• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.302-312
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• 2017

Objectives: In this study, an evaluation of the working environment of furnace workers was performed and the work-relatedness of the occupational diseases were examined Methods: In this study, two electric furnaces at a single casting business site producing manganese-based iron alloy were selected, and occupational exposures to hazardous substances were evaluated for furnace workers and furnace worker assistants. Results: As a result, total dust concentration were $0.407{\sim}3.001mg/m^3$ and respirable dust concentration were $0.196{\sim}0.584mg/m^3$. The highest concentration of crystalline silica was $0.079mg/m^3$ In the case of Masato and Sosuckwhoi crystalline silica, they contained 90.85% and 4.17% respectively. Manganese concentration was the highest at a $0.205mg/m^3$ maximum. The average of black carbon is $11.56{\mu}g/m^3$ and the maximum concentration is $604.23{\mu}g/m^3$. PAHs concentration was the highest at a $78.301{\mu}g/m^3$ of naphthalene. The concentration of carbon monoxide was 18.82 ppm(total average 3.89 ppm) during pouring, and the maximum is 131 ppm. The formaldehyde concentration was 0.003 to 0.007 ppm. Conclusions: It seems that conditions in the past were worse, since casting has recently been performed only twice per day for about 20 minutes, reducing the amount of pouring, and local exhaust systems have been installed one-by-one. In addition, it was judged that the past exposure levels were higher considering the points measured on the back-side due to the risk of damage to the individual samples. It was found that operators could be exposed to high concentrations of crystalline silica, and that they were also exposed to high concentrations of metal(fume) and carbon monoxide during pouring. Therefore, there is a risk that occupational diseases such as lung cancer and COPD may occur with long-term work in such a process.

• Journal of Integrative Natural Science
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• v.4 no.2
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• pp.149-157
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• 2011

Urbanization of the world's population has given rise to more than 450 cities around the world with populations in excess of 1 million (megacity) and more than 25 so-called metacities with populations over 10 million (Brinkhoff, 2010). The United States today has a total resident population of more than 308,500,000 people, with 81 percent residing in cities and suburbs as of mid - 2005 (UN, 2008). Urban meteorology is the study of the physics, dynamics, and chemistry of the interactions of Earth's atmosphere and the urban built environment, and the provision of meteorological services to the populations and institutions of metropolitan areas. While the details of such services are dependent on the location and the synoptic climatology of each city, there are common themes, such as enhancing quality of life and responding to emergencies. Experience elsewhere (e.g., Shanghai, Helsinki, Tokyo, Seoul, etc.) shows urban meteorological support is a key part of an integrated or multi-hazard warning system that considers the full range of environmental challenges and provides a unified response from municipal leaders. Urban meteorology has come to require much more than observing and forecasting the weather of our cities and metropolitan areas. Forecast improvement as a function of more and better observations of various kinds and as a function of model resolution, larger ensembles, predicted probability distributions; Responses of emergency managers, government officials, and users to improved and probabilistic forecasts; Benefits of improved forecasts in reduction of loss of life, property damage, and other adverse effects. A national initiative to enhance urban meteorological services is a high-priority need for a wide variety of stakeholders, including the general, commerce and industry, and all levels of government. Some of the activities of such an initiative include: conducting basic research and development; prototyping and other activities to enable very--short and short range predictions; supporting and improving productivity and efficiency in commercial and industrial sectors; and urban planning for long term sustainability. In addition urban test-beds are an effective means for developing, testing, and fostering the necessary basic and applied meteorological and socioeconomic research, and transitioning research findings to operations. An extended, multi-year period of continuous effort, punctuated with intensive observing and forecasting periods, is envisioned.

• Journal of Life Science
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• v.26 no.6
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• pp.705-710
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• 2016

Colorectal cancer (CRC) is the third most common cancer and a leading cause of cancer-related death worldwide. Although several diagnostic and therapeutic tools have been available, CRC remains difficult to complete cure because of insufficient understanding of the molecular mechanisms underlying this disease progression. MicroRNAs (miRNAs) are small non-coding RNA molecules that strongly regulate gene expression via transcriptional and translational control mechanisms. Many crucial cellular pathways are frequently disrupted in cancer development process due to dysregulation of several miRNAs. Mir-31 functions as an oncogene that modulate expression of multiple cancer related genes. Thus, we aimed to demonstrate clinical relevance of miR-31 in human CRC. Quantitative RT-PCR analysis of miR-31 expression was performed in 175 CRC tissues and 16 normal colonic mucosa (NM). Next, we investigated clinical significances of miR-31 expression in various clinicopathologic features in CRC patients cohort. Mir-31 was significantly up-regulated in CRC tissues compared to NM. In CRC tissues, miR-31 expression level was significantly elevated in a stage-dependent manner, which was associated with poor survival in patients with CRC. High miR-31 levels in CRC tissues significantly correlated with poor prognosis (hazard ratio [HR]=2.4) as well as distant metastasis (odds ratio [OR]=2.3). In conclusion, we identified clinical significance of miR-31 expression in CRC. High miR-31 expression may be clinically able to use as a biomarker for CRC prognosis and predicting metastasis.

