急性核辐射对人的远期效应

内容仅涉及事故性急性核辐射的远期效应：１．日本原爆幸存者（包括宫内受照者约２８００名）的流行病学调查结果，归纳为强关联、弱关联和无关联的远期效应。在第５～１５孕周阶段接受１Ｇｙ照射的胎儿，约有４３％会发生智力发育延迟，为受照０．０１Ｇｙ以下的对比组危险度的５０倍以上。对原爆人群各部位癌症的相对、绝对和归因危险作了介绍。对原爆幸存者受照射后怀孕所生子女（１９４６年５月以后出生），用（１）不利的妊娠结果、（２）死亡事件、（３）携带有性染色体异常儿童的频率、（４）携有由于基因突变引起的血液蛋白电泳变异体儿童的频率等遗传学指标揭示，近爆心（〈２０００ｍ）幸存者（〉１Ｇｙ）所生儿童与远离爆心组（０．０１～０．０９Ｇｙ）相比，仅仅是预期趋势上有差别，实际上未发现有统计学意义的差异。即使如此，这两组儿童间有差异用上述４个指标     

马绍尔群岛放射性落下灰受照居民医学随访近况

本文介绍１９５４年４月氢弹爆炸对马绍尔群岛上居民受放射性落下灰影响３０多年的情况，在人群总体生存情况，死因分析，血液和内分泌改变以及肿瘤发生情况与对照组比较，经统计学处理，显示不出大的差异，但由于氢弹落下灰中放射性磺含量高，甲状腺发病与受照时年龄有关，年轻敏感，发病提前，与日本原爆幸存者的材料有不同特点。     

放射性落下灰地区甲状腺结节发病率高

原爆幸存者的甲状腺疾病随访调查往往忽略了原爆放射性落下灰的效应.日本西山(Nishiyama)地区虽因山脉遮挡而未直接受到原爆辐射,但是接受到落下灰.1969年研究表明,该地区的泥土中~(137)Cs放射性比非尘埃地区高一倍,居民全身放射性增高.作者对原爆后在这一地区居住至少10年并仍住     

评价长期低剂量辐射致癌时存在的问题

根据低剂量辐射例如落下灰受照人群、核反应堆周围居住人员、散在的x射线受照者、核工业工作人员以及宫内受照者等实际受照所作的研究得出的危险估计,和从大剂量照射例如原爆幸存者以及接受医疗照射的个人推导出来的危硷估计是不同的。     

中国六次核试验辐射对哺乳动物的损伤效应研究

目的 研究中国核试验中不同类型辐射对哺乳动物的近期和远期生物学效应,探讨辐射损伤效应机制。方法 1964-1976年间的6次核试验中,在核爆现场和下风向地区布放狗、恒河猴、大白鼠、小白鼠及家兔等哺乳动物,核爆后受到瞬时γ射线和中子外照射,落下灰γ射线、β射线的外照射,落下灰¹³¹I、¹³³I的内照射(食入及吸入),以及内外复合照射;此外,还有2次、3次重复照射,受照射动物的子代照射。动物回收后进行临床医学、病理学、血液学、生物化学、细胞化学、生殖遗传学、细胞遗传学与辐射剂量学等指标观察测试,前后持续22年。结果 核爆后3、7和12个月,受照0.39 Gy后,狗的外周血淋巴细胞染色体畸变率分别为8.63%、7.25%和7.63%,与对照组比较,差异有统计学意义(P<0.01)。在核爆后6个月,受照0.74 Gy的恒河猴的染色体畸变率为21.00%,高于对照组(P<0.01);核爆后8.5年,恒河猴的染色体畸变率为5.52%,高于对照组(P<0.01)。核爆后52 d,大白鼠受照0.65~4.40 Gy后,生殖率下降为30.8%~69.4%,每胎平均仔数减少,与对照组比较,差异有统计学意义(P<0.01)。狗受照0.75和1.73 Gy后,受照后3~7个月精子数量和存活率降为0,且狗精子畸形率增加,达46.79%,高于对照组(P<0.01);狗的精子和睾丸超微结构出现严重的损伤变化。骨髓造血功能破坏,外周血白细胞、淋巴细胞持续减少,血清菲啶溴红络合物荧光强度(核酸含量测定)升高,达18.9%(P<0.05)。受照2.00 Gy以上的狗,5年后发生良性肿瘤53.3%,恶性肿瘤33.3%,高于对照组(P<0.01)。外照射后,狗的睾丸萎缩发病率升高,眼晶状体白内障发病率升高,内照射后甲状腺萎缩发病率升高。放射性灰尘的污染范围大、危害时间长,狗受到落下灰β射线照射后发生皮肤烧伤,恢复慢,有发生癌变的可能。结论 哺乳动物核辐射损伤比单纯中子、γ射线、X射线等照射损伤严重、伤情复杂;核辐射后造血细胞、生精细胞敏感,损伤严重,损伤程度取决于受照剂量,且与照射后时间有关。放射性落下灰的危害范围大、持续时间长,落下灰β射线能造成皮肤烧伤。即使低剂量核辐射,也会造成不容低估的危险。     

