OBJECTIVETo follow up the cohort of a certain factory and analyze the death cause of the employees.

METHODSA dynamic cohort was adopted and the study population consisted of all workers stayed at the factory for more than 1 year. The cohort data was mainly from the personnel ministry in the factory,the death data provided by the personnel ministry,the labour union and the hospital. All cause of death of the all employee and the death condition of radiation group and no-radiation group were analyzed and compared.

RESULTSThe mortality of the workers in the factory was significantly lower than national population, the SMR of all cause of death in all employee, radiation group and no-radiation group were 0.41 (95% CI: 0.37-0.45), 0.24, 0.75 respectively; all cancer death in the three group was 0.59, 0.40 and 0.92. But the death order was different in radiation group and no-radiation group,the order of liver cancer was list first in radiation group, which was unlike that of the nation order and the no-radiation order.

CONCLUSIONThere have no excess death in the factory, but the order of liver cancer is precedence.

Cause of Death ; Cohort Studies ; Female ; Humans ; Male ; Middle Aged ; Neoplasms, Radiation-Induced ; mortality ; Nuclear Reactors ; Occupational Exposure ; Power Plants ; Prospective Studies ; Workplace

PURPOSE: For the research of Boron Neutron Capture Therapy (BNCT), fast neutrons generated from the MC-50 cyclotron with maximum energy of 34.4 MeV in Korea Cancer Center Hospital were moderated by 70 cm paraffin and then the dose characteristics were investigated. Using these results, we hope to establish the protocol about dose measurement of epi-thermal neutron, to make a basis of dose characteristic of epi-thermal neutron emitted from nuclear reactor, and to find feasibility about accelerator-based BNCT. METHOD AND MATERIALS: For measuring the absorbed dose and dose distribution of fast neutron beams, we used Unidos 10005 (PTW, Germany) electrometer and IC-17 (Far West, USA), IC-18, EIC-1 ion chambers manufactured by A-150 plastic and used IC-17M ion chamber manufactured by magnesium for gamma dose. There chambers were flushed with tissue equivalent gas and argon gas and then the flow rate was 5 cc per minute. Using Monte Carlo N-Particle (MCNP) code, transport program in mixed field with neutron, photon, electron, two dimensional dose and energy fluence distribution was calculated and there results were compared with measured results. RESULTS: The absorbed dose of fast neutron beams was 6.47x10-3 cGy per 1 MU at the 4 cm depth of the water phantom, which is assumed to be effective depth for BNCT. The magnitude of gamma contamination intermingled with fast neutron beams was 65.2+/-0.9% at the same depth. In the dose distribution according to the depth of water, the neutron dose decreased linearly and the gamma dose decreased exponentially as the depth was deepened. The factor expressed energy level, D20/D10, of the total dose was 0.718. CONCLUSION: Through the direct measurement using the two ion chambers, which is made different wall materials, and computer calculation of isodose distribution using MCNP simulation method, we have found the dose characteristics of low fluence fast neutron beams. If the power supply and the target material, which generate high voltage and current, will be developed and gamma contamination was reduced by lead or bismuth, we think, it may be possible to accelerator-based BNCT.
Argon ; Bismuth ; Boron Neutron Capture Therapy* ; Boron* ; Cyclotrons ; Electric Power Supplies ; Fast Neutrons* ; Hope ; Korea ; Magnesium ; Neutrons ; Nuclear Reactors ; Paraffin ; Plastics ; Water

Since the nuclear disaster at the Fukushima Daiichi Nuclear Power Plant in 2011, radiation safety has become an important issue in nuclear medicine. Many structured guidelines or recommendations of various academic societies or international campaigns demonstrate important issues of radiation safety in nuclear medicine procedures. There are ongoing efforts to fulfill the basic principles of radiation protection in daily nuclear medicine practice. This article reviews important principles of radiation protection in nuclear medicine procedures. Useful references, important issues, future perspectives of the optimization of nuclear medicine procedures, and diagnostic reference level are also discussed.
Disasters ; Nuclear Medicine ; Nuclear Power Plants ; Radiation Protection

No abstract available.
Korea* ; Mass Screening* ; Nuclear Power Plants* ; Thyroid Gland* ; Thyroid Neoplasms*

No abstract available.
Korea* ; Mass Screening* ; Nuclear Power Plants* ; Thyroid Gland* ; Thyroid Neoplasms*

OBJECTIVES: To assess the availability of the glycophorin A (GPA) assay to detect the biological effect of ionizing radiation in workers exposed to low-doses of radiation. METHODS: Information on confounding factors, such as age and cigarette smoking was obtained on 144 nuclear power plant workers and 32 hospital workers, by a self-administered questionnaire. Information on physical exposure levels was obtained from the registries of radiation exposure monitoring and control at each facility. The GPA mutant assay was performed using the BR6 method with modification by using a FACScan flow cytometer. RESULTS: As confounders, age and cigarette smoking habits showed increasing trends with GPA variants, but these were of no statistical significance. Hospital workers showed a higher frequency of the GPA variant than nuclear power plant workers in terms of the NO variant. Significant dose-response relationships were obtained from in simple and multiple linear regression models. The slope of the regression equation for nuclear power plant workers was much smaller than that of hospital workers. These findings suggest that there may be apparent dose-rate effects. CONCLUSION: In population exposed to chronic low-dose radiation, the GPA assay has a potential to be used as an effective biologic marker for assessing the bone marrow cumulative exposure dose.
Biomarkers* ; Bone Marrow ; Glycophorin* ; Linear Models ; Nuclear Power Plants ; Surveys and Questionnaires ; Radiation, Ionizing ; Registries ; Smoking

