• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1017-1023
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• 2003

Recently, the use an electric apparatus has brought into concerns about health risks from exposure to electromagnetic fields. During the last 2 decades, a number of epidemiological studies have explored the association between childhood leukaemia and residential exposure to power-frequency electromagnetic fields. Several studies have suggested that there is a small excess leukaemia risk with magnetic field exposure above 2 mG. A number of governmental and international organizations have developed exposure gudelines. The most rigid regulation with exposure levels for the elementary school and hospital has been enacted by Switzerland. Although there is no convincing supportive laboratory evidence, and the absence of a plausible biological mechanism of disease causation limits, governments are increasingly called on to adopt precautionary approaches to regulating electromagnetic field exposures. The government would need to establish the policy for electromagnetic fields and continually to be concerned about possible health risks from exposure to electromagnetic fields.

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.506-514
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• 2006

The objectives of this study were to evaluate personal exposure estimated using a time activity pattern and microenvironmental model. The study was carried out for 44 children attending a primary school nearby the lines (school A) and 125 children attending a school away from 154 kV power lines (school B). For children attending school A, the estimated personal level was a little weak correlated with the measured level($Pearson\;r\;=0.34{\sim}0.35$). For children attending school B, the correlation was very low ($Pearson\;r\;=\;0.09{\sim}0.16$) using the TW A Model II, otherwise, TWA Model II-I which considered the average residential MF level according to the distance from the power line and home explained $39{\sim}53%$ of the correlation in MF personal exposures. The estimated personal exposure level was very well represented by the measured exposure level using TWA Model II-2 which consisted on spot and 24 h stationary measurements at subject's home ($Pearson\;r\;=\;0.65{\sim}0.85$). In conclusion, personal magnetic field expsoure estimated using a TWA Model II-2 should be provided for a reasonable estimate of measured exposure in schoolchildren living near the power line.

• Journal of Radiation Protection and Research
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• v.47 no.2
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• pp.93-98
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• 2022

Background: This study aims to derive the characteristics of each work type for industrial radiography based on empirical evidence through expert advice and a survey of radiation workers of various types of industrial radiography. Materials and Methods: According to a Korean report, work types of industrial radiography are classified into indoor tests, underground pipe tests, tests in a shielded room (radiographic testing [RT] room test), outdoor field tests, and outdoor large structure tests. For each work type, exposure geometry and radiation sources were mainly identified through the expert advice and workers' survey as reliable empirical evidence. Results and Discussion: The expert advice and survey results were consistent as the proportion of the work types were high in the order of RT room test, outdoor large structure test, underground pipe test, outdoor field test, and indoor test. The outdoor large structure test is the highest exposure risk work type in the industrial radiography. In most types of industrial radiography, radiation workers generally used ¹⁹²Ir as the main source. In the results of the survey, the portion of sources was high in the order of ¹⁹²Ir, X-ray generator, ⁶⁰Co, and ⁷⁵Se. As the exposure geometry, the antero-posterior geometry is dominant, and the rotational and isotropic geometry should be also considered with the work type. Conclusion: In this study, through expert advice and a survey, the external exposure characteristics for each work type of industrial radiography workers were derived. This information will be used in the reconstruction of organ dose for health effects assessment of Korean radiation workers.

• The Journal of the Korean dental association
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• v.52 no.3
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• pp.132-138
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• 2014

The emergence of Cone Beam Computed Tomography(CBCT) in the late 1990s represented an innovative advancement in the field of dental and maxillofacial radiology because it greatly reduced the radiation exposure to patients and offered 3D images easily. The 3D information generated by this technique brings the potential of improved diagnosis and treatment planning for a wide range of clinical applications in dentistry. The use of CBCT includes diagnosis and surgical assessment of the orofacial hard tissue lesions, dental implant treatment planning and postoperative evaluation, TMJ assessment, diagnosis of craniofacial fracture, orthodontics, endodontics, and so on. All CBCT examinations should be justified on an individualized needs. The clinical benefits to the patient for each CBCT scan must outweigh the potential risks associated with exposure to ionizing radiation. CBCT scans should be taken with initially obtained medical and dental histories of patients and a close clinical examination. CBCT should be considered as an imaging alternative of other conventional radiography in cases where the anatomical structures of interest may not be seen. The smallest possible field of view(FOV) and the lowest setting of tube current and scan time should be chosen, and the entire images scanned should be interpreted by a qualified expert.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.2
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• pp.140-149
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• 2000

In industrial field, there are several operations where a horizontal unidirectional airflow is used to control airborne contaminants. When a worker is immersed in a uniform freestream, a recirculating airflow can be created downstream of the worker by the phenomenon of boundary layer seperation. If the contaminant source and the breathing zone are within this near-wake region, high exposure may occur. The investigation for the effect of contaminant source location on worker exposure was performed by using CFD(Computational Fluid Dynamics). The airflow field was numerically calculated by assuming a steady flow and using the standard $k-{\varepsilon}$ turbulence model. As the results were compared with experimental data, the applicability of CFD was successfully verified. Subsequently, the breathing zone concentrations of the worker were predicted and compared with experimental data. The effects of contaminant density and turbulence intensity of freestream on worker exposure were evaluated.

