Excluding accidental radiation exposures and those received in radiation therapy the largest and most variable component of dose to the public is due to exposure to the naturally occurring radioactive gas radon and its progeny in their homes. On a global basis the annual dose to the general population from radon has been estimated to be 1.2 mSv per year. In many countries however, doses of some tens of mSv/year occur in high radon areas. The principal epidemiologically established risk from radon exposure is lung cancer. Due to synergistic effects in combination with smoking it can greatly amplifies the already high lung cancer risk due to smoking alone. Radon is classified as a Group 1 human carcinogen and is considered by the World Health Organization as being responsible for between 3 and 14% of lung cancers. An important component of a national strategy to reduce public exposure to radon is risk communication. Its main objectives are to raise awareness of the hazard from radon and to encourage radon measurement in homes and to take action to reduce indoor radon concentrations. Here an overview is given of the various components of radon risk communication such as the identification of target audiences, the messages to be used and the appropriate channels of communication.

Institute of Radiation Medicine (IRM), Fudan University originated from Shanghai Institute of Industrial Hygiene which was founded by the Ministry of Health, P. R. China, in 1962. From 1985 to 2000, it was placed under the management of the former Shanghai Medical University, and it was transferred to Fudan University as the former Shanghai Medical University was merged in 2000. In the past nearly 50 years, both fundamental and applied researches on the dose?response relationships of ionizing radiation, prevention, diagnosis, treatment of radiation injury and other related subjects were comprehensively conducted in the IRM, and a lot of fruitful results have been achieved. In this review, the main research results associated with radiation emergency medicine in the IRM were briefly introduced and summarized into the following aspects: Prediction of radiological impacts due to nuclear or radiological terrorism events, Dose estimation, Decorporation of intake radionuclides, Treatment of radiation injury.

The natural radiation level is a good indicator to assess the influence from artificial radiations resulted from some nuclear accident. In this paper, we show the representative maps for the distribution of terrestrial gamma radiation dose rate in Japan before the great earthquake (M 9.0) on 11 March 2011 that attacked mainly northeastern part of Japan and triggered powerful tsunami and serious nuclear accident. The sources of terrestrial gamma radiations are natural radioactive elements that have always existed in the earth. Based on the nationwide data, the average of the dose rate in Japan is estimated to be 50 nGy/h. Also the averages in the northeast and the southwest of Japan are estimated to be 56 and 40 nGy/h, respectively. The geographical variation of the dose rate can be explained in relation to the variation of rocks and soils.

History and progress of the Hakaru-kun project continuing around for a quarter century has been introduced. The core of the project is “Hakaru-kun”, handy-type radiation survey-meters. The authors believe we Japan faced two big turning points on radiation education recently. One is the revision of the government curriculum guidelines for elementary schools and for junior high schools in 2008. In the revised guidelines, a keyword of “radiation” was re-involved at interval of about 40 years. Second is the accident of the Fukushima dai-ichi nuclear power plant of Tokyo Electric Power Cooperation in March, 2011. We should continue serious discussion on the relation and harmonization among environment protection, usage of science and technology, and also safety and security based on the facts and real data with international consensus. Usage of radiation and radioactive materials is now one of the most important discussion points. We should understand most of environment radiation can be easily detected by simple radiation surveymeters. This would be the first step to understand radiation, and then might be connected to public’s real interest in radiation itself. We also hope this activity of the project in Japan would be a good example or model on radiation education in other countries.

In response to an emergency radiological incident there is always a need for fast, reliable methods for the determination of actinides on bioassay samples. This is one of the utmost important for dose evaluation as well as for proper medication for the exposed one. Due to the complexities lying in the biological sample matrix, it is very important to have a proper analytical methodology for estimation of actinides. This paper summaries the basic procedures needed for the accurate and fast measurement of different actinide elements like U, Th, Pu and Am in biological matrices mainly urine and fecal samples and also isotopic ratios. For actinide analysis in biological material the most important steps involved are sample digestion, radiochemical separation, source preparation followed by detection. Depending upon the type of actinide, its concentration, sample size availability careful selection of proper procedure is needed for each step for accurate and reliable measurement. This also briefly describes the improved and modified methodologies for estimation of different actinides in biological matrices at low level by different researchers.

