水电站隧道作业场所空气氡浓度水平调查

目的调查水电站隧道作业场所空气氡浓度水平。方法使用PCMR-2连续测氡仪,在3个水电隧道距洞口350~1350m处,选择检测8个作业场所空气氡浓度水平。结果未通风时空气氡及其子体浓度分别为414~5172Bq/m3、372.6~4654.8Bq/m3,通风时空气氡及其子体浓度分别为30~1360Bq/m3、27~1224Bq/m3,遂道长度与空气氡及其子体浓度相关系数分别为0.035、0.036,P值均大于0.5。结论未通风时隧道作业场所空气氡及其子体浓度高于国家标准,通风可有效降低作业场所空气氡及其子体浓度,空气氡及其子体浓度水平与隧道长度无关。     

枣庄矿区井下氡浓度水平与内照射剂量的估算

大量研究表明,矿井中氡浓度远高于地面环境中的氡浓度,是导致矿工肺癌高发的主要原因之一。国内有些专家对云南锡矿、湖南铀矿等有色金属矿山进行了调查研究,研究结果表明,其肺癌发病主要归因子氡子体的作用。目前,对煤矿井下氡浓度水平与肺癌发病关系的研究国内尚未见到系统     

某输水隧洞作业人员氡累积暴露量与致肺癌关系的初步研究

目的通过测算某输水隧洞作业人员氡子体的累积暴露量,探讨氡引起的职业照射水平与致肺癌的关系。方法分别采用氡和氡子体测量仪器,对现场关注点的氡及其子体水平进行了测量,采用被动式累积探测器对隧洞内氡、钍射气浓度水平进行了检测及数据分析。结果隧洞内关注点氡及平衡氡浓度分布呈现了凌晨高于午后的特点,初步分析了隧洞中氡及钍射气来源,氡子体总暴露量约为49.7 WLM,估算有效剂量约为497 mSv。结论从氡及其子体暴露的个案角度分析,在较短的时间内,作业人员接受氡及其子体暴露量的迅速增加。考虑到同时处于恶劣的隧洞施工条件下(单向掘进通风不良,生产性粉尘暴露量高,隧洞内未采用防氡、降氡措施,引水隧洞内气溶胶水平居高不下等),高氡子体暴露和生产性粉尘(游离SiO_2和ThO_2)对职业性肺癌可能具有协同作用,亟需开展职业性肺癌危害的进一步研究。     

旅游溶洞内氡浓度水平放射防护管理措施的探讨

旅游溶洞内氡及其子体浓度比较高,国内旅游溶洞内氡浓度有的高达5076Bq·m^-3。对溶洞内工作人员,氡子体照射年吸收剂量相当于国家对铀矿山井下工人最大限制剂量的75%。从溶洞内工作人员及广大游客身体健康考虑,本文对放射防护管理措施作了初步探讨。     

山东省黄金矿山氡及其子体浓度调查

调查并检测山东省主要黄金矿山井下,洗选厂房内,生活区居室内空气中氡及其子体浓度;估算井下矿工暴露在氡子体下的年有效剂量当量。氡浓度用气球法,氡子体α潜能浓度用库斯尼茨法测量。结果 井下,洗选厂房内,生活区居室内氡浓度平均值分别为３６７．０Ｂｑ．ｍ＾－３,９．７Ｂｑ．ｍ＾－３,１３．２Ｂｑ．ｍ＾－３;     

阳江天然高本底辐射地区空气中氡、（气/土）及其子体致居民的剂量估算

目的为了估算阳江天然高本底辐射地区空气中氡、及其衰变子体所致居民的平均年有效剂量和某些人体组织或器官的吸收剂量.方法采用瞬间采样法,同时测量阳江天然高本底辐射地区(HBRA)和相邻的正常本底对照地区(CA)空气中氡、 及其衰变子体浓度,计算出调查地区的氡平衡因子F和平衡当量浓度.根据调查地区空气中累积测量氡, 浓度;氡平衡因子F和平衡当量浓度;人员的居留因子,估算了居民的平均年有效剂量和某些人体组织或器官的吸收剂量.结果HBRA室内、外空气中氡浓度分别是49.61Bq@m-3和17.30Bq@m-3,CA是18.1Bq@m-3和11.7Bq@m-3;HBRA室内、外浓度分别是95.16Bq@m-3和9.3Bq@m-3,CA是12.4Bq@m-3和8.1Bq@m-3.HBRA室内、外氡的平衡因子F分别是0.46和0.53,CA分别是0.62和0.63.HBRA室内、外空气中平衡当量浓度分别是6.51 Bq@m-3和0.79Bq@m-3,CA室内、外分别是0.66Bq@m-3和0.33Bq@m-3.结论氡、及其衰变子体所致HBRA和CA居民的平均有效剂量分别是3.28mSv@a-1和1.03mSv@a-1.HBRA的居民支气管上皮组织和肺的吸收剂量分别为5.40mGy@a-1和1.08mGy@a-1,它们的吸收剂量分别约是CA的4倍. 和它的衰变子体致HBRA居民的平均有效剂量是1.75mSv@a-1,它们是所调查的高本底辐射地区内照射剂量主要来源之一.     

