• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.427-439
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• 2021

Objectives: This study aims to investigate differences in microbial contamination according to the duration and environment of mask wearing. Methods: Forty-five participants were recruited from workers in an offices, multi-purpose facilities, and a schools. After wearing of KF94 mask for two. four, and six hours, the microorganisms adsorbed on the outer and inner layers of the mask were inoculated on BAP(Blood Agar Plate), Chocolate agar, and SDA plates. The bacterial count (CFUs: colony-forming units) cultured in each plate was measured and analyzed for changes in filtration efficiency. Results: The microbial contamination of masks worn in classrooms, offices, and multi-purpose facilities showed a significant difference depending on the environment (p<0.000). The measured CFUs increased significantly according to the time wearing the mask. The difference between the inner and outer layers of the mask was also significant (p<0.05). However, there was no statistical difference in the filtration efficiency of the masks by duration time (p=0.515). Conclusions: Masks worn by workers in the offices, multi-purpose facilities, and schools showed an increase of microbial contamination with the amount of time wearing the mask. The results indicate that the masks used in daily life may have adverse health effects if they are worn for a long time or reused over several days without the realizing that the masks can be contaminated with biological hazards. Guidelines on the safe threshold time for mask use should be established through further research.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.347-355
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• 2022

Levels of beauvericin (BEA) and enniatins (ENNs: ENA, ENA1, ENB, and ENB1) were examined in fresh ginger (n = 43) and ginger powder (n = 31) samples from Korea. In the ginger samples, incidence of BEA contamination was highest, at 62.79%, with a maximum detected BEA level of 640.07 ㎍/kg. ENNs in were found in up to 11.63% (ENB, ENB1) of ginger samples, with a maximum detected level of 91.02 ㎍/kg (ENA). In the ginger powders, ENB contamination displayed the highest rate of incidence (70.97%), but the highest level of BEA (1,344.18 ㎍/kg) exceeded that of ENB (413.99 ㎍/kg). The incidences of ENA, ENA1, ENB, and ENB1 presence in ginger powders were 29.03%, 22.58%, 70.97%, and 35.48%, respectively, and their highest detected levels were 220.45, 156.61, 413.99, and 70.29 ㎍/kg, respectively. The incidence of BEA and ENN contamination was higher in ginger powder than in ginger. Respective co-occurrence rates of BEA and ENNs in ginger and ginger powder samples were 16.28% and 64.52%, indicating that the BEA and ENN co-contamination rate was highest in ginger powder as well. This is the first report on the presence and co-occurrence of BEA and ENNs in Korean ginger and ginger powder.

• Research in Plant Disease
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• v.28 no.4
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• pp.179-194
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• 2022

In this review, the mycotoxin contamination of Korean cereals and their products is analyzed by crop based on scientific publications since 2000. Barley, rice, and corn were investigated heavier than the others. The common mycotoxins occurred in all cereals and their products were deoxynivalenol and zearalenone. Nivalenol was detected in all samples analyzed but more frequently or mainly in barley, rice, and oat. Fumonisin was commonly detected in corn and sorghum but also in adlay, millet, and rice. Adlay and millet were similar in the contamination pattern that fumonisin and zearalenone were the most frequently detected mycotoxins. Zearalenone was the most commonly detected mycotoxin with concentrations higher than the national standards (maximum limit), followed by deoxynivalenol, and aflatoxin. However, most occurrence levels were below the maximum limits for respective mycotoxins. This result shows that barley, rice, corn, sorghum, millet, and adlay are more vulnerable to mycotoxin contamination than other cereals and therefore continuous monitoring and safety management are necessary.

• Economic and Environmental Geology
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• v.55 no.6
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• pp.717-726
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• 2022

This study was conducted to assess the geochemical contamination degree of As, Cd, Cu, Pb, Sb, and Zn in the soil and water samples from an abandoned gold mine. Enrichment Factor (EF), Geoaccumulation Index (Igeo), and Pollution Load Index (PLI) were carried out to assess the geochemical contamination degree of the soil samples. Variations of sulfate and heavy metals concentration in water samples were determined to identify the geochemical distribution with respect to the distance from the mine tailing dam. Geochemical pollution indices indicated significant contaminated with As, Cd, Pb, and Zn in the soil samples that areas close to the mine tailing dam, while, Sb showed similar indices in all soil samples. These results indicated that the As, Cd, Pb, and Zn dispersion has occurred via anthropogenic sources, such as mining activities. In terms of water samples, anomalies in the concentrations of As, Cd, Zn, and SO₄^2- was determined at specific area, in addition, the concentrations of the elements gradually decreased with distance. This result implies the heavy metals distribution in water has carried out by the weathering of sulfide minerals in the mine tailing and soil. The study area has been conducted the remediation of contaminated soil in the past, however, the geochemical dispersion of heavy metals was supposed to be occurred from the potential contamination source. Therefore, continuous monitoring of the soil and water is necessary after the completion of remediation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.148-155
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• 2023