Radiation exposure during pregnancy should be avoided for several reasons, including teratogenesis, carcinogenesis, and mutagenesis. However, exposure during pregnancy is often unavoidable because procedures involving radiation are vital for identifying significant maternal and/or fetal complications or trauma. Moreover, women may be exposed to radiation before they are aware of their pregnancy. Radiation exposure through diagnostic and therapeutic procedures a common concern for pregnant women. Most of their anxiety originates from the general view that any radiation exposure is harmful and can result in adverse effects on the fetus. This anxiety can lead to an unnecessary termination of the pregnancy. Therefore, pregnant women should always be informed of the benefits of the procedures and the risks of radiation exposure to the fetus, and allow them to make an informed decision regarding termination of the pregnancy after radiation exposure. The present report focuses on issues related to radiation exposure of pregnant women and fetuses, specifically in Japanese medical institutions.

On 28 March 1979, the most serious accident in the history of USA commercial nuclear power plant operation occurred at the Three Mile Island Nuclear Power Plant. Failure to close a pressure relief valve led to severe damage of uncooled fuel. A series of events then led to core melt and release of fission products. On 26 April 1986, the most severe accident ever to occur in the nuclear industry began at the Chernobyl Nuclear Power Plant. The cause of the accident was a runaway surge in the power level that caused the water coolant to vaporize inside the reactor. This was followed by a steam explosion and fire with release of radioactive materials. On 11 March 2011, a great earthquake and tsunami damaged the Fukushima Daiichi Nuclear Power Plant and caused lose of emergency power supplies for cooling functions. Explosions destroyed the reactor buildings and considerable amounts of radioactive materials were released into the atmosphere and ocean. This paper addresses the cause of the accidents at these three nuclear power plants, the released amount of radioactive materials, and the radioactive contamination and health effects.

On March 11, 2011, a serious accident began at the Fukushima Daiichi Nuclear Power Plant after a huge tsunami hit the plant as a result of the M9.0 earthquake. The regulation values for the radiation and radioactivity in an emergency were noticed, and were not adequate serve for this situation. The existing regulation values concerning the notification criteria for occurrence of an unusual situation and the judgment criteria of an emergency, the radiation dose limits of workers in an emergency, sheltering and evacuation of residents, and oral administration of stable iodine tablet are first described. The regulation values set after the accident are concerned with the intake of foods and drinks, the paddy field soil, going to school and engaging in outdoor activities for kindergarten and school age children, swimming beaches, and ash and fly ash from incinerators, sludge from sewage disposal plants and residual matter from water purification plants.

The present paper deals with the solid state etch-track detectors and their applications to the detection / dosimetry of neutrons, radon, and radon-decay products. Most of the scientists, actively engaged in the late 60’s and in the 70’s for monitoring the occupational neutron-exposure by etch-track detectors, became also involved in the development of personal monitors for the exposure to radon-decay products in mines. The personal dosimetry of neutrons and that of radon decay products have had a parallel history and a lot of common traits, such as the same track detectors, the same etching and counting procedures, the same scientists and/or laboratories involved. These parallel investigations have been conducive to the development of etch-track-based film-badges for the detection of the neutron fluency and the radon concentration respectively. Thanks to these parallel investigations, it was possible to demonstrate that radon may represent a strong disturbing factor for the response of neutron film-badges. In particular, it was finally possible to explain the erratic response obtained in the past with neutron film-badges, based on polycarbonate track detectors, characterized by a large radon sorption. Finally, a strategy similar to that established for neutron dosimetry has been recently proposed to solve the long-standing problem of the dosimetry of radon-decay products.

