著者
Shigenobu NAGATAKI
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.45, no.4, pp.370-378, 2010 (Released:2011-07-12)
参考文献数
12

The latest knowledge encompass findings presented both in individual scientific publications and in internationally accepted reports. This review summarizes the latest knowledge on radiobiological effects on the latter level, using studies of atomic bomb survivors and victims of Chernobyl nuclear power plant accident. First of all, it is important to note that while examining individual patient, it is impossible to distinguish a radiation-induced cancer patient and non-radiation-induced cancer patient even when using state-of-the-art techniques. Therefore, investigation of radiation effects on humans, especially late health effects has been based on the epidemiological and statistical methods. Based on studies on atomic bomb survivors, it is well accepted that there is a linear increase in the risk of cancer with the increase of radiation dose. However, the existence of a threshold is a controversial issue, and health effects with regards to non-cancer diseases are not yet accepted by international authorities. Childhood thyroid cancer has increased after the Chernobyl accident and more than several thousands children are affected by it. However, there is no proof that any disease, with the exception of thyroid cancer and acute radiation effects, has increased after the Chernobyl accident. Finally, it should be mentioned that providing scientific explanation of the results to general public is an honorable duty of concerned scientists.
著者
神田 玲子 辻 さつき 米原 英典
出版者
Japan Health Physics Society
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.49, no.2, pp.68-78, 2014
被引用文献数
1

In general, the press is considered to have amplified the level of public's anxiety and perception of risk. In the present study, we analyzed newspaper article headlines and Internet contents that were released from March 11, 2011 to January 31, 2012 using text mining techniques. The aim is to reveal the particular characteristics of the information propagated regarding the Fukushima NPP Accident. The article headlines of the newspapers which had a largest circulation were chosen for analysis, and contents of Internet media were chosen based on the number of times they were linked or retweeted. According to our text mining analysis, newspapers frequently reported the "measurement, investigation and examination" of radiation/radioactive materials caused by the Fukushima Accident, and this information might be spread selectively via the social media. On the other hand, the words related to health effects of radiation exposure (i. e., cancer, hereditary effects) were rare in newspaper headlines. Instead, words like "anxiety" and "safe" were often used to convey the degree of health effects. Particularly in March of 2011, the concept of "danger" was used frequently in newspaper headlines. These indirect characterizations of the situation may have contributed more or less to the misunderstanding of the health effects and to the enhanced perception of risk felt by the public. In conclusion, there were found no evidence to suggest that newspapers or Internet media users released sensational information that increased the health anxiety of readers throughout the period of analysis.
著者
安齋 育郎
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.10, no.1, pp.41-44, 1975 (Released:2010-02-25)
参考文献数
12
被引用文献数
1
著者
Naoto FUJINAMI Taeko KOGA Hiroshige MORISHIMA Farideh ZAKERI Seiichi NAKAMURA Kanji TORIZUKA Tsutomu SUGAHARA
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.46, no.1, pp.66-69, 2011 (Released:2012-01-25)
参考文献数
11

Individual external doses of inhabitants were examined in high levels of natural radiation areas (HLNRAs) in Ramsar. Each of 15 inhabitants in HLNRAs and 10 inhabitants in a control area carried an electronic personal dosimeter (EPD) for one day in April and in December 2005. In addition, their individual doses were estimated from indoor and outdoor radiation dose rates determined with a NaI (Tl) survey meter. A good correlation existed between the dose rate values obtained through estimation and personal measurement, and estimated annual doses ranged from 0.5 to 32 mGy/y. Each of the dosimetric subjects carried also an optically stimulated luminescence dosimeter (OSLD) for about one month in September 2005, but a few values obtained by these measurements deviated widely from those obtained by one-day measurements with EPDs and those estimated by environmental dosimetry. This deviation might have been due to the fact that these OSLDs were left behind somewhere in houses. Hence, the observed dose values depended heavily on the place where dosimeters had been left, because of the non-uniform distribution of Ra-226 contained in building materials as well as the structure of the house and the existence of shields.
著者
Miroslaw JANIK Shinji TOKONAMI
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.44, no.1, pp.116-121, 2009 (Released:2010-10-08)
参考文献数
34
被引用文献数
2

