江苏省环境氡及其子体浓度与所致居民内照射剂量估算

本文报道了江苏省室内、外空气中氡及其子体旅度水平与所致居民内照射剂量的估算结果。全省室内外氡及其子体α潜能浓度近似服从对数正态分布。室内外样品氡浓度的几何均值分别为13Bq·m^-3和9.9Bq·m^-3, 氧子体α潜能浓度的几何均值分别是3.4×10^-8J·m^-3和2.4×10^-8J·M^-3, 平衡因子F为0.42和0.49。因吸入氡子体所致居民人均年有效剂量当量为0.64mSv。     

福建地区空气中氡及其子体浓度与剂量评价

采用双滤膜法和快速潜能测定法测定了福建省住宅室内、室外以及地下人防洞内空气中氧及其子体浓度.调查结果分析表明,氡及其子体浓度分布,近似服从于对数正态.福建省室内、室外空气中氡浓度几何均值分别为51.8Bq·M^-3与始48.7Bq·M^-3,氡子体a潜能浓度几何均值分刖为13.5×10^-8J·M^-3与11.0×10^-3·M^-3;平衡因子均值分别为0.49与0.53.全省90%住宅内平衡当量氡浓度在75Bq·M^-3以下,在100Bq·M^-3.以上的占3.0‰人防洞内氡子体.潜能浓度变化范周在6.74～840×10^-8J·m.福州地区大部分人防洞内平衡当量氡浓度在200Bq·m^-3以上.全省室内外氡水平地理分布可划为五个区.内地高于沿海,最高水平区域在西南部(即第五区),氡子体a潜能浓度几何均值达54.1×10^-8J·M^-3.全省居民受到室内外氡子体年均暴露量为0.36WLM,所致公众年均有效剂量当量为2.30mSv.     

西藏地区环境氡及其子体浓度与所致公众内剂量调查

本文首次报道了西藏地区用闪烁法和马尔科夫法测定的氡及其子体α潜能浓度。在全区56个调查点, 测量了252问居室和102个室外环境样品。全区室内氡及子体α潜能浓度算术平均值分别为9.6Bq·m^-8和321.0×10^-10J·m^-8, 人口加权均值为9.3Bq·m^-8和280.3×10^-10J·m^-3。全区室外氡及子体α潜能浓度算术平均值为3.9Bq·m^-8和200.2×10^-10J·m^-8, 人口加权均值为3.7Bq·m^-8和168.0×10^-10J·m^-8。西藏室内外氡及子体浓度服从对数正态分布规律。平衡因子分别为0.57和0.64。 居留因子为0.82和0.18。氡及其子体所致西藏公众人均年有效剂量当量为0.43mSv。     

湖南省部分非铀矿山氡的放射卫生学研究

本文报道了湖南省20个非铀矿山的氡子体水平调查结果。平均氡子体浓度在0.21～1107μJm^-3,最高值在O.26～5720lμJm^-3.65%的矿山氡子体浓度超过了我国放射卫生防护标准, 这些矿山矿工接受的氡字体年平均暴露量在o.15～765.7WLM.大部分矿山防护条件较差, 9个矿山已观察到矿工肺癌, 其中50年代建矿的较为突出。     

深圳特区室内氡水平及影响因素

本文采用双滤膜、闪烁法和活性炭法测定了深圳特区各类建筑室内氡及子体浓度.测定结果为,高层建筑、普通楼房、平房和地下室内²²²Rn的平均浓度分别为31.1,15.5,17.8和108Bq·M^-3,室外²²²Rn的平均浓度分别为13.7Eq·M^-3.²²²Rn子体潜能浓度分别为15.8、8.1、10.2,39.9×10^-4WL,室内外平均为8.8×10^-4WL。各类建筑室内平均平衡因子F为0.2,并分析了影响室内氧及子体的因素,估算了所致居民剂量。     

喀斯特地形区域空气中氡浓度调查

1988年1月到1990年3月,用瞬时法和累积法调查了喀斯特地区的一般居民区、铀矿山区和溶洞旅游区空气中氡浓度及其动态变化。贵阳市室内外平均氡浓度为(31.9士9.7)Bq·m^-3和(17.3±4.1)Bq·m^-3,居民接受氡子体的年平均照射剂量为1.35roSy·a^-1.     