一位“老参试”的感言

目的 研究中国核试验中不同类型辐射对动物的近期和远期生物学效应,探讨辐射损伤效应机制。方法 1964—1976年间的6次核试验中,在核爆现场和下风向地区布放狗、恒河猴、大白鼠、小白鼠及家兔等哺乳动物,核爆后受到瞬时γ射线和中子外照射,落下灰γ射线、β射线外照射,落下灰¹³¹I、¹³³I内照射(食入及吸入),以及内外复合照射;此外,还有二次、三次重复照射,受照射动物的子代照射。动物回收后进行临床医学、病理学、血液学、生物化学、细胞化学、生殖遗传学、细胞遗传学与辐射剂量学等指标观察测试,前后持续22年。结果 核爆后3、7和12个月,受照0.39 Gy后,狗的外周血淋巴细胞染色体畸变率分别为8.60%、7.25%和8.70%,与对照组比较,差异有统计学意义(P<0.01)。在核爆后6个月,受照0.74 Gy的恒河猴的染色体畸变率为21%,高于对照组(P<0.01);核爆后8.5年,染色体畸变率为5.52%,高于对照组(P<0.01)。核爆后52 d,大白鼠受照0.65～4.4 Gy后,生殖率下降为30.8%～69.7%,每胎平均仔数减少,与对照组比较,差异有统计学意义(P<0.01)。狗受照0.75和1.73 Gy后,照后3～7个月精子数量和存活率降为零,且狗精子畸形率增加,达46.8%,高于对照组(P<0.01);精子和睾丸的超微结构出现严重的损伤变化。骨髓造血功能破坏,外周血白细胞、淋巴细胞持续减少,血清菲啶溴红络合物荧光强度(核酸含量测定)升高,达18.9%(P< 0.05)。受照2.0 Gy以上的狗5年后发生良性肿瘤53.3%、恶性肿瘤33.3%,高于对照组(P<0.01)。外照射后睾丸萎缩发病率升高,眼晶状体白内障发病率升高,内照射后甲状腺萎缩发病率升高。放射性灰尘的污染范围大、危害时间长,狗受到落下灰β射线照射后发生皮肤烧伤,恢复慢,可癌变。结论 核辐射损伤比单纯中子、γ射线、X射线等照射损伤严重、伤情复杂;核辐射后造血细胞、生精细胞敏感,损伤严重,损伤程度取决于受照剂量,且与照射后时间有关,有特殊规律性;放射性灰尘的危害范围大、持续时间长;落下灰β射线能造成皮肤烧伤。即使低剂量核辐射也会造成不容低估的危险。     

广岛长崎原爆幸存者的体细胞染色体畸变

本文综述广岛,长崎原爆幸存者的体细胞受照后细胞遗传学效应的研究,主要发现如下。(1)辐射诱发染色体结构改变在照后30余年在幸存者外周血淋巴细胞中持续可见；(2)所见到的畸变类型是稳定性畸变如相互易位和臂嗣倒位,而熟知的双着丝点和环的频率在照后数年的血样中已明显减少。这表明含有非稳定性畸变的细胞照射后在体内的淋巴细胞群中经分裂而消失,(3)在两城市幸存者中,染色体畸变量和辐射个体剂量之固有密切关系,但在所有的剂量范围内,广岛的畸变率始终高于长崎。用T65D剂量所见到的两城市同的差别当改用新的原爆剂量系统时差别已不太明显,(4)原爆幸存者的物理剂量估算值在0.5Gy时就可见到畸变细胞率增加,(5)残存的染色体畸变和幸存者的健康状况之瞬的关系问题尚未解决.     

