• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.61-67
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• 2007

With an entering into force of OPRC-HNS started in June 14th 2007, establishment of response system in a nationwide scale to take care of accidents is required to respond rapidly and effectively. This necessities drove us to analyze national contingency plan for chemicals including national response system against accidents, which is in operation in the US. Main characteristics of the system are well described as an integrated incident command system with a cooperation of responsibilities facilities, manpower, and technical support. In addition, state anψor local authorities tend to have responsibilities on management of disaster with its response activities. Polluters are also charged to pay expenses 3 times expensive provided state or local authorities are conducted. In general, response activities are conducted by private sectors. However, the government will take action with Superfund if the response capacity is over than the polluters can. However, safety are regarded as a primary factor to be considered in the response activities, and try not to recover any pollutants. Personals belonging to USCG and EPA are required to complete specialized courses to promαe professional skills, and are also welcomed to participate in "certification program"

• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.42-50
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• 2013

With the rapid change of industry and the development of science and technology, more than 100,000 industrial chemicals are being used and 2,000 new materials are developed every year. Chemical products have had favorable influence on our daily life and contributed very much to the prosper of human culture. But some materials are inherently poisonous and dangerous. Korea ranks as the number 7 in world's chemical products market and the chemical sector is contributing to the economic revival through importing and exporting of the products. With the increasing domestic as well as international interests about REACH and GHS, the need for the effective and efficient chemical material management system is getting bigger and bigger. In this research, we compare the criteria in UN GHS and Safety Control of Dangerous Substances Act of Korea for the development of global standard test methods and the classification and labelling for the chemicals, and suggest an advancement plan for the introduction of the GHS in a building block approach. In addition, providing the harmonized information about chemical hazards is suggested for the elimination of international trade barriers for chemical industries.

• Journal of Life Science
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• v.31 no.9
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• pp.862-872
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• 2021

Recent studies on synthesis of metallic nanomaterials such as silver (Ag), gold (Au), platinum (Pt), cerium (Ce), zinc (Zn), and copper (Cu) nanoparticles (NPs) using plants and microbes are attracted researchers for their wide range of applications in the field of biomedical sciences. The plant contains abundant of bioactive contents such as flavonoids, alkaloids, saponins, steroids tannins and nutritionals components. Similarly, microbes produce bioactive metabolites, proteins and secretes valuable chemicals such as color pigments, antibiotics, and acids. Recently reported, biogenic synthesis of NPs in non-hazardous way and are promising candidates for biomedical applications such as antibacterial, antifungal, anti-cell proliferative and anti-plasmodia activity. All those activities are dose dependent, along with their shape and size also matters on potential of NPs. Microbes and plants are great source of metabolites, those useful in biomedical field, such metabolites or chemicals involved in synthesis of NPs in an ecofriendly way. NPs synthesized using microbes or plant materials are reveals more non-toxic, facile, and cost-effective compare to chemically synthesized NPs. In present review we are focusing on NPs synthesis using biological agents such as microbes (bacteria, fungi and algae) and plant, characterization using different techniques and their antibacterial applications on pathogenic Gram-positive and Gram-negative organisms.

• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.68-76
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• 2021

As hazardous chemicals are releasing in process industries such as chemical & petro-chemical plants, the importance of initial responses has been always emphasized. However, little attention of quantitative analysis of the consequence by different initial responses during releasing of the chemicals has been done. The main objective of current paper is to investigate the effects of initial responses for the release accidents of hydrofluoric acid. For this, a simplified equation that can easily calculate the effect distance by varying concentrations of hydrofluoric acid was firstly deduced. In addition, a causal loops for the initial response steps using the system dynamics technique was constructed during release of 50% hydrofluoric acid. The effect distances according to different scenarios of the initial actions were also quantitatively analyzed by applying the simplified equation to the causal map. As a result, the highest reduction rate on the maximum effect distance was obtained with 'start time of action after leak detection' being about 87% while the lowest was 'arrival time of professional response team' being about 50%, as expected. It is expected that the results gained from the current study can be helpful as of basics of the initial response to the workplace, dealing with the hydrofluoric acid.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.334-343
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• 2023