某铀矿矿工肺功能指标测定及其逐步回归分析

本文测定了某铀矿203名职工的5项肺功能指标VC，FEV1，FEV1％，MMEF和MBC，并了逐步回归分析，发现在可能影响肺功能各项指标的因素中，以呼气氡浓度和矿工氡子体累积暴露水平的作用最大，提示铀矿工长期接触高浓度氡及其子体，其肺功能可能受到一定程度的损害。     

广州某地下人防工事空气氡浓度监测分析

目的 了解广州某地下人防工事空气氡浓度水平及其变化规律。方法 采用RAD7型测氡仪对指挥中心、通道等场所进行瞬时氡浓度测量与分析,并粗略估算氡及其子体所致工作人员年有效剂量。结果 指挥中心、无线通讯室、中央主通道和仓库区通道这4个有人员停留的主要工作场所的日间氡浓度均值分别为106.7、98.4、129.0、111.1 Bq/m³,总体平均为111.0 Bq/m³。²²²Rn子体所致工作人员的年有效剂量当量为0.400 mSv/a。结论 不同场所的氡浓度不尽相同,且其受通风、排水等人为活动的影响呈不同的变化规律。     

非铀矿山氡与矿工肺癌关系的探讨

氡及其子体是一种职业危害因素,关于氡及其子体的危害国内外已有报道。1984～1986年我们对本地区十三个非铀矿矿井氡及其子体浓度与1970～1984年的矿工肺癌发病情况进行了调查。结果发现:     

阳江高本底辐射地区环境中氡及其子体的测量

测量了高本底辐射地区 (HBRA)和相邻的“正常”本底地区 (CA)空气中氡、及其它们的子体浓度和氡的平衡因子F。HBRA室内、外空气中平均氡浓度分别为 42 6和 17 3Bq/ ,CA分别为 13 2和11 7Bq/ 。HBRA室内、外氡子体α潜能值分别是 0 10 9和 0 0 5 1μJ/ ,CA室内、外分别是 0 0 45和0 0 41μJ/ 。子体α潜能浓度HBRA室内、外分别是 0 2 49和 0 0 5 3 μJ/ ,CA分别是 0 0 5 1和 0 0 2 5 μJ/ 。HBRA室内、外氡的平衡因子F分别是 0 46和 0 5 3 ,CA分别是 0 62和 0 64。     

我国锡矿山的辐射水平和放射卫生防护对策研究

目的 探索辐射水平在我国锡矿山的分布情况,在此基础上提出放射卫生防护的建议,为保护锡矿山井下工人身体健康提供科学依据。方法 分析、应用文献资料和现场调查的测量结果,得到了锡矿山井下工作场所的辐射水平。结果 锡矿山井下环境中γ辐射空气吸收剂量率绝大部份属于正常本底辐射水平。早期,锡矿山井下工作场所空气中氡浓度及氡子体α潜能浓度浓典型值分别为3.12 kBq/m³和5.61μJ/m³。目前,绝大多数锡矿山井下工作场所空气中氡浓度及氡子体α潜能浓度,分别低于1 000 Bq/m³和3.57μJ/m³。结论 锡矿山工作人员中凡个人年有效剂量大于1mSv或物料中天然铀比活度大于1 Bq/g的锡矿山均应进行放射卫生防护的审管。锡矿山井下工作场所空气中氡及氡子体α潜能浓度和井下环境中γ辐射空气吸收剂量率管理限值分别为1 000 Bq/m³、3.57μJ/m³和1μGy/h。锡矿山井下矿工个人剂量管理目标值定为10mSv/a。工作人员总的年有效剂量超过10 mSv时,工作人员应视为放射工作人员。     

降氡方法在室内氡污染治理中的应用与分析

目的 探索降低住宅氡及其子体浓度水平的合适方法.方法 选取3个房间分别采取自然通风、空气净化器、密封屏蔽的措施后,使用EQF3120型氡及其子体测量仪测量室内氡及其子体浓度,α核径迹探测器测量室内氡浓度,并比较不同方法的降氡效果.结果 自然通风2～10 h后,房间内氡、结合态氡子体和未结合态氡子体浓度平均降低率分别为8...     

Mortality of Sardinian lead and zinc miners: 1960-88.

