• Economic and Environmental Geology
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• v.34 no.1
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• pp.39-53
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• 2001

Environmental pollution of the Tohyun mine creek area was investigated on the basis of geology, mineralogy and geochemistry. In soils and sediments of the mine area, ${Al_2}{O_3}/{Na_2O}$ and ${K_2}O/{Na_2}O$ ratios are partly negative correlation against ${SiO_2}/{Al_2}{O_3}$, respectively. Geochemical characteristics of some trace and rare earth elements such as V/Ni, Ni/Co, La/Ce, Th/Yb, Th/U, La/Th, ${La_N}/{Yb_N}$, La/Sc and Sc/Th are revealed a narrow range and homogeneous compositions may be explained by simple source lithology. These results suggest that sediments source of the host shale around the mine area could be originated by basic to intermediate igneous rocks. Mineral compositions of soil and sediment near the mine area were partly variable mineralogy, which are composed of quartz, mica, feldspar, chlorite, clay minerals and some pyrite. Soils and sediments with highly concentrated heavy minerals, gravity separated mineralogy, are composed of some pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, goethite and various kinds of hydroxide minerals on the polished sections. As normalized by bed rock composition, average enrichment indices of major elements in sediments, precipitates, farmland soils and paddy soils are 1.0, 1.7, 0.9 and 0.8, respectively. Maximum concentration of environmental toxic elements in the mine creek are detected with Ag = 186 ppm, As = 17,100 ppm, Bi = ]27 ppm, Cd = 77 ppm, Cu = 12,299 ppm, Pb = 8,897 ppm, Sb = 1,350 ppm, W = 599 ppm and Zn = 12,250 ppm, which are increasing with total FeO increasing, and extremely high concentrations of surface sediments and precipitates near the waste rock dump. These toxic elements (As, Bi, Cd, Cu, Pb, Sb, W and Zn) of the samples, normalizing by host rock concentration, revealed that average enrichment index is 106.0 for sediments, 279.6 for precipitates, 3.5 for farmland soils and 1.6 for paddy soils. However, on the basis of EPA values, enrichment indices of all the samples are 40.7, 121.4, 1.3 and 0.6, respectively.

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.255-261
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• 2007

To obtain the risk assessment of hazardous materials with maturing process of Rehmanniae Radix Preparata, the residual heavy metals and pesticides in samples are surveyed. Concentration of As, Cd and Pb during the maturing process of Rehmanniae Radix Preparata of Korea are $0.147{\pm}0.007\;mg/L,\;0.025{\pm}0.001\;mg/L\;and\;0.193{\pm}0.021\;mg/L$, respectively. Concentration of As, Cd and Pb during the maturing process of Rehmanniae Radix Preparat of China are $0.0145{\pm}0.014\;mg/L,\;0.023{\pm}0.002\;mg/L\;and\;0.299{\pm}0.013\;mg/L$, respectively. Concentration of As, Cd and Hg remain unchanged during the maturing process of Rehmanniae Radix Preparata. Concentration of As, Cd and Pb in Rehmanniae Radix Preparat on the Korea are 3.53%, 6.66% and 5.16% for Korea Food & Drug Administration (KFDA) advisory level, respectively. The residual pesticides, such as aldrin, $BHC-{\alpha},\;BHC-{\beta},\;BHC-{\gamma},\;BHC-{\delta}$, captan, chlorfenapyr, chlorpyrifos, DDD, DDE, DDT-o,p, DDT-p.p, dieldrin, endosulfan-sulfate, $endosulfan-{\alpha}$, $endosulfan-{\beta}$, fenitrothion, penthoate, permethrin, quintozene, tolyfluanid and vinclozolin, are not detected in Rehmanniae Radix Preparat on the Korea and China. The hazardous materials in Rehmanniae Radix Preparata on the Korea and China are verified the safety of the residual heavy metals and pesticides compare with Korea Food & Drug Administration (KFDA) advistory level.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.100-106
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• 2011

This study was conducted to investigate the residue amount of harmful materials on the 113 commercial fruit teas (Gugija, Omija, Sansuyu) in Gwangju area. It was performed using the GC-ECD, GC-NPD, GC-MSD and the LC-UVD, LC-FLD, LC-MSD to analyze 200 pesticides. The heavy metals were determined using a Mercury analyzer and AAS. The sulfur dioxides were analyzed by modified Monnier-Williams method. The residual pesticides were detected in 4 samples (Gugija). The mean values of heavy metal contents (mg/kg) were Pb, 0.024; Cd, 0.031; As, 0.010; Hg, 0.003. The measured values of Pb, Cd, As, Hg showed within MRLs. The sulfur dioxides were over MRLs in 4 samples (Gugija). These results will be used to establish on the regulation of commercial fruit teas in Gwangju area.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.151-160
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• 2020