• Biomolecules & Therapeutics
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• v.22 no.6
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• pp.570-576
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• 2014

Studies have demonstrated that electromagnetic waves, as the one of the most important physical factors, may alter cognitive and non-cognitive behaviors, depending on the frequency and energy. Moreover, non-ionizing radiation of low energy waves e.g. very low frequency waves could alter this phenomenon via alterations in neurotransmitters and neurohormones. In this study, short, medium, and long-term exposure to the extremely low frequency electromagnetic field (ELF-EMF) (1 and 5 Hz radiation) on behavioral, hormonal, and metabolic changes in male Wistar rats (250 g) were studied. In addition, changes in plasma concentrations for two main stress hormones, noradrenaline and adrenocorticotropic hormone (ACTH) were evaluated. ELF-EMF exposure did not alter body weight, and food and water intake. Plasma glucose level was increased and decreased in the groups which exposed to the 5 and 1Hz wave, respectively. Plasma ACTH concentration increased in both using frequencies, whereas noradrenaline concentration showed overall reduction. At last, numbers of rearing, sniffing, locomotor activity was increased in group receiving 5 Hz wave over the time. In conclusions, these data showed that the effects of 1 and 5 Hz on the hormonal, metabolic and stress-like behaviors may be different. Moreover, the influence of waves on stress system is depending on time of exposure.

• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.270-277
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• 2023

Exposure to ionizing radiation induces free radicals in human nails. These free radicals generate a radiation-induced signal (RIS) in electron paramagnetic resonance (EPR) spectroscopy. Compared with the RIS of tooth enamel samples, that in human nails is more affected by moisture and heat, but has the advantages of being sensitive to radiation and easy to collect. The fingernail as a biological sample is applicable in retrospective dosimetry in cases of localized hand exposure accidents. In this study, the dosimetric characteristics of fingernails were analyzed in fingernail clippings collected from Korean donors. The dose response, fading of radiation-induced and mechanically induced signals, treatment method for evaluation of background signal, minimum detectable dose, and minimum detectable mass were investigated to propose a fingernail-EPR dosimetry protocol. In addition, to validate the practicality of the protocol, blind and field experiments were performed in the laboratory and a non-destructive testing facility. The relative biases in the dose assessment result of the blind and field experiments were 8.43% and 21.68% on average between the reference and reconstructed doses. The results of this study suggest that fingernail-EPR dosimetry can be a useful method for the application of retrospective dosimetry in cases of radiological accidents.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.1
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• pp.55-61
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• 2011

Cyclonite is a white powder and is very explosive. It can cause seizures (a problem of the nervous system) in human and animals when large amounts are inhaled or eaten. Research papers for workers exposure assesment of the cyclonite are very a few in the world. A field study was conducted at explosive compounds and bomb manufacturing companies to evaluate workers exposure to cyclonite. The airborne average concentration of cyclonite in explosive compounds manufacturing company was $4.10{\mu}g/m^3$(range: ND - $59.92{\mu}g/m^3$), and that of cyclonite in bomb manufacturing company was $31.49{\mu}g/m^3$(range: ND - $291.41{\mu}g/m^3$). Package process and assembly process in both companies were considered the high potential of exposure to cyclonite. Even though all airborne concentrations of cyclonite were lower than occupational exposure standard (MOEL: $500{\mu}g/m^3$), exposure to cyclonite can also occur through dermal contact during manufacture, handling, and clean-up of cyclonite. So control measures for protecting skin absorption of cyclonite were needed for preventing adverse health effect by cyclonite exposure.

• Safety and Health at Work
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• v.4 no.3
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• pp.136-141
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• 2013

Background: Occupational end users of pesticides may experience bodily absorption of the pesticide products they use, risking possible health effects. The purpose of this paper is to provide a guide for researchers, practitioners, and policy makers working in the field of agricultural health or other areas where occupational end use of pesticides and exposure issues are of interest. Methods: This paper characterizes the health effects of pesticide exposure, jobs associated with pesticide use, pesticide-related tasks, absorption of pesticides through the skin, and the use of personal protective equipment (PPE) for reducing exposure. Conclusions: Although international and national efforts to reduce pesticide exposure through regulatory means should continue, it is difficult in the agricultural sector to implement engineering or system controls. It is clear that use of PPE does reduce dermal pesticide exposure but compliance among the majority of occupationally exposed pesticide end users appears to be poor. More research is needed on higher-order controls to reduce pesticide exposure and to understand the reasons for poor compliance with PPE and identify effective training methods.

• Journal of Magnetics
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• v.21 no.2
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• pp.255-260
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• 2016

The health effects of environmental and occupational exposure to steady magnetic fields is a matter of concern. The aim of this study was to evaluate the hematologic effects of exposure to steady magnetic fields at the electrolysis unit of a Copper complex. The population under study was the workers of the electrolysis unit of the copper refinery. The average steady magnetic field in the exposure group was 2.5 mT. The blood indices of workers exposure to steady magnetic fields after adjusting for confounders showed decreased white blood cells (except neutrophils) and increase in the number and volume of platelets. Red blood cells did not show any significant difference. Exposure to steady magnetic fields even in proposed safe limits may have hematologic effects on humans. There is a necessity for more research about the safe doses of exposure to magnetic fields.