An evaluation on the cytogenetic and DNA damages caused by natural radiation was done in eighty eight person living in Botteng village as HLNRA and their matched control in Keang village as normal level natural radiation areas (NLNRA). Their bloods were collected with their full informed consent and culture set up for cytogenetic evaluation as well as nucleic acid damage observation with comet assay and γ -H2AX that were done according to the standard procedures. Lymphocytes were scored manually under microscopic observation for the presence of chromosome aberrations. Radiosensitivity of cells evaluation was also done by challenging these bloods to 1.5 Gy of gamma rays before being cultured. The evaluation showed that frequency of chromosome aberration in HLNRA group was lower (0.00081) compared to control group (0.00125). However, frequency of micronucleus (MN) in HLNRA group was higher (0.0204) than that in control area (0.0172). Nucleoplasmic bridge and nuclear budding are found in extremely low frequency. DNA damage observation with comet assay showed a difference between study and control group, however γ -H2AX analysis showed no any effects observed in lymphocytes for both groups. Our data did not reveal any significant difference (P>0.05) in HLNRA as compared to NLNRA in all parameters (cytogenetics biomarkers) studied which is supported by the nucleic acid damage evaluation. There was a less radiosensitivity observed in lymphocytes of HLNRA group in comparison with controls.

Key words: high natural radiation, dicentrics, MN, DNA damages, γ-H2AX

Disasters, man-made as well as natural environmental events, pose a local and global public health challenge. To address the impact of all forms of disaster and mass casualty events, disaster training must be incorporated into the curricula of healthcare programs. This article describes how one university integrated disaster training through use of a spiral curriculum approach and simulation methodology.

Key words: simulation, disaster training, spiral curriculum

In Ireland radon is a significant public health issue and is linked to up to 250 lung cancer deaths each year. Much work was carried out to address this issue during the 20-year period from 1992 to 2012. Despite this, the Government recognised that a cross-Agency approach was required to comprehensively address this problem and subsequently, the four-year National Radon Control Strategy (NRCS) was launched in 2014. This paper summarises the highlights of the work carried out to implement the NRCS between 2014 and 2018 and it also sets out the research carried out during this period to underpin this work.

Key words: Radon, national strategy, radon related research

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.

Key words: Atmospheric radon, Tohoku-Oki Earthquake, Prediction, Anomalous

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 HPV’s effects on radiosensitivity and prognosis.

Key words: human papillomavirus, head and neck squamous cell carcinoma, radiotherapy, viral, oncogenes

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.

Key words: ICP-MS, Wet digestion system, Uranium, Urine sample

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 β-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.

Key words: Ingestion dose coefficient, absorbed fraction, uncertainty, correlation, dosimetric model, biokinetic model

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).

 Key words: natural radionuclides, drinking water

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.

Key words: radiation accidents, educational symposium, radiation effect