The goal of this study was to investigate the diversity present among wild yeasts obtained from soils of spice fields and from mountain soils, and to further, characterize previously unrecorded novel wild yeast strains. In total, 36 strains from 17 different species of wild yeasts were isolated from 35 soil samples obtained from garlic fields of Geumsan, Chungcheongnam-do, Korea. Among these, six yeast strains of Trichosporon moniliiforme, and four strains each of Papiliotrema flavescens and Candida melibiosica species were isolated. Additionally, 22 strains of 18 different species of wild yeasts were isolated from 32 soil samples collected from the ballonflower and ginger fields of Geumsan, Korea. Finally, 46 strains of wild yeasts were isolated from 35 soil samples obtained from Mt. Daedun in Geumsan, Korea. Among the total of 106 isolated wild yeast strains, 10 strains, including Debaryomyces vindobonensis GHY31-3 represented novel yeast strains which were previously unrecorded. All the 10 previously unrecorded yeasts were oval or global in shape, and five strains, including Filobasidium stepposum SFG1-4 formed ascospores. Three strains, including Pseudozyma alboarmeniaca CD 23-5 grew well in vitamin-free medium. Cell-free extract obtained from Filobasidium magnum SFG1-3 indicated 28.6% of xanthine oxidase inhibitory activity.

• Progress in Medical Physics
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• v.28 no.2
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• pp.45-48
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• 2017

This paper evaluated the amount of radiation generated by wedge filters during radiation therapy using a high-energy linear accelerator, and the dose to the worker during wedge replacement. After 10-MV photon beam was irradiated with wedge filter, the wedge was removed from the linear accelerator, and the dose rate and energy spectrum were measured. The initial measurement was approximately 1 uSv/h, and the radiation level was reduced to 0.3 uSv/h after 6 min. The effective half-life derived from the dose rate measurement was approximately 3.5 min, and the influence of AI-28 was about 53%. From the energy spectrum measurements, a peak of 1,799 keV was measured for AI-28, while the peak for Co-58 was not measured in the control room. The peaks for Au-106 and Cd-105 were found only measurement was done without wedge removement from the linear accelerator. The additional doses received by the radiation worker during wedge replacement were estimated to be 0.08-0.4 mSv per year.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.363-373
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• 2007

To evaluate environment of farm lands using indicator insects and evaluation indices, the insect abundance of which is one of the major criteria for the evaluation of agricultural environment of farm land in urban areas and industrial complex, three sites (Ansan, Daesan, Suncheon) were designated and monitored from 2004 to 2006. The flora of agricultural land was more than urban areas and industrial complex of that in three sites. Soil, water and air pollution of urban areas and industrial complex were more serious than those of agricultural land in three sites. Overall population of insects were high from June to August in the surveyed three sites. Collected insects in agricultural land were 12 order, 106 family and 166 species, those in urban areas were 11 order, 102 family and 148 species, and in industrial complex were 11 order, 100 family and 152 species. Species and population belonging to Coleoptera was dominant in the surveyed sites. The insect diversity indices of farm land were 2.36 in agricultural land, 1.92 urban areas and industrial complex. And agricultural environment of agricultural land was good, urban areas was common and industrial complex was poor. Based on the major criteria of evaluation items, the criteria were selected as diversity index over 2.1, insect indicator Pheropsophus javanus in agricultural land, diversity index 1.5-2.0, insect indicator Nephotettix cincticeps in urban areas, diversity index below 1.5, insect indicator Pagria signata in industrial complex.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.2
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• pp.75-81
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• 2004

A large amount 2.1×106 ㎥ of the polluted sediment was dredged from the Masan Bay and deposited in Gapo confined area, Masan. The dissolved metal concentrations of seawater in the dumping site (Gapo area) were observed during one tidal cycle and compared with those of seawater obtained from Jinhae Bay. The sediment was evaluated as from Non polluted to Moderately polluted by USEPA standards. It was judged that toxicological effects of sediment analyzed ranged from ERL to ERM with copper and zinc, and ERL with cadmium, chrome, lead, and nickel by the Adverse Biological Effects. The pollutant concentration was low in surface sediment compared to deeper sediment since the sediments with relatively low concentrations of pollutant were dumped to the surface. The pollutant concentration was low in surface sediment compared to deeper sediment since the sediments with relatively low concentrations of pollutant were dumped to the surface. The benthic organisms in Gapo area had higher concentrations of trace metals (Oyster: Zn 238.96, Cu 5.29 ㎍/g wet wt., Clam: Zn 17.71, Cu 1.00 ㎍/g wet wt., Mussel. Zn 187.98, Pb 0.28, Cr 0.15, Mn 4.23, Sr 1.45 and Fe 100.33 ㎍/g wet wt.) compared to outside of dumping site. However, the trace metal level in the bivalves was less than the NFPQIS (National Fisheries Products Quality Inspection Service) standard.

