2％（1992年）和0．9％（1993年）。1993年与1991年比较，X2=9．929，P＜0．01。分析显示，高阳性回答李（＞20％）项目减少（1991年6项，1992、1993年均为1项）；低阳性回答率（＜1％）项目增多（1991年63项，1992年94项，1993年101项）。M～R部分因子分析显示，1991、1992年按因子贡献率排在第一、第二位的因子均为不适应（因子贡献率分别为396％、9．3％）和抑郁（分别为93％、9．4％），1993年则为情绪不稳定（41．8％）和不适应（11．3％）。提示，经过飞行院校的学习和锻炼，飞行学员的躯体和精神健康状况均有明显改善，精神症状特征有所变化。     

日本福岛核事故期间环境放射性水平的监测

目的 检测日本福岛核事故期间我国部分地区环境样品中人工放射性核素的含量,评价事故对我国的放射性污染程度.方法 采集大气气溶胶、水、生物、土壤等样品共计118个,采用高纯锗( HPGe)γ谱仪分析样品中131I和137Cs等人工放射性核素的活度浓度.结果 在大气气溶胶样品中陆续检测到了微量131I、134 Cs、137Cs和136Cs,其中4月2日的活度浓度分别达到1720、247、289和23μBq/m3;在1份雨水样品和2份表层土壤样品中,均检测出极微量的131I,比活度分别为2.08 Bq/L,1.82和0.59 Bq/kg;4月2-13日采集的18份蔬菜样品中,均检测出极微量的131I,含量为055 ～2.68 Bq/kg.牛奶、饮用水、海水和海产品中均未检出异常浓度的131I和137Cs.结论 福岛核事故期间,我国的部分环境样品测到了极微量的人工放射性污染,但其对公众成人所致待积有效剂量极其微小,不会影响公众健康.     

浅谈高压注射器在CT增强中的作用

20世纪90年代中期，高压注射器已在北美、欧洲、及日本普及，90年代初开始进入我国并在CT影像诊断、血管造影及MRI检查的应用中得到肯定，如今高压注射器的有无已成为衡量医院检查手段是否完备的依据之一。     

125I-抑制素在大鼠垂体和下丘脑的放射自显影研究

目的研究抑制素（INH）在体条件下能否通过大鼠的血脑屏障及在垂体或下丘脑的分布。方法采用颈静脉灌流和放射自显影技术，将20只SD大鼠分为4组，每组5只，第1～3组（实验组）颈静脉注射^125 I-INH50μl，第4（对照）组注射等量的生理盐水。第1，2，3组分别于注射后30，60和120min断头处死，取出垂体、下丘脑，以生理盐水洗涤，测量放射性计数，取放射性最大组的垂体与下丘脑组织行放射自显影分析。结果第1组垂体的放射性最高[（1008．00±5．78）Bq]，而第2和3组分别为（723．00±4．95）和（491．00±4．90）Bq；1～3组的下丘脑放射性分别为（20．00±1．01），（22．00±0．95）与（19．00±0．73）Bq。第4组垂体与下丘脑的放射性分别为（16．00±1．40），（15．00±0．98）Bq。各实验组大鼠垂体的放射性与对照组差异有统计学意义（P〈0．01），且在注射后30min放射性最大（第1组），60和120min后逐渐降低；而实验组与对照组大鼠的下丘脑放射性差异无统计学意义（P〉0．05）；放射自显影结果示，实验组大鼠的垂体组织上有明显的银颗粒，而对照组没有；实验组和对照组大鼠的下丘脑组织上均未见明显的银颗粒。结论^125I-INH能通过大鼠血脑屏障，垂体在注射后30min放射性最大，在大鼠垂体上有INH结合位点或受体，而在其下丘脑没有。     

苏州市水中放射性水平调查及其质量评价

目的对苏州市水源的放射性水平进行调查和评价。方法采用BH1216型低本地α、β放射性测量装置，用^241Am和优质纯KCl分别作为总α、总β放射性测量的标准源，采用中等厚度相对测量法测定样品中的总α、总口放射性活度。结果苏州市各种水样的总α放射性水平为（2．62±0．17）×10^-2～（8．48±2．80）×10^-2 Bq／L；总β放射性水平为（0．77±0．47）×10^-1～（3．75±0．26）×10^-1 Bq／L；β/α的平均值为1．6—7．2。结论苏州市水源没有受到人工放射性核素的污染，其水源水质量均为优良水平；所有水源中浅井水的总放射性水平最高。     

Low-level measurements of tritium in water.