• Journal of the Korean Institute of Gas
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• v.13 no.6
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• pp.34-38
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• 2009

Nitrous oxide, which is used as an anesthetic gas, has been shown to be a chronic health hazard. It is necessary to monitor and control the nitrous oxide exposure of the operating theaters staff. In this study, N2O exposure level of the operating nurses is assessed with a GC-ECD. The nitrous oxide gas is collected on a molecular sieve 5A contained in a glass tube and desorbed for 12 hours at $100^{\circ}C$ in heating block. As a result of the test using GC-ECD, calibration curve's $R^2$ of $N_2O$ is 0.9992, LOD is $0.96{\mu}g$/injection, LOQ is $3.21{\mu}g$/injection, desorption efficiency is 94.78 4.50% in average and break through is within 10% compared with the concentration. The average concentration before operation is 5.12ppm and it is 42.3ppm during operation. There are a significant difference showing that the P value is lower than 0.05. Assessing exposure level to nitrous oxide based on nurses' working positions, the exposure levels do not show significant difference( P>0.005). And $N_2O$ in active sampling method is higher than passive sampling method(P<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.344-348
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• 2019

This study assessed the microbiological hazards of gloves worn during the shell shucking process of the oyster Crassostrea gigas, and we suggest an in situ method for minimizing microbial contamination. The study consisted of two groups, one in which the working gloves were periodically replaced (PRG) with new gloves, and another in which the gloves were not replaced (NRG). In the PRG group, gloves were replaced every 2 h during 8 h of processing. Food pathogenic bacteria Escherichia coli, Salmonella species, and Listeria monocytogenes were not found in any samples, including gloves and shucked oysters. However, Staphylococcus aureus (SA) was detected in some samples, and the contamination levels were correlated with the working time and the regular replacement of gloves. SA was not detected on gloves or oysters of the PRG group. However, it was detected in the range of <$15CFU/15cm^2$ to $2.9{\times}10^2CFU/15cm^2$ on gloves after 6 h of continuous work, and from <$15CFU/15cm^2$ to $2.23{\times}10^2CFU/15cm^2$ on oysters after 8 h. These results indicate that the SA contamination in shucked oysters originated from the working gloves, and that replacement of working gloves every 2-4 h will minimize SA contamination in oyster products.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.177-184
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• 2021

While veterinary antibiotics are used only in a part of the dose administered, the rest are excreted as urine or feces. Residual antibiotics enter the adjacent agricultural environments by spraying manure-based composts on farmlands and lead to secondary pollution. Therefore, it is necessary to develop the technique for post management such as regulatory levels of antibiotics in the agricultural environments. This study was conducted to compare by different matrices the amount of residual antibiotics such as tetracyclines and sulfonamides, which are known to be frequently used in Korea and to practice risk assessment by different antibiotics in soils before and after application of composts. Pre-treatment with modified typical method using buffer and solid phase extraction showed the recovery of composts and soils was more than 70% at ppb level and the limits of detection were 0.13-0.46 and 0.05-0.25 ㎍/kg, respectively. Analysis of manure-based composts revealed concentrations from 5.38 to 196.0 ㎍/kg for tetracyclines, from below the detection of limit (BDL) to 259.0 ㎍/kg for sulfonamides. In case of agricultural soils, residual concentrations of selected veterinary antibiotics were ranged 0.30-53.3 ㎍/kg, BDL-4.16 ㎍/kg respectively and the concentration level of tetracyclines, which had higher soil distribution coefficient (Kd) values, was higher than that of sulfonamides. There was a difference in human risk assessment by different antibiotics in soil before and after application of composts. But, it was indicated that detection values of all of 5 antibiotics were very safe on the basis that Hazard Quotient was safe below 1.

• Tuberculosis and Respiratory Diseases
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• v.84 no.2
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• pp.125-133
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• 2021

Background: The coronavirus disease (COVID-19) can manifest in a range of symptoms, including both asymptomatic systems which appear nearly non-existent to the patient, all the way to the development of acute respiratory distress syndrome (ARDS). Specifically, COVID-19-associated pneumonia develops into ARDS due to the rapid progression of hypoxia, and although arterial blood gas analysis can assist in halting this deterioration, the current environment provided by the COVID-19 pandemic, which has led to an overall lack of medical resources or equipment, has made it difficult to administer such tests in a widespread manner. As a result, this study was conducted in order to determine whether the levels of oxygen saturation (SpO₂) and the fraction of inhaled oxygen (FiO₂) (SF ratio) can also serve as predictors of ARDS and the patient's risk of mortality. Methods: This was a retrospective cohort study conducted from February 2020 to Mary 2020, with the study's subjects consisting of COVID-19 pneumonia patients who had reached a state of deterioration that required the use of oxygen therapy. Of the 100 COVID-19 pneumonia cases, we compared 59 pneumonia patients who required oxygen therapy, divided into ARDS and non-ARDS pneumonia patients who required oxygen, and then investigated the different factors which affected their mortality. Results: At the time of admission, the ratios of SpO₂, FiO₂, and SF for the ARDS group differed significantly from those of the non-ARDS pneumonia support group who required oxygen (p<0.001). With respect to the predicting of the occurrence of ARDS, the SF ratio on admission and the SF ratio at exacerbation had an area under the curve which measured to be around 85.7% and 88.8% (p<0.001). Multivariate Cox regression analysis identified that the SF ratio at exacerbation (hazard ratio [HR], 0.916; 95% confidence interval [CI], 0.846-0.991; p=0.029) and National Early Warning Score (NEWS) (HR, 1.277; 95% CI, 1.010-1.615; p=0.041) were significant predictors of mortality. Conclusion: The SF ratio on admission and the SF ratio at exacerbation were strong predictors of the occurrence of ARDS, and the SF ratio at exacerbation and NEWS held a significant effect on mortality.

