Consequences of the nuclear power plant accident at Chernobyl

The Chernobyl Nuclear Power Plant accident, in the Ukrainian Soviet Socialist Republic (SSR), on April 26, 1986, was the first major nuclear power plant accident that resulted in a large-scale fire and subsequent explosions, immediate and delayed deaths of plant operators and emergency service workers, and the radioactive contamination of a significant land area. The release of radioactive material, over a 10-day period, resulted in millions of Soviets, and other Europeans, being exposed to measurable levels of radioactive fallout. Because of the effects of wind and rain, the radioactive nuclide fallout distribution patterns are not well defined, though they appear to be focused in three contiguous Soviet Republics: the Ukrainian SSR, the Byelorussian SSR, and the Russian Soviet Federated Socialist Republic. Further, because of the many radioactive nuclides (krypton, xenon, cesium, iodine, strontium, plutonium) released by the prolonged fires at Chernobyl, the long-term medical, psychological, social, and economic effects will require careful and prolonged study. Specifically, studies on the medical (leukemia, cancers, thyroid disease) and psychological (reactive depressions, post-traumatic stress disorders, family disorganization) consequences of continued low dose radiation exposure in the affected villages and towns need to be conducted so that a coherent, comprehensive, community-oriented plan may evolve that will not cause those already affected any additional harm and confusion.     

The Chernobyl experience in the area of retrospective dosimetry

The Chernobyl accident, which occurred on 26 April 1986 at a nuclear power plant located less than 150 km north of Kiev, was the largest nuclear accident to date. The unprecedented scale of the accident was determined not only by the amount of released activity, but also by the number of workers and of the general public involved, and therefore exposed to increased doses of ionising radiation. Due to the unexpected and large scale of the accident, dosimetry techniques and practices were far from the optimum; personal dosimetry of cleanup workers (liquidators) was not complete, and there were no direct measurements of the exposures of members of the public. As a result, an acute need for retrospective dose assessment was dictated by radiation protection and research considerations. In response, substantial efforts have been made to reconstruct doses for the main exposed cohorts, using a broad variety of newly developed methods: analytical, biological and physical (electron paramagnetic resonance spectroscopy of teeth, thermoluminescence of quartz) and modelling. This paper reviews the extensive experience gained by the National Research Center for Radiation Medicine, Academy of Medical Sciences, Ukraine in the field of retrospective dosimetry of large cohorts of exposed population and professionals. These dose reconstruction projects were implemented, in particular, in the framework of epidemiological studies, designed to follow-up the medical consequences of the Chernobyl accident and study health effects of ionizing radiation, particularly Ukrainian-American studies of cataracts and leukaemia among liquidators.     

Lessons from Chernobyl and prognosis for Fukushima: radiological consequences

The following are considered: results of large-scale radiation epidemiological studies of the health effects of the Chernobyl accident, radiation risks for emergency workers and the affected population; and verification of ICRP risk models taking into account data on the Chernobyl accident and preliminary prognostic estimates of potential radiological consequences of the Fukushima disaster.     

Radiation occupational health interventions offered to radiation workers in response to the complex catastrophic disaster at the Fukushima Daiichi Nuclear Power Plant

The Fukushima Daiichi Nuclear Power Plant (NPP) 1 was severely damaged from the chain reaction of the Great East Japan Earthquake and Tsunami on 11 March 2011, and the consequent meltdown and hydrogen gas explosions. This resulted in the worst nuclear accident since the Chernobyl accident of 1986. Just as in the case of Chernobyl, emergency workers were recruited to conduct a wide range of tasks, including disaster response, rescuing activities, NPP containment, and radiation decontamination. This paper describes the types and efficacy of the various occupational health interventions introduced to the Fukushima NPP radiation workers. Such interventions were implemented in order to prevent unnecessary radiation overexposure and associated adverse health effects and work injuries. Less than 1% of all emergency workers were exposed to external radiation of >100 mSv, and to date no deaths or health adversities from radiation have been reported for those workers. Several occupational health interventions were conducted, including setting of new regulatory exposure limits, improving workers'' radiation dosimetry, administration of stable iodine, running an occupational health tracking system, and improving occupational medicine and preventative care. Those interventions were not only vital for preventing unnecessary radiation, but also for managing other general health issues such as mental health, heat illness and infectious diseases. Long-term administration of the aforementioned occupational health interventions is essential to ensure the ongoing support and care for these workers, who were put under one of the most severe occupational health risk conditions ever encountered.     