Using a liquid scintillation counter, an experimental procedure for measuring low-level activity concentrations of tritium in environmental water has been developed by our laboratory, using the electrolytic tritium enrichment. Additionally, some quality tests were applied in order to assure the goodness of the method. Well-known water samples collected in the Tagus River (West of Spain) and the Danube River (Bulgaria), both affected by nuclear plant releases, were analysed and results were compared to previous data. The analytical procedure was applied to drinking water samples from the public water supply of Seville and mineral waters from different springs in Spain in order to characterize its origin. Due to the very low levels of tritium in the analysed samples, some results were reported as lower than the minimum detectable activity concentration (MDA). However, the count rate of these measurements was over the background count rate of LS counter in all the cases. For that reason, an exhaustive discussion about the meaning of the MDA, using an experimental essay, was made in order to establish a rigorous criterion that leads to a reliable value in the case of low-level measurements.     

Design and performance of a mass spectrometric facility for measuring helium isotopes in natural waters and for low-level tritium determination by the 3He ingrowth method

The design and performance of a mass spectrometric system for the measurement of helium isotopes and very low tritium concentrations in natural waters are described and discussed in the light of analytical precision and accuracy. The system consists of a VG 3000 mass spectrometer with a fully automated inlet system for preparation and purification of the samples. Along with this mass spectrometric system, different custom-fabricated units are described, especially designed for taking samples, extracting helium or degassing tritium samples prior to the mass spectrometric analysis.The ³He detection limit of the system is close to 10⁻¹⁶ cm³ STP corresponding to a tritium level of 0.003 TU for a 500 g water sample stored six months for ³He regrowth.A vertical oceanic tritium profile from the south hemisphere is presented as an illustration of the system's capability to detect very low tritium concentrations in the environment.     

我国31个城市饮用水氡浓度初步调查

目的:初步调查我国城市饮用水氡水平、分布特征及其影响因素。方法:按照行政区域采样,选择我国31个省会城市和直辖市,采集市政供水管网末梢水样品406份,基于RAD7 H 2O测量装置,采取闭合回路液—气平衡法,利用抓取模式,通过半导体探测器探测气体回路中氡浓度,经过4个循环周期,推算饮用水氡浓度。 ...     

Tritium activity levels in environmental water samples from different origins.

Tritium activity was determined in environmental waters from different areas of Catalonia, using a distillation procedure before liquid scintillation counting. The developed method was validated by analysing two samples from proficiency tests. In most of water samples (from rivers, rain, mineral bottled waters and tap waters) analysed, the activity values were lower or close to the minimum detectable activity (MDA) for our method which has a value of 0.6 Bq/l. However, the Ebro river samples had a mean activity around 3.6 +/- 0.6 Bq/l. The nuclear power station of Ascó, which is located on the banks of this river, can be a source of tritium production and introduction into the environment, so a more exhaustive study of these waters was carried out. Tritium activities in this river were a long way above the normative limit in Spain for waters intended for human consumption, which is 100 Bq/l.     

氚在孕鼠体内的分布和向胎鼠转移特点的研究

作者重点研究了氚水在孕鼠和胎体内的分布代谢及母体中的氚通过不同转移方式向仔代转移的特点．实验用Ｃ５７ＢＬ纯种小鼠，１次腹腔注入１．８５×１０４Ｂｑ／ｇ体重的氚水。实验结果表明；氚能通过胎盘向胎鼠转移，在氚注入后的第２天母体中所测组织器官中的氚活度占注入量的５１％，到第２０天时为１％～２％．各组织间的氚分布水平相差不大，转移系数为０．９９．母体氚也能通过乳汁向胎鼠转移，表现于氚在母体组织中的活度分布低于氚在仔鼠相同组织中的活度．使氚自母体向仔鼠的转移系数超过１～２．可认为，母体氚通过乳汁向仔鼠的转移比通过胎盘转移的转移系数大，因此其辐射影响更大．     

Measurement of radioactivity in bottled drinking water in Spain.

