Radiation Environment and Medicine 2024 Vol.13, No.2 75–98

Presentation Abstracts of “The 6th Bilateral Workshop on
Radiation Research and Its Related Issues 2023”

December 5–6, 2023
The Office of Atoms for Peace (OAP) of Thailand

Radiation Environment and Medicine 2024 Vol.13, No.2 76

The Project on Indoor Radon Measurement in Kazakhstan.
What Do We Need to Clarify?
Yasutaka Omori1*, Meirat Bakhtin2, Hiromi Kudo1, Chutima Kranrod1, Shinji Yoshinaga 3,
Shinji Tokonami1 and Masaharu Hoshi3
2

1
Hirosaki University, Hirosaki, Aomori, Japan
Astana Medical University, Astana, Kazakhstan
3
Hiroshima University, Hiroshima, Japan

Abstract:
Exposure to radon is the second leading factor causing lung cancer incidence. According to several
epidemiological studies, relative risk of lung cancer was positively correlated with indoor radon
concentration higher than 100 Bq m-3 at statistically significant level and increase rate was 16% per
100 Bq m-3. Statistical estimate implied that radon-attributable lung cancer deaths for 66 countries
totaled 226,057 in 2012 and represent a median of 3.0% of total cancer deaths. The World HealthOrganizations and the International Commission on Radiological Protection recommend a reference
level of indoor concentration as 100-300 Bq m-3 for member states. Radon (Rn-222) has a radioisotopeof thoron (Rn-220). Both of these radionuclides coexist in the living environment and show similar
behavior each other except for different half-lives (3.8 d for radon vs. 56 s for thoron). Thus,
thoron becomes an interfering factor on radon measurements using detectors without appropriate
discrimination functions. In 2000s, passive-type radon-thoron discriminative detectors and thoron
calibration chambers were developed, and studies using such equipment and instruments revealed
that detectors conventionally used in epidemiological studies overestimated radon concentration due
to contribution of exposure to thoron. This finding raises the question that the reported relationshipbetween lung cancer incidence and exposure to radon may include the effect of exposure to thoron
and the risk of radon is higher than that expected. The present authors launched the project onindoor radon measurements in northern Kazakhstan in 2023 to estimate risk of radon inhalation tolung cancer incidence. In northern Kazakhstan, uranium is actively mined and highest lung cancer
incidence is reported. Preliminary survey performed by the authors revealed that 3-mo average
residential radon concentrations are remarkably high, showing 130 to more than 2000 Bq m-3. Thoron
concentrations were lower than radon by one to two orders of magnitude, which indicates that dose
received from exposure to thoron is negligible compared to exposure to radon. The authors plan toexpand the scale of surveys to establish the quantitative relationship between exposure to radon andlung cancer incidence.
Key words:
Radon, lung cancer, Kazakhstan, uranium mine

*Yasutaka Omori: Hirosaki University, Hirosaki, Aomori, Japan
E-mail: ys-omori@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_76
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 77

Dose Estimation for Industrial Radiography Worker
in Accidental Radiation Exposure
Chutima Termsuk*, Aungsumalin Intang, Tanapol Dachviriyakij, Korawee Seajia,
Pongphanot Rindhatayathon, Noppalerk Thongdeelert and Vithit Pungkun
Nuclear and Ionizing Radiation Metrology Section, Regulator y Technical Support Division,
Of f ice of Atoms f or Peace, Bangkok, Thailand

Abstract:
Radiography is one of the most effective tools and widely used for non-destructive testing (NDT) to
inspect and evaluate structures or any damages without destroying objects. Radiography is usuallyusing radioactive material or x-rays generator to produce radiation. So, safety operation procedures
and recommendations are implemented to prevent harmful exposure to workers, public andenvironment. However, radiation accidents can take place. This study presents the dose estimationof 2 radiographers who were exposed radiation from Ir-192 source stuck in the guide tube during
working; Worker 1 who may have received a high dose and injured the left index finger from thisunintentional exposure and Worker 2 who volunteered to secure the source back to the shielding.
Several working scenarios were performed contributing to the possibilities of radiation exposure.
Optically stimulated luminescence dosimeter (OSLD); InLight and NanoDot models with RANDO
and rod phantoms were used to estimate whole body, eye lens and finger doses. The result fromthe scenario shows that Worker 1 was exposed to averaged doses of 171.8, 102.3 and 1773.9 mSv forthe whole body, eye lens and finger respectively which exceeds the annual dose limit. Worker 2
received a dose under the annual dose limit at dose of 3.3, 1.2 and 12.5 mSv for the whole body, eyelens and finger respectively as he recovered the radioactive source with radiation protection rules.
Both workers are suggested to be regularly checked up at the hospital even one of them received adose lower than the annual dose limit. The uncertainty of measurement is reported at 33.0% at k=2
which came from the dosimeter and readout system. This value can be much larger than expected
as several factors may be different between real situations and scenarios. Monte Carlo simulation
can be a good model to predict the possibility and confirm the result. This study shows the feasibilityof scenario-based measurement to estimate a dose delivery in radiation accidents when a dosimeter
is absent.
Key words:
dose estimation, OSL, radiography, radiation accident, Ir-192*Chutima Termsuk: Nuclear and Ionizing Radiation Metrology Section, Regulatory Technical Support Division, Office of Atoms for Peace,
Bangkok, Thailand
E-mail: chutima.t@oap.go.th
https://doi.org/10.51083/radiatenvironmed.13.2_77
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 78

Biodosimetry in Radiation Emergency Medicine:
Current Insights and Its Impact in Asia
Tomisato Miura*, Donovan Anderson, Yohei Fujishima and Ryo Nakayama
Institute of Radiation Emergency Medicine, Hirosaki University, Aomori 036-8564 Japan

Abstract:
Radiation emergency medicine relies on accurate dose estimation through biodosimetry, assessing
biological responses to radiation exposure. This presentation will explore the significance of
biodosimetry in Asia, considering the specific needs of the region. Key criteria for an effective
endpoint in dose assessment are specificity, stability, and dose-dependency, with the dicentricchromosome assay considered as the gold standard due to its fulfillment of these criteria. The
presentation will also encompass cell cycle progression and cytogenetic biodosimetry, summarizing
cytogenetic aberration assays best suited to various exposure scenarios, including partial or priorexposure to ionizing radiation. To improve biodosimetry strategies across Asia, efficiency, highthroughput, and cost-effectiveness are needed. Challenges in biodosimetry, such as incubation
time, chromosome aberration scoring throughput, and addressing large-scale nuclear disasters andterrorism, are globally acknowledged. The development of young human resources for biodosimetryis also an important issue. IREM publishes the Biodosimetry series in journals as user-friendly
educational materials (Nakayama et al., 2022; Anderson et al., 2023). The Asian biodosimetry
network includes the Institute of Radiation Emergency Medicine (IREM) at Hirosaki University.
IREM is working to streamline assays for different radiation scenarios, including shortened blood
cultures for triage scoring (Goh et al., 2023) and enriching metaphase cells in whole blood cultures.
Additionally, IREM is conducting epidemiological studies like chromosome aberration analysis
in Gravesʼ disease patients, emphasizing the importance of local and international biodosimetry
networks. While acknowledging the critical need for funding in research and development, staff
training, and laboratory maintenance, it is important to note that biodosimetry budgets are often
insufficient. Moreover, the evolving trends in biodosimetry will be influenced by new eventsand local government priorities. In closing, it is evident that Asian countries may need distinct
biodosimetry strategies compared to Europe and North America, reflecting the unique challenges
and requirements of the region.
Key words:
Cytogenetic biodosimetry, human resource development, Asian strategy
References:

1． Nakayama R, Abe Y, Goh STV, Takebayashi K, Thanh MT, Fujishima Y, et al. Cytogenetic biodosimetry in radiation
emergency medicine: 4. Overview of cytogenetic biodosimetry. Radiat Environ Med. 2022;11(2):91–103.
2． Anderson D, Abe Y, Goh STV, Nakayama R, Takebayashi K, Thanh MT, et al. Cytogenetic biodosimetry in radiation
emergency medicine: 5. The dicentric chromosome and its role in biodosimetry. Radiat Environ Med. 2023;12(2):121–39.
3． Goh VST, Fujishima Y, Nakayama R, Takebayashi K, Yoshida MA, Kasai K, et al. Manual Scoring with Shortened 48 h
Cytokinesis-Block Micronucleus Assay Feasible for Triage in the Event of a Mass-Casualty Radiation Accident. Radiat
Res. 2023;199(4):385–95.