严重核事故应急救援人员的心理危机干预

切尔诺贝利核事故和福岛核事故表明严重核事故对参与应急救援的人员会产生巨大的心理效应,他们会与事故受害者一样产生一系列的精神心理问题。本文通过分析切尔诺贝利核事故和福岛核事故后应急救援人员产生的精神心理健康问题,借鉴重大自然灾害、疫情等救援人员心理危机干预的方法,结合核事故应急救援人员面临的特殊情况,提出核事故应急救援人员的心理危机干预方法。这套方法包括事故前应急救援人员的心理健康评估与培训、事故中应急救援人员的心理救助、自我调试和心理危机干预以及事故后的长期心理援助。通过有效的心理危机干预,降低核事故对应急救援人员的心理影响。     

Current status and epidemiological research needs for achieving a better understanding of the consequences of the Chernobyl accident

Twenty years after the Chernobyl accident, there is no clearly demonstrated increase in the incidence of cancers in the most affected populations that can be attributed to radiation from the accident, except for the dramatic increase in thyroid cancer incidence among those exposed in childhood and adolescence. Increases in the incidence of cancers and other diseases have been reported in Belarus, the Russian Federation, and Ukraine, but much of the increase appears to be due to other factors, including improvements in diagnosis, reporting, and registration. Recent findings indicate a possible doubling of leukemia risk among Chernobyl liquidators and a small increase in the incidence of premenopausal breast cancer in the very most contaminated districts. Increased risks of cardiovascular diseases and cataracts have also been reported. These findings, however, need confirmation in well-designed analytical epidemiological studies with careful individual dose reconstruction. The absence of demonstrated increases in cancer risk--apart from thyroid cancer--is not the proof that no increase has in fact occurred. Based on the experience of atomic bomb survivors, and assuming that there is a linear, no-threshold dose-response relationship between exposure to ionizing radiation and the development of cancer in humans, a small increase in the relative risk of cancer is expected, even at the low to moderate doses received. Given the large number of individuals exposed, the absolute number of cancer cases caused could be substantial, particularly in the future. It is therefore essential to continue to use population registries to monitor trends in disease morbidity and mortality in the most contaminated areas, as well as among liquidators, in order to assess the public health impact of the accident. Studies of selected populations and diseases are also essential in order to study the real effect of the accident and compare it to predictions. Careful studies may in particular provide important information on the effect of exposure rate and exposure type in the low to medium dose range and on factors that may modify radiation effects. As such, they may have important consequences for the radiation protection of patients and of the general population in case of further nuclear emergencies.     

Patterns of acute leukaemia occurrence among children in the Chernobyl region

BACKGROUND: The Chernobyl nuclear accident of 1986 released large quantities of radioactive material causing widespread contamination. In the Ukraine alone, more than 4 million people were exposed to radiation. The exact health consequences of this exposure are still being assessed. METHODS: To ascertain the effect of in utero radiation exposure and the development of leukaemia, a review was undertaken of leukaemia sub-types occurring among children born in the year of the accident (1986) and followed 10 years post-exposure. A comparison was made of leukaemia cumulative incidence rates among children from both an exposed and unexposed oblast. RESULTS: Rate ratios (RR) for the all cell types grouping of leukaemia revealed that rates in the exposed Oblast were significantly elevated for females, males and both genders combined. Rates of acute lymphoblastic leukaemia (ALL) were dramatically elevated for males and to a lesser extent for females. For both genders combined, the RR for ALL was more than three times greater in the exposed compared to the unexposed region. CONCLUSION: Study results suggest that the increased risk of leukaemia and acute leukaemia among those children born in 1986 and resident in radioactively contaminated territories may be associated with exposure to radiation resulting from the Chernobyl accident.     

