Seung-Cheol Hong

Effects on micronuclei formation of 60-Hz electromagnetic field exposure with ionizing radiation, hydrogen peroxide, or c-Myc overexpression

Purpose: Epidemiological studies have demonstrated a possible correlation between exposure to extremely low-frequency magnetic fields (ELF-MF) and cancer. However, this correlation has yet to be definitively confirmed by epidemiological studies. The principal objective of this study was to assess the effects of 60 Hz magnetic fields in a normal cell line system, and particularly in combination with various external factors, via micronucleus (MN) assays. Materials and methods: Mouse embryonic fibroblast NIH3T3 cells and human lung fibroblast WI-38 cells were exposed for 4 h to a 60 Hz, 1 mT uniform magnetic field with or without ionizing radiation (IR, 2 Gy), H2O2 (100 μM) and cellular myelocytomatosis oncogene (c-Myc) activation. Results: The results obtained showed no significant differences between the cells exposed to ELF-MF alone and the unexposed cells. Moreover, no synergistic effects were observed when ELF-MF was combined with IR, H2O2, and c-Myc activation. Conclusions: Our results demonstrate that ELF-MF did not enhance MN frequency by IR, H2O2 and c-Myc activation.

Evaluation of the Magnetic Field Exposure Level in 60 Hz High Voltage Transmission Lines Nearby Residential Area

In order to evaluate the magnetic field (MF) exposure level in residential areas near high voltage power lines, this research measured MF levels at 120 sites near high voltage transmission lines in the Busan region, Gwangju region, Daegu region and Changwon region from July to December, 2005, and compared and analyzed the efficiencies by measuring and applying the MF emission levels of underground cables and high voltage transmission lines. As a result of the investigation of the MF exposure level by the building usage, the average MF level of 17 locations at schools was that of 10 locations at hospitals that of 76 locations at apartments and that at kindergartens and infant houses . MF exposure was analysed as a function of distance from the source and the MF levels directly below a source were , those within 30 m were , while those within 50 m were , and within 100 m were . In order to determine the difference of MF levels by the actual distance from high voltage transmission line within the same building, the evaluation of the floor position and the MF level has shown that the MF levels were highest in the order of roof, 4th floor, 3rd floor, 2nd floor and 1st floor. Comparison of MF emission intensity of underground cables and high voltage transmission lines, has shown that underground cables have an 86-94% of reduction ratio in MF compared to high voltage transmission lines, thus demonstrating higher efficiency.

ELF-MF occupational exposure in die-casting and electroplating workers in Korea

A 24-h exposure assessment was performed in two groups of blue-collar workers from a die-casting plant and an electroplating plant to investigate levels of exposure to extremely low-frequency magnetic fields (ELF-MFs), using an EMDEX Lite (Enertech, USA) dosimeter. ELF-MF exposure of workers from the die-casting plant (arithmetic M ± SD 0.649 ± 1.343 µT) is higher than in electroplating workers (0.138 ± 0.045 µT). Higher ELF-MF exposure occurred among workers living in the same building as their workplace compared with that among other workers. This study suggests that ELF-MF exposure levels should be taken into consideration when providing dormitories for workers to minimize levels of residential ELF-MF exposure due to emissions from industrial plants. The study recommends that blue-collar workers should be made aware of measures to minimize their exposure to environmental agents such as ELF-MFs and electromagnetic fields during work, such as maintaining a safe distance between machines and avoiding undesirable behavior with equipment.