贵州省居民受天然放射性照射水平的研究与评价

贵州省居民受天然放射性照射水平的研究与评价李锁照陈煜友魏涛喻立新周瑞珍刘玉琴在生活环境中，人们始终受到电离辐射源的照射，其中天然电离辐射源的照射是主要的。我们根据环境贯穿辐射（γ辐射），空气中氡浓度，食品和饮用水中天然放射性核素的含量测定结果，估算了...     

医用辐射所致人群的剂量及其防护问题

医用辐射所致人群的剂量及其防护问题张景源随着医疗保健事业的发展，电离辐射源和放射性核素在医疗中的应用日益广泛，放射诊断与治疗的新技术、新设备不断出现，在提高疾病诊治水平的同时，也增加了人类受电离辐射照射的剂量负担。医疗照射已成为人工电离辐射照射的最大...     

辽宁省公众所受电离辐射照射的基本估计

作者报告了辽宁省公众所受电离辐射照射剂量的综合结果，对其结果进行分析认为：各种主要电离辐射对公众所致的人均年有效剂量当量分别为：宇宙辐射电离成分２５１μＳｖ；地表γ辐射５３７μＳｖ；食品和水中放射性核素３１０μＳｖ；空气中氡及其子体１１６０μＳｖ；医用Ｘ射线９１．１μＳｖ；核医学１６μＳｖ；职业照射０．３９μＳｖ；放射性落下灰４６μＳｖ；燃煤放射性排出物及灰份１００μＳｖ，总计２５１１μＳｖ．各类辐射所占份额是天然辐射８９．９％（２２５８μＳｖ），医疗照射４．３％（１０７．１μＳｖ），职业照射０．０１６％（０．３９μＳｖ），放射性落下灰１．８％（４６μＳｖ），燃煤４．０％（１００μＳｖ）．     

湖北省

在迄今为止人类受电离辐射照射所致剂量中,天然辐射占的比重最大,故调查居民受到天然辐射源照射的辐射水平具有特别重要意义。本文就湖北省天然辐射外照射水平及其对居民所致剂量估算概要报告如下。     

吸入氡子体肺剂量学

吸入氡子体肺剂量学郑文忠筝是大然存在的放射性气体核素，是““ａ的衰变产物．人们吸入第及其子体，使呼吸道受到照射．据联合国原子辐射效应科学委员会（ＵＮＳＣＥＡＲ）估计，人们吸人缘于体的照射剂量可达天然或人工辐射源所致的总辐射剂量的５０＠以上．流行病学调...     

小鼠受γ射线全身照射后FL表达变化的研究

目的 FL(fit3 ligand)是一种作用于早期造血细胞的生长因子，为进一步研究FL水平与辐射所致造血损伤的相关性，观察了小鼠受γ射线全身照射后FL的表达变化。方法以^60Coγ射线全身一次性均匀照射所致骨髓型急性放射病小鼠为模型，应用ELISA、流式细胞术、Western blot法检测照射前后小鼠外周血、骨髓、胸腺与脾脏中FL的表达变化。结果 小鼠受2～10Gyγ射线照射后24h，血清中FL浓度即有增加，并且随时间推移FL水平逐渐升高；吸收剂量在2～6Gy之间时，FL的水平随剂量增加而增加。6Gyγ射线照射后24h，外周血白细胞膜表面FL的表达增加，但24h后细胞膜表面FL的表达没有升高。6Gyγ射线照射后24h，骨髓、胸腺和脾脏有核细胞膜表面FL的表达明显升高，总蛋白中FL的水平亦明显增加。结论 辐射后早期小鼠FL可溶性与膜结合型蛋白的水平都有升高，而且辐射后血清中FL的水平与受照剂量及照射后时间存在相关性。     

利用高剂量受照人群对辐射危险度的流行病学评价

一、引言居民所受的辐射剂量多为低剂量长期照射,最理想的是直接估计低剂量和低剂量率的辐射危险度。来自天然辐射的剂量高于其它任何辐射源,而研究天然辐射效应的困难在于个体之间所接受的剂量差异不大。医用     

放射治疗中的防护与患者受照射剂量的质量控制

医学辐射照射是最大的人工辐射源，据UNSCEAR估计，医学诊断照射占人工辐射源照射约95％以上，约占人类受到总照射量的14％。医用诊断X射线的应用，CT检查和介入程序等高技术的应用持续增长，增加了受检者接受的剂量。随着人口老龄化，肿瘤发病率增高，对放射治疗的需求也在不断增加，根据国际癌病研究机构(IARC)和世界卫生     

德国人正在为CT的过度使用而担心

“德国人正在不必要地接受着大剂量的X线照射。这种照射不是源于真正的健康所需，而是滥用CT检查所致”。这一警告来自德国环境部长Sigmar Gabriel在7月12日发表的一份有关“德国的射线辐射”年度报告中。     

哈密地区环境天然电离辐射源所致居民剂量评价

哈密地区环境天然电离辐射源所致居民剂量评价韦继管，朱向阳，彭莉，孙占裕，张永祥，唐立平，赵永光ＵＮＳＣＥＡＲ在历届报告书中曾估计在世界一般地区公众接受电离辐射剂量的２／３以上来自环境天然电离辐射源，在预见的未来，可能仍保持这种状况。因此，国内、外对环...     

