Radiation Emergency Medicine Vol.2, No.2
- Publisher : Hirosaki University Press
- Language : English
- ISSN : 2186-8026 (PRINT)
- Release : August 2013
- Issue : Hirosaki University Press
- pp. 1-89
Chinese Public Health Response to Accident at Fukushima Daiichi Nuclear Power Plant
On March 11, 2011, a powerful magnitude 9 earthquake caused a substantial tsunami off the northeastern coast of Japan which had a disastrous impact upon the Fukushima Daiichi nuclear power plant, which was to attract worldwide attention. The Chinese Center for Medical Response to Radiation Emergency (National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention (CDC)) carried out the public health response to Fukushima Daiichi accident and had excellent results due to appropriate organization, a timely response, accurate analysis and judgment, decisive support and scientific decision-making and recommendations. The public health response covered risk communication, the measurement of food, drinking water, and monitoring body surface contamination. The response was a field trial of the preparedness of the response system to a nuclear accident and a capacity test on the surveillance and monitoring of public health in China. The response also revealed some problems in the preparedness of the response system to a nuclear accident.
Acute Radiation Syndrome Survivors after Chernobyl Accident: History of Irradiation, Diagnostic Mistakes and Death Reasons in Long-term Period
In 1986 it was officially stated that 237 patients got acute radiation syndrome (ARS) of different severity as a result of the Chernobyl accident but till 1989 this diagnosis was confirmed for 134 persons, including those 28 persons, who died within 11 to 96 days. Amongst 103 patients with unconfirmed ARS the main criteria for retrospective decline of diagnosis in 27 patients with typical clinical symptoms were incompleteness of early haematological data, and in 76 ? the atypical character of haematological parameters recovery after their initial decrease. Of those individuals, 190 were living in the territory of Ukraine, and 19 persons in other republics of the former Soviet Union. Amongst Ukrainian residents 42 (24 ARS survivors and 18 non-ARS patients) have died till the end of 2012. The causes of death included oncological (16 patients from 22 with cancer and leukaemia diagnosed) and cardiovascular (14 patients) diseases, somatic diseases and infections (7 patients), accidents (5 cases). The localisation of cancer was rather different: kidney, colon, stomach, lung, lower jaw, thyroid gland, throat, prostate. Sudden cardiac death was the main reason of cardiovascular mortality whereas acute cerebrovascular disease ranked second and was followed by acute myocardial infarction and chronic heart failure.
Circulatory Disease Risk after Low-level Ionizing Radiation Exposure
Correlation between the Symptoms and the Quality of Life in Prostate Cancer Patients Underwent Radiotherapy
The purpose of this study is to elucidate correlations between the symptoms and the quality of life (QOL) of prostate cancer patients underwent radiotherapy. In addition, this study also aims to gain insights regarding nursing interventions so that the patients could lead more comfortable lives. The subjects were 13 patients who were undergoing radiotherapy for prostate cancer at Hirosaki University Hospital. Patients were asked to record symptoms diary from the start of radiotherapy until the completion of radiotherapy. The QOL was investigated with a commercial questionnaire. In this study, fatigue and pollakisuria tended to appear at an early stage, the number of patients complaining of these symptoms increased, and the degree of symptoms worsened. The QOL did not decrease with radiotherapy. Symptom scores during irradiation were negatively correlated with QOL. It is suggested that to improve QOL of patients during radiotherapy, nursing intervention might be effective to abate symptoms.
Responses of Public Health Nurses to the Consultations Following a Nuclear Disaster - Issues Associated with Level of Knowledge
The purpose of this study is to clarify the responses provided by public health nurses who were consulted by residents after the Fukushima nuclear disaster in 2011. Study participants were eight public health nurses working in health centers in Ibaraki Prefecture. All nurses had experience with the criticality accident in facility of JCO Co., Ltd. in 1999. Semi-structured interviews were conducted from February 10-15, 2012 and comprised the following three questions: (1) What kind of actions did health care providers take following the disaster? (2) What kind of supports were provided to the Fukushima evacuees living in shelters? (3) What have you learned from JCO accident, and how did you put the experience of the JCO accident to an account? Data were analyzed qualitatively. This study was approved by The Committee of Medical Ethics of Hirosaki University Graduate School of Medicine, Hirosaki, Japan. Interviews ranged in length from 70 to 100 minutes and lasted an average of 81 minutes. This study is a qualitative analysis of these interviews. As a result, seven subcategories were classified into three categories. These three categories were: (1) transmitting, (2) understanding, and (3) giving advice. ‘Transmitting’ comprised simply providing information, ‘understanding’ was based on the public health nurses’ understanding, and ‘giving advice’ was based on knowledge, understanding, and judgment.