*Tomisato Miura: Institute of Radiation Emergency Medicine, Hirosaki University, Aomori, 036-8564 Japan
E-mail: tomisato@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_78
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 79

Biodosimetry for High-Dose Radiation
Ryo Nakayama*, Donovan Anderson, Yohei Fujishima and Tomisato Miura
Institute of Radiation Emergency Medicine, Hirosaki University, Aomori 036-8564 Japan

Abstract:
Addressing the response to high-dose radiation accidents is a global concern, given past incidents
like the Chernobyl nuclear power plant accident, the Goiania accident in Brazil, the Tokai village
JCO criticality accident in Japan, and the Shanxi Taiyuan radiation accident in China. In addition, theongoing threat of nuclear terrorism and conflicts demands preparedness for handling individuals
exposed to high radiation doses. This exposure causes significant damage to hematopoietic andgastrointestinal organs and the cranial nervous system, resulting in a variety of symptoms. Early
stem cell transplantation and cytokine therapy are needed to improve the prognosis of these patients(IAEA, 2011). Accurate dose estimation through biodosimetry is necessary for their treatment
decisions. While the dicentric chromosome assay is the gold standard for radiation biodosimetry,the PCC-ring assay should be used for high doses above 5 Gy (Nakayama et al., 2022). In regionswith limited biodosimetry facilities, the chemically-induced PCC method offers an economical andstraightforward solution, notably in Asian countries. In our pursuit of more efficient approaches, weʼve
optimized this method, reducing culture time by 8 hours. Caffeine supplementation (Pujol et al.,2012), known to bypass cell cycle arrest, led to a 1.4-fold increase in analyzable cells for the PCC
assay. Improvements in cell fixation and staining further streamlined the process. As a result, thetime required for dose estimation by the chemically-induced PCC assay was reduced from 55 hours
as in the JCO model case to 43 hours (11 hours total). This method can estimate the dose using thesame analysis as the conventional method. There has been much discussion about how to deal withbiodosimetry for such high-dose exposure accidents, and the technology is advancing every day.
With the recent development of AI and other technologies related to automation, more efficientmethods than those of today will be developed.
Key words:
Biodosimetry, High dose radiation accident, PCC-ring assay
References:

1． IAEA, 2011. Cytogenetic dosimetry: Applications in preparedness for and response to radiation emergencies.
2． Nakayama R, Abe Y, Goh STV, Takebayashi K, Thanh MT, Fujishima Y, et al. Cytogenetic biodosimetry in radiation
emergency medicine: 4. Overview of cytogenetic biodosimetry. Radiat Environ Med. 2022;11(2):91–103.
3． Pujol M, Puig R, Caballin MR, Barrios L, Barquinero JF, et al. The use of caffeine to assess high dose exposures toionizing radiation by dicentric analysis. Radiat Prot Dosim. 2012;149(4):392–8.

*Ryo Nakayama: Institute of Radiation Emergency Medicine, Hirosaki University, Aomori, 036-8564 Japan
E-mail: h21gg802@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_79
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 80

A New Method to Improve Accuracy of Dose Estimationin Biodosimetry
Donovan Anderson1*, Kai Takebayashi1, Naomi Sasaki1, Valerie Swee Ting Goh2, Ryo Nakayama1,
Yohei Fujishima1, Akifumi Nakata 3 and Tomisato Miura1
1
Institute of Radiation Emergency Medicine, Hirosaki University, Aomori 036-8564, Japan
Singapore Nuclear Research and Safety Initiative, National University of Singapore, 138602 Singapore
3
Faculty of Pharmaceutical Sciences Department of Pharmacy, Hokkaido University of Science, Sapporo 060-0812, Japan
2

Abstract:
The dicentric chromosome assay (DCA) remains the “gold standard” in biological dosimetry,
undergoing continuous refinement and validation since the mid-1960s. Using the DCA, it istheoretically possible to estimate an unknown dose to an individual by establishing a correlation
between the number of induced dicentrics following irradiation and the dose applied to generate suchdamage. However, the frequency of dicentrics is influenced by factors like the type of irradiation
source and dose rate (Anderson et al. 2023). Additionally, there are inherent scoring variations
in dicentrics per radiation dose (Gy) among scorers due to the qualitative nature of metaphaseselection (Ainsbury et al., 2009) and the challenge of detecting specific dicentric chromosomes insolid-stained slides, especially those formed by two acrocentric chromosomes. In this study, wedeveloped an innovative staining method that combines conventional solid chromosome staining
with a specialized technique targeting and marking the centromeric region, henceforth called“cTAG”. The cTAG technique streamlines the identification of dicentrics in complete metaphasesby emphasizing centromeres in 1.5 hours. Preliminary results showed that it significantly reduced
disparities in dicentric yield measurements among experienced scorers, decreasing the coefficient ofvariation from 12% with conventional Giemsa staining to 1.2% with the new technique. Furthermore,
the cTAG technique can be applied to de-stained Giemsa slides, facilitating image preparation for
DCA training and development. In the future we will conduct inter-laboratory comparisons using thecTAG technique in DCA to see if scoring variations still occur across laboratories or if disparities are
reduced.
Key words:
Biodosimetry, c-banding, dicentric, absorbed dose
References:1.

Anderson A, Abe Y, Goh VST, Nakayama R, Takebayashi K, Thanh MT, et al. Cytogenetic Biodosimetry in Radiation
Emergency Medicine: 5. The Dicentric Chromosome and its Role in Biodosimetry. Radiation Environment and Medicine.
2023;12(2):121–39.

2.

Ainsbury EA, Livingston GK, Abbott MG, Moquet JE, Hone PA, Jenkins MS, et al. Interlaboratory Variation in Scoring
Dicentric Chromosomes in a Case of Partial-Body X-Ray Exposure: Implications for Biodosimetry Networking andCytogenetic ʻʻTriage Modeʼʼ Scoring. Radiat. Res. 2009;127(6):746–52.