我国医用辐射防护研究概况

医学放射学技术的迅速发展及介入放射学在临床广泛应用，使更多的人受到电离辐射的照射，同时也促进了医疗照射防护工作的发展。文中重点综述了我国医用辐射防护工作者近年来在Ｘ射线ＣＴ的医疗照射防护、对介入放射学工作者的剂量监测以及应用医疗照射防护体系，降低医疗照射剂量等方面所作出的成绩和研究进展     

阳江高天然放射性本底地区流行病学研究近况

目的本文扼要地介绍了高本底辐射研究组近年来，特别是１９９１～１９９８年期间中国和日本合作研究的概况，并对迄今所得到的研究结果作了初步的论证。方法着重介绍方法学的改进和取得的主要研究成果。对两个生物学终点（癌症死亡率和染色体畸变频率）在剂量－效应关系形状的差异和原因作了初步的讨论。结果在增加了观察的人年数，改进了观察方法后仍然复现了高本底地区癌症死亡率未见增加的结果，但现有的结果不是简单的重复，它得到更深层次的剂量学、人口学、统计学和干扰因素研究的支持。对高本底地区居民外周血淋巴细胞染色体畸变频率的增加进行了讨论。它的发生可能与癌症发生的机理不是同一的。对染色体稳定性畸变的研究还需要补充数据。对内照射引起的器官剂量也需要新的数据。结论放射流行病学研究与放射生物学相结合对了解低剂量电离辐射对人类是否产生诱癌效应非常必要     

Current issues and actions in radiation protection of patients

Medical application of ionizing radiation is a massive and increasing activity globally. While the use of ionizing radiation in medicine brings tremendous benefits to the global population, the associated risks due to stochastic and deterministic effects make it necessary to protect patients from potential harm. Current issues in radiation protection of patients include not only the rapidly increasing collective dose to the global population from medical exposure, but also that a substantial percentage of diagnostic imaging examinations are unnecessary, and the cumulative dose to individuals from medical exposure is growing. In addition to this, continued reports on deterministic injuries from safety related events in the medical use of ionizing radiation are raising awareness on the necessity for accident prevention measures. The International Atomic Energy Agency is engaged in several activities to reverse the negative trends of these current issues, including improvement of the justification process, the tracking of radiation history of individual patients, shared learning of safety significant events, and the use of comprehensive quality audits in the clinical environment.     

Patient Radiation Exposure: Imaging During Radiation Oncology Procedures: Executive Summary of NCRP Report No. 184

The National Council on Radiation Protection and Measurements (NCRP) recently assessed patient radiation exposure in the United States, which was summarized in its 2019 NCRP Report No. 184. This work involved an estimation of the number of medical procedures using ionizing radiation, as well as the associated effective doses from these procedures. The NCRP Report No. 184 committee elected to not incorporate radiation dose from radiotherapy into its calculated population dose exposures, as the assessment of effective dose for the population undergoing radiotherapy is more complex than that for other medical radiation exposures. However, the aim of NCRP Report No. 184 was to raise awareness of ancillary radiation exposures to patients undergoing radiotherapy. Overall, it was estimated that annually, in 2016, approximately 800,000 patients received approximately 1 million courses of radiation therapy. Each of these treatments includes various types of imaging that may not be familiar to radiologists or others. Exposures from radiotherapy planning and delivery are reviewed in the report and summarized in this executive summary. The imaging techniques, use of this imaging, and associated tissue doses are described. Imaging can contribute a few percent to the planned treatment doses (which are prescribed to specified target volumes) as well as exposing patients to radiation outside of the target volume (in the imaging field of view).     

X射线全身照射对小鼠脾细胞转铁蛋白受体表达的影响

目的转铁蛋白受体（ＴｆＲ）是Ｔ淋巴细胞受抗原或丝裂原刺激后表达在细胞表面的重要受体之一,与Ｔ细胞的活化和增殖有着密切关系。目前尚未见国内外有关ＴｆＲ辐射效应研究的报道。研究大剂量电离辐射后ＴｆＲ表达的变化及作用,对阐明辐射抑制机体免疫功能的机制有着重要意义。方法本文采用流式细胞术的方法观察了不同剂量Ｘ射线全身照射对小鼠脾细胞ＴｆＲ表达的影响以及４ＧｙＸ射线全身照射后不同时间ＴｆＲ表达的变化。结果０５～６ＧｙＸ射线全身照射后２４小时,脾脏ＴｆＲ阳性细胞数从１Ｇｙ开始随照射剂量的增加而下降,且呈明显的剂量依赖性。４ＧｙＸ射线全身照射后１２～７２小时,脾脏ＴｆＲ阳性细胞数于照后１２小时开始下降,２４、４８小时降至最低值（Ｐ＜０．０５,Ｐ＜０．０１）,７２小时开始回升。结论大剂量电离辐射抑制小鼠脾细胞ＴｆＲ的表达,并有明显剂量依赖性;ＴｆＲ表达的下降可能与辐射抑制ＩＬ２的分泌和ＩＬ２受体的表达有关。     

