• Resources Recycling
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• v.29 no.6
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• pp.41-47
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• 2020

This study was carried out to utilize the coal bottom ash generated in a circulating fluidized bed combustion boiler as a treatment agent for heavy metal ions, and experiments were conducted to remove heavy metal ions from the acid mine drainage. The batch experiments were conducted to investigate the influence of dosage of ash, initial concentration of solution on the removal capacity of heavy metal ions (Cu, Cd, Cr, Pb). The results of the experiment showed that the total removal capacity of heavy metals was 30.8 mg/L and 46.4 mg/g, respectively, under the condition that the concentration of coal ash was added as 15 g/L of heavy materials and 10 g/L of light materials. After that, a long-term column experiment was performed to determine the maximum removal capacity of heavy metal ions (Cu, Cd, Cr, Pb, As), and the removal capacity for each metal component was investigated. After approximately 60 days of operation, the maximum removal capacity of heavy metals was 23.6 mg/g at pH 9.25.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.66-78
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• 1999

The purpose of this study was to investigate the toxic effects of iso-butylalcohol on Sprague-Dawley (SD) rats which were treated 0, 333, 1,000 and 3,000 ppm for 6 hours a day, 5 days a week for 13 weeks by inhalation. Iso-butylalcohol did not induce any abnormal change in the viewpoint of clinical signs, feed consumption, ophthalmic test, urinalysis, hematology and blood biochemistry during and at the termination of the inhalation toxicity test. We did not find any abnormal findings in the gross and microscopic observations due to the inhalation of iso-butylalcohol. There was no alteration in relative organ weight owing to the inhalation of the iso-butylalcohol. In conclusion, concentration was 3,000 ppm in rats under the inhalation of 6 hours a day, 5 days a week for 13 week. Iso-butylalcohol did not show any change in the clinical signs, feed consumption, ophthalmic test, urinalysis, hematology and blood biochemistry, together with no alteration in the gross and pathological findings.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.154-160
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• 2000

Landfill gas (LFG) utilization in old landfill was estimated using LFG models. The results showed that Scholl Canyon model best described the LFG generation. LFG was extracted more than the amount of natural production which caused air inflow from outside that resulted in dilution of methane concentration and increase of oxygen concentration. It was negative for the LFG utilization. Therefore, to use LFG, the plan of stabilization by LFG extraction should be ineffective. The use of LFG will have no problem if LFG is extracted less than the amount of natural production which was estimated based on modeling. At 8 years elapsed from landfill, now, the amount of natural landfill gas production was decreased sharply. The plan for using LFG from old landfill is feasible if LFG is used for the less than the amount of natural production as a small scale even though for the aspect of efficiency, it was less economic than use of LFG just after closing landfilling and it was helpful for stabilization of landfill by LFG extraction.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.1
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• pp.100-109
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• 1993

This study was performed to evaluate the asbestos exposure levels and variations in textile, brake lining manufacturing and slate manufacturing industries. For this study, fifteen plants of brake lining manufacturing industry, 7 plants of textile industry, and 2 plants of slate manufacturing industry were selected and surveyed. Geometric means (GMs) of airborne asbestos concentrations in textile, brake lining manufacturing, and slate manufacturing industries were 1.42 f/cc(0.07-6.1O f/cc), 0.19 f/cc(<0.01-2.67 f/cc) and 0.08 f/cc(0.02-0.67 f/cc), respectively. In textile industry overall GMs of airborne asbestos concentrations in plants with less than 50 workers and in plants with more than 50 workers were 1.60 f/cc and 0.3 f/cc, respectively. Therefore, the size of plant showed some difference in the airborne asbestos concentrations. Three out of 7(42.9%) exceed the Korean standard, 2 f/cc, and every plant exceed the USA standard, 0.2 f/cc of the OSHA-Permissible Exposure Level(OSHA-PEL). Especially, one plant showed the highest average concentration of 2.87 f/cc. In brake lining manufacturing industry, the plants with less than 50 workers showed 0.22 f/cc. The plants with more than 50 workers showed 0.18 f/cc. All plants showed the exposure level below the Korean standard. Five of 15 (33.3%) were above the OSHA-PEL. One plant showed the highest average concentraton of 0.84 f/cc. In slate manufacturing industry, the average exposure level was 0.08 f/cc, and all of the plants were below the Korean standard and the OSHA-PEL.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.65-65
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• 2003