Leukemia following the Chernobyl accident

The accident at the Chernobyl Nuclear Power Plant in Ukraine in 1986 led to a substantial increase of thyroid cancer among those exposed as children. The other cancer that is the most sensitive to the effects of ionizing radiation is leukemia, and this paper evaluates the evidence relating exposure to Chernobyl radioactivity and leukemia risk. Two types of objectives are identified, namely, scientific evidence and public health, and two approaches to addressing such objectives are discussed. Empirical studies in affected populations are summarized, and it is concluded that, possibly apart from Russian cleanup workers, no meaningful evidence of any statistical association between exposure and leukemia risk as yet exists. However, it is important to carry on with such studies to satisfy various public health objectives.     

严重核电站事故情况中的现场心理急救

历史上3起严重核电站事故表明:对公众的社会心理影响是严重核电站事故的最严重影响之一.当严重核电站事故发生时,受心理急救影响区域的个人/群体可能会经历各种应激反应,及时有效的心理急救可以帮助受灾者度过危机,积极的应对当前的生活.本文参考世界卫生组织现场工作者心理救助指南等国内外相关指南、标准,结合核事故心理影响的特点,介...     

Chernobyl vis-à-vis the nuclear future: an international perspective

The paper aims to provide an international perspective on the consequences of the Chernobyl accident vis-à-vis the future development of the use of nuclear energy for peaceful purposes. It describes the major international initiatives that were undertaken over the years in order to quantify the consequences of the Chernobyl accident, and also analyzes the impact of the accident on the development of nuclear energy taking account of the perception of its consequences. The paper revisits the historical saga flowing since the fateful explosion at the Chernobyl Nuclear Power Plant in the Ukraine 20 y ago. It looks at some of the misunderstandings about the consequences of the accident and explores the worldwide nuclear stagnation that followed Chernobyl, surveying the negative public reaction and also the possibilities of a nuclear revival. It finally searches for a way forward, concluding that an effective international nuclear safety regime is urgently needed with the purpose of preventing catastrophes like Chernobyl from occurring and also that the Chernobyl consequences need to be readdressed properly. The paper concludes with an appeal to the radiation protection community to resolve once and for all the difficult issues of attributing health effects to low-level radiation exposure.     

核事故辐射环境航空监测实例及思考

辐射环境航空监测具有快速、高效、覆盖面大的特点,是核事故应急监测中不可替代的重要技术手段。本文重点介绍了前苏联切尔诺贝利核电站核事故、美国三哩岛核电站核事故及日本福岛核电站核事故后开展的辐射环境航空监测行动。辐射环境航空监测技术在确定辐射污染范围、辐射环境调查及为国家相关部门快速提供技术支持方面发挥重要作用,是核事故应急响应行动中重要组成部分。建议有序开展核应急航空监测新型装备技术研究、核事故应急航空监测分析研判研究;有效应对核事故,开展全国核设施周围详细辐射环境水平摸底的航空监测研究。     

切尔诺贝利和福岛核事故的今昔对比及引发世人的深思

目的 重点介绍历史上发生的多起核事故中最为严重的1986年切尔诺贝利核事故和2011年福岛核事故。方法 回顾性分析了切尔诺贝利和福岛两次特大七级核事故的发生及抢险、核事故的剂量及对健康的影响。结果 切尔诺贝利核事故与福岛核事故的发生时间先后相距25年。就近期辐射损伤而言,福岛核事故可能仅次于切尔诺贝利核事故对人员的危害。从远期效应测评,切尔诺贝利核事故对抢险人员、附近居民、受放射性污染的不同年龄段人员带来的健康危害的现状也可能是福岛人明天的预警。结论 切尔诺贝利和福岛这两次特大七级核事故对当地居民健康及核工业发展等带来的负面影响是惨痛的,只有尽可能遏制核事故的发生,才能确保核安、辐安、民众心安。     

The chernobyl accident 20 years on: an assessment of the health consequences and the international response