*Donovan Anderson: Institute of Radiation Emergency Medicine, Hirosaki University, Aomori, 036-8564 Japan
E-mail: ande4163@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_80
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 81

Annual Effective Dose Due to External Exposure
at Hamadori District in Fukushima Prefecture
Yuki Oda1, Mizuki Kiso1, Aoi Sampei1, Hiroki Hashimoto1, Yasuyuki Taira 2, Yasutaka Omori3,
Hirofumi Tazoe3, Chutima Kranrod3, Mayumi Shimizu3, Hiromi Kudo3, Naofumi Akata 3,
Ryohei Yamada 3, Masaru Yamaguchi1, Masahiro Hosoda1, 3* and Shinji Tokonami3
Hirosaki University Graduate School of Health Science, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
Department of Global Health, Medicine and Welf are, Atomic Bomb Disease Institute, Nagasaki University,
1-12-4 Sakamoto, Nagasaki 852-8523, Japan
3
Institute of Radiation Emergency and Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
1

2

Abstract:
Ever since the accident at TEPCOʼs Fukushima Dai-ichi Nuclear Power Plant (FDNPP) has passed
for 12 years, a part of residents is still concerned about radiation exposure to radionuclides fromthe environment. In this study, we carried out measurement of the absorbed dose rate in air andassessment of annual effective dose at Kawauchi Village, Tomioka Town, and Okuma Town inFukushima Prefecture, which are in Hamadori District, to clarify the external exposure dose to the
public from artificial radionuclides based on natural radionuclides for use in risk communication withresidents. The measurement point was selected in a 2 km × 2 km mesh, and spot measurement anda car-borne survey were conducted using a 3 in × 3 in cylindrical NaI (Tl) scintillation spectrometer.
The measurement points were shared using the Global Positioning System. The ambient dose rates
in the air from natural radionuclides, artificial radionuclides by spot measurement, and artificial
radionuclides by car-borne survey were 0.022-0.069, 0.018-2.394, and 0.001-1.610 µSv h-1, respectively.
The areas with high dose rates contain mountainous areas and areas where decontamination has
not yet implemented. The annual effective doses from natural radionuclides at Kawauchi, Tomioka,
and Okuma were 0.17-0.35, 0.13-0.28, and 0.15-0.28 mSv, respectively. The annual effective doses from
artificial radionuclides in the residential zones at Kawauchi, Tomioka, and Okuma were 0.04-0.29,
0.16-0.70, and 0.31-0.73 mSv, respectively. All the measurement points in the residential zone were
below the reference level of 1 mSv in the existing exposure situation reported by the ICRP. This data
can be used as background data and the comparison between the past and the present, natural andartificial. It is also useful for the residents and those who are considering returning. This work was
supported by the Research Project on the Health Effects of Radiation organized by the Ministry of
the Environment, Japan.
Key words:
Fukushima, external exposure, dose assessment*Masahiro Hosoda: Hirosaki University Graduate School of Health Science, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
E-mail: m_hosoda@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_81
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 82

Dose Assessments Due to Inhalation of Radonand Thoron at 70 Dwellings in the Coastal Areaof Fukushima
Masahiro Hosoda1*, Yuki Oda1, Chutima Kranrod1, Aoi Sampei1, Mizuki Kiso1, Yasuyuki Taira 2,
Yasutaka Omori1, Hirofumi Tazoe1, Naofumi Akata1, Mayumi Shimizu1, Hiromi Kudo1,
Ryohei Yamada1, Yuki Tamakuma 3 and Shinji Tokonami1
2

1
Hirosaki University, Hirosaki City, Aomori, Japan
Formerly of Nagasaki University, Nagasaki City, Nagasaki, Japan
3
Nagasaki University, Nagasaki City, Nagasaki, Japan

Abstract:
We are conducting a research project on dose assessment for residents in the coastal area of
Fukushima Prefecture. This project estimates annual effective doses from inhalation, ingestion andexternal exposure. These dose estimates cover both artificial radionuclides, such as radiocesium, andnatural radionuclides. The doses from both sources will be compared to enable the local population
to assess the influence of the FDNPP accident on the total dose. We have selected three coastal
communities: Kawauchi Village, Tomioka Town and Okuma Town. In this presentation, we would
like to show the results of indoor and outdoor radon and thoron progeny concentrations, as well as
atmospheric 137Cs concentrations. Indoor radon concentrations are measured in 70 dwellings (every
30 dwellings in Kawauchi Village and Tomioka Town and 10 dwellings in Okuma Town) usingradon-thoron discriminative monitors (RADUET, Radosys, Hungary). In addition, passive radon andthoron progeny monitors (progeny monitor) are installed in each house along with the RADUETs.
These monitors will be replaced every three months for one year in order to assess the annual
effective dose, taking into account the seasonal variation of each concentration. We have selected thetwo locations in each municipality for outdoor radon measurements using RADUETs. Airborne dust
is collected using a high-volume sampler at 500 L/min for 24 hours, and then 137Cs concentrations
are measured using a HPGe detector. The annual means of indoor radon concentrations in Kawauchi
Village, Tomioka Town and Okuma Village were evaluated to be 20 ± 10, 18 ± 12 and 19 ± 16 Bq/m3,
respectively. In addition, the annual means of EETC in each municipality were evaluated to be 1.1± 1.1, 0.4 ± 0.3 and 0.8 ± 0.8 Bq/m3, respectively. On the other hand, the concentrations of radon and137
Cs in the atmosphere at six measurement sites were estimated to be 7 ± 4 Bq/m3 and 44 ± 54
μBq/m3, respectively. The annual effective doses due to inhalation of natural (radon and thoron)
and artificial (137Cs) radionuclides were estimated to be 0.81 mSv and 1.1 nSv, respectively. Thus,
the contribution of annual effective doses due to airborne artificial radionuclides are quite small
compared to the natural sources. We will summarise the comprehensive doses from natural andartificial components to enable better radiation risk communication to residents. This work is
supported by Research Project on the Health Effects of Radiation organized by Ministry of theEnvironment, Japan.
Key words:
Fukushima, coastalarea, inhalationdose, radon, EETC, passivemonitor*Masahiro Hosoda: Hirosaki University, Hirosaki City, Aomori, Japan
E-mail: m_hosoda@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_82
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 83

The Effective Dose from Inhalation of Radonand Thoron in the Dwelling around the Tin Mineand Smelter Area in Bangka, Indonesia
Pradana Radhia1, 2, Eka D. Nugraga1, N. Shilfa Sharah1, Yasutaka Omori3, Wahyudi Wahyudi1,
Untara Untara1, Kurnia Irwan4, Safitri Rini5, Chutima Kranrod3, Michiya Sasaki6, Devriany Ade7,
N. Rachman Agus1, Kurniawan Rusbani1, Nirwani Leli1, Nurokhim Nurokhim1,
Masahiro Hosoda 2, 3 and Shinji Tokonami3*
Research Center f or Safety, Metrology, and Nuclear Technology, The National Researchand Innovation Agency of Indonesia (BRIN), Tangerang Selatan, Indonesia
2
Department of Radiation Science, Graduate School of Health Sciences, Hirosaki University, Hirosaki, Japan
3
Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Japan
4
Departement of Chemistr y, Padjadjaran University, Bandung, Indonesia
5
Departement of Physics, Syiahkuala University, Banda Aceh, Indonesia
6
Biology and Environmental Chemistr y Division, Sustainable System Research Laborator y,Central Research Institute of Electric Power Industr y, Chiba, Japan
7
Health Ministr y Polytechnic of Pangkal Pinang, Bangka Tengah, Indonesia
1

Abstract:
Inhalation of radon (222Rn) and thoron (220Rn) gases is considered to be the largest contributor to
the radiation dose received from natural radiation due to the abundance of 238U and 232Th in theenvironment. Bangka Island in Indonesia is one of the largest tin mining areas in the world, with thesource of the tin being the granite formation which also contains relatively high levels of naturally
occurring radioactive material. Therefore, there is reasonable concern about the possibility ofelevated levels of radon and thoron in the area. In this study, the daily variation of radon and thoron
was investigated using an electrostatic collection-type monitor, RAD7. The seasonal variation ofradon and thoron progeny was measured using a passive radon-thoron discriminative monitor
called RADUET and a deposition rate-based thoron progeny monitor. The passive monitors were
installed in 135 dwellings for a period of one year, including the dry and rainy seasons. The annual
effective dose was then estimated from the annual indoor radon concentration and equilibrium
equivalent thoron concentration (EETC). The result shows that the radon concentration peaks at 41
Bq m-3 at midnight when the ventilation of the dwelling was closed, while the thoron concentration
peaks at 172 Bq m-3 at midday. The result also shows that on Bangka Island, radon concentrations
did not indicate significant seasonal variation, possibly due to a minimal change in ventilation rate.
Meanwhile, the thoron progeny was higher in the dry season, possibly due to the lower ambient
aerosol concentration in the rainy season. The estimated annual effective dose from the inhalationof radon and thoron on Bangka Island ranges from 1.1 to 10.2 mSv, with an arithmetic mean andstandard deviation of 4.0 ± 2.1 mSv. From the total inhalation dose, the dose from thoron was thelargest contributor with an arithmetic mean of 3.1 ± 2.0 mSv. The study highlights the importance ofthe effective dose from thoron inhalation.
Key words:
Bangka, Indonesia, Tin mining, Radon, Thoron, Progeny*Shinji Tokonami: Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Japan
E-mail: tokonami@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_83
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 84