Background: South Korea's Act on Registration and Evaluation, etc. of Chemicals (known as K-REACH) was established to protect public health and the environment from hazardous chemicals. 4,4'-Methylenedianiline (MDA), which is used as a major intermediate in industrial polymer production and as a vulcanizing agent in South Korea, is classified as a toxic substance under the K-REACH act. Although MDA poses potential ecological risks due to industrial emissions and hazards to aquatic ecosystems, no ecological risk assessment has been conducted. Objectives: The aim of this study is to assess the ecological risk of MDA by identifying the actual exposure status based on the K-REACH act. Methods: Various toxicity data were collected to establish predicted no effect concentrations (PNECs) for water, sediment, and soil. Using the SimpleBox Korea v2.0 model with domestic release statistical data and EU emission factors, predicted environmental concentrations (PECs) were derived for ten sites, each referring to an MDA-using company. Hazard quotient (HQ) was calculated by ratio of the PECs and PNECs to characterize the ecological risk posed by MDA. To validate the results of modeling-based assessment, concentration of MDA was measured using in-site freshwater samples (two to three samples per site). Results: PNECs for water, sediment, and soil were 0.000525 mg/L, 4.36 mg/kg dw, and 0.1 mg/kg dw, respectively. HQ for surface water and sediment at several company sites exceeded 1 due to modeling data showing markedly high PEC in each environmental compartment. However, in the results of validation using in-site surface water samples, MDA was not detected. Conclusions: Through an ecological risk assessment conducted in accordance with the K-REACH act, the risk level of MDA emitted into the environmental compartments in South Korea was found to be low.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.523-541
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• 2023

As accessibility to 3D printers increases, there is a growing frequency of exposure to chemicals associated with 3D printing. However, research on the toxicity and harmfulness of chemicals generated by 3D printing is insufficient, and the performance of toxicity prediction using in silico techniques is limited due to missing molecular structure data. In this study, quantitative structure-activity relationship (QSAR) model based on data-centric AI approach was developed to predict the toxicity of new 3D printing materials by imputing missing values in molecular descriptors. First, MissForest algorithm was utilized to impute missing values in molecular descriptors of hazardous 3D printing materials. Then, based on four different machine learning models (decision tree, random forest, XGBoost, SVM), a machine learning (ML)-based QSAR model was developed to predict the bioconcentration factor (Log BCF), octanol-air partition coefficient (Log Koa), and partition coefficient (Log P). Furthermore, the reliability of the data-centric QSAR model was validated through the Tree-SHAP (SHapley Additive exPlanations) method, which is one of explainable artificial intelligence (XAI) techniques. The proposed imputation method based on the MissForest enlarged approximately 2.5 times more molecular structure data compared to the existing data. Based on the imputed dataset of molecular descriptor, the developed data-centric QSAR model achieved approximately 73%, 76% and 92% of prediction performance for Log BCF, Log Koa, and Log P, respectively. Lastly, Tree-SHAP analysis demonstrated that the data-centric-based QSAR model achieved high prediction performance for toxicity information by identifying key molecular descriptors highly correlated with toxicity indices. Therefore, the proposed QSAR model based on the data-centric XAI approach can be extended to predict the toxicity of potential pollutants in emerging printing chemicals, chemical process, semiconductor or display process.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.1
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• pp.30-38
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• 2009

