Radiation Environment and Medicine
Online ISSN : 2432-163X
Print ISSN : 2423-9097
ISSN-L : 2423-9097
Volume 7, Issue 2
Radiation Environment and Medicine
Displaying 1-9 of 9 articles from this issue
Special Contribution
Review
  • Yumi Yasuoka, Hiroyuki Nagahama, Jun Muto, Takahiro Mukai
    2018 Volume 7 Issue 2 Pages 86-94
    Published: August 30, 2018
    Released on J-STAGE: October 27, 2022
    JOURNAL FREE ACCESS

    This review summarizes anomalous variations in radon concentration in Fukushima, Miyagi, and Tochigi Prefectures prior to the 2011 Tohoku-Oki Earthquake. Atmospheric radon concentrations in Fukushima, Hokkaido (Sapporo), and Wakayama Prefectures were analyzed based on at least five years of raw data, whereas the data periods obtained in at Miyagi (around approximately four years of data) and Tochigi (around approximately three years of data) Prefectures before the 2011 Tohoku-Oki Earthquake were shorter than five years. The data were fitted using sinusoidal regression to describe seasonal variations in atmospheric radon concentration. In 72% of prefectures, including the Miyagi and Tochigi Prefectures, the anomalous data extracted from the normal pattern of annual radon variation could be used to identify earthquake activity. We obtain anomalous results that the radon concentrations were simultaneously reduced in the Fukushima, Miyagi, and Tochigi Prefectures before the 2011 Tohoku-Oki Earthquake by analyzing the variations in radon concentration based on the normal seasonal variations in atmospheric radon concentration approximated by the sinusoidal regression curves.

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  • Motoaki Yasuda*
    2018 Volume 7 Issue 2 Pages 95-101
    Published: August 30, 2018
    Released on J-STAGE: October 27, 2022
    JOURNAL FREE ACCESS

    Tumor volume is reportedly the most important factor influencing the outcome of radiotherapy for various types of tumors, including head and neck squamous cell carcinomas (HNSCCs). However, other factors have also been found to affect radiosensitivity, including the primary site and highrisk human papillomavirus (HPV) infection; the latter may increase radiosensitivity. Paradoxically, molecular biological studies have revealed that the oncogenic HPV E6 and E7 proteins possess anti-apoptotic or immune-evading functions. In this review, the impact of HPV infection in HNSCC is discussed, including molecular mechanisms of carcinogenesis, the prevalence of HPV infection in HNSCCs, and HPVʼs effects on radiosensitivity and prognosis.

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Regular Article
  • Akari Homma, Hirofumi Tazoe, Masatoshi Yamada, Shingo Terashima, Yoich ...
    2018 Volume 7 Issue 2 Pages 102-109
    Published: August 30, 2018
    Released on J-STAGE: October 27, 2022
    JOURNAL FREE ACCESS

    Internal ionizing radiation exposure dose is estimated indirectly by bioassay of biological samples such as feces and urine. In order to establish a method for internal exposure dose estimation for urine samples, we evaluated sample pretreatment by wet digestion prior to radionuclide measurement by inductively coupled plasma mass spectrometry. Wet digestion method was selected so that not only thorium and uranium but also 90Sr and 99Tc in urine samples could be determined. Analysis of thorium and uranium in tap water of Hirosaki city, and of mineral water and urine samples provided by the residents of Fukushima prefecture were performed using the resulting bioassay protocol. The concentrations of 232Th in urine samples were 4.8 to 43.1 ppt and 238U concentrations were 25.8 to 133.2 ppt, which were higher than those in the corresponding water and mineral water samples. These values are thought to be affected by the thorium and uranium content of both food and drinking water. Pretreatment of urine samples for thorium and uranium for inductively coupled plasma mass spectrometry was established as a bioassay for internal exposure dose estimation.

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  • Atangana Bingana Martin Serge, Saïdou, Oumarou Bouba
    2018 Volume 7 Issue 2 Pages 110-116
    Published: August 30, 2018
    Released on J-STAGE: October 27, 2022
    JOURNAL FREE ACCESS

    The aim of this study is to assess the contribution of the correlation between absorbed fractions of organs/tissues, to the overall relative uncertainty of the ingestion dose coefficients, otherwise of biokinetic and dosimetric models of α-, β-, αγ-, and βγ-emitters. 238U an αγ-emitter, and 210Pb an βγ-emitter were considered for calculations. The overall relative uncertainty of the ingestion dose coefficient ranging from 124% to 175% for 238U, and 206% to 287% for 210Pb was assessed, by ranging the relative uncertainty on the numbers of transformations, the absorbed fractions, the radiation and tissue weighting factors, and the wall parameter from 5% to their nominal values in the literature and by considering the weighting correlated coefficient between absorbed fractions at 5%, to take into account of the importance of the target or source organs/tissues according to their specific absorbed fractions. Finally the correlation between absorbed fractions of organs/tissues mostly affects the weighted relative uncertainty of absorbed fractions at around 88%. But because of the low contribution of this parameter in the assessment of overall relative uncertainty, this correlation between absorbed fractions has a very low impact in the final result.

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Note
  • Jing Chen
    2018 Volume 7 Issue 2 Pages 117-120
    Published: August 30, 2018
    Released on J-STAGE: October 27, 2022
    JOURNAL FREE ACCESS

    A recent review of radioactivity in Canadian public water supply systems estimated that the average effective dose resulting from drinking water intake would be 4.2 µSv per year. That review did not consider the presence of 228Ra, because data for 228Ra in drinking water are limited in Canada. Using available data from the environmental monitoring program conducted by the Radiation Protection Bureau, Health Canada, in Regina, Elliot Lake and Port Hope, the average 228Ra concentration was found to be 7 mBq/L. If the corresponding dose is included in the calculation of the national average annual dose from natural radionuclides in drinking water, it nearly doubles. The average effective dose resulting from drinking water intake should be revised to 7.5 µSv per year to include 228Ra. This is still well below the Canadian recommended reference level of 100 µSv/year (0.1 mSv/year).

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Report
  • Ryo Saga, Takakiyo Tsujiguchi, Masaru Yamaguchi, Yasuyo Fukushi, Yohei ...
    2018 Volume 7 Issue 2 Pages 121-124
    Published: August 30, 2018
    Released on J-STAGE: October 27, 2022
    JOURNAL FREE ACCESS

    With many nuclear facilities located in Japan, it is necessary to prepare for radiation accidents. Radiation accidents such as that at the Fukushima Daiichi Nuclear Power Plant and the Chernobyl nuclear accident caused the release of radioactive substances. Because of such accidents, the influence of radiation on human health began to receive greater attention. In Aomori Prefecture, northern Japan, Hirosaki University is the focal point for preparing for disaster and cooperating with local residents. Therefore, accurate knowledge and experience on the influence of radiation on the human body is required. Since 2014, the Educational Symposium on Radiation and Health (ESRAH) by Young Scientists has been co-hosted with Hokkaido University. To support the learning of young researchers, top-class researchers from abroad are invited to give educational lectures, facilitating the international exchange of ideas between researchers in various fields. In this meeting, networks and knowledge among young researchers are cultivated, and the human resources capable of playing a role in radiation emergency medicine are nurtured. The 4th ESRAH meeting took place in 2017. Herein we report the meeting findings.

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