• Journal of the Korean Society of Radiology
• /
• v.11 no.7
• /
• pp.555-564
• /
• 2017

The current radiation risk assessment for occupational exposure is based on the measured exposure dose and health checkups of workers. This people-centered risk assessment may occur errors because absence of using personal dosimeter or unrelated health symptoms of individuals lead to difficulties in obtaining accurate data from workers. In addition, although the established legal upper dose limit was used as a reference for the assessment, it does not imply that this limit is the optimal dose of radiation workers should get; ALARA principle should always be appreciated. Therefore, a new risk assessment model that can take account of all the important factors and implement optimization of radiation protection is required at the national level. In this paper, based on the KOSHA Risk Assessment, we studied on the workplace-centered risk assessment model for radiation field rather than the people-centered. The result of the study derived a right model for radiation field through the analysis of the risk assessment methods in various fields and also found data acquisition methods and procedures for applying to the model. Multidimensional model centering on the workplace will enables more accurate radiation risk assessment by using a risk index and radar plot, and consequently contribute to the efficient worker management, preemptive worker protection and implementation of optimization of radiation protection.

• Journal of Nutrition and Health
• /
• v.41 no.5
• /
• pp.402-413
• /
• 2008

This study was performed to investigate Apolipoprotein E phenotypes and the relationship among lipid levels, nutrient intakes, lifestyles and risk factors between subjects with and without hyperlipidemic risk. The data were collected from 675 industrial male workers who had completed annual medical examination. Compared to the normal group, the hyperlipidemic risk group in Apo E3 and E4 had significantly higher BMI (p < 0.05) and showed significantly higher body fat (%), waist circumference and WHR in all types of Apo E (p < 0.05). In addition, the hyperlipidemic risk group had significantly higher total cholesterol, LDL-cholesterol, triglyceride and AI than the normal group in all types of Apo E (p < 0.05). Intakes of protein, calcium, phosphorus, iron, vitamin A, vitamin B1, vitamin B2, vitamin C and niacin in Apo E3 were significantly lower in the hyperlipidemic risk group than in the normal group (p < 0.05). In the logistic regression analysis, after adjustment for other factors, Apo E2 + E4, waist and WHR were the significant risk factors associated with hyperlipidemia, but protein intakes were associated with significantly lower risks of hyperlipidemia (p < 0.05). In conclusion, genetic factor (Apo E2 or Apo E4), anthropometric index and nutrient intake seem to influence hyperlidemic risk. Further studies and efforts will be needed to evaluate the independent relationships among hyperlipidemic risk factors.

• Korean Journal of Environmental Biology
• /
• v.19 no.1
• /
• pp.19-24
• /
• 2001

Agricultural pesticides may cause certain biological risks since they are widely used to eradicate pests. Agricultural disasters may arise even from the possibility of their synergistic interaction with other harmful enviromnetal factors. The effect of pesticide on radiation-induced DNA damage in human blood lymphocytes was evaluated by the single cell gel electrophoresis (SCGE) assay. The lymphocytes, with or without pretreatment of the pesticide, were exposed to 0-2.0 Gy of $^60 CO$ gamma ray. Significantly increased tail moment, which was a marker of DNA strand breaks in SCGE assay, showed an excellent dose-response relationship. The present study confirms that the pesticide has the cytotoxic effect on lymphocytes and that it shows the synergistic interaction with radiation on DNA damage as well. The results may have a role of providing biological information necessary for the prevention of environmental disaster.