日本广岛原爆幸存者NK细胞的变化

本文报道126名原爆幸存者NK细胞的变化及其对IL-2刺激的反应能力。结果表明；同一年龄组内各剂量照射组NK细胞活性和数量,皆无明显差异。但比较不同受照年龄组,则反映出辐射对小年龄组(<14岁)主要起抑制作用,中间年龄组(15～24岁)变化不明显；大年龄组(>25岁)NK细胞活性有上升趋势。尤其是0.01～1Gy和>1Gy两组内上述年龄组间差异有显着性(P<0.05).说明儿童期受照可能对NK细胞活性产生明显的远后效应。     

受照人群中T细胞抗原受体基因表达缺陷的T淋巴细胞突变率

用双色流式细胞术检测了被调查者外周血CD4~+T细胞中T细胞抗原受体(TCR)基因(α或β)表达缺陷的T细胞突变率(MF).调查对象为:原爆幸存者,氧化钍胶体(含放射性~228Th)使用者,用~(131)I治疗的甲状腺疾病患者,一名在切尔诺贝利核电站事故中严重受照者.以前的研究表明,未受过明显较大电离辐射照射的健康人员的外周血CD4~+T细胞中TCR表达缺陷的MF为2.5×10~(-4).在203名原爆幸存者中,78人受到近距离照射(DS86剂量≥1.5Gy),男女之MF分别为4.0×10~(-4)和2.7×10~(-4);125人受到远距离照射(DS86剂量<0.005Gy),男女之MF分别为0.33     

25例过量受照人员的远期辐射医学效应

目的 探讨过量受照人员的远期健康效应.方法 对25例受照剂量为0.10～0.33 Gy的人员,进行照后32 ～41年的医学随访.观察临床表现、眼晶状体、细胞遗传学指标、免疫功能、内分泌功能等指标的变化.结果 受照者无力型神经衰弱症状发生率高.2例分别患肝癌、食管癌;7例出现晶状体后囊下点状混浊,1例疑似放射性白内障;外周血淋巴细胞染色体畸变率和微核率显著高于对照组(x2=8.88、8.71、40.60、45.63,P＜0.05);受照组血清IgG平均值显著高于对照组(t =2.16,P＜0.05),IgM平均值显著低于对照组(t=2.03,P＜0.05);受照组血清三碘甲状腺原氨酸(T3)、甲状腺素(T.)、促甲状腺素( TSH)平均值均在正常范围,但显著低于对照组(t=2.40、3.54、2.13,P＜0.05).结论 过量照射对晶状体、免疫系统、细胞遗传学指标存在一定的影响,观察过量受照人员的远期医学效应有重要意义.     

The Body at War

Abstract

The criteria certifying atomic bomb disease adopted by the Japanese government are very different from the actual state of the survivors. The criteria are based on epidemiological research by the Radiation Effects Research Foundation, the successor to the Atomic Bomb Casualty Commission (ABCC). The ABCC studied only the effects of primary radiation from the atomic bombing on the survivors of Hiroshima and Nagasaki, and ignored the damage from residual radiation. Analysis of the incidence of acute radiation disease, the rate of chromosomal aberrations, and the relative risks of chronic disease among the survivors, shows that the effects of residual radiation from fallout exceeds that of primary radiation in the area more than 1.5–1.7 km distant from the hypocentre of the Hiroshima bombing. The effects of internal exposure due to intake of tiny radioactive particles are more severe than those of external exposure, explaining the difference between the official criteria and the actual state of the survivors.     