The mortality of 4740 male workers of two lead and zinc mines was followed up from 1960 to 1988. Exposure to respirable dust was comparable in the two mines, but the median concentration of silica in respirable dust was 10-fold higher in mine B (12.8%) than in mine A (1.2%), but the mean annual exposure to radon daughters in underground workplaces differed in the opposite direction (mine A: 0.13 working levels (WL), mine B: 0.011 WL). Total observed deaths (1205) were similar to expected figures (1156.3) over a total of 119 390.5 person-years at risk. Underground workers of mine B had significant increases in risk of pulmonary tuberculosis (SMR 706, 95% confidence interval (95% CI) 473-1014) and non-malignant respiratory diseases (SMR 518; 95% CI 440-1606), whereas the only significant excess at mine A was for non-malignant respiratory diseases (SMR 246; 95% CI 191-312). Total cancer and lung cancer mortality did not exceed the expectation in the two mines combined. A 15% excess mortality for lung cancer, increased up to an SMR 204 (95% CI 89-470) for subjects employed > or = 26 years, was, however, found among underground workers in mine A who on the average experienced an exposure to radon daughters 10-fold higher than those of mine B. By contrast, despite their higher exposure to silica, mine B underground workers experienced a lower than expected lung cancer mortality. A ninefold increase in risk of peritoneal and retroperitoneal cancer combined was also found among underground workers of mine A (SMR 917; 95% CI 250-2347; based on four deaths). A causal association with workplace exposures is unlikely, however, as the SMR showed an inverse trend by duration of employment. These findings are consistent with low level exposure to radon daughters as a risk factor for lung cancer among metal miners. Exposure to silica at the levels estimated for the mine B underground environment did not increase the risk of lung cancer.     

Measurements of radon-daughter concentrations in and around dwellings in the northern part of The Netherlands; a search for the influences of building materials, construction and ventilation

The concentration of radon daughters has been determined in and around 80 dwellings located in the northern part of the Netherlands by using a one-filter method. Median values of 2.0 and 0.4 mWL were measured for the indoor and outdoor concentrations, respectively. The average outdoor concentration was about an order of magnitude higher for wind directions between SE and SW than for SW-NW. On the average, dwellings with double-pane windows and/or concrete floors were found to have significantly higher radon concentrations than those with single-pane windows and/or wooden floors. For the living room of a particular dwelling 18 measurements were carried out. The data for this dwelling indicate a linear relation between the concentration indoors and outdoors with a slope of 3.8 +/- 2.0. This unexpected behaviour is thought to be related to ventilation via the crawl space. Measurements of ventilation patterns and measurements of radon concentrations in the living room and the crawl space are consistent with this picture.     

寿光日光温室春秋季氡浓度变化趋势及辐射剂量估算

目的初步了解日光温室中氡浓度的本底值和变化趋势,估算温室作业人员氡及其子体造成的年均辐射剂量,探讨温、湿度对氡浓度的影响。方法 2009年5月和10月分别对选定的2座温室进行调查,使用Model1027连续测氡仪和干湿球温度计对温室环境中的氡浓度、温度和相对湿度进行8h连续监测。结果在测定范围内,5月温室氡浓度、温湿度最大值分别为355.0Bq/m3、30.5℃和93%,10月各指标的最大值分别为235.4Bq/m3、37.5℃和72%;根据实际情况粗略估算的温室作业人员年均辐射剂量为0.8686mSv。结论温度和相对湿度可能是影响温室中氡浓度的重要因素;温室作业人员由于职业因素所造成的氡及其子体的辐射剂量略高于当地平均室内暴露所造成的辐射剂量,氡子体对作业人员健康的影响应引起重视。     

Radon concentrations in elementary schools in Kuwait

Measurements of indoor radon concentrations were performed in 25 classrooms in the capital city of Kuwait from September 2003 to March 2004 using track etch detectors. The investigation was focused on area, ventilation, windows, air conditioners, fans, and floor number. All the schools have nearly the same design. Mean indoor radon concentration was higher for case subjects (classrooms) than for control subjects (locations in inert gas, p < 0.001). The mean alpha dose equivalent rate for case subjects, 0.97 +/- 0.25 mSv y, was higher than the radiation dose equivalent rate value of control subjects, 0.43 +/- 0.11 mSv y. The average radon concentrations were found to be 16 +/- 4 Bq m for the first floor and 19 +/- 4.8 Bq m for the second floor after subtraction of the control. These values lead to average effective dose equivalent rates of 0.40 +/- 0.10 and 0.48 +/- 0.12 mSv y, respectively. The equilibrium factor between radon and its progeny was found to be 0.6 +/- 0.2.     

Current status of programmes to measure and reduce radon exposure in Irish workplaces.