In Poland there are some special regions in which the natural background radiation is obviously higher than in neighboring areas. This paper presents a review of recent radiation measurements taken in the Polish environment. Natural sources including radon, potassium, uranium and thorium as well as artificial sources such as cesium are characterized. Their contribution to the annual radioactivity dose rate is described.
著者
古賀 佑彦
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.24, no.1, pp.39-42, 1989 (Released:2010-02-25)
参考文献数
8
著者
辻村 憲雄
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.54, no.1, pp.40-44, 2019-04-18 (Released:2019-09-03)
参考文献数
21

Rainwater containing radioactive materials originating from the USA’s nuclear weapon test conducted at Bikini Atoll was observed throughout Japan in 1954. It has been reported that the maximum gross beta activity observed at that time in Kyoto was 523 pCi/mL (19,000 Bq/L). This measurement, however, focused on the gross beta activity contained in a small amount of rain sampled at the beginning of rainfall, which is different from present observations that are based on the average gross beta activity contained in rain collected during a 24-h period. As a result of reviewing and converting the 1954 data to be equivalent to current measurement, the maximum value was reduced to 50 pCi/mL (1,800 Bq/L), with a resultant surface deposition density of 310 mCi/km2 (11,000 MBq/km2). These values are well below 1/10 of the past maximum observed a few days after China’s fifth nuclear weapon test in 1966.
著者
松原 孝祐 Thunyarat CHUSIN 大久保 玲奈 小川 善紀
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.53, no.4, pp.238-246, 2018 (Released:2019-03-03)
参考文献数
39

Evaluation of radiation dose from medical exposure is important because the use of ionizing radiation in medical field contributes significantly to the exposure of the population. In plain radiography, the entrance skin dose, which is absorbed by the skin as it reaches the patient, is generally estimated. It is calculated from the air kerma at the same focus skin distance on the beam central axis measured with a dosimeter. In fluoroscopy, the indirect monitoring using dose-area product meter is generally performed for estimating the entrance skin dose in real-time to avoid skin injuries. In mammography, the average glandular dose is estimated because mammary glands have more sensitive to radiation than skin. The European Organization for Quality-Assured Breast Screening and Diagnostic Services protocol has been used to estimate average glandular dose from full-field digital mammography in Japan. Although volume CT dose index or dose-length product, as seen on CT consoles, do not represent the actual dose for the patient, they are measured to assist in quality control and optimization as well as the air kerma rate at the patient entrance reference point in fluoroscopy and the average glandular dose in mammography. For the purpose of patient dose evaluation, physical dose measurements using an anthropomorphic phantom and Monte Carlo simulations can estimate patient organ doses from medical exposure.
著者
稲葉 次郎
出版者
Japan Health Physics Society
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.12, no.2, pp.109-116, 1977 (Released:2010-02-25)
参考文献数
9

As any radiation exposure may involve some degree of risk the International Commission of Radiation Protection recommends that any unnecessary exposure be avoided, and that all doses be kept ALARA, i. e., as low as is readily achievable, economic and social considerations being taken into account. To define the level at which it can be said that a dose is ALARA the use of cost- (or risk-) benefit analysis is required. In making a cost-benefit calculation the most difficult step is the conversion of positive and negative effect into a consistent set of units, i. e., conversion of man-rem into dollars. This paper presents the monetary value of population dose which appeared in the past reports (six papers reffered by ICRP Publication 22, BEIR Report and NRC-10CFR50, App. I).We must be very careful in the application of cost-benefit analysis to decision making of individual cases, but the estimated risk in monetary term may help us at least to check whether we act in a consistent way.
著者
Haruyuki OGINO Takatoshi HATTORI
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.49, no.4, pp.194-198, 2014 (Released:2015-12-18)
参考文献数
18
被引用文献数
4 4

This study was designed to calculate the background lifetime risk of cancer mortality in Japan. The mortality and population data obtained from national surveys for the vital statistics and population census in 2010 are stratified at 5-year age intervals of 0-4, 5-9, ..., 80-84 with a final open interval of 85+ for use in a life table. It was found that the gender-averaged background lifetime risk of cancer mortality ranges from 23.7% to 28.3% among 47 prefectures, and the arithmetic mean was calculated to be 25.4%. It is important to consider the incremental risk of cancer mortality posed by exposure to ionizing radiation (e.g., an additive lifetime risk of 0.5% at the effective dose of 100 mSv) in the context of the level of the background lifetime risk of cancer mortality of the exposed population.
著者
鈴木 将文 佐々木 守 菊池 浩司
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.53, no.4, pp.207-218, 2018 (Released:2019-03-03)
参考文献数
17