Changes in Nurses’ Impression of Radiation after Attending Educational Seminars on Radiation
The aims of this study were to investigate the changes in nurses’ impressions of radiation after they attended seminars about radiation, to discuss the educational effect and the impact of seminars on the impression of radiation and to obtain suggestions for the content of radiological education. Subjects included 27 nurses who had attended the seminars on radiation held in 2011 and 2012. To assess each subject’s background parameters and pre- and post-seminar impression of radiation, we distributed questionnaires before and after the seminar. A scale to rate their impressions of radiation consisted of 17 items classified into the following 3 factors: affectivity, usefulness, and certainty. The number of valid responses for the questionnaire was 19 (70.4%). No significant differences between the seminar participants in 2011 and those in 2012 were observed for age, nursing experience, frequency of attending seminars about radiation, familiarity with radiation, and work experience in working at a radiology department. In addition, when we compared the subjects’ impressions of radiation before and after they attended the seminars, the impression scores did not show any significant differences. We compared the impressions of radiation of 19 nurses who participated in the seminars in 2011 and 2012 before and after the seminars. The post-seminar scores were significantly higher than the pre-seminar scores for 9 items of affectivity. Both usefulness and certainty showed no significant differences between before and after seminars. Even if the subjects understand that radiation is useful when it is used in the medical field safely and correctly, We suggest that radiological education and seminars may increase nurses’ understanding with regard to radiation and encourage nurses to have positive impressions related to affectivity.
Mitochondrial Superoxide Production and Redox Status in Human Monocytic Cells after Ionizing Irradiation
Low linear energy transfer ionizing radiations, such as X-rays, generate reactive oxygen species (ROS), which cause biological damage. Our recent study demonstrated that high-dose X-ray irradiation induced the expression of antioxidant enzyme heme oxygenase-1 (HO-1) in human monocytic leukemia THP1 cells depending on the generation of secondary ROS, not primary ROS which are generated directly by X-irradiation. However, the source of generation of secondary ROS in X-irradiated THP1 cells remains unknown. To address this question, we investigated the kinetics of mitochondrial superoxide production in X-irradiated THP1 cells. Further, we investigated the types of ROS involved in the induction of HO-1 after X-irradiation. Mitochondrial superoxide generation in X-irradiated THP1 cells increased 3 h after X-irradiation, whereas secondary intracellular ROS generation was observed 24 h after irradiation. Treatment with polyethylene glycol catalase partly inhibited the upregulation of HO-1 by 5 Gy irradiation. We suggest that mitochondria are the source of the X-irradiationinduced secondary peak of intracellular ROS generation in THP1 cells and that hydrogen peroxide is partly involved in the upregulation of HO-1 after X-irradiation. Given that the kinetics of ROS and antioxidants are important factors for the cellular response in irradiated cells, these results will be helpful for treating radiation-induced injuries, such as acute radiation syndrome.
Effect of Whole Body X-irradiation on the Rat Glutathione-related Antioxidant System
Ionizing radiation generates free radicals and ROS, and it has been reported that glutathione(GSH)-dependent antioxidant system is modulated in irradiated tissue and serum even after 24h of irradiation. However, dose-dependent effect on the system has not been clarified and there is no report on effect of irradiation to urinary GSH-dependent enzyme activities. Therefore, in present study, rats were exposed to a single X-irradiation at several doses; 1, 3, 5, and 7 Gy, and after 24h of irradiation, each liver, kidney, testis, and small intestine was exenterated and GSH content and activities of glutathione S-transferase (GST), glutathione reductase (GR), seleniumindependent peroxidase and selenium-dependent peroxidase were assayed. Furthermore, those activities of serum and urine were assayed. In urine, effect of 2 and 4-Gy irradiation was also investigated. GR activity was up-regulated in liver and testis whereas GST activity was impaired in kidney. GSH content was increased in small intestine. However, these modulation were not in a dose-dependent manner. On the other hand, all of serum enzyme activities were unaffected, and most urinary enzyme activities were increased in a dose-dependent manner up to 2 Gy. Thus, it was demonstrated that X-ray modulated GSH-dependent antioxidant system of several tissues in dose-independent and tissue-specific manner, and it increased most urinary enzyme activities dose dependently. These results suggest that urinary GSH-related enzyme activities could be applicable for dose assessment in radiation emergency aid.