The objective of this study was to evaluate the effects of occupational exposure to styrene on the components of metabolic syndrome. We surveyed 263 employees, among whom 117workers we ere chronically exposed to styrene in glass-reinforced plastic boat manufacturing factories and 146 controls had never been occupationally exposed to styrene as will as hazardous chemicals. The general and job characteristics such as age, smoking and drinking habit, working hours and duration were not significant different except sleeping hours(p<0.05). Among the components of metabolic syndrome, the systolic blood pressure, total cholesterol, HDL-cholesterol and fasting glucose were significantly higher in exposed workers. On multiple logistic regression analysis for the components of metabolic syndrome, waist circumference was insulin (OR=1.129), blood pressure was MA(OR=14.724), fasting glucose(OR=1.191) and metabolic syndrome(OR=1.110) were significantly associated with insulin. The mean concentration of airborne styrene was $ 38.1{\pm}40.1$ ppm, blood concentrations of glucose and insulin and levels of HOMA-IR in over 50 ppm exposed group were higher than in blow 50 ppm exposed group. These results suggested that the exposure of styrene affects blood pressure, fasting glucose and insulin levels and that dysfunction and/or declination in glucose and insulin metabolism might induced ultimately insulin resistance and metabolic syndrome.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.266-272
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• 2013

Objectives: This study aimed to evaluate the effects of low-level exposure to toluene on T lymphocytes subpopulations.s. Methods: The study lasted from April to October 2010. The subjects were 390 male workers, among whom 137 were chronically exposed to toluene in video-tape manufacturing factories and 253 were controls had never been occupationally exposed to hazardous chemicals. The subpoupulations of CD4+, CD8+, CD16+ (natural killer cells) and total (CD3+) T lymphocytes were examined by two-color staining using monoclonal antibodies. The general and job characteristics of subjects were assessed through a self-administered questionnaire. Results: There was no significant difference in general and job characteristics between both groups. No significant difference in lipid peroxide level was observed between the control and exposed workers, but the concentration of hydrogen peroxide was significantly higher in the exposed workers. The numbers of CD16+ T lymphocytes in controls were significantly higher than those in exposed workers, but no significant differences were found in CD4+, CD8+ and CD3+ T lymphocytes. Hydrogen peroxide levels showed a significantly negative correlation with CD8+ (r = -0.29, p < 0.01), CD16+ (r = -0.56, p < 0.01) and CD3+(r = -0.22. p < 0.01), and toluene levels was significantly negative correlated with CD3+ (r = -0.29, p < 0.05). Conclusions: Our results suggest that chronic low-level exposure to toluene affects cell-mediated immunity and the effects might mediate through ROSs (Reactive Oxygen Species) such as hydrogen peroxide.

• Journal of the Korean Institute of Gas
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• v.17 no.6
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• pp.73-82
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• 2013

With remarkable development of industry and technology, various chemical articles are developed to improve the quality of human life, yet some of chemicals are hazardous to human and the environment. However, safety control of chemical articles such as transportation, storage, and handling is emerging as a major issue lately. The road transportation needs well-organized safety management system, especially it has high probability of accidents. In this research, we point out problems in current state and related regulation of transportation of dangerous goods to compare the regulation in UN-RTDG. In addition, we suggest the enhancement law, the plan for standardization of classification in road transportation of dangerous goods and harmonization of labeling in transportation of dangerous goods to contribute to human health and environment protection.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.14-20
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• 2015

A Large Eddy Simulation(LES) was performed for the prediction of unsteady dispersion behavior of hydrogen fluoride (HF). The HF leakage accident occurred at the Gumi fourth industrial complex was numerically investigated using the Fire Dynamics Simulator (FDS) based on the LES. The accident area was modeled three-dimensionally and time-varying boundary conditions for wind were adopted in the simulation for considering the realistic accident conditions. The Message Passing Interface (MPI) parallel computation technique was used to reduce the computational time. As a result, it was found that the present LES simulation could predict the unsteady dispersion features of HF near the accident area effectively. The dispersion behaviors of the leaked HF was much affected by the unsteady wind direction. The LES could predict the time variation of the HF concentration reasonably and give an useful information for the risk analysis while the prediction with the time-averaging concept of HF concentration had a limitation for the amount of HF concentration at specific location point. It was identified that the LES is very useful to predict the dispersion characteristics of hazardous chemicals.