Since the JCO criticality accident in 1999, it has been thought to be prudent to prepare a system for radiation emergency medicine. The Great East Japan Earthquake measuring 9.0 on the Richter scale occurred in Japan on March 11, 2011, and this earthquake and tsunami caused serious damage to the Fukushima Daiichi Nuclear Power Plant (NPP) of Tokyo Electric Power Co. (TEPCO). Hospitals that had been designated as radiation emergency facilities lost their function because they were located in the evacuation areas, and community lifelines such as water supply and electricity were severely damaged. However, hospitals not thusly designated could not receive patients from NPP because of concerns about the health effects of radiation from patients. In Japan, local governments with nuclear facilities such as NPPs run the training system of radiation emergency for medical professionals. However, those without nuclear facilities do not have the system. Therefore, education and training were restricted to related organizations and agencies. From the response to this accident, we learned that all hospitals, their staffs and first responders need knowledge about radiation and the basics of radiation emergency medicine. The response to this accident has also highlighted the challenges of a radiation emergency medical response system for a combined disaster. In our efforts for recovery from the damages, reconstruction of the medical system for radiation emergency in the affected areas has to be accelerated, since reactors have not been stabilized and many workers are still involved in recovery work, with high risks of radiation exposure at the NPP site. From our response to this combined disaster of earthquake, tsunami, and radiation, we also learned that there is an urgent need for an all-hazards approach.

Murine allogeneic umbilical cord blood cells (UCBCs) were studied for their ability to reconstitute the hematopoietic system. UCBCs obtained from fetuses of C57BL/6 mice, which were transgenic for green fluorescent protein (GFP), were transplanted into RAG2(-/-)BALB/c mice. For comparison, bone marrow cell (BMC) transplantation was also performed. At 16 weeks after transplantation, phenotypically mature GFP-positive immune cells of donor origin, including T cells, B cells, monocytes, and granulocytes, were detected in the recipients’peripheral blood, even after major histocompatibility complex-mismatched UCBC transplantation. Functional analysis showed that mice with allogeneic UCBC transplants accepted skin grafts from both BALB/c and C57BL/6 mice. However, these chimeric mice completely rejected skin grafts from third-party C3H/HeJ mice, indicating that both CD8+ killer and CD4+ helper T cells were functionally mature in the recipients. In addition, 2,4,6-trinitrophenyl-keyhole limpet hemocyanin (TNP-KLH) immunized mice with UCBC transplant produced both TNP-specific IgM and IgG antibodies. These findings indicate the ability of recipient mice to develop antibody responses with Ig class switching to T-cell-dependent antigens, thereby confirming that both B cells and CD4+ helper T cells derived from allogeneic UCBC were immunologically competent. Furthermore, we have demonstrated for the first time that B-1a cells, which produce natural IgM antibodies against pathogens such as Streptococcus pneumoniae and the influenza virus, can be generated from UCBCs but not from BMCs.

The frequency of chromosome aberrations correlates with the radiation dose, therefore measuring chromosome aberrations in peripheral lymphocytes obtained from exposed persons is considered the most reliable, specific, and sensitive biomarker for dose estimation. The inf luence of radiation is evaluated by analyzing chromosome aberrations in dicentric and premature chromosome condensation (PCC) assays. It has been suggested that the degree of chromosome condensation may have significant effects on the detection of ring-chromosomes, small fragments, and translocations. In order to investigate the effects of colcemid treatment on chromosome condensation, we compared the relative length of chromosome 2, which identification is easy and contains approximately 8.1% of genome DNA, in lymphocytes treated with 0.01, 0.03, 0.05, and 0.1 μg/ml colcemid for 2, 24, and 48 h each. Our data showed that the　most elongated chromosomes were obtained from the lymphocytes treated with 0.01 μg/ml colcemid for 2 h. Furthermore, it has been reported that calyculin A treatment results in induction of PCCs with over-condensed chromosomes, then, we analyzed the effect of colcemid-block on chromosome condensation in PCC assay. PCC cells with the over-condensed chromosomes were observed frequently in PCC assay combined with colcemid-block. Since colcemid treatment has　large influence on chromosome condensation, it is necessary to choose the optimal conditions for the biodosimetry analysis of each chromosome aberration.

