黄山市环境辐射水平及居民受照剂量调查分析

目的研究黄山市环境辐射水平及居民受照剂量,为辐射防护和经济建设提供背景资料。方法采用FD-71型闪烁辐射仪,测量室内外、道路γ辐射剂量率;采用低本底闪烁测氡仪,测量氡浓度;采用γ能谱分析方法,测量建材中放射性核素226Ra、232Th、40K的含量。结果室内、室外、道路γ辐射剂量率均值分别为12.2×10-8Gy.h-1、8.5×10-8Gy.h-1、8.6×10-8Gy.h-1。地球γ辐射水平室内比室外高,平均比值为1.44,道路与室外的γ辐射水平差异无统计学意义。室内和室外宇宙射线辐射剂量率分别为2.7×10-8Gy.h-1和3.0×10-8Gy.h-1。室内、室外氡浓度均值分别为27.3 Bq.m-3和13.2 Bq.m-3。建筑材料除碳化砖及个别类型中的样品外,其他建材内、外照射指数均低于国家标准。结论黄山市环境辐射外照射所致居民人均年有效剂量当量为0.92mSv,其辐射水平属正常本底水平;室内、外氡浓度致居民受到的人均年有效剂量当量为1.88 mSv。在世界值范围内,传统建材放射性核素含量与世界建材典型值比较接近,其他建材有部分则高于世界建材典型值,应引起相关部门的注意。     

Population dose due to natural radiation in Hong Kong

In densely populated cities such as Hong Kong where people live and work in high-rise buildings that are all built with concrete, the indoor gamma dose rate and indoor radon concentration are not wide ranging. Indoor gamma dose rates (including cosmic rays) follow a normal distribution with an arithmetic mean of 0.22 +/- 0.04 microGy h(-1), whereas indoor radon concentrations follow a log-normal distribution with geometric means of 48 +/- 2 Bq m(-3) and 90 +/- 2 Bq m(-3) for the two main categories of buildings: residential and non-residential. Since different occupations result in different occupancy in different categories of buildings, the annual total dose [indoor and outdoor radon effective dose + indoor and outdoor gamma absorbed dose (including cosmic ray)] to the population in Hong Kong was estimated based on the number of people for each occupation; the occupancy of each occupation; indoor radon concentration distribution and indoor gamma dose rate distribution for each category of buildings; outdoor radon concentration and gamma dose rate; and indoor and outdoor cosmic ray dose rates. The result shows that the annual doses for every occupation follow a log-normal distribution. This is expected since the total dose is dominated by radon effective dose, which has a log-normal distribution. The annual dose to the population of Hong Kong is characterized by a log-normal distribution with a geometric mean of 2.4 mSv and a geometric standard deviation of 1.3 mSv.     

南宁市医院室内氡浓度及γ辐射水平所致工作人员剂量

目的 了解南宁市医院放射科与核医学科室内氡浓度和γ照射量率水平,估算工作人员受照剂量,为辐射防护管理提供依据。方法 采用ATD累积氡探测器和FH40G环境X、γ剂量率仪测量室内外氡浓度和γ照射量率。结果 核医学、放射科地下和地面工作场所、工作人员和居民受照剂量分别是1.98 mSv、1.84 mSv、1.62 mSv、1.48 mSv和1.49 mSv。结论 核医学科工作人员受到的附加剂量主要与放射性同位素的用量与防护条件有关。放射科工作人员剂量增高的原因主要来自氡污染产生的内照射。     

