氡及其子体对小鼠血液和骨髓细胞的影响

目的研究氡及其子体对小鼠造血系统的影响。方法观察小鼠外周血血常规的变化及用3H-TdR掺入法观察小鼠骨髓细胞DNA合成能力的变化。结果小鼠吸入氡及其子体后,红细胞压积(HCT)明显下降。高剂量组骨髓细胞3H-TdR掺入量显著减少。结论吸入氡及其子体后可引起贫血症状,并在较高剂量下抑制骨髓细胞DNA合成。     

氡及子体吸入对BALB/c小鼠造血功能影响的研究

目的 研究氡及其子体吸人对BALB／c小鼠造血功能的影响。方法雄性BALB／c小鼠吸人氡及其子体的累积剂量分别达0、21、33工作水平月(working level month，WLM)后，观察小鼠外周血血常规的变化，及小鼠脾脏指数、肾脏指数、胸腺指数的变化。同时检测了小鼠骨髓细胞DNA含量、骨髓有核细胞计数和骨髓粒细胞集落(CFU-G)增殖的变化。结果小鼠吸入氡及其子体后，与对照组相比，外周血中血细胞计数和红细胞平均值有显著性变化，红细胞、红细胞压积显著减少，提示有贫血症状；高剂量组血小板明显减少，而此剂量组脾脏指数增高，表明血小板可能分布异常；低剂量组DNA含量显著减少，骨髓有核细胞计数和CFU-G的增殖能力各剂量组无显著改变。结论在该实验的染毒剂量下，氡及其子体吸入可引起小鼠红细胞、HCT显著减少，血小板明显降低和脾脏指数增高，低剂量组DNA含量明显降低。     

氡暴露对大鼠淋巴细胞的免疫毒性

[目的]通过研究氡暴露对大鼠胸腺、脾脏、外周血及骨髓淋巴细胞的损伤作用,探讨氡对大鼠免疫功能的影响,为探索氡致机体免疫损伤的可能机制提供实验资料。[方法]将15只健康雄性Wistar大鼠随机分成3组,每组5只,动物整体暴露于HD-3型多功能生态氡室,累积受照剂量分别达200工作水平月（WLM）和400WLM后,腹主动脉采血,胸腺、脾脏制成单细胞悬液,分离股骨取骨髓。采用五分类血液分析仪进行骨髓、外周血细胞计数及分类。采用荧光探针检测不同剂量氡暴露组淋巴细胞内活性氧（ROS）、游离钙离子浓度、线粒体膜电位（MMP）水平的变化。采用碘化丙啶（PI）染色后,观察脾脏、胸腺淋巴细胞周期及凋亡率。[结果]200WLM氡暴露组大鼠外周血淋巴细胞数为（6．84土1．40）×10-9／L,高于对照组的（3．34±1．10）×10-9／L（P〈0．01）,2剂量组骨髓淋巴细胞计数均明显增加（P〈0．01）;200WLM组胸腺淋巴细胞ROS高于对照组（P〈0．01）,骨髓、外周血淋巴细胞MMP低于对照组（P〈0．01）,脾脏、胸腺淋巴细胞钙离子浓度明显升高（P〈0．01）;与对照组比较,胸腺细胞Go／G,期细胞比例明显降低,而s期细胞比例显著升高,脾脏细胞则相反;200WLM氡暴露组胸腺细胞凋亡率为（1．63±0．46）％,高于对照组的（0．69±0．64）％（P〈0．05）,而400WLM氡暴露组未见明显改变。[结论]氡及其子体可暴露对大鼠免疫细胞和免疫功能产生毒性作用。     

Correlation between cytogenetic biomarkers obtained from DC and CBMN assays caused by low dose radon exposure in smokers

Abstract

Purpose: Radon is of health concern because they can cause lung cancer when inhaled over many years. Cytogenetic biomarkers proved to be excellent methods to detect and estimate radiation induced DNA damage. Two well established cytogenetic assays are available to detect the DNA damage caused by ionizing radiation namely Dicentric (DC) assay and Cytokinesis-Blocked Micro Nucleus (CBMN) assay. Chromosomal aberrations such as dicentric and acentric fragments can be analyzed in DC assay. Micronuclei and Nucleoplasmic bridges can be analyzed in CBMN assay. The present study focuses on correlation between the aberrations observed in DC and CBMN assay caused by low doses of radon in smokers.

Material and methods: Blood samples were collected, after prior consent, from smokers as well as healthy non-smoking individuals and exposed in vitro to radon ranging between 0–5.2 mGy using a simple, portable irradiation assembly designed and tested at authors’ laboratory.

Results: A significant increase in frequencies of dicentrics and excess acentric fragments were observed with increasing dose. Interestingly in CBMN assay also, the frequencies of micronuclei and nucleoplasmic bridges were increased with dose. There was a significant correlation between nucleoplasmic bridges and dicentrics for both smokers and non-smokers. Significant correlation between acentric fragments and micronucleus was observed only for non-smokers.