The radioactive parameters in the Spanish regulations on water intended for human consumption (law decree 140/2003) have been determined in 30 different brands of some of the most common bottled mineral waters produced and consumed in Spain. These waters are not included in this legislation but if their consumption increases, the dose of radiation in the population may also increase. After gross alpha activity, gross beta activity, gross beta without potassium contribution and tritium activity had been determined, only a few samples (16% of the samples analysed) were over the normative limit for gross alpha activity (0.1 Bq/l), whereas all the samples were below the normative limits for the other parameters. For samples with high gross alpha activity values, (226)Ra and (224)Ra were determined. The values were between 0.01 and 1.52 Bq/l, and between 0.01 and 0.38 Bq/l, respectively, so alpha activity should be considered to be of natural origin.     

Inter-laboratory comparison measurements of radiochemical laboratories in Slovakia

The first inter-laboratory comparison organized by the radiochemistry laboratory of Water Research Institute (WRI) in Bratislava was carried out in 1993 and since then is it realized on an annual basis and about 10 radiochemical laboratories from all over Slovakia are participating. The gross alpha and gross beta activities, and the activity concentrations of ²²²Rn, tritium, and ²²⁶Ra, and U_nat concentration in synthetic water samples are compared. The distributed samples are covering the concentration range prevailing in potable and surface waters and are prepared by dilution of certified reference materials. Over the course of the years 1993–2008, we observed the improvement in the quality of results for most of the laboratories. However, the success rate of the gross alpha determination activity is not improving as much as the other parameters.     

Tritium monitoring around a nuclear power station in normal operation

Tritium concentrations were measured in various environmental materials around a typical nuclear power station in Japan. Sampling was carried out once a month over a year. Clearly elevated tritium was observed on one occasion in pine needles and surface soil in accordance with a high tritium concentration in seawater, though no incidental tritium increase was observed in atmospheric water vapour, hydrogen and methane.     

生物样品中氚的前处理装置的设计

目的 为监测生物样品中氚,设计一套前处理装置,并进行性能评估.方法 使用标准氚水拟合探测效率的标准曲线.利用高、中、低3种不同活度标准氚水和3H-TdR,分别测定自由水氚和有机氚的前处理化学回收率,并对3种生物样品中氚进行比对测量.结果 拟合的标准曲线可以用于环境中氚放射性测量,氚的仪器探测效率为23.3%.该装置在处理加标样的40.0 g的大米样品时,对标准氚水和3H-TdR平均化学回收率为95.4%,重复性较好.本单位和江苏省辐射环境监测管理站的生物样品比对测量结果分别为小麦1.74和1.80 Bq/kg,紫菜3.44和2.50 Bq/kg,茶叶3.28和5.50 Bq/kg,比对结果接近.结论 设计的前处理装置可以用于环境生物样品中有机氚的测量.

Abstract：

Objective To design a new pre-treatment device and to evaluate its efficiency in order to monitor the tritium levels in biological samples.Methods The detection efficiency of tritium was determined with standard tritiated water.Recovery of tritiated water and organically bound tritium (OBT) were detected with high, medium and low activities of standard tritiated water and 3H-TdR (tritiated thymidine), respectively.Comparison of three kinds of biological samples using different pre-treatment devices was shown.Results The standard curve can be used in environmental tritium measurement and the detection efficiency for tritium was 23.3%.When 40.0 g rice with standard HTO or 3H-TdR was pretreated with this device, the average recovery of HTO and OBT was about 95.4% , which showed good reproducibility.The comparison results were similar.Conclusions The pre-treatment device can be used to survey the OBT in environmental biological samples.