Statistical-Based Modeling Strategy for Entrance Skin Dose Estimationin Patient Undergoing Body Interventional Radiology
V. PONG INWONG1, S. BURANURAK 2*, A. AHOOJA 1, J. WONGWIWATCHAI1,
V. PUNGKUN3 and P. PAJAPO2
1

Department of Radiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
2
Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
3
Nuclear and Radiation Metrology Section, Office of Atoms for Peace, Bangkok, Thailand

Abstract:
Nowadays, inter ventional radiology (IR) plays an important role in a wide range of invasive
diagnostic imaging and minimally invasive imaging-guided therapeutic procedures. However, theradiological risk associated with unwanted side ef fects in patients is a concern. Radiation-induced
er ythema, skin burns, and epilation have been reported in the literature. For safety reasons,risk assessment in IR patients is quantiﬁed with the entrance skin dose (ESD) exceeding 2 Gy is
unacceptable. However, direct dose measurement for each patient is labor-intensive and impracticalbecause the detector probe may cause perturbation on the X-ray image during a ﬂuoroscopy-guided
procedure. The purpose of this study is to develop a statistical-based model for ESD estimation in
the body-IR procedures by using simple quantities derived from the DICOMRDSR data. As a result,a simplified ESD calculation model is introduced without complicated parameters generally usedin conventional calculation methods, such as a backscatter factor and a mass-energy absorption
coefﬁcient. This user-friendly ESD calculation method makes it easy for patients and medical staff
to calculate the dose they received by themselves after ending each IR examination. The models areclassiﬁed into two groups of body-IR procedures: 1) the vascular procedure includes TACE and TAE,
and 2) the non-vascular procedure includes PTBD and PCD. The study provides that the simpliﬁed
regression models are sufﬁcient to estimate the patient entrance skin dose for both groups of bodyIR procedures, accounting for a 95% conﬁdence interval.
Key words:
Body interventional radiology, entrance skin dose assessment, radiological hazard*S. BURANURAK: Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand
E-mail: bsirit@kku.ac.th
https://doi.org/10.51083/radiatenvironmed.13.2_84
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 85

Morphological Characteristics of Respiratory Tract on Inhalation Dose
Assessments for Japanese Populations
Aoi Sampei1, Mizuki Kiso1, Hiroki Hashimoto1, Yuna Sakai2, Takeshi Morita 3, Minoru Osanai4,
Yasutaka Omori4, Shinya Kakehata 3, Fumiyasu Tsushima5, Masahiro Hosoda1, 4, Yoko Saito1,
Shingo Kakeda5 and Shinji Tokonami4*
Graduate School of Health Sciences, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, Japan
2
School of Health Sciences, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, Japan3
Department of Radiology, Hirosaki University Hospital, 33 Honcho, Hirosaki, Aomori, Japan
4
Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, Japan
5
Graduate School of Medicine, Hirosaki University, 5 Zaif u-cho, Hirosaki, Aomori, Japan
1

Abstract:
The Human Respiratory Tract Model (HRTM) proposed by the ICRP is used to assess internal doses
due to inhalation of radioactive aerosols1). The morphological information on the respiratory tract inthe HRTM was based on a few cases of Caucasians. In this study, we evaluated the morphologicalcharacteristics of the respiratory tract for Japanese using computed tomography to examine
whether the HRTM could be adapted to other racial groups. Patients without disease affecting theanalysis were selected and the diameter, length, and subcarinal angle to trachea axis were measured
using software (Thoracic VCAR software, GE Healthcare Japan). As a result, we analyzed 100
males and 109 females. The diameter of the bronchi was slightly different from that in the HRTM
because it was created from a cast replica and this study was implemented based on images taken
during inspiration. Although the HRTM defines a bronchial structure as the symmetrical shape,
differences in bronchial length were observed between the left and right lungs even if the bronchial
generation was the same. The similar morphological characteristics have been reported in Chineseand Koreans2, 3). In the ICRP publication 66, tracheal and bronchial dimensions are correlated withpatientʼs height, but no correlation was found in the present study. From an anatomical point ofview, it is difficult to conclude that the HRTM reproduces the actual respiratory airway. How thedifferences affect particle deposition in the respiratory tract should be examined. This work waspartially supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant No.
JP20H00556.
Key words:
X-ray Computed Tomography, Human Respiratory Tract Model, Trachea, Radioactive Aerosol
References:

1.

ICRP. 1994. Human Respiratory Tract Model for Radiological Protection. ICRP Publication 66. Ann. ICRP 24 (1–3).

2.

Mi W, Zhang C, Wang H, Cao J, Li C, Yang Li, et al. Measurement and analysis of the tracheobronchial tree in Chinese
population using computed tomography. PLoS One. 2015;10(4):e0123177.

3.

Kim D, Son JS, Ko S, Jeong W, Lim H. Measurements of the length and diameter of main bronchi on three-dimensional
images in Asian adult patients in comparison with the height of patients. Journal of cardiothoracic and vascularanesthesia. 2014;28(4):890–5.

*Shinji Tokonami: Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori, Japan
E-mail: tokonami@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_85
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 86

Development of Electrically Conductive Carbon Fiber Reinforced Plastic
Composite for Airplane with Lightning Strike Protection Property
Tatsuhiro Takahashi*, Erika Nozawa and Ryoma Tokonami
Graduate School of Organic Materials Science, Yamagata University, Yonezawa, Japan

Abstract:
Carbon fiber reinforced plastics (CFRP) composites, having high mechanical strength and lightweight, have been already utilized in not only sports goods, such as running shoes, bicycle etc. but
also airplane. It is known the half of B787 is made of CFRP, instead of metals. CFRP, consisting ofthermosetting epoxy resin matrix and carbon fiber reinforcement, has no electrically conductivity
toward thickness direction, because the epoxy resin matrix is not electrically conductive.
The lightning strike protection is one of the most critical requirement for the safe flight. The
conventional airplane itself, made of all metals, has the lightning strike protection property, however,
CFRP needs the electrically conductive metal mesh surface layer for the protection, which causes
the additional complex manufacturing process. Therefore, the development of electorally conductive
CFRP, without using the metal mesh, has been awaited using electrically conductive matrix. For thedevelopment, we have been closely collaborating with Japan Aerospace Exploration Agency (JAXA)
and The Universiy of Tokyo. The present presentation provides the novel matrix material design for
the electrically conductive thermosetting resins, the lightning strike protection performance using
artificial lighting strike test, and the development current status.
Key words:
Carbon fiber reinforced plastic, lightning strike protection, airplane, electrically conductive
References:

1.

Takahashi K, Yaginuma K, Goto T, Yokozeki T, Okada T, Takahashi T, et al. Electrically conductive carbon fiber
reinforced plastics induced by uneven distribution of polyaniline composite micron-sized particles in thermosetting
matrix, Comp Sci Technol. 2022;228:109642.

2.

Takahashi K, Nagura K, Takamura M, Goto T, Takahashi T. Development of Electrically Conductive Thermosetting
Resin Composites through Optimizing the Thermal Doping of Polyaniline and Radical Polymerization Temperature,
Polymers. 2022;14:3876.

3.