Rays as weapons

PURPOSE: Ionizing radiation is being regarded as life threatening. Therefore, accidents in nuclear power plants are considered equal threatening as nuclear bomb explosions, and attacks with dirty bombs are thought as dangerous as nuclear weapon explosions. However, there are differences between a nuclear bomb explosion, the largest imaginable accident in a nuclear power plant, and an attack with a dirty bomb. It is intended to point them out. METHOD: The processes are described, which damage in a nuclear bomb explosion, in the largest imaginable accident in a nuclear power plant, and in an attack with a dirty bomb. Their effects are compared with each other, i.e. explosion, heat, shock wave (blast), ionizing radiation, and fallout. RESULTS: In the center of the explosion of a nuclear bomb, the temperature rises to 100Mio degrees C, this induces damaging heat radiation and shock wave. In the largest imaginable accident in a nuclear power plant and in the conventional explosion of a dirty bomb, the temperature may rise up to 3000 degrees C, heat radiation and blast are limited to a short distance. In nuclear power plants, explosions due to oxyhydrogen gas or steam may occur. In nuclear explosions the dispersed radioactive material (fall out) consists mainly of isotopes with short half-life, in nuclear power plants and in dirty bomb attacks with longer half-life. The amount of fall out is comparable in nuclear bomb explosions with that in the largest imaginable accident in a nuclear power plant, it is smaller in attacks with dirty bombs. An explosion in a nuclear power plant even in the largest imaginable accident is not a nuclear explosion. In Hiroshima and Nagasaki, there were 200,000 victims nearly all by heat and blast, some 300 died by ionizing radiation. In Chernobyl, there have been less than 100 victims due to ionizing radiation up till now. A dirty bomb kills possibly with the explosion of conventional explosive, the dispersed radioactive material may damage individuals. The incorporation of irradiating substances may kill and be difficult to detect (Litvinenko). A new form of (government supported) terrorism/crime appears possible. CONCLUSION: The differences are important between a nuclear weapon explosion, the largest imaginable accident in a nuclear power plant, and an attack with a dirty bomb. Nuclear weapons kill by heat and blast; in the largest imaginable accident in a nuclear power plant, they are less strong and limited to the plant; an attack with a dirty bomb is as life threatening as an ("ordinary") bomb attack, dispersed radiating material may be a risk for individuals.     

Cover-up of the effects of internal exposure by residual radiation from the atomic bombing of Hiroshima and Nagasaki

The criteria certifying atomic bomb disease adopted by the Japanese government are very different from the actual state of the survivors. The criteria are based on epidemiological research by the Radiation Effects Research Foundation, the successor to the Atomic Bomb Casualty Commission (ABCC). The ABCC studied only the effects of primary radiation from the atomic bombing on the survivors of Hiroshima and Nagasaki, and ignored the damage from residual radiation. Analysis of the incidence of acute radiation disease, the rate of chromosomal aberrations, and the relative risks of chronic disease among the survivors, shows that the effects of residual radiation from fallout exceeds that of primary radiation in the area more than 1.5-1.7 km distant from the hypocentre of the Hiroshima bombing. The effects of internal exposure due to intake of tiny radioactive particles are more severe than those of external exposure, explaining the difference between the official criteria and the actual state of the survivors.     

Occupational radiation exposure: population studies

Occupational exposure to ionizing radiation in the medical setting differs from the acute exposure received by survivors of atomic bomb blasts. Yet, atomic bomb survivors' disease and mortality outcomes have been the standard data source on the effects of ionizing radiation on humans. Therefore, the prevailing estimated risks of ionizing radiation may not apply to radiologic technologists and other medical radiation workers. Carefully designed epidemiological trials provide evidence that helps determine the strength of association between exposure and onset of disease in selected populations. This article reviews radiation effects, explains some basic design concepts of epidemiologic trials and surveys the epidemiology literature related to radiation exposure to humans, with special attention to radiology staff.     