The aim of this study was to investigate the effect of resveratrol on the oxidative stress-induced inhibition of gap junctional intercellular communication (GJIC) in HaCaT keratinocyte. Anti-oxidative activity of resveratrol was measured by a,a-diphenyl-b-picrylhydrazyl (DPPH) assay and dichlorodihydrofluorescein diacetate oxidation assay. GJIC of HaCaT keratinocyte was assessed using the scrape loading/dye transfer technique. Western blots and reverse transcription-polymerase chain reaction were also analyzed for Connexin 43 protein and mRNA expression, respectively. Resveratrol scavenged directly the stable DPPH radical over a concentration range of 4 mg/$\mell$ (78.2 $\pm$ 2.7% of control) to 500 mg/$\mell$ (29.9 $\pm$ 4.2% of control) and prevent to increase the intracellular fluorescence induced by oxidative stress significantly. Ultraviolet A irradiation (UVA) and 12-O-tetradecanoylphorbol-13-acetate markedly reduced GJIC, which was restored by resveratrol. There were no significant differences in the level of Connexin 43 protein and mRNA expression among any of the experimental groups. Our data suggests that resveratrol has the protective effect on the oxidative stress-induced inhibition of gap junctional intercellular communication in HaCaT keratinocyte and this protection is likely due to the scavenging of reactive oxygen species.

• Journal of Ginseng Research
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• v.42 no.1
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• pp.90-97
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• 2018

Background: Antihyperglycemic effects of Panax ginseng berry have never been explored in humans. The aims of this study were to assess the efficacy and safety of a 12-wk treatment with ginseng berry extract in participants with a fasting glucose level between 100 mg/dL and 140 mg/dL. Methods: This study was a 12-wk, randomized, double-blind, placebo-controlled clinical trial. A total of 72 participants were randomly allocated to two groups of either ginseng berry extract or placebo, and 63 participants completed the study. The parameters related to glucose metabolism were assessed. Results: Although the present study failed to show significant antihyperglycemic effects of ginseng berry extract on the parameters related to blood glucose and lipid metabolism in the total study population, it demonstrated that ginseng berry extract could significantly decrease serum concentration of fasting glucose by 3.7% (p = 0.035), postprandial glucose at 60 min during 75 g oral glucose tolerance test by 10.7% (p = 0.006), and the area under the curve for glucose by 7.7% (p = 0.024) in those with fasting glucose level of 110 mg/dL or higher, while the placebo group did not exhibit a statistically significant decrease. Safety profiles were not different between the two groups. Conclusion: The present study suggests that ginseng berry extract has the potential to improve glucose metabolism in human, especially in those with fasting glucose level of 110 mg/dL or higher. For a more meaningful benefit, further research in people with higher blood glucose levels is required.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.2
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• pp.148-156
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• 1994

Chloral hydrate(CH), an intermediate metabolite of trichloroethylene(TRI) is reduced to trichloroethanol(TCE-OH), and is oxidized to trichloroacetic acid(TCA) by the nicotinamide adenine dinucleotide(NAD)-dependent enzymes such as alcohol dehydrogenase(ADH) and aldehyde dehydrogenase(ALDH) in liver. This study was performed to find out the change of activity of ADH and ALDH with increasing amount of TRI. Intraperitoneal injection of TRI were done to the male Sprague Dawely rats(mean body weight, $170{\pm}10g$) in com oil at the dosage of 150, 300, 600 mg/kg for 2 days. The results of experiments are following : 1. The contents of xenobiotic metabolic enzymes in liver are tended to be decreased with increasing amount of, but not significantlly (p>0.05). 2. Activity of ADH in microsome is decreased(p<0.05), and activity of ALDH is increased with amount of TRI(P<0.05). 3. Total trichloro-compounds(TTC) concentration in urine are increased with amount of TRI, but the ratio of between the TCE-OH and the TCA were not shown any critical change. These results suggests that the ALDH in microsome may be related to metabolism of TRI, but ADH was nothing less than the effected to metabolism of TRI.