This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.010⁴ cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 10⁵ cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.3
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• pp.45-56
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• 2024

Heavy metals emitted from urban development do not decompose in the soil and remain for long periods, continually impacting the environment. Since the mid-1990s, there has been increasing societal concern in South Korea regarding soil contamination, prompting various legislative revisions to reduce pollution. This study utilizes the Environmental Impact Assessment Support System (EIASS) to investigate projects in the metropolitan area that have exceeded the Ministry of Environment's soil contamination concern levels from 1989 to 2022 and to examine improvements in the environmental impact assessment (EIA) process. The results reveal that the average concentrations of nine contaminants-cadmium (Cd), copper (Cu), arsenic (As), mercury (Hg), lead (Pb), hexavalent chromium (Cr6+), zinc (Zn), nickel (Ni), and fluoride (F)-have all increased over the years. Among these, Zn had the highest relative proportion, with 37.5% of the 40 sites exceeding environmental concern levels. Investigation of 19 specific projects at these exceedance sites showed that only 7 had documented analyses of contamination causes and remediation plans, and just one had contracted additional remediation services, though results from these efforts were found to be lacking. Furthermore, since 2019, a significant proportion of these sites were involved in residential developments, likely due to government initiatives in new city development and extensive housing supply plans. This research emphasizes the importance of public disclosure of the processes and outcomes of remediation efforts on historically contaminated soils prior to project development. It discusses improvements to the EIA by reviewing current legislation and international examples. The findings of this study are expected to heighten public awareness about heavy metal contamination and enhance transparency in soil remediation efforts, contributing to sustainable environmental management and development.

• Journal of Environmental Health Sciences
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• v.50 no.2
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• pp.102-112
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• 2024

Background: Despite the rise in the number of domestic indoor climbing gyms, there is a lack of specific hygiene standards and research on the holds installed in them. Holds can act as vectors for microbial transmission through the hands, posing a risk of infectious diseases, especially with damaged skin. Objectives: The aim of this study is to investigate the contamination level and species of microorganisms on holds according to the management methods practiced in indoor climbing gyms and identify effective strategies for reducing microbial contamination. Methods: We investigated factors that may influence microbial contamination of holds, including hold management methods, user information, and hygiene management at three climbing gyms in Seoul. A total of 72 holds were sampled, 18 for each management method of brushing, high-pressure washing, and ethanol disinfection. Samples were cultured on LB and blood agar at 37℃ for 48 hours to calculate CFUs. PCR assay targeting 16S rRNA was carried out to identify microorganisms. Dunn-Bonferroni was employed to see the microbial reduction effect of the management method and the difference in microbial contamination by management method and climbing gym. Results: As a result of microbial identification, microorganisms such as Bacillus, Staphylococcus, and Micrococcus, which were derived from various environments such as skin and soil, were discovered on the surface of the climbing hold. Among the discovered microorganisms, some species had potential pathogenic properties that could cause food poisoning, gastrointestinal disease, bacteremia, and sepsis. All hold management methods were effective in reducing microorganisms (p<0.05), with ethanol disinfection being the most effective (p<0.001). Conclusions: Our results indicate that there are potential pathogens on holds that demand thorough management for microbial prevention. Proposed methods include regular brushing and ethanol disinfection in addition to high-pressure washing with long cycles, which are the existing forms of hold management. Further studies on shoe management are advised to curb soil-derived microorganisms.

• Journal of Food Hygiene and Safety
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• v.20 no.1
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• pp.43-47
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• 2005

This study monitored and compared the contamination levels of total aerobic bacteria, coliforms, Escherichia coli, and L. monocytogenes of either lettuce, sesame leaf, or cucumber sampled from either 15 super markets(SM) or 21 traditional markets(TM) located in both Seoul and the southern part of Gyunggi. Contamination levels of total aerobic bacteria and coliforms in lettuce, sesame leaf, or cucumber from SM or TM were not (p>0.05) significantly different. The highest contamination levels of total aerobic bacteria were observed in lettuce and followed by sesame leaf and cucumber. The contamination levels of total aerobic bacteria in lettuce, sesame leafs, and cucumbers were $7.01{\pm}0.14\;log_{10}CFU/g(SM)$ and $7.10{\pm}0.11\;log_{10}CFU/g(TM)$, $6.69{\pm}0.20\;log_{10}CFU/g(SM)$ and $6.44{\pm}0.13\;log_{10}CFU/g(TM)$, and $5.37{\pm}0.25 \;log_{10}CFU/g(SM)$ and $5.27{\pm}0.19\;log_{10}CFU/g(TM)$, respectively. A similar pattern of contamination rank was observed with the coliforms in three vegetables as was observed with the total aerobic bacteria E. coli were not significantly (p>0.05) different between SM and TM and isolated over $30\%$ in lettuce and sesame leaf and below $10\%$ in cucumbers. L. monocytogenes were not detected in all three vegetables(ND: cucumber <3 CFU/g, lettuce and sesame leaf <10 CFU/g). The microbial contamination levels determined in the present study may be used as the primary data to execute microbial risk assessment of fresh vegetables.

