某军事作业坑道内空气中氡浓度水平调查

天然放射性惰性气体氡 (radonRn)存在于室外空气和含工作场所在内的所有建筑物中 ,因此 ,它既是住宅内又是工作场所一个不可避免的辐射照射源[1] 。氡衰变时放出α射线并产生一系列放射性更强的子体。这些子体可悬浮在空气中 ,附着在空气中的尘埃上 ,形成放射性气溶胶 ,当被人体吸入后 ,沉积在支气管内的表面上和肺部 ,产生内射危害 ,影响身体健康 ,严重者可导致肺癌。地下坑道内的氡及其子体浓度一般高出地面 1～2个数量级。为了解某军事作业坑道内空气中氡浓度水平 ,有针对性地采取必要的降氡措施 ,指导部队做好卫生防护工作 ,我们于 2 0…     

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。     

某地下施工坑道放射性水平调查

目的 调查地下施工坑道中放射性水平,获取工作人员年受照有效剂量,为对工作人员实施放射性职业危害评价提供科学依据。方法 使用FH40G多功能辐射监测仪及RAD7测氡仪对坑道工作场所的γ射线剂量率及氡浓度实施测量。结果 由γ射线所致的外照射年有效剂量平均值为1.207mSv;由氡所致的内照射年有效剂量平均值为1.196mSv。工作人员受到的总的个人年有效剂量平均值为2.402mSv。结论 所测的地下坑道工作场所放射性水平符合国家标准规定。     

地下坑道氡水平调查

目的 对某部所属14条坑道进行氡及其子体的调查,掌握坑道氡污染的水平,评价其对官兵身体健康的影响。方法 采用固体径迹图像分析方法。结果 57%的坑道超过《坑道氡及其子体放射防护规定》中的氡浓度500 Bq·m^-3限值。其中氡浓度在500~1 000 Bq·m^-3的有6条,占42.9%;超过1 000 Bq·m^-3的有2条,占14.3%;氡及其子体对作业人员照射所致年有效剂量为0.32~2.61 mSv,均值为1.64mSv。结论 在确保坑道内工作、训练正常运行的同时,应加强坑道通风,加大空气循环速度;尽量减少人员在坑道内的停留时间,减少氡对人体的危害;在打造和被覆坑道过程中,应尽可能选择铀、镭含量低的地域,使用闭孔性材料。     

温泉水放射性水平及泉水浴房内空气中氡浓度调查

本文报道了某市温泉水管理单位的温泉水放射性水平，泉水浴房内及周围室内空气中氡及其子体浓度。提出了工作人员应对浓度较高的氡及其子体的危害，采取放射卫生护护措施。     

17条坑道氡水平监测与分析

坑道所处地区差异、结构特点等因素,直接影响坑道内氡的水平。为掌握其特点和变化规律,我们对两省地的17条坑道氡浓度进行了监测。     

异常高氡温泉的辐射水平与健康影响研究

目的对降札温泉周围环境的γ辐射水平、室内外空气氡浓度、水中氡浓度、土壤中放射性核素含量进行测量,并对染色体进行检查,进而对降札温泉内各类人员可能受到的辐射影响进行分析和评价。方法结合对降札温泉水中氡浓度测量结果和各类人员的内外受照剂量的估算结果 ,与国家相关标准进行对比。结果降札温泉内管理员和居民受照剂量为6.04mSv,超过了我国居民所有天然辐射源产生的年有效剂量总和2.3mSv,儿童受到的辐射剂量为260mSv,超过了我国电离辐射防护与辐射源安全基本标准(GB18871-2002)的控制限值50mSv。温泉水中氡、镭等放射性核素、总α、总β放射性也比较高,已达到医疗温泉标准。有一处用于饮用、洗脸、洗眼的泉水中氡浓度为242.6Bq/L,超出了生活饮用水水质参考指标及限制中的氡浓度限制111Bq/L。结论降札温泉附近的居民或管理员、儿童等大部分人员所受到的内外照射剂量均超过了国家标准,温泉水中氡、镭等放射性核素、总α、总β放射性也比较高,显然降札温泉氡污染严重,会对长期居住在附近的居民、游客和患者的健康造成影响。     

氡的危害及防护措施

氡的危害报导日渐增多,英国目前肺癌终生危险度约6％归于氡的照射。由于国内大量利用地下设施,使得在地下设施工作的人员所受氡的辐射高于地面上工作人员的1—3倍。所以地下设施必须采取通风降低室内氡浓度,保护广大地下工作人员的健康。     

湖南某铅锌金矿井下放射性水平调查与评价

目的调查湖南某铅锌金矿井下放射性水平,评价放射性危害程度及来源。方法对井下不同位置γ剂量率以及氡浓度进行实地测量,估算井下工作人员所受年有效剂量。结果井下矿区γ剂量率范围为(0.05~0.63)μSv/h。累积测量氡浓度范围为(52~721)Bq/m~3,井下工作人员所受最大年有效剂量约为4.84 mSv。结论根据本次调查,该矿井下工作场所氡浓度较高,存在放射性危害,应采取相应防护措施。     