• Korean Journal of Environmental Agriculture
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• v.39 no.2
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• pp.83-88
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• 2020

BACKGROUND: This study was carried out to investigate residual characteristics of diethofencarb during ginseng cultivation and processing, and to establish the maximum residue limits (MRL) of ginseng and its processed products. METHODS AND RESULTS: Supervised field trials were conducted from three fields located at Seosan, Goesan and Jeongeup in Korea. Diethofencarb 25% WP was diluted by 500 times and sprayed 4 times onto the ginseng with 10 days interval. The samples were collected at 80 days after final application. The residual amounts of diethofencarb ranged from 0.074 to 0.460 mg/kg in fresh ginseng, from 0.292 to 0.720 mg/kg in dried ginseng, and from 0.208 to 0.557 mg/kg in red ginseng. These data exceeded the ginseng's MRL, 0.3 mg/kg. The processing factors of diethofencarb in processed products were found to be 2.64 and 1.99, respectively for dried and red ginseng. CONCLUSION: Given the lower residual concentration of red ginseng that goes through a more complicated process than dried ginseng, the residual concentrations of diethofencarb in processed ginseng products were found to be dependent on processing method. Therefore, it is necessary to reconsider the MRL of diethofencarb in fresh ginseng and its processed products.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.111-114
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• 2003

Conjugated linoleic acid (CLA), known to possess various beneficial effects such as anticarcinogenic, antioxidative, and cholesterol-depressing, has been used as a health supplementary food in Japan and the USA. Optimum condition for CLA production without causing changes in quality of kimchi was determined using Bifidobacterium sp., a CLA-producing microorganism, as a starter in culture broth, freeze-dried culture, and encapsulated culture. Results revealed encapsulation was most ideal for maintaining the ability of bacterium to produce CLA during kimchi fermentation. Exogenous linoleic acid (LA) which is a substrate for conversion to CLA was not added to kimchi since LA was already exists in red pepper. Changes in sensory properties of kimchi and production of CLA were measured after inoculation of the encapsulated starter. The optimum inoculation concentration of the encapsulated starter was 0.1% (w/w) for production of CLA without causing changes in kimchi taste.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.595-601
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• 2017

Background: Red ginseng oil (RGO) is produced by supercritical $CO_2$ extraction of secondary products derived from Korean Red Ginseng extract. As the use of RGO has increased, product safety concerns have become more important. Methods: In the present study, the subacute oral toxicity and bacterial reverse mutagenicity of RGO were evaluated. Sprague-Dawley rats were orally administered with RGO for 28 d by gavage. Daily RGO dose concentrations were 0 mg/kg body weight (bw), 500 mg/kg bw, 1,000 mg/kg bw, or 2,000 mg/kg bw per day. Bacterial reverse mutation tests included five bacterial strains (Escherichia coli WP2 and Salmonella typhimurium TA98, TA100, TA1535, and TA1537), which were used in the presence or absence of metabolic activation. The plated incorporation method for mutation test was used with RGO concentrations ranging from $312.5{\mu}g$ to $5,000{\mu}g$ per plate. Results: The subacute oral toxicity test results did not reveal any marked changes in clinical characteristics. There were no toxicological changes related to RGO administration in hematological and serum biochemical characteristics in either control or treatment animals. Furthermore, no gross or histopathological changes related to RGO treatment were observed. The bacterial reverse mutation test results did not reveal, at any RGO concentration level and in all bacterial strains, any increase in the number of revertant colonies in the RGO treatment group compared to that in the negative control group. Conclusion: The no-observed-adverse-effect level of RGO is greater than 2,000 mg/kg bw and RGO did not induce genotoxicity related to bacterial reverse mutations.