Kumar V, Yokozeki T, Okada T, Hirano Y, Goto T, Takahashi T, et al. Polyaniline-based all-polymeric adhesive layer: An
effective lightning strike protection technology for high residual mechanical strength of CFRPs, Composites Scienceand Technology. 2019;172:49–57.

*Tatsuhiro Takahashi: Graduate School of Organic Materials Science, Yamagata University, Yonezawa, Japan
E-mail: effort@yz.yamagata-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_86
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 87

Introduction of Coupled Map Latticeand Its Application to Simulate the Complex Mechanism of Change
from Fresh Cream to Butter via Whipped CreamErika Nozawa*
Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan

Abstract:
Coupled map lattice (CML) is a powerful simulation approach that reproduces well complex anddiverse patterns and motions in dynamical phenomena with spatial degrees of freedom (Kaneko andTsuda, 2001). Indeed, CML has simulated various phenomena such as full range boiling (Yanagita,
1992), convection with turbulence transition (Yanagita and Kaneko, 1993), cloud formation predicting
ʻguerrilla rainstormsʼ (Yanagita and Kaneko, 1997), and astronomical formation of grand-design
spirals (Nozawa, 2020, 2030). We proposed a CML for simulating phase inversion processes (Fujita,
2006) from fresh cream to butter via whipped cream. It is one of complex systems approaches to thepattern formation and self-organization of diverse food textures appearing in the phase inversion
processes. The proposed CML has three field variables, surface energy, cohesive energy, andvelocity of the emulsion defined on a two-dimensional square lattice, and is constructed by the three
simple procedures, whipping, coalescence, and flocculation, acting on the field variables. In thesimulations, we have observed two different phase inversion processes at high and low whipping
temperatures (WTs). The overrun and viscosity changes in these processes are consistent withthose in experiments. The two processes give rise to distinctive spatial patterns of overrun (surface
energy) and viscosity (cohesive energy), and are characterized on the viscosity-overrun plane
which is one of the state diagrams, as the viscosity-dominant process at high WT and the overrundominant process at low WT, respectively. The butters obtained in the two processes were of low
overrun and viscosity and of high overrun and viscosity, respectively in the butter region, and had,so to say, sof t & creamy and hard & f luf f y texture patterns. In the presentation, we will design a
new texture (f luf f y & creamy with moderate f irmness) by controlling the cooking parameters of the
CML procedures based on the above texture difference.
Key words:
coupled map lattice, dairy products, phase inversion, overrun, viscosity, food texture
References:1.

Fujita S. 2006. Shokuhin no Nyuka [Food Emulsions]. Tokyo: Saiwaishobo. (in Japanese)2.

Kaneko K, Tsuda I. 2001. Complex systems: Chaos and beyond. Berlin: Springer.

3.

Nozawa E. Coupled map lattice for the spiral pattern formation in astronomical objects. Physica D. 2020;405:132377.

4.

Nozawa E. 2023. Jammed Keplerian gas leads to the formation and disappearance of spiral arms in a coupled map lattice
for astronomical objects. Progress of Theoretical and Experimental Physics. 2023, 063A02.

5.

Yanagita T. Coupled map lattice model for boiling. Phys Lett A. 1992;165:405–8.

6.

Yanagita T, Kaneko K. Coupled map lattice model for convection. Phys Lett A. 1993;175:415–20.

7.

Yanagita T, Kaneko K. Modeling and characterization of cloud dynamics. Phys Rev Lett. 1997;78:4297–300.

*Erika Nozawa: Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
E-mail: wrr@e-rika.net
https://doi.org/10.51083/radiatenvironmed.13.2_87
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 88

Preparation of Barium Sulfate Polymer Composites Using Tapioca-Starchand Its X-Ray Shielding Properties
Ryoma Tokonami1*, Minoru Osanai2, Masahiro Hosoda 2, 3, Shinji Tokonami3 and Tatsuhiro Takahashi1
21Graduate School of Organic Materials Science, Yamagata Univrsity, Yonezawa, Japan
Hirosaki University Graduate School of Health Sciences, Hirosaki University, Hirosaki, Japan
3
Institute of Radiation Emergency Medicine, Hirosaki University, Hirosaki, Japan

Abstract:
Lead (Pb) have often been used as radiation shielding materials in various fields, including theaerospace and medical fields together with nuclear power plants. However, lead has several
disadvantages. As the replacement, the composites, consisting of barium or bismuth having highatomic number and rubber or resin as the matrix, have been reported. In this research, we prepared
the composites using barium sulfate and biodegradable polymer, consisting of glycerol and tapioca
starch. The mechanical properties, such as softness and strength, controlled by optimizing thethree-component materials, which will be presented together with X-ray shielding properties. In ourprevious study1), the effect of the inorganic filler surface modiﬁcation on the mechanical property
was shown. Here, we proposed a biodegradable additive, Tannic Acid (TA), as a new approach forthe surface modification and its effect will be presented. Barium sulfate (BaSO4), having the particle
diameter of 10μm, was used. Glycerol is a liquid component to make thermal processability for
Tapioca-starch. In addition, Tannic acid (TA) was used for surface modification between matrix
and BaSO4. Samples was produced using bath-type melt mixing at 120℃and 30rpm for 10min. The
mechanical properties of the biodegradable composites, consisting of glycerol and tapioca-starch,suggested that the composites are very soft due to low tensile strength, modulus and high strain. By
the addition of BaSO4 30vol%, the mechanical property of the composites was dramatically improved.
On the other hand, TA coated BaSO4 made the elongation at break larger, which can be interpretedby the effect of hydrogen bond between the matrix and surface. The present ﬁnding demonstrated
that this proposed approach using TA as the surface modiﬁcation will be one of the most effective
and attractive approaches to enhance the flexibility of radiation shielding composite materials
including large amount of inorganic ﬁller particles.
Key words:
X-ray shielding, Composites, Biodegradable, Barium sulfate
References:1.

Tokonami R, Aoki K, Goto T, Takahashi T. Surface Modiﬁcation of Carbon Fiber for Enhancing the Mechanical Strengthof Composites. Polymers. 2022;14(19):3999*Ryoma Tokonami: Graduate School of Organic Materials Science, Yamagata Univrsity, Yonezawa, Japan
E-mail: t231142d@st.yamagata-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_88
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 89

An Appropriate Concrete Mixtures to Improve for Nuclear
and Radiation Facilities in Thailand
Panupong PINGISH and Sanya TEDTHONG
Nuclear and Radiation Inspection Division, Office of Atoms for Peace, Bangkok, THAILAND

Abstract:
The main aim of this paper is looking for suitable local minerals to conduct high density concreteby analysis context factors. Radiation shielding by high density concrete are used in nuclear andradiation facilities. Especially, in cases of new construction or improvement the previous site bychanged applications such as wall or ceiling and limited areas should be considered. High density
concrete or heavy weigh concrete is designed by using heavy weight aggregates such as ilmenite,barite, magnetite, limonite or hematite etc. The basic definition of high density concrete or heavy
weigh concrete should have density greater than 2600 kg/m3 while mix concrete for general
construction about 1700 kg/m3. Itʼs well known that, more density of concrete is more ability ofmaterials to protect high energy ray and electromagnetic wave such as gamma ray or X-ray. The
comparison by linear attenuation coefficient (μ) and density of materials (ρ) are used for verification.
However, the context for each country is different situations and resources. The factors forconsideration are depended on policy of facilities, radiation safety, finance and physical characteristic
besides strength and bearing capacity. The analysis for several dimensions to choose operational
options are needed. The result of this paper is an option to improve shielding for radiation safety
purpose in Thailand.
Key words:
high density concrete, heavy weigh concrete, radiation shielding, radiation protection
References:1.

Ouda A. 2014. Development of high-performance heavy density concrete using dif ferent aggregates for gamma-ray
shielding. Housing and building national research. 2015;11:328–38.