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。     

Evaluation and equity audit of the domestic radon programme in England

The UK has a radon programme to limit the radon risk to health. This involves advice on protective measures in new buildings, technical guidance on their installation, encouragement of radon measurements and remediation in existing dwellings in high radon areas. We have audited the radon programme at the level of individual homes to identify factors that influence the likelihood of remediation. 49% of the householders responded to our survey and 30% of the respondents stated that they had done some remediation to reduce the indoor radon levels. We found that householders with higher incomes and higher socio-economic status are more likely than others to remediate. Householders are less likely to remediate if they have one of the following: living in a property with a high radon concentration, current smokers in the dwelling, being unemployed or an unskilled worker, long length of time living in that property or elderly (65+ years) living by themselves. Householders appeared to be more likely to remediate if they considered the information on radon and its risk to be very clear and useful. This emphasises the importance of communication with householders.     

Occupational doses from radon in Spanish spas

Recent international recommendations have included exposure to natural radiation as one of the sources to monitor in certain occupationally exposed groups. Among those mentioned are workers in thermal spas, who may be exposed to high radiation doses due to the high concentration of radon in the indoor air of the spa. This paper presents the methodology and the results of an evaluation of radiation doses to the staff in different thermal spas in Spain. Different series of samples were collected and measurements made for the radon concentrations in water in 54 spas and in air in 20 spas. In six of the latter group, the air radon concentration was studied in different working areas occupied by the employees. The radon concentrations in water were between <2 and 775 x 10(3) Bq m(-3). The radon concentrations in air were between <10 and 5,200 Bq m(-3). The latter were used to estimate the dose received by each occupational group in the spa by taking into account the radon concentration in their main working area. By means of an exposure-dose conversion factor of 1.43 Sv per J h m(-3), the estimated effective doses were found to lie between 1 and 44 mSv y(-1). This upper limit is higher than the recommended annual limit of 20 mSv y(-1) for an occupational dose.     

Radon in Irish schools: the results of a national survey.

This paper presents the results of a survey of radon concentrations in Irish primary and post-primary schools. The objective of this survey was to assess the distribution of radon in Irish schools and to identify those requiring remedial work to reduce radon exposure to children and staff. All primary and post-primary schools were invited to participate in the survey. Indoor radon concentrations were measured during the academic year using integrating passive alpha track-etch detectors with a measurement period from three to nine months. The survey was carried out on a phased basis from 1998 to 2004 and is one of the most comprehensive of its kind undertaken in Europe. Measurements were completed in 38 531 ground floor classrooms and offices in 3826 schools, representing over 95% of the approximate 4000 primary and post-primary schools in Ireland. Of these, 984 schools had radon concentrations greater than 200 Bq m(-3) in 3028 rooms and 329 schools had radon concentrations in excess of 400 Bq m(-3) in 800 rooms. The average radon concentration in schools was 93 Bq m(-3). This results in an annual average effective dose to an Irish child from exposure to radon of 0.3 mSv per year, assuming that the long-term radon concentration is equal to the radon concentration present during the working hours and that the annual average occupancy is 1000 h per year. A programme of remediation of schools with radon concentrations above 200 Bq m(-3) has been put in place.     

Do the UK workplace Radon Action Levels reflect the radiation dose received by the occupants?

In the UK, Action Levels for radon have been established at 400 Bq m(-3) for the workplace and 200 Bq m(-3) for the home. We have estimated the dose received by occupants of rooms with radon levels near or above the Action Level, using hourly radon readings, and a questionnaire to record occupancy. In the workplace, results for 73 staff suggest that doses are lower than expected, partly due to part-time working and partly due to the mobility of staff. The 75% quantile for the series, corrected to a 37 hour week, is 5.2 mSv at 400 Bq m(-3). Compared to the current annual limit for radiation workers, the Action Level could be increased, but the current Action Level is compatible with the recent EEC Directive requiring a lower dose limit. However, when raised radon levels in the workplace were reduced by remediation in the series we studied, the dose reduction to staff was consistently around half of the radon level reduction. Although it would be appropriate to study more locations, this suggests an Action Level for remediated workplaces of 200 Bq m(-3). Finally, in a limited series of dose assessments in domestic properties, we found that doses could considerably exceed 5 mSv at the 200 Bq m(-3) Action Level, primarily because the sample included an example of high occupancy, in our case several Asian wives in purdah, whose occupancy was almost total.     

Local health campaigns to reduce lung cancers induced by radon and smoking—Who responds?