Nuclear disasters had been considered extremely rare, but the Fukushima Daiichi nuclear crisis that accompanied the Great East Japan Earthquake caused people’s awareness to change considerably. Many regions with nuclear related facilities, such as Fukui Prefecture, have a chronic shortage of doctors, and therefore do not have the means to employ radiation emergency medicine specialists. General practitioners that can provide comprehensive medical care including emergency and radiation emergency medical care are appropriate in such regions. Fukui University began to train general practitioners skilled in emergency medicine and familiar with radiation emergency medical care from 2009. It is both the role and responsibility of teaching hospitals to coordinate with local governments and train doctors suited to support hospitals in these regions.

The aim of this study was to clarify the perceptions of health sciences students on radiation risk. Subjects were first-year students of a health sciences school in 2010. A questionnaire survey regarding radiation was conducted among 201 students majoring in nursing, radiological technology, medical technology, physical therapy, and occupational therapy at H University. The survey consisted of questions associated with radiation itself and questions on “risk of damage to one’s health by radiation or radioactive substances” (health risk of radiation). We compared answers among the students in each major. Students who did not study physics in high school were significantly more likely to report a fear of radiation from natural resources, such as rocks and soil, than radiological technology students. The rate of students selected the physics were significant differences between nursing students and radiological technology students. The items of “X-ray and CT photogram” and “Mr.And Madam Curie” and “Chernobyl” scored significantly lower in nursing students. We conclude that differences in risk perception of radiation may be due to educational background.

We interviewed seven public health nurses who responded to the radiation disaster at the Tokai Village JCO nuclear accident in 1999 to learn about their experiences and determine the type of training that would be helpful in the future. This study was approved by the Committee of Medical Ethics of Hirosaki University Graduate School of Medicine, Hirosaki, Japan. Interviews ranged in duration from 45 minutes to 1.5 hours and were conducted on November 24 and 25, 2010. Data were compiled from all interviews and analyzed qualitatively. Three primary categories and nine subcategories summarizing experiences and need for future training were　identified. The three primary categories were: (1) activities for reducing residents’ anxiety; (2) mental attitude toward a radiation disaster; and (3) training of public health nurses as representatives of the local government. Results showed that one of the most critical roles of public health nurses after a radiation accident is to control and calm anxieties experienced by residents living in the area. By establishing training strategies based on experience gained in the JCO accident, we will be able to prepare inexperienced persons who may need to respond to future emergencies.

Residents living close to the Fukushima nuclear power plant were forced to evacuate because of the accident caused by the Great East Japan Earthquake on 11 March, 2011. Management of health problems among evacuees became a pressing need. The aim of this study was to identify conditions among evacuees in past disasters that would require rehabilitative care. Through literature searches, we identified deep-vein thrombosis (DVT) and disuse syndrome as potential targets for rehabilitation among evacuees. For both conditions, aggressive exercise therapy was recommended following the disaster. Rehabilitation specialists should also convey correct information to evacuees about radiation in order to reduce their uneasiness.

The purpose of this study is to clarify the current status of disaster prevention and support measures throughout the whole disasters at home-visit nursing stations. The study involved a cross-sectional survey of 81 directors of home-visit nursing stations in 6 prefectures having nuclear facilities, which are located in eastern Japan. The survey was carried out by a questionnaire, which asked about knowledge and recognition of disaster prevention and disaster support measures including nuclear disaster management. Most of participants felt that their knowledge regarding disaster support was insufficient, but they generally recognized necessity of disaster prevention and support measures against natural disasters. Over 80% of participants were unaware of 7 categories, including knowledge on nuclear disasters and disaster prevention, medical systems and responsibility in the time of the nuclear disaster, and municipal and prefectural assistance. Most of participants were unaware of the implementation of emergency drills. Furthermore, they were unaware of the role of home nursing in time of the nuclear disaster. These results collectively suggest that visiting nurses must participate in measures against nuclear disasters organized by local governments; disaster drills and training sessions, in order to improve their awareness of nuclear disaster. This will enhance their awareness of disasters and it will promote revision of disaster manuals.

