• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.2
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• pp.98-104
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• 2001

전자장(EMF)에 의한 생체영향에 관한 연구에 있어서 사람에게 직접 실험하는 것은 윤리적으로나 객관적으로 제한점이 많다. 따라서 생체에 대한 유무해성을 파악하기 위해 in vitro 나 인강과 유사한 동물실험을 통해 그 영향을 조사하고 그 결과를 생체와 연관지어 예측하는 것은 기본 단계이다. 본 연구에서는 세포 및 동물실험을 위한 직류 및 교류(ELF) 자기장 발생장치를 헬름홀츠 코일과 솔레노이드 코일을 이용하여 구성하였으며, 실험시 중요한 자계의 균일도를 각각 비교하였다. 또한 발생자계의 패턴을 DC, 정현파, 구형파, 삼각파, 펄스 형태로 변화 시 킬수 있도록 컨드롤러를 내장시켰다. 발생 자계의 크기는 직류에서 최대 100 Gauss(10mT), 60Hz 정현파에 대해서는 최대 Gauss(2mT)의 출력이 가능하도록 설계하였다.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.1
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• pp.42-51
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• 2012

Objectives: To compare the exposure level of extremely low frequency (ELF) magnetic fields among semiconductor workers, shipyard welders and office workers. Methods: To measure the ELF magnetic field concentration, EMDEX LITE (Enertech, USA) were used and monitored for eight hours continuously. Five companies handling the electric and magnetic field (EMF) source were investigated, which the exposure groups were classified into three groups: semiconductor workers, welders, and office workers. Welder group was chosen as a high exposed group and office group as a low exposed group. Results: The arithmetic mean (${\pm}SD$) and geometric mean (GSD) of personal exposure level of semiconductor workers were 0.73 (${\pm}1.33$) ${\mu}T$, 0.43 (2.88) ${\mu}T$, respectively. The ceiling value ranged between 0.18 and 123.2 ${\mu}T$. Welders were exposed high with the arithmetic mean value of 3.46 (${\pm}\;13.46$) ${\mu}T$ and geometric mean value of 0.45 (4.70) ${\mu}T$, respectively, and ceiling value range of 75.5~129.6 ${\mu}T$. The exposure levels of office workers were low compared to other exposed groups; the arithmetic mean 0.05 (${\pm}0.13$) ${\mu}T$, geometric mean 0.03 (2.38) ${\mu}T$ and ceiling value range 0.37~3.35 ${\mu}T$. This study revealed statistically significant differences of the mean ELF magnetic field exposure doses among three groups (p < 0.01). Conclusions: The average ELF magnetic field exposure doses of semiconductor workers were much higher than those of office workers in control group, but were lower than those of welders in high exposure group.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 1999.07a
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• pp.117-129
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• 1999

Acute effects of locally applied of static magnetic field (SMF) and extremely low frequency electromagnetic field(ELF-EMF) to the cutaneous tissue within a rabbit ear chamber (REC)were evaluated under conscious conditions. Rabbits with the REC were subjected to intravital microscopical investigation by use of microphotoelectric plethysmography(MPPG). There was no dose-response relationship between the extent of vasomotion changes and frequencies(0,20,50, 100Hz)or power levels (1, 5, 10, 25, 50, 100, 200 mT). Under low vascular tone the both fields induce vasodilatation. The effects of SMF (1 mT) on the cutaneous microcirculatory system induced the vasodilatation with enhanced vasomotion under nor-adrenaline-induced high vascular tone as well as the vasoconstriction with reduced vasomotion under acetylcholine-induced low vascular tone. This suggests that the SMF can modulate vascular tone due to the modification of vasomotion biphasically in the cutaneous tissue.

• Journal of the Korean Society of Safety
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• v.36 no.4
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• pp.20-28
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• 2021

With an increase in the commercialization of electricity, and the development of advanced and large electric devices and various wireless radio wave services, concerns over the effects of electromagnetic fields on human health have increased. Accordingly, the World Health Organization encouraged the development of international standards by establishing the 'International Electromagnetic Fields Project' in 1996 based on studies on the harmful effects of electromagnetic fields on the human body. Moreover, the National Institute of Environmental Health Sciences (NIEHS) classified electromagnetic fields as possible carcinogens under Group 2B category, even though they have been found to have a weak correlation with those effects on human health. Mid-to-large-sized electric facilities used at industrial sites mostly adopt a commercial frequency of 60 Hz, and workers handling these facilities are exposed to such extremely low frequency (ELF) fields for a long time. A previous study suggested that exposure to ELF electromagnetic fields with frequency ranges from 0 to 300 Hz, even for a short time, at densities higher than 100 μT may have harmful effects on human body as it affects the activation of nerve cells in the central nervous system by inducing an electric field and current and stimulating muscles and the nervous system in the body. Such studies, however, focused on home appliances used by ordinary people, and research on facilities utilizing high-capacity current and operated by workers at industrial sites is lacking. Therefore, in this study, a 3000 kilowatt generator, which is a high-capacity electric facility employed at industrial sites, was investigated, and the size of the magnetic fields generated during its no-load and high-load operations per distance to produce a map was measured to reveal spots deemed hazardous according to domestic and international exposure standards. The findings of this study is expected to alleviate workers' anxiety about the harmful effects of magnetic fields on their body and to minimize the level of exposure during operations.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.376-383
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• 2012