Evaluation of the genotoxic effects of chronic low-dose ionizing radiation exposure on nuclear medicine workers

IntroductionNuclear medicine workers are occupationally exposed to chronic ionizing radiation. It is known that ionizing radiation may have damaging effects on chromosomes. In the present study, we investigated the genotoxic effects of ionizing radiation on nuclear medicine workers. We used two different indicators of genotoxicity methods: sister chromatid exchange (SCE) and micronucleus (MN).MethodsThe present research was carried out using 21 nuclear medicine workers (11 females and 10 males) during two periods: during normal working conditions and after a 1-month vacation. The radiation dose varied from 1.20 to 48.56 mSv, which accumulated during the occupational exposure time between two vacations. Peripheral blood samples were taken from each subject for two distinct lymphocyte cultures (SCE and MN) in each period.ResultsIn nearly all subjects, SCE values increased significantly during radiation exposure compared to the postvacation period (P<.05). Similarly, MN frequencies in most of the subjects increased significantly during radiation exposure compared to the postvacation period (P<.05).ConclusionsThis study revealed that both SCE and MN frequencies in most of the subjects were significantly higher during exposure to ionizing radiation than after a 1-month vacation period. However, this genotoxic effect was reversible in most of the subjects.     

A cytogenetic approach to the effects of low levels of ionizing radiations on occupationally exposed individuals

The aim of the present study was to assess occupationally induced chromosomal damage in hospital workers exposed to low levels of ionizing radiation. Thirty-two interventional cardiologists, 36 nuclear medicine physicians and 33 conventional radiologists were included in this study, along with 35 healthy age- and sex-matched individuals as the control group. We used conventional metaphase chromosome aberration (CA) analysis, cytokinesis-block micronucleus (MN) assay as important biological indicators of ionizing radiation exposure. Occupational dosimetry records were collected over the last year (ranged from 0.25 to 48 mSv) and their whole life exposure (ranged from 1.5 to 147 mSv). The results showed significantly higher frequencies of dicentric and acentric CAs (p < 0.001) and MN (p < 0.01) in all exposed groups than in the controls. Taking all the confounding factors into account, no obvious trend of increased chromosomal damages as a function of either duration of employment, exposed dose, sex or age was observed. Interventional cardiologists had the highest rates of CA and MN frequencies between the worker groups, though the differences were not significant. These results indicate that long term exposure to low dose ionizing radiation could result in DNA damage. Hence, the personnel who work in the hospitals should carefully apply the radiation protection procedures.     

低剂量辐射诱导的远期兴奋效应研究

探讨低剂量电离辐射（Ｄ１）诱导兴奋效应的远期效应及其对子代的影响。方法以小鼠为实验材料，观察经Ｄ１剂量照后７５天交配所生的小鼠发育指标并测定成熟后免疫功能，对其亲代受照鼠Ｄ１剂量作用后８０天观察非程序ＤＮＡ合成（ＵＤＳ）值。结果Ｄ１照后８０天时对射线诱导的ＤＮＡ损伤修复能力提高，仔鼠出生后死亡率低，体重增加，开眼时间提前。结论说明Ｄ１剂量照射后远期某些指标表现出兴奋效应，而且可以在Ｆ１中显现，但仔鼠成熟后这种反应消失。     

低水平环境因子与适应性反应

简要叙述了低水平环境因子诱导适应性反应的研究现状。强调了极低剂量率电离辐射诱导适应性反应的可能及其剂量效应和时间效应关系的特点。分析了低水平电离辐射诱导适应性反应机理研究的最新进展。讨论了低水平环境因子诱导适应性反应科学资料的实际应用前景。提出了今后进一步研究的建议     

放射工作人员染色体畸变研究现状

长期暴露于低剂量电离辐射会对放射工作人员的辐射敏感组织器官造成损伤。目前,常用于评价慢性低剂量电离辐射所致辐射损伤的主要细胞遗传学指标是外周血淋巴细胞染色体畸变。本文对国内外放射工作人员暴露于低剂量电离辐射所致细胞遗传学效应的调查和研究进行综述,了解目前放射工作人员外周血淋巴细胞染色体畸变检测的现状及存在的问题,为国内开展放射工作人员染色体畸变检测与评价提供参考。