Radiation Environment and Medicine Vol.8, No.1
- Publisher : Hirosaki University Press
- Language : English
- ISSN : 2423-9097 (PRINT), 2432-163X (ONLINE)
- Release : February 2019
- Issue : Hirosaki University Press
On the Occasion of the Publication of a New Journal
“Radiation Environment and Medicine”
I am privileged with the honor of sending my short message on the occasion of the publication by Hirosaki University Press of a new journal “Radiation Environment and Medicine”. This journal was previously published under the other title, “Radiation Emergency Medicine”, from 2012 through 2015 concurrently with the inauguration of the program to foster human resources in radiation emergency medicine that was approved by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan in 2010. This success is greatly indebted to the enthusiasm of the then President of Hirosaki University, Dr. Masahiko Endo, who firmly believed the necessity of establishing a stronghold on radiation emergency medicine in the northern region of Japan.
Having been launched by the Ex-President Dr. Masahiko Endo and continuously supported by the present President Dr. Kei Sato, the program has been run steadily by efforts of faculty members and students of Hirosaki University. Thereby, the publication of the journal overcame start-up problems and recently the Editorial Board discussed how to further upgrade the journal. In order to invite more submissions of papers, the Editorial Board decided to broaden the scope of the journal by incorporating “radiation environmental issues”. Thus, the journal wasrelabeled as “Radiation Environment and Medicine.”
I sincerely hope that not only domestic but also world-wide researchers in the related fields will contribute their scientific outcomes to the new journal.
Akihiro Shima, Ph.D.
Professor Emeritus, The University of Tokyo
Ex-Member of the External Evaluation Board of the Program
Hirosaki University has issued Radiation Emergency Medicine (REM) since 2012. An educational program for professionals in Radiation Emergency Medicine was initiated in 2010, and our prompt response to the Fukushima nuclear accident which occurred in 2011 motivated the publication of this journal. Many prestigious scientists from not only Japan, but also foreign countries have contributed to REM thus far.
In addition, the inaugural symposium was held in February 2012, with a focus on natural radiation exposures and low-dose radiation epidemiological studies (NARE2012). The symposium attracted more than 150 participants from 30 countries. Additionally, the ninth symposium in the series of international symposia on Natural Radiation Environment (NRE9), which commenced in the 1960s, was held in September 2014. A special session on the Fukushima nuclear accident was also included in the symposium. Approximately 200 participants from 35 countries attended NRE9. According to these two large symposia, many scientists in the world now recognize Hirosaki University as one of the prominent Japanese institutions, whose faculty conduct research on a wide spectrum of radiation topics.
Last August (2015), the Nuclear Regulation Authority designated Hirosaki University as having two important centers which cover radiation emergency medicine and radiation emergency medical assistance. In addition to these domestic situations, there have been recent developments worldwide in the area of natural radiation exposures and their control. For instance, the World Health Organization (WHO) released a handbook on indoor radon in 2009, and more recently the European Radon Association was formed to address the health burden due to indoor radon in Europe. It is of interest to note that the International Atomic Energy Agency (IAEA) released a revised version of the Basic Safety Standards (BSS), which includes protection of the public against indoor exposure to radon and other natural sources of radiation last May (2015) .
From such international circumstances, many articles concerning environmental radiation and radioactivity, including natural radiation exposure studies, have been published in Radiation Emergency Medicine. Therefore, the editorial board elected to change the journal name to Radiation Environment and Medicine as the continuation of Radiation Emergency Medicine from the publication of Volume 5. The scope of the journal now widely covers not only medical issues including radiation emergency medicine, but also environmental issues.
On behalf of the editorial board, we welcome your submission to the new REM.
Shinji Tokonami, Ph.D.
Radiation Environment and Medicine
Assessment of Safecast bGeigie Nano Monitor
The bGeigie Nano Monitor is a radiation monitor based on a Geiger Muller tube (GM) detector developed by the team at Safecast as an affordable and easy to use mobile radiation monitoring device for public use as part of its citizen science project. The bGeigie Nano Monitor is said to detect alpha, beta and measure gamma radiation accurately to within a 15% uncertainty, as well as the ability for this measured data to be uploaded to a Safecast API website. The objective of this study was to evaluate the bGeigie Nano Monitor’s accuracy and reliability in both measuring and recording radiation from alpha, beta and gamma sources.
It was found that the bGeigie Nano Monitor is very accurate in the dose rate range of 5-900 μSv/h. Above this dose rate the accuracy of the measurements were not as reliable as the monitor was brought closer to the 1000 μSv/h limit of detection. The monitor was capable of detecting beta and gamma radiation from the tested sources of 241Am, 90Sr/90Y and 137Cs. During the assessment of the monitor it was found that it could take up to a minute for the measured dose rate exposed to a source to stabilise, it was also found that after being exposed to a high dose rate it took up to a minute to return to background dose levels after the removal of the radiation source.
In conclusion, the bGeigie Nano Monitor is capable of being an easily assembled radiation monitor for the public to accurately measure the dose rates of radioactivity in their area and to share this monitoring data through the Safecast API website.
