Electromagnetic fields of all frequencies represent one of the most common and fastest growing environmental influences, about which anxiety and speculation are spreading. All populations are now exposed to varying degrees of electromagnetic field, and the levels will continue to increase as technology advances. The objectives of this study were to measure and analyze emitting characteristics of extremely low frequency electromagnetic field at micro-environments. We measured magnetic field at microenvironments such as home, school, educational institute, internet pc game room for children attending the primary school. The range of time weighted average (TWA) of 60 Hz EMF in micro-environment were 0.26∼ 7.62 mG and the highest TWA 7.62 mG was measured in PC room possessed more than 50 computers. We will measure personal exposure levels of primary students and analyze correlation between major micro-environments and personal exposure level.

The present study investigated the hypothesis that a extremely low frequency magnetic field (ELF-MF) partially suppresses the synthesis of human growth hormone (HGH) in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 μT, whereas the levels for the primary schoolchildren living away from overhead transmission power line was 0.05 μT. From simple analyses, the mean growth hormone levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, and statistically significant differences in the levels of the growth hormone (p = 0.0316), whereas not statistically significant differences in the levels of the growth hormone related to the distance from residence to power line less and more than 100 m by cut-off point (p = 0.4017). In conclusion, these results may indicate that urinary levels of nocturnal growth hormone are altered in primary schoolchildren exposed to extremely low frequency magnetic field at overhead transmission power line.

We performed numerical analyses on the optimal discharge angle of a 4-way cassette air conditioner, which is mounted on the ceiling of the classroom, by using thermal comfort and ventilation indices. We analyzed the effective draft temperature, the local mean age and the local mean residual life time with respect to the variation of the air discharge angle of the air conditioner in all occupied zone. Air diffusion performance index, local supply effectiveness and local exhaust effectiveness were used to investigate the optimal value of air discharge angle. From the results, we found out that the optimal discharge angle of the air conditioner is about 40 degrees in the present model.

A ventilation system comprising a dielectric barrier discharger and UV‐TiO2 photocatalyst filters was designed and tested for simultaneous removal of gaseous and particulate contaminants in a test chamber. The DBD was used as the 1st stage of ESP for particle charging and gas decomposition. Charged particles were collected in the 2nd stage of ESP by an applied DC electric field. The UV‐TiO2 photocatalyst filters were used for decomposing gaseous species including O3 which was inherently produced by the DBD. Particle removal efficiencies based on mass and number were approximately 83.0% and 88.8%, respectively, after the ventilation system was operating for 5 hours. HCHO removal efficiency was approximately 100% for 1∼5ppm of upstream concentration condition. TVOC removal efficiency was 99.0% and 99.6% for 1 ppm and 5 ppm of upstream concentration conditions, respectively.

The antimicrobial activity of metallic nanoparticles against bacteria was investigated. Silver, copper, and titania nanoparticles were tested. The bacteria species E. coli and B. subtilis were selected as models for Gram-negative and Gram-positive bacteria, respectively. Bacteriological tests were performed in Luria-Bertani (LB) medium or Nutrient (NT) medium on solid agar plates containing different concentrations of nanoparticles in the range of 0 to 150 μg/mL. Silver and copper nanoparticles were shown to be an effective bactericide. However, titania nanoparticles were found to be ineffective as an antimicrobial agent. It appears that E. coli cells are more sensitive to the copper nanoparticles than to silver nanoparticles and B. subtilis cells have similar sensitivity against both copper and silver nanoparticles.

Nowadays, cremation is becoming generalized and also the frequency of utilization of cremation is increasing in Korea. Futhermore, there is a possibility that indoor air pollution is caused by particles, gas pollutants or microbial pollutants from laying down and cremation of corpses, and also the bereaved family and grievers inside the crematory. Therefore, the major goals in this study were that first, we investigated and analyzed the air quality of particular indoor environments such as the crematory. Second, we assessed the health risk for workers. Finally, we collected and assessed the basic data in special indoor environments because this kind of study had not been performed. We sampled and analyzed PM10 (heavy metal), VOCS, HCHO, infectious microorganisms to grasp the characteristics of indoor air quality in the crematory through sampling four times from 7th July to 16th October in 2004. Besides, we did personal air sampling of PM10 (heavy metal) and VOCS to grasp personal exposure of workers from indoor hazardous air pollutants. We conjectured that main sources of pollutants in crematory are cremation, buried corpses, and moving of grievers, also increasing the seriousness of microbial pollutants gathering strength, especially. As we assessed infectious microorganisms of indoor air and executed research for indoor hazardous air pollutants, we want to offer the way of study and policy of management for particular indoor environments like a crematory.

Increasing public concerns over odors and air regulations in nonattainment zones necessitate the remediation of a wide range of odorous compounds used for industrial purpose. Currently, spraying technique using neutralizing essential oils is utilized to treat ammonia odors. The chemical analysis was performed to analyze the composition of an essential oil by GC-MS. The monoterpenes in an essential oil react with ammonia by neutralization and their reaction mechanism was elucidated. However, little information is available on the neutralization reaction with rendering air pollutants in detail. The objective of this study was to clarify the possibility of the neutralization of odors sprayed in indoor and determine the removal efficiencies in the misty aerosol by different input odor concentration. It was found that an ammonia was significantly removed by the spraying technique, and the removal efficiency of ammonia was 98 %. The removal efficiencies of ammonia were also studied by the optimal conditions such as temperature and pH.