• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.78-85
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• 1995

Ornithine decarboxylase(ODC) is an indicate enzyme in carcinogenesis. We divided Sprague Dawley rats into six groups: control, electric field exposure, X-ray only irradiation, X-ray irradiation with electric field exposure group, Sr-90 injected group and Sr-90 and electric field complex exposure group. The ODC activity was measured in rat's bone marrow cell every week. The results were summarized as follows: The ODC activitied was increased in X-ray irradiated, Sr-90 injected and Sr-90 and electric field complex exposed group as compared with that of control(p<0.05). The ODC activity was increased comparing that of control neither in X-ray and electric field complex exposed group nor electric field only exposed group. This result suggests that the electric field doesn't have myeloid carcinogenicity and myeloid cancer incidence caused by ionized radiation is suppressed by electric field exposure.

• Journal of Environmental Health Sciences
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• v.20 no.3
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• pp.61-77
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• 1994

Sprague Dawley rats were exposed to electric fields (6,000 V, 10 kV/m, 30 min/day, 6 days per week) and injected strontium 90 (681 kbq/rat, one time) through abdominal cavity (strontium 90 and electric field complexed exposure group). In parallel, series with the electric field exposure only, strontium 90 injection only and control groups were run. Every group was consisted of 110 rats (55 male and 55 female). This animal experiment was performed from May to December in 1993. This results were conducted to investigate the effect of electric field for 11 weeks. The results are summarized as follows: 1. Ornithine decarboxylase (ODC) activity in rat's bone marrow cells: The ODC values was significantly increased in Sr$^{90}$ injection group and Sr$^{90}$ and electric field complexed exposure group as compared with that of control group (p<0.05). The ODC value was significantly decreased in electric field and Sr$^{90}$ complexed exposure group in comparison with Sr$^{90}$ injection group (p<0.05). The ODC values of electric field only exposure group was not different to that of control group (p>0.05). 2. The amount of Sr$^{90}$ accumulation in the femur, kidney and spleen:The accumulation amount of Sr$^{90}$ in the femur of Sr$^{90}$ injection group represented higher value than that of electric field and Sr$^{90}$ complexed exposure group (p<0.05). In the kidney and spleen, the difference between electric field and Sr$^{90}$ complexed exposure group and Sr$^{90}$ injection group wasn't observed. 3. The counts of white cells in blood of Sr9?injection group was decreased as compared with the value from control group and electric field and Sr$^{90}$ complexed exposure group (p<0.05). The rat's body weight, red blood cell counts and the weight data of liver, kidney and spleen did not show differences among four groups.

• 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).

• Journal of Environmental Health Sciences
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• v.26 no.3
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• pp.55-60
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• 2000

Wire codes, introduced by Wertheimer and Leeper, are interesting largely because several case-control studies have reported associations between them and certain types of cancers, including childhood leukemia. This paper is concerned with the reliability of wire codes as a surrogate for residential electric and magnetic field, divided into four categories based on the electrical wiring within 40m of homes. To examine the correlation between spot measurements and wire codes, EMF was measured by using HI-3604 and classified by wire codes. The correlation between long-transformed RMS of magnetic field and wire codes was 0.81. But the correlation between log-transformed RMS of electric field and wire codes was 0.27. The results led us to determine a four category from of the Wertheimer and Leeper code that 1) may be useful in domestic epidemiological studies and 2) is not suitable for electric field exposure. Thus, the critical point of exposure assessment in residential magnetic field is to classify a wire code precisely.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.3-5
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• 1997

The relation between electric current and magnetic field under three overhead transmission lines being operated was studied. It was examined for a difference each other in comparison with calculated value and measured value for current, magnetic field. With magnetic field equations made out, The magnetic field distribution around transmission lines had made to figure out with easy by load electric current value. Additionally, we are going to describe the distribution curve of magnetic exposure volume for KEPCO's T/L.