未结合氡子体份额的研究

表征未结合氡子体性质的主要参数是扩散系数,作者使用扩散管在常温常压下,测量得出该系数为0.059cm^-·s^-1。未结合氡子体份额的大小与空气中的气溶胶微粒浓度有关,我们的测量说明了这一点,工作区平均f_a=0.07,无人作业区f_a=0.11。使用Raabe的计算模型得出了不同微粒浓度下的来结合氡子体份额f_p。ICRP应用f_p=0.05计算剂量,导出的空气限制浓度,只有当微粒浓度大于10⁵cm^-3时,限制值才是安全的。当微粒浓度在10⁴cm^-3时,就不一定安全了。近来一些调查资料发现,单位暴露量产生的肺癌发病率比早年的要高,可能是现代矿井通风比早年的要好,微粒浓度降低,f^p值增大之故。日前使用通风降氡、过滤清除氡子的防护措施,需从微粒浓度和f^p值的测定上做进一步研究。     

北京地区室内氡水平及影响因素

采用无源活性炭室内氡探测器和瞬时抓测技术研究了北京地区室内氡的地域分布和时间变化。全市范围的调查于1985年初结束,共调查了537个居室,其绝大多数是有代表挂的普通楼房和平房。调查结果表明,室内氡浓度呈对数正态分布,90%以上后室的氡浓度小于60Bq?M^-3,平房和楼房内的年平均值分别为25.9Bq?M^-3和15.2Bq?M^-3。全市按房子数加权的年平均氡浓度约为20.6BqBq?M^-3.假定F值为0.5,居留因子为0.8,则估计的等效平衡氡浓度为11.2Bq?M^-3,年暴露量为0.18WIJM。本文还估计了氡子体产生的年集体有效剂量当量。     

山东省环境中氡及其子体浓度与所致剂量的研究

本文采用闪烁法和Thomas三段法测量了山东省室外148个测量点的氧浓度、92个测量点的氧子体浓度, 其几何均值分别为4.76Bq·m^-3、1.54×10^-3J·m^-3 F值为0.60；室内46个测量点的氡及其子体浓度, 几何均值分别为18.0Bq·m^-3、4.50×10^-8·Jm^-3 F值为0.45。室内、外氡及其子体浓度均遵从对数正态分布。垒省每个居民吸八氧及其子体所致年有效剂量当量为0.58mSv。     

河南省环境氡水平及所致公众剂量

用闪烁室法测量了河南省室内外空气中氡浓度。结果表明, 室内外环境氡浓度量对数正态分布, 95%的居室氡浓度小于55Bq·m^-3。全省室内外平均氡浓度分别为21.5Bq·m^-3和16.4Bq·m^-3。若室内外平衡因子F分别米取0.5和0.6, 则氡子体所致公众年有效剂量为0.97mSv, 年集体有效剂量约为7× 10⁴man·sv。     

室内氡暴露居民肺癌p53和k-ras基因突变

目的：检测室内高氡暴露地区居民肺癌P53和k-ras基因突变,方法：采用PCR扩增,PCR－SSCP电泳和序列分析方法。结果：9例标本中有5例p53PCR-SSCP电泳呈阳性结果,其中3例经克隆测序发现有碱基置换,结论：室内氡浓度在200－350Bq.m^-3.a^-1范围内的7例肺癌病例中有5例发生P53基因突变,P53基因突变还可能与肺癌患者的年龄吸烟史有关。     