Cardiovascular disease among atomic bomb survivors

Abstract

Purpose: The profile of cardiovascular disease in Japan has been different from that in Western countries. Hypertension was the major cause not only for hemorrhagic stroke but also for ischemic stroke and heart disease in the past, and the influence of hypertension has decreased with calendar years because of reduced salt intake and westernization of lifestyle, and also improved medical care. The health status of atomic bomb survivors has reflected this profile as well as radiation effects. It is also likely that this cohort has been affected by the difficult conditions experienced in the aftermath of the war and atomic bombings. In this article, we tried to make a consistent interpretation of epidemiological findings of atomic bomb radiation effects on cardiovascular disease.

Conclusion: Among the atomic bomb survivors, radiation exposure was associated with some cardiovascular diseases that are often associated with hypertension, and dose response appeared to be primarily non-linear among those who were exposed at younger ages. These effects are thought to reflect the nature of whole body irradiation. But, some findings remain inconsistent, possibly because of possible misclassification in death certificate diagnoses in the Life Span Study as well as selected information from the Adult Health Study which was limited to participants, focused on specific outcomes, and gathered in selected periods of follow-up. Therefore, a comprehensive and balanced interpretation of the results from both groups is necessary.     

Hematological aftermath of the radiation accident in Istanbul

Purpose: The effects of radiation exposure are long-lasting. Long-term monitoring is imperative to diagnose late effects and improve our far-sightedness about possible events in the future. A radiation accident occurred in Istanbul in 1998 that resulted in mild to moderate acute radiation syndrome (ARS). In this study we aimed to investigate the changes in hematological parameters at the long-term follow-up of ARS patients.

Methods: Ten adults were hospitalized after exposure to a 60Co source. Seven were diagnosed as having ARS and had severe and symptomatic pancytopenia. All of the exposed people recovered following intensive treatment. Treatment was supportive with transfusion, granulocyte-colony stimulating factor, and anti- infective management covering antifungal agents. Patients were closely monitored. Nine years after the accident, the initial and follow-up complete blood count examinations and peripheral blood smears (PBS) were comparatively evaluated by an experienced hematologist. The hematological laboratory values of the patients on admission, after treatment, and nine years after the accident were documented and compared.

Results: Biodosimetric analysis revealed that whole-body doses ranged from 1–1.9 Gy. All subjects have shown complete recovery of the hematological laboratory values after treatment. All but one of the subjects showed complete blood cell recovery. The improvement of the blood cell count of the excepted patient stalled at a mildly reduced level and his bone marrow was still hypocellular nine years after the accident; however, no malignant changes were detected. Values at admission were significantly different compared with post treatment and present values of all patients. Post treatment and follow-up values were similar. One of the patients died of lung cancer. None of the patients developed hematological malignancy.

Conclusions: In this study, the recovery from ARS was complete after treatment. The small population, short follow-up period, and the relatively small doses resulted in no long-term adverse effects, as would be predicted.     

The thyroid dose burden in medical imaging A re-examination

Radiation is the best defined causative factor in thyroid cancer. The thyroid is especially susceptible to injury from radiation to which it may be exposed in a variety of circumstances in addition to natural background: radiotherapy, including, historically, therapy of such benign conditions as ring worm and haemangiomata, radiation exposure in nuclear accidents and fallout from nuclear bomb tests, and diagnostic exposures, particularly in the relatively high dose CT examination of head and neck. Both use of CT and the incidence of thyroid cancer appear to be increasing worldwide and it has been suggested that there may be a causative relationship between the two. It has been further posited that the iodine content of the thyroid might play a role in increasing the radiation dose absorption. Indeed, on the same basis, iodine administered in the form of an X-ray contrast-enhancing agent might also be expected to play some role in increasing thyroid radiation absorption resulting in a yet higher dose burden in any give circumstances than is generally assumed. In view of the importance of these ideas we have performed some calculations to estimate the magnitude of the iodine effects. We conclude that they are not great enough to cause concern.     