• Journal of electromagnetic engineering and science
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• v.15 no.3
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• pp.134-141
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• 2015

The effect of a 60 Hz time-varying electric field was studied using a facing-electrode device (FED) and a coplanar-electrode device (CED) for further investigation of the genotoxicity of 60 Hz time-varying magnetic field (MF) from preceding research. Neither a single 30-minute exposure to the CED or to the FED had any obvious biological effects such as DNA double strand break (DSB) and apoptosis in cancerous SCC25, and HeLa cells, normal primary fibroblast IMR90 cells, while exposures of 60 Hz time-varying MF led to DNA damage with induced electric fields much smaller than those used in this experiment. Nor did repetitive exposures of three days or a continuous exposure of up to 144 hours with the CED induce any DNA damage or apoptosis in either HeLa or IMR90 cells. These results imply that the solitary electric field produced by time-varying MF is not a major cause of DSBs or apoptosis in cancer or normal cells.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.5
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• pp.687-697
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• 1998

In spite of increasing public concern about the human exposure to electric and magnetic fields(EMFs), there is little information about the EMF levels in the vicinity of power facilities and of home appliances. To provide such information, a nationwide survey for EMFs near overhead transmission lines has been conducted. The median values of the electric fields and magnetic fields of 153 transmission lines were 0.47 kV/m and 11.6 mG, respectively. The maximum values were 3.16 kV/m and 125 mG. These were low values in comparison with any EMF guidelines or standards of advanced contries. Measurements of the magnetic fields of typical home appliances and daily human exposure records have been also conducted. These magnetic field values were comparable to those of the transmission lines.

• Journal of Magnetics
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• v.19 no.2
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• pp.174-180
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• 2014

In this paper, a new and simple method is proposed to quickly estimate the induced electric field in the human child exposed to a 100 kHz-10 MHz magnetic field, for the sake of electromagnetic field (EMF) safety assessment. The quasi-static finite-difference time-domain (FDTD) method is used to calculate the induced electric fields in high resolution 3D human child models with various body size parameters, in order to derive the correction factor for the estimation equation. The calculations are repeated for various frequencies and incident angles of the magnetic field. Based on these calculation results, a new and simple estimation equation for the 99th percentile value of the body electric field is derived that depends on the body size parameters, and the incident magnetic field. The estimation errors were equal to or less than 5.1%, for all cases considered.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.132-140
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• 2009

For human exposure assessment of UHF RFID system, electric field distribution of commercial 900[MHz] RFID antenna was measured and analyzed. Also, SAR(Specific Absorption Rate) of RFID antenna was calculated by simulation, and compared with basic restrictions in EMF guidelines. For EMF exposure assessment according to EN and IEC standards, the reader was tested for the normal operation, and electric field from RFID antenna was measured at various distances and angles. For electric field measurement, narrow band isotropic electric field probe was used, and the measurements were made at 0.3, 0.5, 1.0 and 1.5[m] for every 15[$^{\circ}$] angle from the antenna. Also, the rationale for measurement distance in EN and IEC standards is analyzed from the measurement results.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1139-1146
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• 2007

Cultures of Saccharomyces cerevisiae were subjected to the effect of PEF (pulse electric field) and a source of selenium. The culture period after which yeast cells were subjected to PEF treatment was optimized, as was the duration of the exposure. Optimization of the nutrient medium composition in S. cerevisiae cultures resulted in an over 1.8-fold increase in selenium accumulation with relation to cultures on the initial substrate. Optimization of the pH value and of culture duration resulted in selenium accumulation increase by approximately 78%. A significant correlation was found between the accumulation of selenium in yeast cells and its concentration in the culture substrate. The highest accumulation of selenium in the biomass of yeast, approx. $240\;{\mu}g/g$ d.m., was obtained after 15-min exposure to PEF on a 20-h culture. An approx. 50% higher content of selenium in cells was recorded, as compared with the control culture without the application of PEF.