BACKGROUND: The Chernobyl accident in 1986 caused widespread radioactive contamination and enormous concern. Twenty years later, the World Health Organization and the International Atomic Energy Authority issued a generally reassuring statement about the consequences. Accurate assessment of the consequences is important to the current debate on nuclear power. OBJECTIVES: Our objectives in this study were to evaluate the health impact of the Chernobyl accident, assess the international response to the accident, and consider how to improve responses to future accidents. DISCUSSION: So far, radiation to the thyroid from radioisotopes of iodine has caused several thousand cases of thyroid cancer but very few deaths ; exposed children were most susceptible. The focus on thyroid cancer has diverted attention from possible nonthyroid effects, such as mini-satellite instability, which is potentially important. The international response to the accident was inadequate and uncoordinated, and has been unjustifiably reassuring. Accurate assessment of Chernobyl's future health effects is not currently possible in the light of dose uncertainties, current debates over radiation actions, and the lessons from the late consequences of atomic bomb exposure. CONCLUSIONS: Because of the uncertainties over the dose from and the consequences of the Chernobyl accident, it is essential that investigations of its effects should be broadened and supported for the long term. Because of the problems with the international response to Chernobyl, the United Nations should initiate an independent review of the actions and assignments of the agencies concerned, with recommendations for dealing with future international-scale accidents. These should involve independent scientists and ensure cooperation rather than rivalry.     

Late cancer and noncancer risks among Chernobyl emergency workers of Russia

The presented work summarizes data on estimated radiation risks among Chernobyl emergency workers of the Russian Federation. In 1991-1998, the excess relative risk (ERR) of death from malignant neoplasm was statistically significant: excess relative risk per 1 Gy (ERR/Gy)=2.11 with 95% confidence interval (CI) (1.31-2.92). In 1991-2001, the ERR estimation for incident solid cancers gives a positive, but statistically insignificant value: ERR/Gy=0.34 with 95% CI (-0.39; 1.22). In 1986-2003, radiation risk for leukemia incidence was investigated. During the first 10 y after the Chernobyl accident (1986-1996) the relative risk (RR) of leukemia (excluding chronic lymphocytic leukemia) was statistically significant: RR=2.2 with 95% CI (1.3-3.8) for emergency workers with doses>0.15 Gy in comparison with less exposed workers. In 1986-2000, a statistically significant dose response was observed for incident cerebrovascular diseases: ERR/Gy=0.39, 95% CI=(0.004; 0.77). For doses>0.15 Gy a statistically significant risk of cerebrovascular diseases as a function of mean daily dose was observed: ERR per 0.1 Gy d(-1)=2.17 with 95% CI=(0.64; 3.69). Different but overlapping cohorts of Russian emergency workers were used for these estimations. No adjustments were made for recognized risk factors for cerebrovascular diseases. All results should be considered as preliminary.     

Chernobyl radionuclide distribution, migration, and environmental and agricultural impacts

The distribution and migration of radionuclides released into the environment following the Chernobyl accident in 1986 are described. The Chernobyl disaster resulted in the consumption of farm products containing radionuclides as a source of irradiation of the population due to the prevalence of a rural type of human nutrition in the affected region. Economic and radiologic importance of countermeasures for reducing the impacts of the accident are described. The basic radioecological problem is described in which the area where direct radiation contamination of biota was observed is considerably smaller than the zone where concentrations of radionuclides through the food chain exceeded the permissible standards. The radiation-induced effects in biota in the affected area are described. In the long-term post-accident period, the radionuclide distribution between components of ecosystems (including humans) and doses are considered in comparison to a technologically normal situation of nuclear power plant operation. This analysis demonstrates that if radiation standards protect humans, then biota are also adequately protected against ionizing radiation.     

The risk of radiation-induced cerebrovascular disease in Chernobyl emergency workers

The paper deals with estimating radiation risks of non-cancer diseases of the circulatory system among the Chernobyl emergency workers based on data from the Russian National Medical and Dosimetric Registry. The results for the cohort of 61,017 people observed between 1986 and 2000 are discussed. These are essentially updated results for the similar cohort that was studied by authors earlier in 1986-1996. Newly discovered is the statistically significant dose risk of ischemic heart disease [ERR Gy = 0.41, 95% CI = (0.05; 0.78)]. Confirmation is provided for the existence of significant dose risks for essential hypertension [ERR Gy = 0.36, 95% CI = (0.005; 0.71)] and cerebrovascular diseases [ERR Gy = 0.45, 95% CI = (0.11; 0.80)]. In 1996-2000, the assessed ERR Gy for cerebrovascular diseases was 0.22 with 95% CI = (-0.15; 0.58). Special consideration is given to cerebrovascular diseases in the cohort of 29,003 emergency workers who arrived in the Chernobyl zone during the first year after the accident. The statistically significant heterogeneity of the dose risk of cerebrovascular diseases is shown as a function of the duration of stay in the Chernobyl zone: ERR Gy = 0.89 for durations of less than 6 wk, and ERR Gy = 0.39 on average. The at-risk group with respect to cerebrovascular diseases are those who received external radiation doses greater than 150 mGy in less than 6 wk [RR = 1.18, 95% CI = (1.00; 1.40)]. For doses above 150 mGy, the statistically significant risk of cerebrovascular diseases as a function of averaged dose rate (mean daily dose) was observed: ERR per 100 mGy d = 2.17 with 95% CI = (0.64; 3.69). The duration of stay within the Chernobyl zone itself, regardless of the dose factor, had little influence on cerebrovascular disease morbidity: ERR wk = -0.002, with 95% CI = (-0.004; -0.001). The radiation risks in this large-scale cohort study were not adjusted for recognized risk factors such as excessive weight, hypercholesterolemia, smoking, alcohol consumption, and others.     