Key words: Safecast, radiation monitor, citizen science
Quantitative and Visual Image Quality Evaluation between CsI and Gd2O2S:Tb Scintillator Types of Irradiation Side Sampling Flat-Panel Detector Systems for Reduction of Radiation Exposure
Flat-panel detector (FPD) systems have been widely used instead of computed radiography (CR) systems for radiation diagnosis. Indirect FPD systems have either CsI or Gd2O2S:Tb (GOS) types of scintillators. CsI FPDs can achieve comparable image quality whilst using lower dose imaging than GOS FPDs. Additionally, irradiation side sampling FPDs (ISS-FPDs) have better resolution characteristics than penetration side sampling FPDs (PSS-FPDs). In order to investigate exposure dose reduction, an analysis of both quantitative image quality metrics and visual evaluation of CsI and GOS ISS-FPDs was performed. Image quality was evaluated by detective quantum efficiencies and contrast-to-noise ratios, whilst visual evaluation was performed by inverse image quality figures (IQFinv) and area under the curves (AUCs) of the receiver operating characteristic (ROC) curves. The results suggest that CsI can produce comparable images to GOS with a dose reduction of 42-44% according to the image quality evaluation and 37-46% according to the visual evaluation.
Key words: flat-panel detector, CsI, Gd2O2S:Tb, reduction of radiation exposure, image quality
Survey on Training of the Nuclear Emergency Medical Assistance Team and Their Educational Needs
Hirosaki University provides regular training to the Nuclear Emergency Medical Assistance Team (NEMAT), which is owned by a nuclear emergency core hospital since 2017. In this paper, we provide details of the NEMAT training that was held by Hirosaki University in March 2018, and discuss the satisfaction level and educational needs of the trainees who participated in the 2018 NEMAT training. After the training, which provides a combination of table-top lecture and practical training, we conducted a survey on the NEMAT training held by Hirosaki University. Out of 40 trainees, 33 (82.5%) stated that they were either “extremely satisfied” or “slightly satisfied” with the training program. Upon investigating the educational needs of the trainees, we found that many of them wanted insights on regulated science, such as “dispatch criteria of NEMAT” and preparation of radiation emergency medical manual at own hospital.” Based on these results, we suggested that the curriculum of the future training program should be developed after taking into account trainees’ comments.
Key words: radiation accidents, nuclear disaster, radiation emergency medicine, educational activity, nuclear emergency medicine assistance team
Study of Chemical Etching Conditions for Alpha-particle Detection and Visualization Using Solid State Nuclear Track Detectors
We evaluate radon/thoron and its progeny concentration using passive-type monitors using CR-39 plates. After exposure, it is necessary to do chemical etching for CR-39 plates. In the present study, we considered shortening of chemical etching time for CR-39 and enlargement of the track diameter (i.e. etch pit diameter) aiming for introduction of automatic counting system in the future. Optimum conditions were determined by changing solution concentration, solution temperature and etching time. As a result, the optimized conditions (concentration, temperature and etching time) were determined to be 8 M NaOH solution, 75°C and 10 hours. This result of etching time showed that the chemical etching was completed in less than half of conventional etching time. Furthermore, it was suggested that shorter etching time would be possible if we do not consider the enlargement of conventional track diameter.
Key words: solid state nuclear track detector, chemical etching, condition optimization, etching time, solution concentration/temperature, track diameter
Fostering Nuclear Science in Schools through Innovative Approaches: IAEA Perspectives
The industrial and economic growth involving nuclear science and technology (NST) necessitates an increase in the demand for human resource development in the nuclear sector. It is vital to enhance the understanding of students on NST to reach out to the next generation of scientists and engineers. The International Atomic Energy Agency (IAEA) has been strengthening the education of NST in secondary schools to support sustainability of applications of nuclear technology in member states. The implementation of the IAEA Technical Cooperation (TC) project RAS/0/065 during 2012-2016 provided valuable proficiency in successfully introducing NST in secondary schools in the Asia-Pacific region in selected pilot countries. The initiative between 2015-2016 trained 15 teachers through the IAEA fellowship program in turn trained over 1364 other teachers thus creating a critical mass of trained teachers in 4 pilot countries (Malaysia, Indonesia, Philippines and United Arab Emirates) reaching out to a total of 24,717 students in secondary schools in just over one year. The project led to development of education materials, hands-on exercises, as well as co-curricular activities which made nuclear concepts more interesting to students. Countries that implemented the activities have demonstrated the success that can be achieved by the partnership of two sectors – the nuclear sector providing the technical and scientific expertise and the educational sector ensuring the delivery of the topics in the classroom. Encouraged by the success achieved, a new TC project “Educating Secondary Students and Science Teachers on Nuclear Science and Technology, RAS0079” has been initiated in 2018 expanding the project to other member states in the Asia-pacific region. The details of these resources, the activities conducted and their impact as well as planned activities of the new project with a goal to reach one million students during the next four years are presented in this paper.
Key words: Human resource development, nuclear science and technology, NST education, education, secondary school education, WOW factor, cloud chamber, soft skills development