崇明县空气中氡浓度水平调查与评价

目的 了解崇明县室内外氡浓度水平并估算其所致公众的受照剂量。方法 根据2010年全国人口普查崇明县乡镇人口比例、房屋建筑类型、建筑年代和主体建筑材料等对测量样本进行分类选择。使用美国Durridge公司制造RAD7型电子氡气检测仪对室内外氡进行测量,数据采用SPSS 17.0软件进行统计分析。结果 本次调查的室内²²²Rn浓度范围为5.75~195.29 Bq/m³,平均浓度为(25.76±2.07) Bq/m³。约有73.89%的房屋内氡浓度低于40 Bq/m³。室外²²²Rn浓度的范围为5.70~19.32 Bq/m³,平均浓度为(9.92±1.43) Bq/m³。结论 本次调查的崇明县室内氡浓度均未超过国家推荐的控制限值。崇明县居民吸入氡所致人年均有效剂量为0.74 mSv。     

Nationwide survey of radon levels in Korea

A nationwide radon survey was conducted to provide data on the annual average indoor radon concentration in Korean homes. This survey also provided data on the variation of radon concentration with season, house type, and building age. The arithmetic mean (AM) of annual radon concentration in Korean homes was 53.4 +/- 57.5 Bq m(-3). The indoor radon concentration showed a lognormal distribution with a geometric mean (GM) and its standard deviation (GSD) of 43.3 +/- 1.8 Bq m(-3). The radon concentrations in the traditional Korean-style houses were about two times higher than those in apartments and row houses. The average annual outdoor radon concentration was 23.3 Bq m(-3). The average annual effective dose to the general public from radon was 1.63 mSv y(-1).     

Anomalously high radon concentrations in dwellings located on permeable glacial sediments.

Indoor radon concentrations were measured in different seasons in 104 dwellings located on a highly permeable ice-marginal moraine in Kinsarvik, Western Norway. The measurements revealed the highest indoor radon levels ever detected in Norway and extreme variations in seasonal and short-term indoor radon levels. Annual average indoor radon concentrations up to 56 000 Bq m(-3) and a mean value of 4340 Bq m(-3) for the whole residential area are reported. By using the ICRP conversion factors to effective dose, these indoor radon values correspond to a total annual effective dose of 930 mSv and 72 mSv, respectively. By using the conversion as recommended by UNSCEAR, the effective doses would be about 50% higher. The indoor radon concentrations are found to be strongly influenced by thermally induced flows of radon-bearing soil air directed towards the upper part of the ice-marginal deposit in winter and towards the area of lowest elevation in summer. The pattern of seasonal variations observed suggests that in areas where thermal convection may occur, annual average indoor radon levels should be derived from measurements performed both in summer and in winter.     

Population attributable fraction for lung cancer due to residential radon in Switzerland and Germany

Studies on miners as well as epidemiological studies in the general population show an increased lung cancer risk after exposure to radon and its progeny. The European pooled analysis of indoor radon studies estimates an excess relative risk of 8% (16% after correction for measurement uncertainties) per 100 Bq m(-3) indoor radon concentration. Here, we determine the population attributable fraction (PAF) for lung cancer due to residential radon based on this risk estimate for Switzerland and Germany. Based on regionally stratified radon data, the PAF was calculated following the World Health Organization concept of global burden of disease, compared to a realistic baseline radon concentration equal to the outdoor concentration. Lifetable approaches were used taking smoking and sex into account. Measurement error corrections were applied to both risk estimates and the radon distribution. In Switzerland, the average indoor radon concentration is 78 Bq m(-3), resulting in a PAF of 8.3%. Therefore, 169 male lung cancer deaths and 62 deaths in women can be attributed to residential radon per year. For Germany, the average indoor radon concentration is 49 Bq m(-3), corresponding to a PAF of 5.0% (1,422 male and 474 female deaths annually). In both countries, a large regional variation in the PAF was observed due to regional differences in radon concentrations and population structure. Both calculations show a strong dependency on the risk model used. Risk models based on miner studies result in higher PAF estimates than risk models based on indoor radon studies due to different assumptions regarding exposures received more than 35 years ago. The use of a non-zero baseline radon concentration also contributes to the lower PAF estimates reported here. Although the estimates of the population attributable fraction of residential radon presented here are lower than previously reported estimates, the risk is still one of the most widespread environmental hazards. Radon monitoring and radon reduction programs are therefore important issues for environmental public health management.     