National legislation, which implements European Council Directive 96/29/EURATOM in Ireland, sets a reference level of 400 Bq m(-3) averaged over any 3 month period for radon exposure in the workplace and also empowers the Radiological Protection Institute of Ireland to direct employers to have radon measurements carried out. This legislation came into effect in May 2000. Radon measurements have already been completed in show caves and other underground workplaces. Between 1998 and 2001, over 33 800 individual radon measurements were carried out in all ground floor offices and classrooms in 3444 schools nationwide as part of a programme undertaken jointly with the Department of Education and Science. Where the average indoor radon concentration in one or more rooms exceeded 200 Bq m(-3), remedial measures were implemented. For concentrations up to 400 Bq m(-3) this involved increased ventilation while for higher concentrations an active sump was normally installed. The results of the survey, as well as the effectiveness of the different remedial strategies, are discussed. In the case of other above ground workplaces, different approaches have been adopted. As a first step, workplaces in two known high radon areas were directed to have radon measurements carried out. This programme had limited success because of problems in obtaining accurate workplace databases and a general lack of awareness on the part of employers of the issues involved. From a sample of 2610 employers directed to measure radon, only 408 actually completed measurements and 37 workplaces were identified as having average 3 month average radon concentrations above 400 Bq m(-3). A total of 1356 employers ignored all correspondence, some of which was sent by registered post and signed for on receipt. Current initiatives are focused on the provision of information and include newspaper advertising as well as publications aimed specifically at both employer and employee representative groups. The ability to provide accurate information that encourages both measurement and remediation is seen as central to an effective radon workplace programme.     

Measurement of the equilibrium factor between radon and its progeny in the underground mining environment

A scintillation cell and a portable radiation spectrometer for radon progeny were respectively employed to measure the concentration of radon and that of its progeny in the underground gold mine environment. The measured concentrations were subsequently used to calculate the equilibrium factor between radon and its progeny. The results obtained indicate that various locations underground have different values of radon concentration and ratios of radon concentration to its progeny concentration. The differences can be ascribed to variations in grades of uranium at different locations and to some environmental factors such as ventilation, particle concentration, and the deposition of the progeny on surfaces or on the atmospheric aerosol.     

云南省某矿区氡浓度水平调查分析

目的 调查云南省某锡矿、铜矿及非矿区居室内空气中的氡浓度以及相应采样点自来水中氡浓度，估算人体受照剂量。方法 径迹法测量锡矿、铜矿井下、地上工作场所空气中的氡浓度，使用RAD7仪器连续测量法测得居室内空气中氡浓度、RAD7水氡测量系统测量自来水氡浓度。评估不同来源氡所致受照剂量的贡献。结果 锡矿的矿下、地上工作场所空气平均氡浓度分别为（7 473 ±3 105）Bq·m⁻³和（332 ±238）Bq·m⁻³，其所致年剂量贡献分别为（29.44 ±12.23）mSv和（2.50 ±1.79）mSv；铜矿井下、地上工作场所空气中氡浓度分别为（4 477 ±5 152）Bq·m⁻³和（110 ±32）Bq·m⁻³，其所致年剂量贡献分别为（17.64 ±20.30）mSv和（0.83 ±0.24）mSv；居室空气氡浓度（76 ±33）Bq·m⁻³及年剂量贡献（2.01 ±0.87）mSv。铜矿及锡矿的自来水氡浓度测量结果分别为（1.66 ±2.00）Bq·L⁻¹和（3.94 ±1.81）Bq·L⁻¹，高于市内32个采样点自来水氡浓度（0.39 ±0.21）Bq·L⁻¹。结论 目前所测区域水氡所致剂量贡献相对较小，锡矿、铜矿区井下工作场所空气氡浓度值得关注，应重视对矿工使用防护用具的宣传教育工作。     

The equilibrium factor F

Consideration of the equilibrium factor F between the concentration of the radon daughters and the concentration of radon is a part of the evaluation of the measurements of radon daughter concentrations in dwellings when applying limits. Measurements of radon, radon daughters and air exchange rates have been carried out in 225 dwellings in Sweden. The F-factors have been compared with the theoretical model described by Wicke, taking into account the wall effect. The parameters of the model are discussed. The situation of the dwelling and the habits of the occupants can be expected to have the greatest importance for the F-factors although the ventilation rate is usually the most important modifying factor. For low air exchange rates (l less than 0.30 hr-1) the probability that the F-factors were between 0.28 and 0.74 was 95% calculated according to the t-distribution. The arithmetical mean was found to be 0.51. For air exchange rates close to the average rate (0.30 less than l less than 0.60 hr-1), the F-factors were between 0.21 and 0.66 with a mean of 0.43, and for high air exchange rates (l greater than 0.60 hr-1) the F-factors were between 0.21 and 0.47 with a mean value of 0.33.