2.

Daungwilailuk T, Yenchai C, Rungjaroenkiti W, Pheisusom P, Panwisawas C, Pansuk W. Use of barite concrete forradiation shielding against gamma-rays and neutrons. Sciencedirect. 12, Construction and building materials. 2022;326:
126838.

*Panupong PINGISH: Nuclear and Radiation Inspection Division, Office of Atoms for Peace, Bangkok, THAILAND
E-mail: panupong.p@oap.go.th
https://doi.org/10.51083/radiatenvironmed.13.2_89
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 90

Muncipal Inspection Services for Radioactivity in Food For SelfConsumption in Fukushima and Utilizaition of State-Of-The-Art
Equipment for Testing
Takahiro Yamada1*, Katsuki Kitano2, Yumiko Asakura 3, Mihoko Kikuchi3 and Takahiro Fukuhara 3
1
Atomic Energy Research Institute, Kindai University, Higashiosaka, Japan
Faculty of Science and Engineering, Kindai University, Higashiosaka, Japan
3
Fukushima environmental measurements and radioactivity monitoring association, Japan
2

Abstract:
Since the accident at the Fukushima Daiichi NPS, food inspection for radioactivity in home-grownproducts and wild foods collected by residents for their own consumption has been conducted in
Fukushima. To inspect these foods, 300 temporary inspection stations were set up in public halls
or assembly halls in municipalities. Due to a decrease in the number of inspections required, somelaboratories have been consolidated or closed, but inspections are still ongoing. The conventional
gamma-ray spectrometry technique using a NaI (Tl) scintillation spectrometer was utilized for thetesting. Since the scintillation detector is inferior to the Ge detector in energy resolution, a screening
method was applied for the inspection. For conventional radioactivity measurement in foods,
however, sample preparation procedures, such as cutting and machining techniques, are required tohomogenize radioactivity. Therefore, it is difficult to use measured cut samples for self-consumption
even if radioactivy are not detected. Under such situations, municipal laboratories were strongly
requested by residents to return the measured samples for their own consumption. In response tosuch a demand, state-of-the-art device named “non-destructive radioactivity measurement device”
was launched to measure radioactive cesium in whole samples contained in a plastic bag so that all
products can be inspected without any sample preparation procedures (Ishii, 2015). The device wasinstalled in municipal food inspection stations in 2015. A total of 83835 samples were tested in 2015, of
which 68 % were measured with the non-destructive radioactivity measuring devices. Although thenumber of tests decreased year by year down to about 18000 samples in 2022, 84 % of all samples were
tested with non-destructive devices. The test pass rate (<50 Bq kg-1) for about 350000 samples since2015 has exceeded 90%, indicating that efficient screening tests have helped the residents. In case ofusing such non-destructive measurement devices, it would be important to determine the approximate
detection efficiency for samples of various sizes and shapes, within acceptable uncertainty, only fromthe information on mass and type of the sample. The performance evaluation of such devices had
been conducted by Yamada et al. (2023). Furthermore another approach using artificial radioactive
samples was adapted.to determine possible uncertainties arising from variation of sample shapes. As apreliminary result, 10 % or less standard uncertainty due to variation of sample shapes were observed.
Key words:
Radioactivity, Food inspection, Gamma spectrometry
References:1.

Ishii K. Development of non-destructive radioactive contamination food monitor. Isotope News. 2015;729:21–7(in Japanese).

2.

Yamada T, Furutaka K, Hachinohe M, Hachisuka A. Applicability of non-destructive equipment for radioactivity
measurement to screening radio-cesium in foods Appl. Radiat. Isot. 2023;126:93–9.

*Takahiro Yamada: Atomic Energy Research Institute, Kindai University, Higashiosaka, Japan
E-mail: tyamada@kindai.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_90
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 91

Neutron Shielding and Mechanical Properties of Recycled High-Density
Polyethylene (r-HDPE) Composites
Donruedee Toyen1, 2, Ekachai Wimolmala 3, Kasinee Hemvichian4,
Pattra Lertsarawut4 and Kiadtisak Saenboonruang2, 5*
Department of Materials Science, Faculty of Science, Kasetsart University, Bangkok, Thailand
2
Special Research Unit of Radiation Technology f or Advanced Materials (RTAM),
Faculty of Science, Kasetsart University, Bangkok, Thailand
3
Polymer PROcessing and Flow (P-PROF) Research Group, Division of Materials Technology, School of Energy, Environment
and Materials, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
4
Thailand Institute of Nuclear Technology (Public Organization), Nakhon Nayok, Thailand
5
Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Bangkok, Thailand
1

Abstract:
Utilization of effective and improved neutron-shielding materials is one of the main radiation safety
principles that aim to reduce risks from excessive neutron exposure. Despite their great benefits,
exposure to high neutrons could cause acute health effects such as skin burns and chronic radiation
syndromes, which can increase the risk of longer-term effects such as cancer and death. In orderto reduce risks from exposure, this research aimed to develop eco-friendly neutron-shielding
materials based on the addition of 0–20%wt of gadolinium oxide (Gd2O3) in recycled high-density
polyethylene (r-HDPE) composites. The results indicated that the abilities to attenuate thermal
neutrons were noticeably enhanced with the increase of Gd2O3 contents. Furthermore, the additionof Gd2O3 particles to the r-HDPE composites generally led to higher values of tensile modulus
and surface hardness (Shore D). The results also revealed that the composites with 5-%wt. Gd2O3
exhibited higher tensile strength, elongation at break, and crystallinity than those from other filler
contents. In addition, the results on the effects of 70-kGy gamma irradiation on the properties of
the r-HDPE composites suggested that gamma aging decreased neutron shielding properties but
did not noticeably change mechanical properties of the composites. By comparing the shielding
performances from this work with those from commercial 5%-borated PE composites, the developedr-HDPE composites exhibited higher overall radiation shielding and mechanical properties, implying
the potential of utilizing r-HDPE composites as eco-friendly materials that surpassed stringent
requirements in radiation safety.
Key words:
r-HDPE, Gd2O3, Neutron shielding, Mechanical properties*Kiadtisak Saenboonruang: Special Research Unit of Radiation Technology for Advanced Materials (RTAM), Faculty of Science, Kasetsart
University, Bangkok, Thailand
E-mail: Kiadtisak.s@ku.th
https://doi.org/10.51083/radiatenvironmed.13.2_91
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 92

Research Activity of The Department of Radiochemistry
and Radioecology, and Study on Internal Exposure Dose Assessment
by Beverages
Khemruthai Kheamsiri1*, Ryohei Yamada 2, Haruka Kuwata1 , Chutima Kranrod3,
Tarika Thumvijit4, Hirofumi Tazoe3 and Naofumi Akata 2*
1
Graduate School of Health Sciences, Hirosaki University, Japan
Department of Radiochemistr y and Radioecology, Institute of Radiation Emergency Medicine, Hirosaki University, Japan3
Department of International Cooperation and Collaborative Research, Institute of Radiation Emergency Medicine, Hirosaki University, Japan
4
Faculty of Associated Medical Sciences, Chiang Mai University, Thailand
2