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。     

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.     

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 concentration measurements and personnel exposure levels in Bavarian water supply facilities

As part of a study covering the whole of Bavaria, the southern most of Germany's 16 states, water supply facilities were examined to determine the radon (222Rn) concentrations in ground water and indoor air and the radon exposure to the staff working in these buildings. Bavaria can be divided into ten geological regions of different geogenic radon potential. From each region, a number of water supply facilities proportional to the size of the region were selected for measurements. Over 500 of a total number of 2,600 water supply facilities were asked to take a 1-L groundwater sample and expose several track-etch detectors in order to obtain the mean room concentration of the main staff work places. In addition, for a period of 2 mo, the personnel had to wear a track-etch detector during the time they spent in the supply facilities. The resulting measurements were then used to estimate their individual effective dose of radon and its progenies. In the East Bavarian crystalline region, the region of the highest geogenic radon potential within Bavaria, indoor radon gas concentrations of up to 400 kBq m(-3) were observed. About 10% of the process controllers in this region are subjected to an annual effective dose of more than 20 mSv. In the other Bavarian regions, only 2% of staff exposure levels exceed this limit. The correlation between the radon concentration measurements of the indoor air, the ground water, and individual personnel exposure levels was determined. The average ratio of the radon indoor air to the processed groundwater concentration is 0.14. But due to the different types of ventilation in the various supply facilities, there can be great variations in this figure. Therefore, there is no clear relationship between the groundwater and the indoor air concentration of a supply facility. This study also reveals no clear relationship between radon indoor air concentrations and the personnel exposure levels of a supply facility.     

Radon concentration in two largest cities in semitropical Taiwan.

Grab sampling either using the active charcoal method in combination with an ionization chamber or using a working level monitor was performed for the measurement of radon concentration in Taiwan's two largest cities Taipei and Kaohsiung. Long-term monitoring of radon concentration in dwellings and business buildings was also carried out with cellulose nitrate films as the alpha detectors. The average indoor radon concentration in these two cities is 17 +/- 6 Bq m-3. The outdoor radon concentration is about one-half of that on average. As assessed according to the model of UNSCEAR 1988, the induced effective dose equivalent is 0.67 mSv y-1. Radon concentration in coal mines showed an average of 88.5 +/- 9.5 Bq m-3.     

降札温泉空气氡浓度水平调查

目的在既往调查的基础上,进一步了解当地居民、游客、治疗疾病的患者的洗浴模式等情况,并对当地的室内外氡浓度进行测量。方法采用ATD短期累积测量法和连续测量法测量室内外氡浓度,并与国家相关标准进行对比。结果室内外氡浓度几乎全部高于电离辐射防护与辐射源安全基本标准(GB18871-2002)中的住宅中氡持续照射的优化行动水平400Bq/m3(平衡因子0.4)。部分浴室中氡浓度高于地热水应用中放射卫生防护标准(GBZ124-2002)中地热水浴疗室平衡当量氡浓度400Bq/m3的控制限值。结论降札温泉室内外氡浓度水平非常高,会对附近的居民、游客和患者的健康造成影响。     

Radon exposure of the skin: II. Estimation of the attributable risk for skin cancer incidence.

