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
Wei ZHANG Chunyan WANG Deqing CHEN Masako MINAMIHISAMATSU Hiroshige MORISHIMA Yongling YUAN Luxin WEI Tsutomu SUGAHARA Isamu HAYATA
出版者
Journal of Radiation Research 編集委員会
雑誌
Journal of Radiation Research (ISSN:04493060)
巻号頁・発行日
vol.45, no.3, pp.441-446, 2004 (Released:2004-12-22)
参考文献数
26
被引用文献数
16

Cytogenetic investigation of stable-type aberrations (translocations) was carried out with our improved methods on 28 elderly individuals in a high-background radiation area (HBRA) in China, and on 24 elderly individuals in a control area (CA). The level of radiation in HBRA is 3 to 5 times higher than in CA. The mean frequencies of translocations per 1,000 cells in HBRA and CA were 12.4 ± 5.3 and 10.0 ± 3.8, respectively. No significant difference was found in the frequencies between HBRA and CA (P>0.05, Mann-Whitney U test). When elderly individuals in HBRA and CA were classified into four subgroups of HBRA nonsmokers, HBRA smokers, CA nonsmokers, and CA smokers, a significant difference was found in the frequencies between CA smokers and CA nonsmokers (P<0.05, Mann-Whitney U test). Furthermore a tendency of difference (a near T-value of 0.05 level) was found in a comparison of HBRA smokers vs. CA nonsmokers. The present results indicate that the elevated level of natural radiation in HBRA plays a less significant part than smoking in bringing about the induction rate of stable-type aberrations (translocations) in those areas.
著者
JIANMING ZOU QUANFU SUN SUMINORI AKIBA YONGLING YUAN YONGRU ZHA ZUFAN TAO LUXIN WEI TSUTOMU SUGAHARA
出版者
Journal of Radiation Research 編集委員会
雑誌
Journal of Radiation Research (ISSN:04493060)
巻号頁・発行日
vol.41, no.SUPPL, pp.S53-S62, 2000 (Released:2001-10-19)
参考文献数
17
被引用文献数
41

The main purposes of this study were to identify the major determinants of nasopharyngeal carcinoma (NPC) in the high-background radiation areas (HBRA) in Yangjiang, China and to evaluate their potential confounding effects on the NPC risk associated with exposure to high background radiation. A matched case-control study was conducted using those who died of NPC during the period 1987-1995. Two controls were randomly selected for each case from those who died from causes other than malignancies and external causes. Cases and their controls were matched with respect to sex and the years of birth and death (±5 years). Study subjects' next-of-kin were interviewed using a standardized questionnaire to collect information on socioeconomic status, dietary habits, tobacco smoking and alcohol consumption, disease history, pesticide use, medical X-ray exposure, the family history of NPC and so on. We succeeded in interviewing 97 cases and 192 controls. Univariate conditional logistic regression analysis showed that NPC risk was associated with the consumption of salted fish, homemade pickles, and fermented soy beans, education levels, the history of chronic rhinitis, and the family history of NPC. Multivariate conditional logistic regression analysis revealed that education levels (Odds ratio (OR) for middle school or higher levels vs. no school education=3.8, 95% CI=1.2 to 11.8), salted fish intake (OR=3.2, 95% CI=1.7 to 6.1), the history of chronic rhinitis (OR=3.6, 95% CI=1.3 to 10.1), and the family history of NPC (OR=14.2, 95% CI=2.7 to 73.4) were independent risk factors of NPC. Tobacco smoking (OR=1.2, 95% CI=0.7 to 2.1), and alcohol consumption (OR=0.9, 95% CI=0.5 to 1.9) were not significantly related to NPC risk. The ORs of NPC risk comparing HBRA and a nearby control area before and after adjustment for the major risk determinants identified in the present study were 0.86 (95% CI=0.50 to 1.50) and 0.87 (95% CI=0.45 to 1.67), respectively. Salted fish intake was a strong risk factor of NPC. Education, the history of chronic rhinitis and the family history of NPC were also related to NPC risk. The exposure to high background radiation in HBRA of Yangjiang was not related to NPC risk with or without the adjustment for those major risk determinants of NPC.
著者
QUANFU SUN SUMINORI AKIBA ZUFAN TAO YONGLING YUAN JIANMING ZOU HIROSHIGE MORISHIMA HIROO KATO YONGRU ZHA TSUTOMU SUGAHARA LUXIN WEI
出版者
Journal of Radiation Research Editorial Committee
雑誌
Journal of Radiation Research (ISSN:04493060)
巻号頁・発行日
vol.41, no.SUPPL, pp.S43-S52, 2000 (Released:2001-10-19)
参考文献数
18
被引用文献数
19

A study was made on cancer mortality in the high-background radiation areas of Yangjiang, China. Based on hamlet-specific environmental doses and sex- and age-specific occupancy factors, cumulative doses were calculated for each subject. In this article, we describe how the indirect estimation was made on individual dose and the methodology used to estimate radiation risk. Then, assuming a linear dose response relationship and using cancer mortality data for the period 1979-1995, we estimate the excess relative risk per Sievert for solid cancer to be -0.11 (95% CI, -0.67, 0.69). Also, we estimate the excess relative risks of four leading cancers in the study areas, i.e., cancers of the liver, nasopharynx, lung and stomach. In addition, we evaluate the effects of possible bias on our risk estimation.