Proliferation and Differentiation of Human Hematopoietic Stem/Progenitor Cells Exposed to Low-dose X-irradiation
Hematopoietic stem/progenitor cells (HSPCs) can self-renew and differentiate into all hematopoietic lineages, and are extremely sensitive to oxidative stresses. Exposure of HSPCs to ionizing radiation causes a marked suppression of mature blood cell production in a dosedependent manner. However, little information about the long-term effects of low-dose X-irradiation on the stemness of human HSPCs has been reported. The present study investigated the biological characteristics of the differentiation and proliferation of low-dose X-irradiated human CD34+ HSPCs. Highly purified CD34+ cells exposed to low-dose X-rays were cultured in liquid and semisolid media supplemented with an optimal cytokine combination. The liquid medium was cultured for 14 days; no significant differences in total cell number were observed between nonirradiated and X-irradiated cultures. The expression levels of cell surface antigens such as CD34, CD38, and CD45 on cells harvested from X-irradiated culture were similar to those of cells from non-irradiated culture. However, a significant reduction was observed in the number of burstforming unit erythroid (BFU-E) cells between non-irradiated and 0.5 Gy X-irradiated cells in the myeloid progenitor assay on day 14; moreover, concurrently, radiation-induced γ-H2AX foci were significantly greater on day 14 than on day 0. These results suggest that low-dose X-irradiation is associated with clonal growth suppression of BFU-E cells.
Healthcare of 18 Workers who Supported the Regulation of Radiological Contaminations at the Fukushima Daiichi Nuclear Power Plant
The Great East Japan Earthquake on March 11, 2011 generated large tsunami waves that struck the Fukushima Daiichi nuclear power plant (F1-NPP) of Tokyo Electric Power Company, Inc. (TEPCO). This disaster led to the enormous release of radioactive material into the surrounding environment. In order to support recovery efforts at the F1-NPP, a number of workers have been dispatched to the site. In this study, the peripheral blood samples from 18 workers dispatched to the F1-NPP from May to June 2011 to support the regulation of radiological contamination were collected before and after work, and hematology and blood biochemistry were analyzed for worker healthcare administration. The physical external radiation doses of workers were estimated in the range of 0.2-4.8 mSv, which do not pose a health risk. The results of hematological analysis did not identify health hazards related to work at the F1-NPP. Furthermore, C-reactive protein levels, which are used as a biomarker for estimating exposure dose, were within the ormal range except for those of 1 worker, nand no findings suggested hypothyroidism. As expected, no negative effects on health were observed due to the external exposure dose in workers who supported the recovery of the F1-NPP.
Distribution of Radioactive Cesium in Ostrich (Struthio camelus) after the Fukushima Daiichi Nuclear Power Plant Accident
Enormous amounts of radioactive substances were released into the environment by the Fukushima Daiichi Nuclear Power Plant (FNPP) accident. Radioactive contamination was widely observed and food inspection of radioactivity becomes indispensable. In this paper, we examined radioactive contamination in ostriches (Struthio camelus) after the FNPP accident. Cesium-137 (137Cs, half-life: 30.07 y) and 134Cs (half-life: 2.065 y) were observed in the skeletal muscles of the ostriches located in Kanto region (137Cs: 19.2 ± 11.7, 134Cs: 18.3 ± 11.3 Bq/kg in the muscles, 150 km from FNPP), while no contamination was observed in those located in Tokai region (450 km from FNPP), Tohoku region (180 km from FNPP), and Hokuriku region (140 km from FNPP). We confirmed that detectable radioactive cesium was not found in the liver before the FNPP accident (obtained 2010 November, in Kanto region). Other radioactive nuclides such as 129mTe and 110mAg were not detected in all samples examined. It was considered that the radioactive materials transported in March 2011 were major contributors to the low level contaminations in ostriches located in Kanto region.
An Investigation of Gamma-ray Dose Rate in the Central Area of Hirosaki City, Japan
Hirosaki University has launched an education program on radiation emergency medicine. It includes a practical training exercise on radiation measurements, which assumes a radiation emergency accident in Aomori Prefecture. This paper presents results of a gamma-ray dose rate survey conducted in Hirosaki City as the practical training. Gamma-ray dose rate was measured using two pocket survey meters of the same type. The measurements were conducted by two groups. Each had a pocket survey meter and measured gamma-ray dose rate at 1 m above the ground. The measurement at one point took around 1 min and each group repeated the actions of moving some distance and taking another measurement. One group surveyed along the main streets of Hirosaki City, especially the central area where the Neputa festival is held every summer, and the other group made a survey in Hirosaki Park, a popular place for outdoor activities in the spring. The rationale for choosing these locations was based on the assumption that surveys of ambient radiation dose rate are useful for protection against external exposure and planning suitable routes for evacuation. The arithmetic mean (± standard deviation) for a total of 73 points along the main streets was 31 ± 8 nGy/h, while the arithmetic mean for 68 points in Hirosaki Park was 23 ± 3 nGy/h. According to another study, artificial radionuclides were not found in the gamma-ray energy spectrum obtained just before the present training survey. This means that the present results did not include effects of artificial radionuclides and they were the natural background radiation level in Hirosaki City.