While the use of radioactive materials around the world offers a wide range of benefits in medicine, industry and research, radiation accidents also occur in world-wide. The objective of this article is to provide useful information about radiation accidents to the medical personnel. For this, I attempted to document the circumstances leading to the accident and the subsequent medical treatment and health consequences of the victims. Radiation accidents described in this article are Chernobyl nuclear power plant accident, nuclear weapon accident in bikini atoll, major industrial accidents (Ir-192 Peruvian accident, Ir-192 internal contamination accident in Korea, Tokaimura accident in Japan) and Cs-137 contamination accident in Brazil. After reviewing major radiation accidents, I summarized the lessons to be learned from these accidents and presented the helpful institutes that can offer useful helps when radiation accident occurs.
Academies and Institutes ; Accidents, Occupational ; Brazil ; Korea ; Nuclear Power Plants ; Radioactive Hazard Release* ; Weapons

OBJECTIVE: This study was conducted to evaluate the reliability of a questionnaire from an epidemiological study for nuclear power plants workers in Korea. METHODS: Among a total of 8,832 nuclear power plants workers who participated in the questionnaire survey, we selected 646 workers who repeatedly submitted the self-reported questionnaire. The reliability of the questionnaire for the categorical items was measured using kappa statistics and percentages of exact agreement, false disagreement and positive disagreement. Significance was evaluated for the continuous items by paired t-tests and intra-class correlation coefficients (ICCs). RESULTS: The questionnaire was observed to be highly reliable for the smoking history (kappa=0.85), which is known as an important confounding factor in assessing the cancer risk among radiation workers. Education level as a surrogate for the socio-economic status also appeared to be highly reliable with a kappa=0.89 and 95.09% of exact agreement. The history of alcohol drinking, medical exams and diseases showed more than moderately good agreement between the first and second responses (kappa>0.4). The self-reported values for physical measurements, the smoking period and smoking amount, and the period of alcohol drinking were highly correlated between the two responses (ICC>0.7). CONCLUSIONS: The questionnaire from an epidemiological study for nuclear power plants workers in Korea was found to be reliable for most items. To estimate the cancer or noncancer risk for nuclear power plants workers, we need to use the national database for incidence of diseases or death from diseases and the exposure history, and the medical records as well as the data collected from this study.
Alcohol Drinking ; Epidemiologic Studies ; Incidence ; Korea ; Medical Records ; Nuclear Power Plants ; Questionnaires ; Smoke ; Smoking

Radionuclides were deposited at forest areas in eastern parts of Japan following the Fukushima Daiichi Nuclear Power Plant incident in March 2011. Ectomycorrhizal (EM) fungi have important effects on radiocaesium dynamics in forest ecosystems. We examined the effect of colonization by the EM fungus Astraeus hygrometricus on the uptake of cesium (Cs) and potassium (K) by Pinus densiflora seedlings. Pine seedlings exhibited enhanced growth after the EM formation due to the colonization by A. hygrometricus. Additionally, the shoot Cs concentration increased after the EM formation when Cs was not added to the medium. This suggests that A. hygrometricus might be able to solubilize Cs fixed to soil particles. Moreover, the shoot K concentration increased significantly after the EM formation when Cs was added. However, there were no significant differences in the root K concentration between EM and non-EM seedlings. These results suggest that different mechanisms control the transfer of Cs and K from the root to the shoot of pine seedlings.
Cesium* ; Colon* ; Ecosystem ; Forests ; Fungi ; Japan ; Nuclear Power Plants ; Pinus* ; Potassium ; Radioisotopes ; Seedlings* ; Soil

OBJECTIVES: We conducted a meta-analysis to investigate the relationship between low external doses of ionizing radiation exposure and the risk of cancer mortality among nuclear power plant workers. METHODS: We searched MEDLINE using key words related to low dose and cancer risk. The selected articles were restricted to those written in English from 1990 to January 2009. We excluded those studies with no fit to the selection criteria and we included the cited references in published articles to minimize publication bias. Through this process, a total of 11 epidemiologic studies were finally included. RESULTS: We found significant decreased deaths from all cancers (SMR = 0.75, 95% CI = 0.62 - 0.90), all cancers excluding leukemia, solid cancer, mouth and pharynx, esophagus, stomach, rectum, liver and gallbladder, pancreas, lung, prostate, lymphopoietic and hematopoitic cancer. The findings of this meta-analysis were similar with those of the 15 Country Collaborative Study conducted by the International Agency for Research on Cancer. A publication bias was found only for liver and gallbladder cancer (p = 0.015). Heterogeneity was observed for all cancers, all cancers excluding leukemia, solid cancer, esophagus, colon and lung cancer. CONCLUSIONS: Our findings of low mortality for stomach, rectum, liver and gallbladder cancers may explained by the health worker effect. Yet further studies are needed to clarify the low SMR of cancers, for which there is no useful screening tool, in nuclear power plant workers.
Humans ; Neoplasms, Radiation-Induced/*mortality ; *Nuclear Power Plants ; Occupational Diseases/*mortality ; Occupational Exposure/adverse effects ; Radiation Monitoring