• Nuclear Engineering and Technology
• /
• v.45 no.1
• /
• pp.1-12
• /
• 2013

This paper describes the radiation doses to human and non-human biota in the Republic of Korea, as a result of the Fukushima nuclear accident. By using the measured airborne activity and ground deposition, the effective and thyroid doses of five human age groups (infant, 5 years, 10 years, 15 years and adult) were estimated by the ECOSYS code, and the whole body absorbed dose rate of the eight Korean reference animals and plants (RAPs) was estimated by the K-BIOTA (the Korean computer code to assess the risk of radioactivity to wildlife). The first-year effective and thyroid human doses ranged from 5.7E-5 mSv in the infant group to 2.0E-4 mSv in the 5 years group, and from 5.0E-4 mSv in the infant group to 3.4E-3 mSv in the 5 years group, respectively. The life-time (70 years) effective and thyroid human doses ranged from 1.5E-4 mSv in the infant group to 3.0E-4 mSv in the 5 years group, and from 6.0E-4 mSv in the infant group to 3.5E-3 mSv in the 5 years group, respectively. The estimated maximum whole body absorbed dose rate to the Korean RAPs was 6.7E-7 mGy/d for a snake living in soil (terrestrial biota), and 2.0E-5 mGy/d for freshwater fish (aquatic biota), both of which were far less than the generic dose criteria to protect biota from ionizing radiation. Also, the screening level assessment for ERICA's (Environmental Risks from Ionizing Contaminants: Assessments and management) limiting organisms showed that the risk quotient (RQ) for the estimated maximum soil and water activity was significantly less than unity for both the terrestrial and freshwater organisms. Conclusively, the radiological risk of the radioactivity released into the environment by the Fukushima nuclear accident to the public and the non-human biota in the republic of Korea is considered negligible.

• Nuclear Engineering and Technology
• /
• v.54 no.4
• /
• pp.1431-1438
• /
• 2022

In this study, natural radioactivity concentrations and dosimetric values of fly ash samples were evaluated for the landfill area of the coal-fired power plant (CFPP) complex at Binh Thuan, Vietnam. The average activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K were 93, 77, 92 and 938 Bq kg^-1, respectively. The average results for radon dose, indoor external, internal, and total effective dose equivalent (TEDE) were 5.27, 1.22, 0.16, and 6.65 mSv y^-1, respectively. The average emanation fraction for fly ash were 0.028. The excess lifetime cancer risks (ELCR) were recorded as 20.30×10^-3, 4.26×10^-3, 0.62×10^-3, and 25.61×10^-3 for radon, indoor, outdoor exposures, and total ELCR, respectively. The results indicated that the cover of shielding materials above the landfill area significantly decreased the gamma radiation from the ash and slag in the ascending order: Zeolite < PVC < Soil < Concrete. Total dose of all radionuclides in the landfill site reached its peak at 19.8 years. The obtained data are useful for evaluation of radiation safety when fly ash is used for building material as well as the radiation risk and the overload of the landfill area from operation of these plants for population and workers.

• Journal of Radiation Protection and Research
• /
• v.48 no.2
• /
• pp.84-89
• /
• 2023

Background: Food consumption is one of the most important routes for radionuclide intake for the public; therefore, there is the need to have a comprehensive understanding of the amount of radioactivity in food products. Consumption of radionuclide-contaminated food could increase potential health risks associated with exposure to radiation such as cancers. The present study aims to determine radioactivity levels in some food products (milk, rice, sugar, and wheat flour) consumed in Mali and to evaluate the radiological effect on the public health from these radionuclides. Materials and Methods: The health impact due to ingestion of radionuclides from these foods was evaluated by the determination of activity concentration of radionuclides ²³⁸U, ²³²Th, ⁴⁰K, and ¹³⁷Cs using gamma spectrometry system with high-purity germanium detector and radiological hazards index in 16 samples collected in some markets, mall, and shops of Bamako-Mali. Results and Discussion: The average activity concentrations were 9.8±0.6 Bq/kg for ²³⁸U, 8.7±0.5 Bq/kg for ²³²Th, 162.9±7.9 Bq/kg for ⁴⁰K, and 0.0035±0.0005 Bq/kg for ¹³⁷Cs. The mean values of radiological hazard parameters such as annual committed effective dose, internal hazard index, and risk assessment from this work were within the dose criteria limits given by international organizations (International Commission on Radiological Protection and United Nations Scientific Committee on the Effects of Atomic Radiation) and national standards. Conclusion: The results show low public exposure to radioactivity and associated radiological impact on public health. Nevertheless, this study stipulates vital data for future research and regulatory authorities in Mali.