A preceding companion paper has reviewed the various factors which form the chain of assumptions that are necessary to support a suggested link between radon exposure and skin cancer in man. Overall, the balance of evidence was considered to be against a causal link between radon exposure and skin cancer. One factor against causality is evidence, particularly from animal studies, that some exposure of the hair follicles and/or the deeper dermis, as well as the inter-follicular epidermis, is required-beyond the range of naturally occurring alpha particles. On this basis any skin cancer risk due to radon progeny would be due only to beta and gamma components of equivalent dose, which are 10-100 times less than the alpha equivalent dose to the basal layer. Notwithstanding this conclusion against causality, calculations have been carried out of attributable risk (ATR, the proportion of cases occurring in the total population which can be explained by radon exposure) on the conservative basis that the target cells are, as is often assumed, in the basal layer of the epidermis. An excess relative risk figure is used which is based on variance weighting of the data sources. This is 2.5 times lower than the value generally used. A latent period of 20 years and an RBE of 10 are considered more justifiable than the often used values of 10 years and 20 respectively. These assumptions lead to an ATR of approximately 0.7% (0.5-5%) at the nominal UK indoor radon level of 20 Bq m(-3). The range reflects uncertainties in plate-out. Previous higher estimates by various authors have made more pessimistic assumptions. There are some indications that radon progeny plate-out may be elevated out of doors, particularly due to rainfall. Although average UK outdoor radon levels ( approximately 4 Bq m(-3)) are much less than average indoor levels, and outdoor residence time is on average about 10%, this might have the effect of increasing the ATR several-fold. This needs considerable further study. Ecological epidemiology data for the South West of England provide no evidence for elevated skin cancer risks at radon levels <100 Bq m(-3). Case-control or cohort studies would be necessary to address the issue authoritatively.     

Indoor radon and lung cancer in France

BACKGROUND: Several case-control studies have indicated an increased risk of lung cancer linked to indoor radon exposure; others have not supported this hypothesis, partly because of a lack of statistical power. As part of a large European project, a hospital-based case-control study was carried out in 4 areas in France with relatively high radon levels. METHODS: Radon concentrations were measured in dwellings that had been occupied by the study subjects during the 5- to 30-year period before the interview. Measurements of radon concentrations were performed during a 6-month period using 2 Kodalpha LR 115 detectors (Dosirad, France), 1 in the living room and 1 in the bedroom. We examined lung cancer risk in relation to indoor radon exposure after adjustment for age, sex, region, cigarette smoking, and occupational exposure. RESULTS: We included in the analysis 486 cases and 984 controls with radon measures in at least 1 dwelling. When lung cancer risk was examined in relation to the time-weighted average radon concentration during the 5- to 30-year period, the estimated relative risks (with 95% confidence intervals) were: 0.85 (0.59-1.22), 1.19 (0.81-1.77), 1.04 (0.64-1.67), and 1.11 (0.59-2.09) for categories 50-100, 100-200, 200-400, and 400+ becquerels per cubic meter (Bq/m), respectively (reference <50 Bq/m). The estimated relative risk per 100 Bq/m was 1.04 (0.99-1.11) for all subjects and 1.07 (1.00-1.14) for subjects with complete measurements. CONCLUSIONS: Our results support the presence of a small excess lung cancer risk associated with indoor radon exposure after precise adjustment on smoking. They are in agreement with results from some other indoor radon case-control studies and with extrapolations from studies of underground miners.     

Indoor radon exposure and lung cancer risk: a review of case-control studies

BACKGROUND: Radon is a radioactive gas that tends to accumulate in indoor environment. A causal relationship between lung cancer and radon exposure has been demonstrated in epidemiologic studies of miners. The objective of this paper is to present the results of case-control studies of lung cancer risk associated with indoor radon exposure. METHODS: Case-control studies published since 1990 are included in this review. This type of protocol is particularly well suited for studying the relationship between indoor radon exposure and lung cancer risk, taking into account possible confounding factors such as tobacco smoking. The characteristics and results of these studies are summarized. The limitations associated with each of these studies are also discussed. RESULTS: The results of available studies are relatively concordant and suggest a positive association between lung cancer risk and indoor radon exposure with an estimated excess relative risk of about 6 to 9% per 100Bq/m3 increase in the observed time-weighted average radon concentration. The order of magnitude of this estimation agrees with extrapolations from miners but some studies may suffer from inadequate statistical power. CONCLUSION: At present, efforts are underway to pool together the data from the existing studies of indoor radon. This pooling analysis with thousands of cases and controls will provide a more precise estimate of the lung cancer risk from indoor radon exposure and explore the effect of modifying factors, such as smoking.     