• Journal of Food Hygiene and Safety
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• v.35 no.6
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• pp.587-601
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• 2020

Exposure to hazardous substances occurs through multiple pathways. Aggregated risk assessment, which includes all potential exposure pathways to a single toxicant, is necessary to prevent exposure to harmful substances. We aimed to estimate cadmium and lead exposure through various media, such as food, water, air, smoking, cosmetics, and female hygiene products. This study covered 10,733 subjects from the Seventh Korea National Health and Nutrition Examination Survey(2016, 2017). Dietary exposure was estimated using 24-hour recall data. For water and inhalational exposure, regional variations were considered. Water was classified as tap, bottled, and public water. Inhalational exposure was estimated using the '2014 Time Use Survey' based on daily lifestyle and social status. The frequency and volume of cosmetic usage were randomly approximated by sex and age. Post-menarcheal and premenopausal women were assumed to use feminine hygiene products. Non-carcinogenic aggregated risks were estimated using the Aggregate Risk Index from EPAs and the Total Exposure Hazard Index from Korean government guidelines. For carcinogenic risk assessment, excessive cancer risk was estimated. Ingestion, especially food, was the major route for both cadmium and lead exposure. Smoking was also associated with high cadmium exposure. Exposure to lead from cosmetics was remarkable but not critical. In aggregate risk assessments, median cadmium and lead exposure did not exceed the reference value. Sex, age, smoking status, and income affected exposure levels, unlike to regional variations.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.199-209
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• 2022

In this study, we analyzed the preparedness of Korean citizens for earthquake hazards. For this purpose, we developed a questionnaire on the preparedness of citizens for earthquake hazards, consisting of three constructs (knowledge, awareness, and management). A total of 1,256 citizen responses were collected through probability proportionate-to-size sampling and then subjected to Rasch analysis, inferential statistical analysis, and cluster analysis. The findings are as follows. First, questionnaire analysis showed that overall, the earthquake preparedness of citizens was 'normal', with a lower management score than knowledge and awareness scores. Second, analysis of variables related to preparedness for earthquake hazards, gender, education level, actual distance, and safety awareness were found to influence preparedness for earthquake hazards. Third, correlation analysis revealed a high correlation between the three constructs of preparedness for earthquake hazards, namely knowledge, awareness, and management, indicating a structurally close relationship with each other. In addition, even if gender and education level differed, these structural correlations were similar. Through cluster analysis, the citizens were further divided into five groups; the group with moderate levels of the three constructs accounted for the majority of citizens. Considering these findings, we propose an educational orientation that fosters the preparedness of citizens for earthquake hazards.

• Korean Journal of Environmental Agriculture
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• v.41 no.2
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• pp.108-114
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• 2022

BACKGROUND: This study was performed to determine residual characteristics of soil-treated metalaxyl-M and dinotefuran in crown daisy and to evaluate the risks from intake of the residual pesticides in the crop. METHODS AND RESULTS: The pesticide granules were treated in soil on two levels, and the plants samples were collected 51 days after seeding. The analytes were extracted and partitioned using the QuEChERS extraction packet (MgSO₄ 4 g, NaCl 1 g). The quantitative methods for metalaxyl-M and dinotefuran were validated in linearity, accuracy, and precision. Risk assessments of the pesticides were performed using Korea national nutrition statistics 2019. CONCLUSION(S): The residual concentrations of metalaxyl-M in crown daisy were 0.09-0.10 mg/kg (for the treatment at 6 kg/10 a) and 0.17-0.19 mg/kg (12 kg/10 a), respectively. The residual concentrations of dinotefuran in the crop were 0.53-0.75 mg/kg (3 kg/10 a) and 1.17-1.26 mg/kg (6 kg/10 a). The amounts of pesticides were less than MRL (Maximum Residue Limits) according to the Korean MFDS (Ministry of Food and Drug Safety). The HI (Hazard Index) of metalaxyl-M and dinotefuran for consumers was 0.0075% and 0.2250%, respectively. For females in the age between 50-64, the major consumer group, the HIs of the pesticides were <3%. Considering the consumption of crown daisy, they are not considered to be of toxicological concern.