• Toxicological Research
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• v.28 no.1
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• pp.5-9
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• 2012

It has been shown that the accumulation of prion in the cytoplasm can result in neurodegenerative disorders. Synthetic prion peptide 106-126 (PrP) is a glycoprotein that is expressed predominantly by neurons and other cells, including glial cells. Prion-induced chronic neurodegeneration has a substantial inflammatory component, and an increase in the levels of matrix metalloproteinases (MMPs) may play an important role in neurodegenerative development and progression. However, the expression of MMPs in PrP induced rat astrocytes and microglia has not yet been compared. Thus, in this study, we examined the fluorescence intensity of CD11b positive microglia and Glial Fibrillary Acidic Protein (GFAP) positive astrocytes and found that the fluorescent intensity was increased following incubation with PrP at 24 hours in a dose-dependent manner. We also observed an increase in interleukin-1 beta (IL-$1{\beta}$) and tumor necrosis factor alpha (TNF-${\alpha}$) protein expression, which are initial inflammatory cytokines, in both PrP induced astrocytes and microglia. Furthermore, an increase MMP-1, 3 and 11 expressions in PrP induced astrocytes and microglia was observed by real time PCR. Our results demonstrated PrP induced activation of astrocytes and microglia respectively, which resulted in an increase in inflammatory cytokines and MMPs expression. These results provide the insight into the different sensitivities of glial cells to PrP.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.2
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• pp.106-117
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• 2006

We measured the concentrations of organic matter and metallic elements (Al, Fe, Cr, Mn, Ni, Cu, Zn, As, Cd, Pb and Hg) in the surface sediments of Masan Harbor (in the southern sea, Korea) to evaluate the geochemical characters of sediment and the pollutions by organic matter and metallic elements. The mean grain size of the surface sediments in the study area ranged from $5.6{\phi}$ to $7.8{\phi}$, indicating silt sediment. The water content of the surface sediments exceeded 60% except at some stations. The contents of ignition loss (IL), total organic carbon (TOC) and total nitrogen (TN) ranged from 7.2-14.3%, 1.2-3.2%, and 0.10-0.28%, respectively. Based on the C/N ratios, the organic matter in the surface sediments of Masan Harbor may originate from terrigenous sources including fluvial inputs (mainly sewage in urban areas). The chemical oxygen demand (COD) and acid volatile sulfide (AVS) ranged from $11.3-29.9\;mgO_2/g\;dry$ and 0.20-4.47 mgS/g dry, respectively, and low concentrations were observed near a shipping route. In addition, the concentrations of metallic elements showed large spatial variations in Masan Harbor and the distributions of metallic elements were also comparable to those of organic matter. This implies that the distributions of organic matter and metallic elements in the surface sediments of Masan Harbor are mainly controlled by biogenic matter and artificial action (mainly dredging). In addition, we calculated the enrichment facto. (EF) and geoaccumulation index (Igeo) in order to evaluate pollution by metallic elements. The enrichment of metallic elements relative to Al was three to eighteen times higher at the study sites, compared to levels in the Earth's crust except for Fe, Ni and Mn. In addition, the Igeo class indicated that the surface sediments in the study area were moderately to strongly polluted in terms of metallic elements.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.207-207
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• 2008

ZnO is one of the widely utilized n-type semiconducting oxide materials in the field of optoelectronic devices. For its application to the fabrication of promising ultraviolet (UV) photodetectors, ZnO with various structures has been extensively studied. However, study on the photodetectors using zero-dimensional (0-D) ZnO nanoparticle is scarce while the 0-D nanoparticle structure has many advantages compared to the other dimensional structures for absorption of light. In this study, the photocurrent characteristics of ZnO nanoparticles were investigated through a simply pasting of the nanoparticles across the pre-patterned electrodes. Then the photoluminescence (PL) characteristic, photocurrent response spectrum, photo- and dark-current and photoresponse spectrum were investigated with a He-Cd laser and an Xe lamp. An dominant PL peak of the ZnO nanoparticles was located at the wavelength of 380 nm under the illumination of 325-nm wavelength light. The ratio of photocurrent to dark current (on/off ratio) is as high as 106 which is considerable value for promising photodetectors. On the other hand, the time constants in photoresponse were relatively slow. The reasons of the high on/off ratio and relatively slow photoresponse characteristic will be discussed.