The aim of this study was to clarify the risk perception of radiation among nursing students and the relationship between risk perception of radiation and student grade level. A questionnaire survey was administered to 341 nursing students, from freshmen to seniors, at X University. Students learn about radiation risk starting from their sophomore year through lessons on radiotherapy, radiological examinations, and nursing for radiotherapy. We then measured responses to questions regarding risk perception and factors inf luencing risk perception, including fear of radiation (fear), difficulty understanding radiation (difficulty), understanding the effects of radiation on the human body (understanding), and interest in radiation (interest). Data were collected and analyzed during April and July 2010. A total of 292 nursing students (33 men, 259 women) completed the survey. Information about radiation was obtained primarily from lectures at school (n = 240) and from television (n = 203). Significantly more freshmen students than students in other grades obtained information from television. Risk perception on radiation didn’t change greatly and understanding level increased as grade went upward, but interest to radiation decreased after learning basic knowledge about radiation. It is important to examine an educational content and the method for the continuance of the interest to radiation after learning basic knowledge of radiation.

A 60 × 60 response matrix for a NaI(Tl) scintillator was derived to unfold pulse height distributions of gamma rays due to fallout released in the Fukushima nuclear reactor accident. The unfolded energy spectra yielded information concerning radioactivities and dose rates in the fallout field. The accuracy of the evaluated radioactivities and dose rates was discussed by comparing with other data.

In connection with the East Japan great earthquake, the radioisotope by the accident of the first nuclear power plant of Fukushima was emitted. The radioisotope which exceeds a fiducial point in water purification plants, such as Kanamachi Purification Plant, was detected, and purification of radioactive contamination water is needed. Moreover, the high concentration contaminated water in a nuclear power plant is emitted to the sea, and quick decontamination is pressing need. The purpose of this research is purification of radioactive contamination water. The removal experiment of radioactive iodine 131 was conducted using various water-purifying　filters. As a result, the extraction ratio of a maximum of 99.6% was shown. Thereby, a waterpurifying filter has the decontamination effect of radioisotope, and suggested the possibility of large-scale purification of high concentration contaminated water.

Soil capability to adsorb radiocesium as a function of soil particle size was evaluated and the radiocesium distribution was visualized by imaging plate measurements. SA soil sample (about 3 kg wet weight) was collected from Kashiwa City, Chiba Prefecture, Japan which is known to have relatively high radioactively contaminated areas. After drying, it was divided into seven subsamples based on the soil particle sizes. Radiocesium concentration in the soil sub-sample for particles below 106 μm (smallest size) was about 9 times higher than that for particles of 800 – 1000 μm (second largest size). The images obtained for the radionuclide distribution of the particle size sub-samples were verified by the radiocesium concentrations measured with a high purity germanium detector. It seemed that the amount of clay mineral in the sub-sample of the smallest size soil particles was greater than the amount in the sub-sample of the second largest soil particles.

One of the most effective treatments of asthma is the cave therapy. The hospital cave in Tapolca (Hungary) has been used for treatments for the past decades. In summer, the ²²²Rn concentration may even reach 20 kBq/m3 (17 times higher than winter); the role of radon in the treatment of asthma is still not clarified. Daughter elements of ²²²Rn (²¹⁰Pb; ²¹⁰Po) with longer half-lives may accumulate in the blood, increasing the radiation dose of the human body. The changes of the ²¹⁰Po concentration in blood samples taken from the patients were examined in winter and in summer. The samples were dissolved with HNO3 and HCl, and the sources were prepared by spontaneous deposition on stainless steel. The ²¹⁰Po concentration was measured using a semi-conductor detector α-spectrometer. To increase measurement accuracy, ²⁰⁹Po tracer was added to the samples. In 63 samples the measured ²¹⁰Po activity-concentrations were between 0.035 and 0.800 mBq/g. After the therapy the ²¹⁰Po concentration in the blood of the patients was increased in all cases. Based on this result, it was possible to calculate the absorbed dose of the patient during the treatment, which ranged from 4.24.10^-16 to 5.85.10^-13 J/kg, the mean value being 1.04.10^-13 J/kg.