A number of scientific researches are currently being conducted on the potential health hazards of power frequency electric and magnetic field (EMF). There exists a non-objective and psychological belief that they are harmful, although no scientific and objective proof of such exists. This possible health risk from ELF magnetic field (MF) exposure, especially for children under 17 years of age, is currently one of Korea's most highly contested social issues. Therefore, to assess the magnetic field exposure levels of those children in their general living environments, the personal MF exposure levels of 436 subjects were measured for about 6 years using government funding. Using the measured database, estimation formulas were developed to predict personal MF exposure levels. These formulas can serve as valuable tools in estimating 24-hour personal MF exposure levels without directly measuring the exposure. Three types of estimation formulas were developed by applying evolutionary computation methods such as genetic algorithm (GA) and genetic programming (GP). After tuning the database, the final three formulas with the smallest estimation error were selected, where the target estimation error was approximately 0.03 ${\mu}T$. The seven parameters of each of these three formulas are gender (G), age (A), house type (H), house size (HS), distance between the subject's residence and a power line (RD), power line voltage class (KV), and the usage conditions of electric appliances (RULE).

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.167-167
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• 2004

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.2-4
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• 2007

대다수 국민들이 많은 불안감을 갖고 있는 극저주파전자계(ELF EMF)의 건강영향에 대한 논쟁배경, 전자파와 전자계의 특성 구분, 국민의 전자계에 대한 인식도 조사, 전력시설 건설반대 민원현황을 분석한다. 또한 전자계 건강영향 동물실험 결과, 국내 전력시설별 전자계의 노출현황 둥을 분석하고, 세계보건기구(WHO)의 국제권고기준에 따라 국내 전력시설의 전자계 안전성에 대하여 논하고자 한다.

• Journal of Environmental Health Sciences
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• v.38 no.1
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• pp.18-30
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• 2012

Objectives: The purpose of this study was to estimate the exposure level to extremely low frequency-magnetic fields (ELF-MF) among a selected Korean population using 24-hour personal exposure measurement. Methods: Participants were randomly selected for the measurement of MF exposure under the assumption that the subjects are representative of the overall Korean population. Levels of personal exposure to MF were measured according to the subject's daily activities. Results: The 24-hour time-weighted average (TWA) of 250 participants was $1.56{\pm}4.56$ mG (GM, GSD: 0.79, 2.46 mG). Personal exposure levels for females were higher than for males. The highest personal exposure level was shown in the age group between 20-60 years old. Personal exposure levels according to job category were higher for the non-occupational group than for the occupational group. Conclusions: Our results showed MF exposure exceeding 2 mG per day among 11.3% of the Korean population, indicating a somewhat higher percentage compared to the EMF RAPID Program's results for the U.S population.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.6
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• pp.526-534
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• 2009

The magnetic field of the extremely low frequency that occurs in the substation facilities was surveyed to present ways to broaden understanding of the magnetic field characteristics. We have investigated the level of the magnetic fields in the substation areas and control rooms of 25 substations in the metropolitan area in accordance with the measurement method of IEC CISPR(IEC/TC106 PT 62110). We propose objective and reliable policy approaches such as the electromagnetic field certification system to more accurately understand the property of magnetic field.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.276-281
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• 2010

In this paper, an electromagnetic induction on a telecommunication line by the distribution line of a power provision system or a feeder line of an electrified railway system has been verified through experiments. The basic cause of induction occurrence by these practical power provision systems is the returning current through the earth. This principle has been confirmed by the experiments documented in this paper which implemented these mechanisms to incur an induction. Experimental methods were used to produce the returning current through the earth. The experiment to find a relationship between inducing strength and the distance between the two phase lines in a power provision line has also been included to confirm that, when the distance is enlarged, the induction effect increases as the cross-nullification effect of magnetic fluxes decreases. An experiment for the existence of a shielding effect by another conduction length material has been addedas a protection measure against the induction.