The potential risk from 222radon posed to archaeologists and earth scientists: reconnaissance study of radon concentrations, excavations, and archaeological shelters in the Great Cave of Niah, Sarawak, Malaysia

This reconnaissance study of radon concentrations in the Great Cave of Niah in Sarawak shows that in relatively deep pits and trenches in surficial deposits largely covered by protective shelters with poor ventilation, excavators are working in a micro-environment in which radon concentrations at the ground surface can exceed those of the surrounding area by a factor of > x 2. Although radon concentrations in this famous cave are low by world standards (alpha track-etch results ranging from 100 to 3075 Bq m(-3)), they still may pose a health risk to both excavators (personal dosemeter readings varied from 0.368 to 0.857 mSv for 60 days of work) and cave occupants (1 yr exposure at 15 h per day with an average radon level of 608 Bq m(-3) giving a dose of 26.42 mSv). The data here presented also demonstrate that there is considerable local variation in radon levels in such environments as these.     

云锡矿工肺癌病因的干预性流行病学研究

本文按干预性流行病学原则,用队列方法研究了“砷、氡”引起矿工肺癌的假说。矿方为了预防尘肺,于50年代中期开始采用了湿式作业,井下砷的平均浓度由70年代的平均浓度0.29mg/m~3,下降到80年代的0.010mg/m~3;肺癌发病粗率也由50年代的160/10万,下降到80年代的20/10万。同期氡子体一直保持?较高水平。工人受氡子体辐射的累积剂量,平均为409WLM,超出发生肺癌的剂量3倍。所获得的干预法剂量-反应关系提示,砷与肺癌呈明显的因果关系,而氡子体的作用在100WML水平未显出联系。     

Residential radon exposure and risk of lung cancer in Missouri.

OBJECTIVES: This study investigated residential radon exposure and lung cancer risk, using both standard radon dosimetry and a new radon monitoring technology that, evidence suggests, is a better measure of cumulative radon exposure. METHODS: Missouri women (aged 30 to 84 years) newly diagnosed with primary lung cancer during the period January 1, 1993, to January 31, 1994, were invited to participate in this population-based case-control study. Both indoor air radon detectors and CR-39 alpha-particle detectors (surface monitors) were used. RESULTS: When surface monitors were used, a significant trend in lung cancer odds ratios was observed for 20-year time-weighted-average radon concentrations. CONCLUSIONS: When surface monitors were used, but not when standard radon dosimetry was used, a significant lung cancer risk was found for radon concentrations at and above the action level for mitigation of houses currently used in the United States (148 Bqm-3). The risk was below the action level used in Canada (750 Bqm-3) and many European countries (200-400 Bqm-3).     

Seasonal variation in indoor radon concentrations in dwellings in six districts of the Punjab province, Pakistan

An indoor radon measurement survey has been carried out in six districts of the Punjab province. These included Gujranwala, Gujrat, Hafizabad, Sialkot, Narowal and Mandibahauddin districts. In each district, 40 representative houses were chosen and indoor radon levels were measured in these dwellings in autumn, winter, spring and summer seasons using CR-39 based NRPB radon dosimeters. After exposure to radon, the CR-39 detectors were etched in 25% NaOH at 80 degrees C and track densities were related to radon concentration levels. From the observed data, average radon concentration levels and a seasonal correction factor were calculated. The average 222Rn concentration level was found to vary from 40 +/- 15 to 160 +/- 32 Bq m(-3) and 38 +/- 17 to 141 +/- 26 Bq m(-3) in the bedrooms and living rooms of the houses surveyed, respectively. The annual mean effective dose received by the occupants has been calculated using ICRP (1993 Ann. ICRP 23) and UNSCEAR (2000 Sources and Effects of Ionizing Radiation (New York: United Nations)); it varied from 1.2 to 1.7 mSv and from 1.8 to 2.4 mSv, respectively.