Prevalence of atherosclerosis in relation to atomic bomb radiation exposure: an RERF Adult Health Study

PURPOSE: To determine whether exposure to atomic bomb radiation altered the prevalence of asymptomatic atherosclerosis. MATERIAL AND METHODS: In a cross-sectional analysis, we examined aortic arch calcification by plain chest radiography and common carotid artery intima-media thickness (IMT) by ultrasonography among 1804 survivors of the atomic bombing in Hiroshima. We evaluated the association between atherosclerotic changes and radiation exposure, while adjusting for potentially confounding factors. RESULTS: Multivariate logistic regression analysis showed that aortic arch calcification was significantly associated with radiation exposure (p < 0.05). The odds ratio at 1 Gy was 1.30 (95% confidence interval [CI]: 1.05 - 1.53) for men and 1.31 (95% CI: 1.13 - 1.51) for women. Carotid artery IMT did not vary significantly with radiation dose (p = 0.18). CONCLUSION: Radiation dose contributed to the prevalence of aortic atherosclerosis but not carotid artery atherosclerosis in atomic bomb survivors.     

四例骨髓型急性放射病患者受照后12年医学随访观察

目的 通过对1999年河南省发生的“4.26”60Co源辐射事故所致的4名骨髓型急性放射病患者受照后12年医学随访观察,探讨电离辐射远后效应,为核事故医学应急的救治和随访提供临床资料和积累经验.方法 采用“一对一”和“多对一”的方式采集病史,观察和记录“梅”、“旺”、“天”、“民”4名患者的临床症状和体征.实验室及器械检查包括血细胞分析、肝肾功能、甲状腺功能、体液免疫、性激素水平、肿瘤标志物及眼科检查、甲状腺彩超、腹部B超、心电图及胸部X片检查,评价其全身情况.辐射遗传学分析包括外周血淋巴细胞染色体畸变分析和微核分析.应用实时荧光定量PCR法,检测其外周血GADD45和nm23-H1基因的mRNA表达,与健康对照人群相比较.采用卡特尔16种个性因素测验(16PF)、抑郁自评量表(SDS)、焦虑自评量表(SAS),对4名患者实施心理测评.结果 4名患者受照后12年造血免疫功能基本恢复正常.“天”乙肝两对半的检查结果中,表面抗原(HBsAg)及核心抗体(HBcAb)为阳性,乙肝病毒复制转为慢性期,传染性弱.4人眼晶状体均有不同程度的混浊性改变,“梅”受照后3年即发生放射性白内障.“梅”、“天”、“民”性激素水平仍有异常.外周血淋巴细胞染色体畸变分析可见少许断片和双着丝粒,但易位率仍较高.分子生物标志物外周血GADD45和nm23-H1基因mRNA定量分析较正常对照组差异无统计学意义.心理测评发现,“梅”重度抑郁、焦虑,其余3人存在紧张、焦虑、恐慌情绪.结论 对4名骨髓型急性放射病患者进行了较为系统的医学随访观察和心理测评,为类似病例的临床救治和随访提供资料.     

Quantification of radiation-induced genetic risk

Associated with technical advances of our civilization is a radiation- and chemically-induced increase in the germ cell mutation rate in man. This would result in an increase in the frequency of genetic diseases and would be detrimental to future generations. It is the duty of our generation to keep this risk as low as possible. The estimation of the radiation-induced genetic risk of human populations is based on the extrapolation of results from animal experiments. Radiation-induced mutations are stochastic events. The probability of the event depends on the dose; the degree of the damage does not. The different methods to estimate the radiation-induced genetic risk will be discussed. The accuracy of the predicted results will be evaluated by a comparison with the observed incidence of dominant mutations in offspring born to radiation exposed survivors of the Hiroshima and Nagasaki atomic bombings. These methods will be used to predict the genetic damage from the fallout of the reactor accident at Chernobyl. For the exposure dose we used the upper limits of the mean effective life time equivalent dose from the fallout values in the Munich region. According to the direct method for the risk estimation we will expect for each 100 to 500 spontaneous dominant mutations one radiation-induced mutation in the first generation. With the indirect method we estimate a ratio of 100 dominant spontaneous mutations to one radiation-induced dominant mutation. The possibilities and the limitations of the different methods to estimate the genetic risk will be discussed. The discrepancy between the high safety standards for radiation protection and the low level of knowledge for the toxicological evaluation of chemical mutagens will be emphasized.