We converted the measured values to the measurement value of 1 m height obtained by the calibrated survey meter by using the regression of the car-borne survey measurements on existing survey meter measurements of the absorbed dose rate in air. Detailed investigation was conducted for all factors considered to potentially influence the measured value. The equation made by these factors was nearly accordance with this regression. The result of converting the measurement results into the survey meter measurement value was 22-111 nGy h-1. Comparing the distribution map of environmental gamma-ray dose rate by car-borne survey with a geological map shows that the area with high gamma-ray dose rate coincides well with areas of Granitoid, Paleogene system and Tertiary Volcanic Rocks. The area with low gamma-ray dose rate coincides with areas of Quaternary Volcanic Rocks and their surroundings. The source of these rocks is considered to be volcanic ejecta. The annual effective dose from the geometric mean value in Aomori prefecture was estimated to be about 0.21 mSv y-1. This value is lower than the annual external dose that would be obtained by exposure to the average terrestrial gamma-ray dose rate in Japan.
著者
JAEA大洗プルトニウム 汚染事故ワーキンググループ 岩井 敏 佐々木 道也 桧垣 正吾 山西 弘城 甲斐 倫明
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.53, no.4, pp.271-281, 2018 (Released:2019-03-03)
参考文献数
15

On June 6, 2017, in the hood of the analyzing room at Plutonium Fuel Facility of Oarai Research and Development Center in Japan Atomic Energy Agency, five workers were checking the storage container of fast reactor nuclear fuel material. Around 11:15 a.m., vinyl bags in the container of the fuel material including plutonium and enriched uranium burst during the inspection work. All the workers heard the bang; which caused misty dust leakage from the container. This event caused significant skin α-contamination for four workers and nasal cavity α-contamination for three workers. Decontamination was conducted for workers in the shower room. Then, the five workers were transferred to the Nuclear Fuel Cycle Engineering Laboratory to evaluate inhalation intake of plutonium etc. in lungs. The maximum values of 2.2 × 104 Bq for 239Pu and 2.2 × 102 Bq for 241Am were estimated by the lung monitor. From these results, injection of chelate agent was conducted for prompt excretion of plutonium etc. Next morning, the five workers were transferred to the National Institute of Radiological Sciences for treatments including decontamination of their skin and measurement by lung monitor. Then no obvious energy peak was confirmed for plutonium. The Japan Health Physics Society launched the ad-hoc working group for plutonium intake accident around the middle of June to survey issues and to extract lessons on radiological protection. We will report the activity of the working group.
著者
Shin'ichi KUDO Keiko YOSHIMOTO Hiroshige FURUTA Kazumasa INOUE Masahiro FUKUSHI Fumiyoshi KASAGI
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.53, no.3, pp.146-153, 2018 (Released:2018-11-27)
参考文献数
41
被引用文献数
1

Whether exposure to radiation at low dose and at low dose rate is related to leukemia mortality and morbidity remains controversial. Cohort studies of nuclear workers chronically exposed to radiation at low dose and at low dose rate in their workplaces provide an opportunity to directly evaluate the risks of leukemia in the lower dose ranges. Previous findings have come mostly from Western countries, with few from Asian countries. The present study aimed to examine radiation’s effects on mortality from leukemia, in a cohort of Japanese nuclear workers. The cohort consisted of 204,103 workers, who were followed from 1991 to 2010, with a total of 2.89 million person-years. The mean age and mean cumulative dose at the age at the end of follow-up were 55.6 years and 13.8 mSv. During the study, 209 leukemia deaths were observed. The linear excess relative risk (ERR) for all types of leukemia was negative, but not significant (ERR/Sv = -0.54; 90% confidence interval; -4.04, 2.96). Specific types of leukemia also showed no significant risks. A significant radiation-leukemia association for mortality was not observed in this study of Japanese nuclear workers. The cohort, however, is still young. Further follow-up is needed to obtain more reliable estimates of leukemia risks for Japanese workers exposed to low dose and low-dose rate radiation.