核燃料元件厂和气体扩散厂工人死因回顾性调查

本研究对核燃料元件厂和气体扩散厂职工１９７１～１９８５、１９８６年期间受照剂量及死因进行了回顾性调查，结果是放射组职工人均年剂量低于１ｍＳｖ，至１９８５年底的累积剂量１０ｍＳｖ左右。观察放射组３６５２人，对照组５３９３人，两组分别累积５３８１３和８１６５０人年。全死因死亡：放射组１０４例（死亡率１９３．２６×１０－５），对照组２５３例（死亡率３０９．８６×１０－５），其中癌症死亡前者４９例（死亡率９１．０６×１０－５），后者８２例（死亡率１００．４３×１０－５）；全死因死亡率经年龄调整后，两组间差异无显著性，死亡按１９７３～１９７５年全国癌亡率为标准计算ＳＭＲ，两组间差别亦无显著性，并且均小于１。因此，在低水平辐射环境中未见癌症增加现象。     

基于EPA/BEIR-VI模型的我国居室内氡致肺癌风险估计

目的:估计我国居室内氡导致的居民肺癌归因份额。方法:利用较为权威且适用的EPA/BEIR-VI风险模型,基于我国2015年肺癌死亡率、全死因死亡率以及有代表性的吸烟率和居室内氡平均浓度,预测我国居室内氡浓度水平致肺癌死亡风险。结果:非吸烟男性人群居室内氡致肺癌死亡超额相对危险(ERR)高于吸烟人群,且达到年龄为50岁时...     

Transformation of lung cells from inhalation of radon daughters in dwellings: a preliminary study

There is now world-wide concern for the quantification of lung cancer risk due to indoor radon, but the recent estimates are based on epidemiological studies of miners alone. The present attempt is a preliminary study of the alteration of lung stem cells irradiated by alpha particles emitted by radon daughters. Local energy deposited has been calculated for alpha particles, emitted from radon daughters lining the mucous layer in the respiratory tracts. This calculation has then been followed by dose evaluation and estimation of transformation of lung cells as a function of age. Mean life span of the stem cells was varied between 5 and 45 years to simulate living conditions in different environments. The cumulative fraction of transformed cells after 40 and 70 years has been calculated for radon concentration in the range 23-230 Bq/m3. Increase of the fraction of transformed cells with radon concentration was exponential. It has been assumed that causes other than radiation increase the rate of cell death of mature and stem lung cells, and hence the turnover of stem cells to replace them. It is concluded that the rate of transformation of cells is small for low radon concentration even late in age for non-polluted environments. For radon concentrations of 50 and 100 Bq/m3 the fractions of transformed cells are 0.2 and 6 per cent, respectively for an exposure time of 70 years.     

空气质量指数与室外氡子体浓度的相关性研究

目的 研究不同空气质量指数(air quality index,AQI)下氡子体的分布特征,评价雾霾天气暴露人群的健康风险。方法 利用EQF3120测量仪监测放射性核素氡及其子体浓度,空气质量指标数据由苏州工业园区环境监测站提供。运用SPSS 16.0对氡及其子体与空气质量指标等数据进行统计描述、主成分分析及简单相关分析。运用氡剂量计算公式估算环境氡暴露致肺部区域有效剂量。结果 苏州市工业园区冬季雾霾天气结合态氡子体与NO₂、SO₂、O₃、PM10和PM2.5均存在相关关系,²¹⁴Bi与其相关系数分别为0.741、0.681、-0.431、0.597和0.675;且结合态氡子体与PM2.5的相关系数>与PM10的相关系数;当AQI>200,居民在室外接收氡及其短寿命子体的有效剂量为0.63 mSv/年。结论 随着AQI的增大,结合态氡子体浓度增大,未结合态氡子体浓度变化不大;雾霾天气增加了暴露人群吸入氡的辐射风险。     

Radon: is it a problem?

Radon gas is a major source of radiation exposure to the general public. Radon-222 is a product of uranium-238, present in varying concentrations in all soils. Radon enters buildings from soil, water, natural gas, and building materials. Its short-lived breakdown products, termed "radon daughters," include alpha-emitting solids that can deposit in the lungs. Firm evidence links lung cancer risk in miners with high exposure to radon daughters. The amount of risk associated with the much lower but chronic doses received in buildings is difficult to establish. By some extrapolations, radon daughters may be responsible for a significant number of lung cancer deaths. The existence or extent of synergism with smoking is unresolved. Local conditions can cause high levels of radon in some buildings, and measures that reduce indoor radon are of potential value.     