• Journal of the Korean Society of Safety
• /
• v.31 no.5
• /
• pp.22-27
• /
• 2016

The Electrostatic Charge Prevention Technology is a core factor that highly influences the yield of Ultra High Resolution Flat Panel Display and high-integrated semiconductor manufacturing processes. The corona or x-ray ionizations are commonly used in order to eliminate static charges during manufacturing processes. To develop such a revolutionary x-ray ionizer that is free of x-ray radiation and has function to control the volume of ion formation simultaneously is a goal of this research and it absolutely overcomes the current risks of x-ray ionization. Under the International Commission on Radiological Protection, it must have a leakage radiation level that should be lower than a recommended level that is $1{\mu}Sv/hour$. In this research, the new generation of x-ray ionizer can easily control both the volume of ion formation and the leakage radiation level at the same time. In the research, the test constraints were set and the descriptions are as below; First, In order not to leak x-ray radiation while testing, the shielding box was fully installed around the test equipment area. Second, Implement the metallic Ring Electrode along a tube window and applied zero to ${\pm}8kV$ with respect to manage the positive and negative ions formation. Lastly, the ion duty ratio was able to be controlled in different test set-ups along with a free x-ray leakage through the metallic Ring Electrode. In the result of experiment, the maximum x-ray radiation leakage was $0.2{\mu}Sv/h$. These outcome is lower than the ICRP 103 recommended value, which is $1{\mu}Sv/h$. When applying voltage to the metallic ring electrode, the positive decay time was 2.18s at the distance of 300 mm and its slope was 0.272. In addition, the negative decay time was 2.1s at the distance of 300 mm and its slope was 0.262. At the distance of 200 mm, the positive decay time was 2.29s and its slope was 0.286. The negative decay time was 2.35s and its slope was 0.293. At the distance of 100 mm, the positive decay time was 2.71s and its slope was 0.338. The negative decay time was 3.07s and its slope was 0.383. According to these research, the observation was shown that these new concept of ionizer is able to minimize the leakage radiation level and to control the positive and negative ion duty ratio while ionization.

• The Journal of the Korea Contents Association
• /
• v.14 no.1
• /
• pp.356-363
• /
• 2014

Recently pediatric CT has been performed by reduced dose according to tube current modulation이라고, this fact has a possibility more reduce a dose because of strong affect depend on tube current modulation. Almost all MDCT snow show and allow storage of the volume CT dose index (CTDIvol), dose length product (DLP), and effective dose estimations on dose reports, which are essential to assess patient radiation exposure and risks. To decrease these radiation exposure risks, the principles of justification and optimization should be followed. justification means that the examination must be medically indicated and useful. Results is using tube current modulation이라고 tend to the lower kV, the lower effective dose. In case of use a low dose CT protocol, we found a relatively lower effective dose than using tube current modulation. Average effective dose of our studies(brain, chest, abdomen-pelvis) less than 47%, 13.8%, 25.7% of germany reference dose, and 55.7%, 10.2%, 43.6% of UK(United Kingdom) reference dose respectively. when performed examination for reduced dose, we must use tube current modulation and low dose CT protocol including body-weight based tube current adaption.

• Journal of Radiation Protection and Research
• /
• v.24 no.3
• /
• pp.171-184
• /
• 1999

In this paper, using statistical theory the basic concepts and the formulars of lower limit of detection were deasribed. Assuming that risks of 5% are acceptable (95% confidence level), lower limits of detection were calculated on the measuring apparatus for alpha, beta and gamma nuclides. Also, on the basis concepts of lower limit of detection, the MDA values were calculated for the radionuclides detected easily in the environment. These results make it possible to evaluate confidence limits on the radioanalytical results in the environmental sample.

• Korean Journal of Digital Imaging in Medicine
• /
• v.13 no.3
• /
• pp.105-109
• /
• 2011

With the development of medical technologies and the growth of household incomes, most of the people have become to be interested in health as it leads to significant early detection and cure of diseases. However the pattern of disease becomes diverse and it makes the imaging diagnosis department crowded with many patients. Therefore the opportunistic infection could be serious there. The hospital becomes the place which provides high risks of infection danger but it is true that the opportunistic infection of the hospital employees is not still recognized well. The imaging diagnosis department has developed a lot but it becomes the medium of secondary infection of patients and employees. So this study analyzesthe status of bacteria infection of the examination table, the handle of diagnostic equipment and the hands of radiation staffs in imaging diagnosis department of the general hospitals and individual ones. And the result shows that some bacteria were found even though it's little. We are trying to make the hospitals to be free of secondary infection securing safety measure to prevent the secondaryinfection from occurring to patients and hospital employees.