• Economic and Environmental Geology
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• v.34 no.3
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• pp.271-281
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• 2001

The characteristics of the heavy metal contamination in the soils affected by the tailings of the Palbong mine have been studied. The soils in the studied area consist mostly of loam by the particle size analysis, but a little of it, located near the stream, consist of loamy sand to sandy loam, finally to loam downward. The organic contents of soils are significantly low aoom 2 percent and the pH is in acidic ranging 6.0 $\pm$ 0.1. The samples of the parent rocks, the normal soils, the tailings and the channel deposits from the studied area were chemically analysed. From the result, the heavy metal concenlration of the soils is a little Jow compared with that of the parent rocks, shows the hydrologic process of the surface and the groundwater. The contamination of the tailings from the ore mining are high in lead, copper and arsenic. In the channel deposits the concenlrations of lead and copper are abnormally high but that of arsenic is uniquely low. And most of heavy metal contamination are decreased with the distance from the mine. It is caused by the properties of the surface and the ground water during the process of the heavy metal migration. The correlation-coefficient between sand and silt contents and the concentrations of Cd, Cu and Pb are significant but the amounts of As and Hg are increased with the clay contents. The dispersion of the heavy metals with the distance shows that the concentrations of them in the soils sampled at distance of 100 m to 200 m along the stream started near the Palbong mine are extremely high compared with those from other distances. These discrepancies are significant in Cd, Cu, Pb and Hg, but low in As. All the samples contain below detection limit of Cr+6 In the present stream water the concentrations of the heavy metals are not detected. So, it is interpreted that the concentrations in the soils are caused by the activities of the mining during the operation and have been continued by the dispersion from the tailings since after the closure of the mining, especially by the surface and ground water. The concentrations are diminished with the distance from the mining site, but in the interval of 800-2000 m increases abruptly. In the soil samples counted on the dispersion direction by wind, the lowering of the concentration is relatively uniform with the distance from the mining site. So, the rapid increase of the heavy metal concentrations is presumed to have been caused by the ground-water movement. In the migration of the heavy metals, the groundwater conditions, such as pH, Eh, the contents of colloidal particles, and Mn and Fe oxides are closely involveo. Integrating with these factors, it is interpreted that the groundwater conditions which have caused the heavy metal contamination of the studied area are those that the pH is about 3 in oxidized conditions, the contents of the colloidal particles are low, and Mn and Fe oxides are not involved in the migration of the heavy metals. Meanwhile, the vegetables growing on the soils in the studied area are not affected by the contamination of the heavy metals.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.189-194
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• 2014

This study was conducted to evaluate microorganism contamination of food utensils and service facilities in school and to prevent hazards by food poisoning occurrence. As a result, the highest number of microorganism growth plate ($12.3{\pm}2.6$) was detected in total bacteria test plate, and also observed $10.3{\pm}3.9$ growth plates in Staphylococcus aureus test plate and $9.5{\pm}3.9$ growth plates in E. coli and coliform bacteria test plate. But we could detect to the lowest number of growth plates ($1.5{\pm}1.0$) in Vibrio test plate. We also assessed that floors were appeared to the highest microorganism contamination rate in food utensils and service facilities. Therefore, $4.5{\pm}0.6$ growth plates was detected in pre-operation floor and $4.3{\pm}1.0$ growth plates in floor. And high level of microorganism contamination also observed in tables as $3.3{\pm}1.0$ growth plates in cooking table and $3.0{\pm}0.0$ growth plates in dining table. The level of microorganism contamination of food utensils such as kitchen knife, cutting board, and food tray were lower than that in food service facilities. We analysed microorganism contamination according to purpose of use in kitchen knifes and cutting boards. The microorganism contamination rate in fish kitchen knife ($2.0{\pm}0.8$) and fish cutting board ($1.3{\pm}1.5$) were slightly higher than that of others purpose of use. As a result of microorganism identification, various strains of microorganism were contaminated in food service facilities and some strains could detected more than two times. Especially, Staphylococcus aureus was repeatedly identified in cooking table, trench, and kitchen knife. Bacillus cereus was identified in kitchen knife, and then Pseudomonas fluorescens and Pseudomonas aeruginosa were also detected in food utensils and service facilities as known to food spoilage microorganisms. Klebsiella pneumoniae was detected four times repeat, which widely distribute natural environment as normal bacterial flora but sometimes cause acute pneumonia. These results suggest that food utensils and service facilities are contaminated with not only major food poisoning microorganisms such as Staphylococcus aureus, but also food spoilage microorganisms. Taken together, strict personal hygiene control and efficient food service facilities management will be needed to enhance food safety in school feeding and to improve student health.