氡及其子体诱发肺癌的实验观察

This paper oescrloes animal experiments carried out in an uranium mine gallery for the purpose of investigating the relationship between animals' exposure to radon and its daughters and the incidence of chronic health hazards.100 white rats and 400 C-57 black rats were placed in the atmosphere with high level radon and its daughters in an uranium mine to unde~o experiments of radon I nhalation.Their accumulated exposure doses were 2500 and 1170 WLM respectively After a continued observation over a period of one year and nine months,no remarkable increment of lung cancer incidence due to radon and its daughters was noted in the animals.     

甘肃某矿区周围居民恶性肿瘤死亡调查

目的 评价核设施在正常运行50年后对周围人群的健康影响.方法 调查甘肃某矿区周围30 km范围内居民2004-2008年人口资料、全部实体癌和白血病的死亡率.结果 调查地区居民2004-2008年全癌死亡率和标化死亡率分别为95.51/105和93.56/105,白血病死亡率和标化死亡率分别为2.44/105和2.22/105.对照区2004--2008年间恶性肿瘤死亡率和标化死亡率分别为106.88/105和89.31/105,白血病仅死亡1例,死亡率为3.56/105.结论 甘肃某矿区运行50年后,周围居民的恶性肿瘤和白血病死亡率未见增加,该矿区的生产和运行未对周围居民健康造成不良影响.

Abstract：

Objective To evaluate the cancer risk among the inhabitants around a certain nuclear facility of Gansu Province after operation for nearly 50 years.Methods Specially developed forms were filled by countryside doctors in the villages 30 km on the leeward or at the lower reaches of Yumen City,Gansu Province where a nuclear facility had operated for nearly 50 years,to register the relevant data of those who died of solid cancer and leukemia during the period from 1 January 2004 to 31 December 2008 based on the relevant data and household survey.A town 90 km away from the nuclear facility with 4181 people were regarded as control area.Results The crude mortality and standardized mortality rate(SMR) of cancer were 95.51×10-5 and 93.56×10-5.respectively.The crude mortality and SMR of leukemia were 2.44×10-05 and 2.22×10-05, respectively.and the crude mortality and SMR of cancer were 106.88×10-05, and 89.31×10-5, respectively.The crude mortality and SMR of leukemia were 2.44×10-05 and 2.22×10-5, respectively in the investigated area,and the crude mortality of leukemia was 3.56×10-5 (only one leukemia cage died)in the control area in the same time.The cancer and leukemia mortality rates of the investigated area were similar to those of control area.Conclusions Nuclear facility does not significantly increase the cancer mortality among the residents living nearby.     

Risk coefficient of radon-induced lung cancer and combined effect of arsenic in miners of Yunnan tin mine of China

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过滤室内空气对降低居民室内氡照射的效果研究

目的 研究空气净化器过滤室内空气对室内氡子体行为的影响,探讨该方法对降低居民室内氡照射的效果。方法 构建理论模型计算室内空气过滤前后室内氡子体的浓度,基于结合态和未结合态氡子体的剂量转换系数,评估过滤室内空气对居民氡照射剂量的降低效果,并在密闭房间内进行部分实验验证。结果 室内空气的过滤速率越大,氡子体的去除效率越明显。在一个气溶胶初始浓度为10 000 cm^-3的密闭室内,当过滤速率>10 h^-1时,氡子体总浓度可下降90%以上。但不同过滤速率下,未结合态氡子体浓度均有所增高。室内氡子体浓度变化和居民氡照射剂量下降与净化器的过滤速率密切相关,过滤速率越大,降低剂量的效果越快越好。当过滤速率>5 h^-1时,净化器可降低居民内照射剂量70%以上。结论 空气净化器过滤室内空气虽然会导致未结合态氡子体浓度上升,但仍能有效地降低氡子体所致居民的暴露剂量。