The impact of the Chernobyl accident on radiation protection

The science of radiation protection is a fundamental outgrowth of peaceful and military applications of ionizing radiation and the use of nuclear energy. Scientific progress in radiation protection has not, however, been as dramatic as progress in other scientific endeavors, because many users of ionizing radiation have perceived that the major technical and institutional problems have already been solved. This misperception is not based on solid fact and is not shared by radiation protection professionals, who have a broader vision of both past achievements and problems remaining in this area. Experience gained as a consequence of the Chernobyl accident has highlighted new problems and demonstrated the urgency of finding better answers to some old questions. This paper addresses the future impact of the recent Chernobyl accident on the science of radiation protection. In summary, the accident demonstrated that particular emphasis should be directed toward: Improvement of dosimetric and health-effects models for predicting the consequences of exposure of the public to low doses of ionizing radiation. Development of optimized, realistic countermeasures and improvement in emergency preparedness. Education of the public, including students, scientists and politicians with regard to radiation protection issues. Development of advanced computer programs and radiation instruments for evaluating reactor accidents and their consequences. Transfer of learned concepts, methods and approaches to other scientific fields, such as environmental sciences, toxicology, pharmacology, etc.     

Mental health consequences of the Chernobyl disaster

The psychosocial consequences of disasters have been studied for more than 100 years. The most common mental health consequences are depression, anxiety, post-traumatic stress disorder, medically unexplained somatic symptoms, and stigma. The excess morbidity rate of psychiatric disorders in the first year after a disaster is in the order of 20%. Disasters involving radiation are particularly pernicious because the exposure is invisible and universally dreaded, and can pose a long-term threat to health. After the Chernobyl disaster, studies of clean-up workers (liquidators) and adults from contaminated areas found a two-fold increase in post-traumatic stress and other mood and anxiety disorders and significantly poorer subjective ratings of health. Among liquidators, the most important risk factor was severity of exposure. In general population samples, the major risk factor was perceived exposure to harmful levels of radiation. These findings are consistent with results from A-bomb survivors and populations studied after the Three Mile Island nuclear power plant accident. With regard to children, apart from findings from ecological studies that lack direct data on radiation or other teratologic exposures and local studies in Kiev, the epidemiologic evidence suggests that neither radiation exposure nor the stress of growing up in the shadow of the accident was associated with emotional disorders, cognitive dysfunction, or impaired academic performance. Thus, based on the studies of adults, the Chernobyl Forum concluded that mental health was the largest public health problem unleashed by the accident. Since mental health is a leading cause of disability, physical morbidity, and mortality, health monitoring after radiation accidents like Fukushima should include standard measures of well-being. Moreover, given the comorbidity of mental and physical health, the findings support the value of training non-psychiatrist physicians in recognizing and treating common mental health problems like depression in Fukushima patients.     

The results of clinico-hygienic research in the region of the Mozyr industrial center following the accident at the Chernobyl Atomic Electric Power Station]

The dose of radioactive irradiation received by the workers of the Mozyr industrial area after the Chernobyl power plant accident cannot result in specific lesions, but a nonspecific effects of low radiation doses, chemical substances of low intensity and other occupational factors are possible. A possible radiation origin of the astheno-depressive and astheno-somatic disorders developing by nonspecific stress mechanisms is to be investigated.