Conclusions: By considering the correlation between the two cytogenetic assays, the CBMN assay can be used as an alternative to DC assay for non-smokers. In case of smokers, nucleoplasmic bridges can be used to measure the radiation exposure. This study is first of its kind to correlate the cytogenetic biomarkers obtained from DC and CBMN assay for smokers with very low doses of radon.     

2009年上海市地铁车站放射性水平

[目的]了解上海市地铁车站空气氡浓度和环境γ辐射水平与变化趋势。[方法]于2009年8月至12月,在上海市已开通并在地下运行的地铁线路(1、2、4、6、8和9号线)共98个站点中随机抽取73个地铁站点,进行环境放射性水平(包括空气氡浓度和环境地表γ辐射剂量率)检测。瞬时氡浓度检测采用AB-4连续型氡测量仪,环境地表γ辐射剂量率检测采用FD-3013H智能化X/γ辐射仪。[结果]上海市6条地铁线路各站点空气氡浓度的均值为9.9Bq/m3,范围为1.2～28.4Bq/m3,明显低于国家标准规定限值。此外,各站点的环境地表γ辐射剂量率均值为(0.14±0.02)μSv/h,范围为0.07～0.24μSv/h,在天然本底辐射水平波动范围内。[结论]上海市投入运营的地铁线路各站点放射性水平属天然本底辐射水平,空气氡浓度明显低于国家标准规定限值。     

Impact of radon and combinatory radon/carbon dioxide spa on pain and hypertension: Results from the explorative RAD-ON01 study

Objectives: Therapies with low doses of radon have beneficial effects on patients suffering from chronic painful degenerative and inflammatory diseases. We already showed that this is accompanied by systemic immune modulations. We here focus on pain-reducing effects of very low doses of radon by adding carbon dioxide water and its impact on heart rate variability (HRV), blood pressure and free radicals.

Methods: 97 of 103 patients receiving radon spa (1.200?Bq/l at 34?°C or 600?Bq/l, 1?g/l CO₂ at 34?°C) were monitored before and at three different time points after therapy. Individual pain perception was analyzed and the capability to process radicals. At each time point, the hypertensive patients (n?=?46) were examined over 24?h for blood pressure and HRV.

Results: Long-term pain reduction was observed in the majority of patients. A modulation of superoxide dismutase was identified, presumably representing a priming effect for lowering radiation stress. Further, lowering of blood pressure, especially in those patients who additionally received carbon dioxide, was seen. Radon did in particular impact on HRV implying lasting relaxation effects.

Conclusion: Radon/carbon dioxide spa efficiently reduces pain. In particular, patients simultaneously suffering from painful and cardiovascular diseases should be treated by combination of radon and CO₂.     

降扎乡高氡温泉周围居民血浆中8-羟基脱氧鸟苷和硫氧还蛋白还原酶水平的研究

目的：探讨长期多次接触高氡温泉对机体氧化损伤及抗氧化水平的影响。方法：简单随机抽样法选取降扎乡氡温泉周边居民38人作为高氡组,选取阿西茸乡居民39人作为对照组。采用酶联免疫吸附试验（ELISA）检测2组人群血浆中8-羟基脱氧鸟苷（8-OHdG）和硫氧还蛋白还原酶（TrxR）的水平。采用Mann-Whitney U检验比较两组间8-OHdG和TrxR水平的差异。采用问卷调查判断居民对氡的认知情况。结果：高氡组居民外周血血浆中8-OHdG水平明显降低,TrxR水平明显升高（Z=-3.316,-3.773,P均 < 0.05）,分别是对照组的0.571和2.325倍。将氡暴露纳入回归分析,居民氡暴露对8-OHdG和TrxR差异性表达的影响均有统计学意义（P均 < 0.05）。两组居民对氡、氡对人体健康的影响及减氡措施均缺乏了解。结论：长期多频次接触氡温泉有可能在一定程度上增强机体抗氧化应激能力,降低机体氧化损伤水平。当地居民对氡的健康危害认知严重缺乏,应加强居民的健康教育。     

Procedures for the determination of Rn exhalation and effective Ra activity in soil samples

Two methods for measuring ²²²Rn exhalation and effective ²²⁶Ra in soil samples were studied. In the first determination, the method employed was based on the adsorption of radon onto activated charcoal and subsequent measurement of the activity of its daughters with an HPGe (high-purity germanium) detector. In the second, vials containing an aqueous suspension of the sample, mixed with an insoluble high efficiency mineral oil scintillation cocktail, were measured using a low-level liquid scintillation counter. Studies of optimum sampling time, efficiency in both procedures, variation of ²²⁶Ra efficiency with quenching, as well as the effect of sample amount and granulometry upon the quenching parameter, were carried out. The two methods were applied to the determination of ²²²Rn exhalation and effective ²²⁶Ra in environmental samples.     

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。     

四川省阿坝州室内氡及子体水平与剂量估算

本文用闪烁法及马尔科夫法测定了521间房屋的室内氡及子体浓度。其氡浓度算术均值为22.7Bqm~(-3),几何均值为16.3Bqm~(-3);子体潜能算术均值为6.02mwl,几何均值为3.94mwl,室内氡浓度遵从对数正态分布规律。人均年吸收剂量当量为1.05msv。