The greatest risk factor for lung cancer is smoking, the second largest factor being raised radon levels at home. Initiatives to stop smoking and reduce domestic radon levels have met with some success, but in both cases a significant proportion of those affected have not taken action.The two risk factors combine, so that those who smoke and live in a house with high radon levels are at higher risk than if exposed to only one of the two threats. There is the potential for combined public health campaigns to better target those affected.Using postal questionnaires, we collected demographic information of those in Northamptonshire, UK, a radon Affected Area, who participated in Smoking Cessation Programmes, and compared these to a recent study by our group of those who had taken action to reduce radon. The comparison suggests that these two groups are significantly different, and in some cases differ from the general population. In addition, those who continue to quit smoking at 1 year were more likely to have children under 18 at home, and live with a parent or partner compared to those who had relapsed after the previous assessment at 4 weeks.There is merit in extending Smoking Cessation Programmes to include advice on reducing the risks from radon.     

Survey of 222Rn concentrations in the air of a tunnel located in Nagano City using the solid-state nuclear track detector method.

The survey of 222Rn concentration in the air of tunnels constructed during World War II has been performed using a solid-state nuclear track detector technique. For the practical application of this technique to the determination of 222Rn concentrations in air, some basic properties were experimentally examined on the cellulose nitrate film, Kodak LR 115 type II. The calibration coefficient of the cellulose nitrate film used is determined from a correlation between the 222Rn concentration in air and the observed number of perforated etched tracks for widespread radon concentrations. The slope of the linear relationship observed yields a calibration coefficient of (0.00209 +/- 0.00018) tracks cm(-2) (Bq m(-3) h)(-1). From the survey of 222Rn concentration in the air of tunnels, the concentration of several thousand Bq m(-3) was observed at the inner most area of the tunnel, and the seasonal variation was clearly observed. The exponential distribution of radon concentration as a function of distance from the openings of the tunnel suggests that the radon concentration in the tunnel is basically governed by diffusion and mixing of radon gas with air.     

Occupational injuries by hour of day and day of week: a 20-year study

Objective: To examine by hour of day and day of week the 750,000 compensation claims that were lodged by male workers in Queensland, Australia, during the 20‐year period from 1968 to 1988, including an investigation into some possible reasons for the increased number of claims on Mondays and the reduced number of claims on Fridays. Method: The study was based on the collection entitled Industrial Accident Statistics (Bulletin 79), published annually by the Australian Bureau of Statistics, Queensland office. This was the only State collection to include data on compensated injuries categorised by hour of day and day of week. There was no Australia‐wide dataset of compensated occupational injuries. Results: Compensation claims were not evenly distributed through the working week. There were more injuries on Mondays (23.6% of the total) than on Tuesdays (21.8%), than on Wednesdays (20.3%), than on Thursdays (18%), than on Fridays (16.3%). There were more injuries in the mornings than in the afternoons for every day of the working week. Conclusions and Implications: This study confirms the existence of a steady reduction in workers' compensation injury claims on successive days of the working week. One possible explanation for this finding is offered as a basis for further research into the reasons for this trend. Hopefully, the results of these and later studies may suggest remedial measures that will help reduce the number of occupational injuries.     

十堰市城区居民室内氡浓度调查结果与分析

目的 对十堰市城区居民室内氡浓度进行监测,分析居民室内氡浓度水平及影响因素。方法 从2019年4月到7月,采用RSKS标准型探测器对十堰市城区共计125户居民室内氡浓度进行测量并分析。结果 2019年所监测的十堰城区居民室内氡浓度结果呈偏态分布,范围为13.8～145 Bq/m³,M(P₂₅,P₇₅)为38.3(29.0,62.0) Bq/m³,居民因吸入氡及其子体产生的年均有效剂量估算值为0.52～5.50 mSv,M(P₂₅,P₇₅)为1.45(1.10,2.36) mSv,与相关文献一致;不同建筑结构(H=14.10,P<0.001)、楼层(H=24.41,P<0.001)和地区(H=8.963,P<0.05)均是居民室内氡浓度水平的影响因素,且差异均有统计学意义。结论 十堰市城区居民室内氡浓度小于国家标准限值,但在日常生活中还是需要注意采取合适的方法,尽量降低家中氡浓度。     

哈尔滨工程大学室内氡浓度水平及评价

目的 了解哈尔滨工程大学室内氡浓度的水平,并进行剂量水平评价。方法 采用双滤膜法连续测量哈尔滨工程大学室内氡浓度,并对氡的危害进行评价。结果 哈尔滨工程大学室内氡及其子体对人体造成的年辐射剂量为1.48 mSv,略高于我国平均水平。结论 哈尔滨工程大学室内氡浓度偏高,可以从"截源"、"消散"两个方面来降低室内氡浓度。     

Indoor radon measurements in New Jersey, New York and Pennsylvania

The distribution of 222Rn concentrations in 33 buildings near Canonsburg, PA, Lewiston, NY and Middlesex, NJ was investigated over a 2-yr period. One or 2 week-long time-integrated measurements of radon concentration, repeated several times during the study period, were obtained in the living and working areas of the buildings. Average air concentrations of radon, measured over the study period, varied from 0.32 to 4.5 pCi/l. among the buildings, but in only one building did the annual radon concentration exceed the U.S. Nuclear Regulatory Commission's limit of 3pCi/l. for continuous exposure in uncontrolled areas.