Abstract:
The Depar tment of Radiochemistr y and Radioecology is par t of the Institute of Radiation
Emergency Medicine at Hirosaki University which carries out chemical approaches to evaluate
radiation exposure and the course on radiochemical technique training. The current research
themes are as follows; the study of internal radiation dose through bioassay, tritium in environmental
and biological samples, radioecology in the Fukushima area, and isotope geochemistr y. Our
department focuses on tritium monitoring since it is also released into the environment by nuclear
facilities. Tritium released into the atmosphere on an annual basis from nuclear power plants aroundthe world was estimated to be equivalent to approximately 15-20% of the yearly rate at which cosmic
rays produce tritium. Recently the issue of tritium has also raised public concern since the Japanese
government decided to discharge the ALPS-treated water into the ocean. Therefore, continuing
tritium monitoring also holds signiﬁcant value for the public. Additionally, the study on radionuclides
content and their annual effective dose in beverages is also one of the related topics. Radionuclides
emitted into the environment can end up in the atmosphere, surface water, or groundwater.
Ingestion is the primar y mechanism responsible for the internal exposure of the human body toionizing radiation. It is crucial to examine how radionuclides migrate and accumulate throughout
the food chain. Humans and beverages are intimately associated since humans consume beverages
to quench their thirst, stay hydrated, and enjoy a variety of ﬂavors and nutritional beneﬁts. Given
that they make up a large portion of the diet and can have varied ef fects on health, beverages
are considered an important issue. Additionally, some literature highlights the need for precise
data in food monitoring at the initial levels in order to improve ef fect estimates of radionuclide
contamination. Thus, the goal of this study is to evaluate radionuclides in beverages in order tocreate a preliminary database for more accurate evaluation in the future (Pintilie-Nicolov et al., 2021).
Key words:
radionuclides, tritium monitoring, internal dose, beverages
Reference:

Pintilie-Nicolov V, Georgesou PL, Iticescu C, Moraru DI, Pintilie AG. The assessment of the annual effective dose due toingestion of radionuclides from drinking water consumption: calculation methods. J Radioanal Nucl Chem, 327(1). https://doi.
org/10.1007/s10967-020-07438-5*Khemruthai Kheamsiri: Graduate School of Health Sciences, Hirosaki University, Japan*Naofumi Akata: Department of Radiochemistry and Radioecology, Institute of Radiation Emergency Medicine, Hirosaki University, Japan
E-mail: h23gg703@hirosaki-u.ac.jp, akata@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_92
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 93

Evaluation of Radioactive I-131 in Wastewater from Nuclear Medicine
Sunanta Sawikan* and Purin Chaiwong
Inspection of Nuclear and Radiation Division /Of fice of Atoms f or Peace, TH AIL AND

Abstract:
Iodine-131 is a radioactive substance widely used in nuclear medicine, particularly in the treatmentof hyperthyroidism and thyroid cancer. To treat patients with hyperthyroidism, a low activity
dosage of approximately 100 - 1000 MBq (2.7 - 27 mCi) is administered. For the treatment of thyroid
cancer, a high activity dosage of 3.7 – 11.1 GBq (100 - 300 mCi) is required, necessitating the patientʼs
hospitalization to isolate them from others. It takes approximately 2 - 3 days in order to decrease theradiation dose rate to a safe level (50 micro sievert per hour at 1 meter), before the patient returns
home. The wastewater generated by patients during treatment is contaminated with radioactive
waste (Iodine-131). Therefore, a specialized decay tank is necessary to store I-131 until its activity
level is within the legal limit before discharge to the public. This level must not exceed 1x10^9becquerels per year, as required by Ministerial regulations on the release of radioactive waste (B.E
2018).
Key words:
wastewater, nuclear medicine, decay tank

*Sunanta Sawikan: Inspection of Nuclear and Radiation Division /Office of Atoms for Peace, THAILAND
E-mail: Sunanta.p@oap.go.th, purin.c@oap.go.th
https://doi.org/10.51083/radiatenvironmed.13.2_93
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 94

Water Quality Analysis for Comprehensive Evaluation of Combined
Exposure from Heavy Metals and Radionuclides
Hirofumi Tazoe1*, Yuki Oda 2, Mizuki Kiso2, Aoi Sampei2, Hiroki Hashimoto2, Yasuyuki Taira 3,
Yasutaka Omori1, Chutima Kranrod1, Mayumi Shimizu1, Hiromi Kudo2, Naofumi Akata1, Ryohei Yamada1,
Masaru Yamaguchi2, Masahiro Hosoda1, 2 and Shinji Tokonami1
1

Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
2
Hirosaki University Graduate School of Health Science, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan3
Department of Global Health, Medicine and Welf are, Atomic Bomb Disease Institute, Nagasaki University,
1-12-4 Sakamoto, Nagasaki 852-8523, Japan

Abstract:
Ever since the accident at TEPCOʼs Fukushima Dai-ichi Nuclear Power Plant (FDNPP) has passed
for 12 years, a part of residents is still concerned about radiation exposure to radionuclides fromthe environment. Our study employed a method that compares the effects of anthropogenic andnatural radionuclides, evaluating the dose exposures to ambient radiation, inhalation of atmosphericaerosols, and ingestion of drinking water on three municipalities in the Hamadori region of
Fukushima Prefecture, near the FDNPP. This presentation focuses on the analysis of water samples
used as drinking water. Particularly in Kawauchi, well water is the primary source for drinking,distinguishing it from the other areas. All water sources for drinking undergo regular analysis forwater quality and radionuclide concentrations by the local government, being lower the guidancelevel of drinking water in Japan. Drinking water samples were collected from tap water or well
water used in residentsʼ homes at Kawauchi, Tomioka and Okuma from March 2022 to March
2023. In addition to 222Rn and 137Cs concentrations analysis, concentrations of major ions and traceelements including Cd, As, Cr, Pb, Cs (stable) and 238U were determined by ion-chromagraphy and
ICP-MS. 222Rn concentrations obtained at Kawauchi, Tomioka, and Okuma ranged from 17–399
Bq L -1, <55 Bq L-1, and <12 Bq L -1, respectively. Notably, the 222Rn concentrations in six out of ten
houses at Kawauchi exceeded 100 Bq L-1 as a reference level reported by the EU. Abukuma granite
belt, characterized by elevated 238U concentrations, is widely distributed as bedrock in Fukushima
Prefecture including Kawauchi. High concentration of 238U were observed in water samples collectedfrom Kawauchi and Okuma, with maximum of 0.039 Bq L-1. This observation suggests that groundwater played a significant role in interacting with granite bedrock and transporting 238U. This work
was supported by the Research Project on the Health Effects of Radiation organized by the Ministryof the Environment, Japan.
Key words:
Fukushima, water quality, radionuclide, heavy metal*Hirofumi Tazoe: Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
E-mail: tazoe@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_94
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 95

Comparison of Gamma-Ray Dose Rate Map Using Car-Borne Survey
and Man-Borne Survey
Mizuki Kiso1, Haruka Kuwata1, Yuki Oda1, Worawat Poltabtim1, Saowarak Musokawan1,
Chutima Kranrod2, Yasutaka Omori2, Masahiro Hosoda1, 2 and Shinji Tokonami2*21
Graduate School of Health Sciences, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan

Abstract:
Hirosaki University mainly uses the car-borne and man-borne methods to measure gamma rays with
the Global Positioning System (GPS). The car-borne method is capable of measuring large areas ina short time, while the man-borne method is capable of investigating details of places inaccessible
by car. However, the values associated with these methods have not been compared. Recently,
a man-borne survey was conducted in Hirosaki City in September 2022; this survey produced agamma dose rate map by Worawat et al., 2023. However, this study aims to compare the dose
rate profile using both methods of a car-borne survey and a man-borne survey with the previous
results. The car-borne survey method was employed in Hirosaki City, Japan, using a 3 × 3 NaI(Tl)scintillation spectrometer with a GPS receiver, which were used to count the number of gamma-rays
with latitude and longitude. The meter was installed in the car during the measurement process.
In addition, the shielding factor of the car-body was determined by the count rate ratio of the carinterior and exterior. Subsequently, the absorbed dose rate in air was also calculated using the
response matrix method from the gamma-ray pulse height distribution obtained during the fixedpoint measurement; this method established a relationship between the absorbed dose rate in air andthe total counts of the gamma-ray pulse height distribution. Finaly, the absorbed dose rate in air was
evaluated from the ongoing count rate; a dose rate map was then created. The average absorbed
dose rate in air was estimated to be 23 ± 10 nGy h-1 (19-29 nGy h-1) in Hirosaki City by the car-borne
survey method. Conversely, the average absorbed dose rate in air was estimated to be 32 ± 15 nGy h-1(7-146 nGy h-1) by the man-borne survey method reported by Worawat et al. (2023). Thus, the carborne survey results in this study had a lower value and a smaller range of the average absorbed
dose rate in air than the man-borne survey. Thus, it could be seen that the locations that showeda relatively high degree of human-borne behavior were locations near sidewalks covered in stonematerials. In the case of car-borne survey, the car was traveled on the road covered with asphalt, andit may far from the sources, so it had shown a lower value than the man-borne survey. Nevertheless,there was a good agreement between both methods when they were conducted on asphalt areas.
Key words:
Car-borne survey, Man-borne survey, Absorbed dose rate in air
Reference:

Poltabtim W, Musokawan S, Thumwong A, Omori Y, Kranrod C, Hosoda M, et al. Estimation of Ambient Dose Equivalent
Rate Distribution Map Using Walking Survey Technique in Hirosaki City, Aomori, Japan. Int J Environ Res Public Health.
2023;20(3):2657.

*Shinji Tokonami: Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan
E-mail: tokonami@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_95
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 96

Development of Machine Learning Based Computer Software
for Alpha Track counting on CR-39 Using YOLOv8
Instance Segmentation Model
Pannathad Panthanuwong* and Rawiwan Kritsananuwat
Department of Nuclear Engineering Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand

Abstract:Rn, or radon, is a radioactive element with an atomic number of 86 and exists in the form of ascentless gas that can be found in natureʼs surroundings or underground material. The ef fects ofradon and its progeny on humans and the environment are highly concerning, which makes radon
analysis and detection important. In radon concentration measurement, itʼs dif ficult to count anenormous amount of track using bare eyes, which is why the most frequently used method to countalpha track on a passive detector is ImageJ. But there is a huge ﬂaw in this method that causes anerror in tracking measurements. This study aims to create ML-based software capable of effectively
separating tracks from contamination stains. The results show that ML-based software is capableof counting alpha tracks more ef ficiently and precisely, but there are some limitations in image
resolution and the low number of data points used, causing some errors that should be improved.
222

Key words:
Alpha track, CR-39, Image Segmentation, 222 Rn, Radon, Ultralytics YOLOv8*Pannathad Panthanuwong: Department of Nuclear Engineering Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand
E-mail: peakssp@yahoo.com
https://doi.org/10.51083/radiatenvironmed.13.2_96
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 97

Investigation for Adaptation of Tritium Analysis in Fish Samples Usinga New Combustion System
Haruka Kuwata1*, Khemruthai Kheamsiri1, Ryohei Yamada 2, Hideki Kakiuchi3,
Toshiya Tamari4, Nagayoshi Shima4 and Naofumi Akata 2
1

Department of Graduate School of Health Sciences, Hirosaki University, Japan
2
Institute of Radiation Emergency Medicine, Hirosaki University, Japan
3
Institute f or Environmental Sciences, Japan
4
Kyushu Environmental Evaluation Association, Japan

Abstract:
The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident resulted in a large amountof contamination, and decommissioning was required to remove the damaged reactors anddecontaminate the surrounding areas has been under way. The contaminated water in FDNPP istreated by the Advanced Liquid Processing System (ALPS), but tritium in the water cannot be
removed by the system. The Japanese government then decided to release that water into the ocean,which was carried out by Tokyo Electric Power Company in August 2023. Therefore, it is crucial
to understand the environmental impact of tritium and its behavior, as there are concerns about
internal exposure to tritium and harmful rumors. To study the effects of tritium on the environment,
it is important to determine the concentration of tritium in environmental samples. However,organically bound tritium (OBT) which is bound to the carbon skeleton of organic materials analysis
requires several pre-treatments and time. In particular, the combustion process is dif ﬁcult due tosudden ignition depending on the samples. The recovery of combustion water therefore requires
skilled techniques. For this reason, data on OBT in environmental samples is limited. In this study,
a semi-automatic combustion system was developed to enable the combustion of water easily,
safely, and with reproducibility in the combustion process. Combustion tests were carried out onfour dif ferent fish samples. To achieve combustion without ignition, combustion conditions were
investigated by adjusting the temperature increase program and gas flow rate. In addition, thevalidity of this method was then veriﬁed by evaluating the volume of combustion water recovered.
Furthermore, to verify the validity of this method, an analysis was performed on a standard ﬁshsample, and a comparative test was performed with other analytical methods. The results of thistest confirmed that the four types of fish were able to complete the combustion operation without
sudden ignition. Combustion water recovery rates exceeded 80%. However, sudden ignition wasoften observed in black rockfish and trout. Therefore, it was possible to prevent sudden ignition byadjusting the sample volume and gas flow rate. Comparative tests of fish standard samples showedsimilar values of 2.01 ± 0.54 Bq/L for this method and 2.11 ± 0.17, 1.72 ± 0.09 Bq/L for the mass
spectrometer method. Therefore, it was confirmed that this combustion device is effective for the
analysis of OBT. The method is expected to make obtaining OBT data easier and safer, as well as
contribute to a better understanding of tritium environmental impact and behavior.
Key words:
Organically bound tritium analysis, semi-automatically combustion system, tritium analysis*Haruka Kuwata: Department of Graduate School of Health Sciences, Hirosaki University, Japan
E-mail: h23gg702@hirosaki-u.ac.jp
https://doi.org/10.51083/radiatenvironmed.13.2_97
Copyright © 2024 by Hirosaki University. All rights reserved.

Radiation Environment and Medicine 2024 Vol.13, No.2 98

Radiological Emergency Due to Cs-137 in Prachinburi, Thailand:
Challenge for Thailand in Radiological Emergency Preparedness
and Response
Kitkawin Aramrun*, Theerapatt Manuwong, Piyaporn Sinsrok, Theerawat Pluemjit,
Siriporn Pumsawai, Ngampol Saengdokmai, Juknarin Domwun, Supatcha Rattanasupa,
Manit Buranasil and Panupong Pingish
Of fice of Atoms f or Peace, 16 Vibravadi Rangsit Road, Ladyao, Chatuchak, Bangkok 10900, Thailand

Abstract:
In March 2023, there were two radiological incidents in Prachinburi province, Thailand whichwere interested to public as well as both national and international medias. The first emergency
was a missing radioactive source of caesium-137 (Cs-137) contained in a metal cylindrical shielding
from a radiation facility, and the second was the detection of metal ash contaminated caesium-137
at a metal foundry. It has not been conﬁrmed whether those two emergency situations are linked
to each other. The situations caused people confusing and concern about radiation health ef fects
and the release of caesium-137 into the environment, which need to be considered in radiation
measurements both people and the environment around the affected areas. Local and international
medias were also interested to those radiological emergencies from which relevant organizations
responded on press conference, media inter view, public communications during the situations.
There are challenges on emergency preparedness and response that need to be considered as lesson
learns from the emergencies in Prachinburi for improving Thailandʼs systems and capabilities in
preparedness and response in the case of radiological emergencies efﬁciently. This study presentsscientific information on the radiological emergencies in Prachinburi and responding details of
relevant organizations as the lesson learns and challenges for further improvement of radiologicalemergency preparedness and response in Thailand.
Key words:
Radiological emergency, Cs-137, Radioactive source*Kitkawin Aramrun: Office of Atoms for Peace, 16 Vibravadi Rangsit Road, Ladyao, Chatuchak, Bangkok 10900, Thailand
E-mail: Kitkawin.a@oap.go.th
https://doi.org/10.51083/radiatenvironmed.13.2_98
Copyright © 2024 by Hirosaki University. All rights reserved.