• Environmental Analysis Health and Toxicology
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• v.10 no.1_2
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• pp.37-46
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• 1995

The purpose of this research is to estimate a safe environmental level of human exposure to thresholding-acting toxicants in drinking water and recommend the acceptable levels and management plans for maintaining good quality of drinking water' and protecting health hazard. This research has been funded as a national project for three years from 1992 to 1995. This study(the second year, 1993-1994) was conducted to monitor 39 species of noncarcinogenic chemicals such as volatile organic compounds(VOCs), polynuclear aromatic hydrocarbens(PAHs), pesticides and heavy metals of drinking water at some area in six cities of Korea, and evaluate health risk due to these chemicals through four main steps (hazard identification, exposure assessment, dose-response assessment and risk characterization) of risk assessment in drinking water. In hazard identification, 39 species of non-carcinogenic chemicals were identified by the US EPA classification system. In the step of exposure assessment, sampling of tap water from the public water supply system had been conducted from 1993 to 1994, and 39 chemicals were analyzed. Inclose-response assessment for non-carcinogens, reference doses(RfD) and lifetime health advisories(HAs) of lifetime acceptable levels were calculated. In risk characterization of detected chemicals, the hazard quotients of noncarcinogens were less than one except those of manganese and iron in D city.

• The Journal of Engineering Geology
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• v.22 no.3
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• pp.353-363
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• 2012

The geology of Ulleung-Do is dominated by volcanic rocks with low strength and trachytic rocks with high strength but containing vertical joints that yield easily. Consequently, rockfalls along roadcuts are a major geological hazard, with the potential to affect the ring road of Ulleung-Do. In this study, we performed three types of rockfall hazard-risk assessment on the 3-km-long section of the ring road expected to have the highest possibility of rockfall. We used a rockfall ranking sheet in a roadside landslide hazard map, the Slope Stability Inspection Manual for National Highways (Japan), and a rockfall hazard rating system for inspection from the Japan Highway Public Corporation. We also employed the evaluation criteria of 'RHRS' developed by the Federal Highway Administration (FHA). An analysis of roadcuts at 27 sites with regard to geographic and geological conditions resulted in the identification of three classes of rockfall hazard (high, medium, and low). Of note, over 74% of slopes were assessed as high- and medium-class. Finally, a rockfall hazard map of the northeast region of Ulleung-Do was produced based on the evaluation results.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.4
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• pp.293-300
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• 2012

Objectives: In chemical hazard communication, information receiver's perception is a important factor, but the study on the perception was few. Therefore, this study evaluated the perception of managers and workers group about chemical hazard communication by chemical hazard communication tools that were being used in fields. Methods: 91 managers and 238 workers were surveyed in two companies where use chemicals. All subjects were asked about the comprehensibility and perception for MSDS and GHS Pictograms being used in their workplaces through face-to-face interviews. Results: Most of the respondents knew MSDS, and more than half of the respondents had used MSDS once or more per year. The level of use to find the information on chemicals with MSDS was higher in the managers in comparison with workers. Also, the managers could understand and find the information on MSDS easier(p < 0.05). In the question asking the meaning of GHS Pictograms, the managers responded more correctly, as well(p < 0.05). 86.8% of the managers and 62.6% of the workers were conscious of the possible health hazards of chemicals that they could be exposed at work. However, among the respondents conscious of the health hazards, only less than 70% were well aware of the contents of the health hazards correctly. Conclusions: In chemical hazard communication, it is very important to evaluate whether information receiver have proper and correct knowledge and perception or not and actions based on the evaluations as well as provide correct information.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1294-1301
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• 2010

In this study, a case study, where a hazard management for tunnel collapses has been quantitatively undertaken based on the KICT Tunnel Hazard(KTH) index, is presented. From this, it was able to timely inform the field engineers when the more detailed investigation is required for checking if any risky factor is shown on the tunnel face. At the same time, variable additional information such as sensitivities of major influence factors are also provided to field engineers from the methodology given in this study. The additional information would be helpful for better understanding of tunnel hazard level at the current tunnelling stage and following the required actions for more detailed checks of risky factors.

• Structural Engineering and Mechanics
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• v.69 no.3
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• pp.317-326
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• 2019

This research aims to assess the tight seismic risk curve of the intake tower at Geumgwang reservoir by considering the recorded historical earthquake data in the Korean Peninsula. The seismic fragility, a significant part of risk assessment, is updated by using Bayesian inference to consider the uncertainties and computational efficiency. The reservoir is one of the largest reservoirs in Korea for the supply of agricultural water. The intake tower controls the release of water from the reservoir. The seismic risk assessment of the intake tower plays an important role in the risk management of the reservoir. Site-specific seismic hazard is computed based on the four different seismic source maps of Korea. Probabilistic Seismic Hazard Analysis (PSHA) method is used to estimate the annual exceedance rate of hazard for corresponding Peak Ground Acceleration (PGA). Hazard deaggregation is shown at two customary hazard levels. Multiple dynamic analyses and a nonlinear static pushover analysis are performed for deriving fragility parameters. Thereafter, Bayesian inference with Markov Chain Monte Carlo (MCMC) is used to update the fragility parameters by integrating the results of the analyses. This study proves to reduce the uncertainties associated with fragility and risk curve, and to increase significant statistical and computational efficiency. The range of seismic risk curve of the intake tower is extracted for the reservoir site by considering four different source models and updated fragility function, which can be effectively used for the risk management and mitigation of reservoir.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.2
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• pp.140-148
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• 2012

Objectives: This study was performed to provide harmonized guidelines on health and environmental classification criteria and its results of chemicals in Korea. Methods: Firstly, The history of GHS implementation in UN and Korea was reviewed. Secondly, the differences in classification criteria on health and environmental hazards among UN GHS and two Korean government agencies, Korea Ministry of Employment and Labour (KMoEL) and Korea Ministry of Environmental (KMoE). The classification results were compared between classifications of Korea Occupational Safety and Health Agency (KOSHA) based on KMoEL and classifications of Korea National Institute of Environmental Research (KNIER) based on KMoE. Finally, an inter-agency harmonization on the classification criteria and the results was suggested by comparing the classification results of 5 chemicals; Benzene, carbon disulfide, formaldehyde, toluene-2,4-diisocyanate, and trichloroethylene. Results: KMoEL and KMoE revised regulations on chemical management and published a Notices on GHS classification criteria according to UN GHS document. However, the hazard to the ozone layer contained in the latest edition of UN GHS document published in 2011 was not included yet. The differences in classifications of 5 chemicals between KOSHA and KNIER were 36.2% in health hazards and 23.4% in environmental hazards, respectively. In conclusion, we suggested that a new revision be needed to include newly contained hazard and inter-agency working party be organized to harmonize classification results.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.111-115
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• 2009

In Korea, the probabilistically developed seismic hazard maps are used with deterministically derived seismic site coefficients in developing the design response spectrum of a specific site. Even though the seismic hazard maps and seismic site coefficients are incompatible, the current design code ignores such incompatibility. If the seismic hazard map and seismic coefficients are both developed in identical probabilistic framework, such problems can be solved. Unfortunately, the available method cannot be use to derive "true" probabilistic site coefficients. This study uses the ground motion time histories, which were developed as the result of a new probabilistic seismic hazard analysis in the companion paper, as input motions in performing one-dimensional equivalent linear site response analyses, from which the uniform hazard response spectra are generated. Another important characteristic of the hazard response spectra are that the uncertainties and randomness of the ground properties are accounted for. The uniform hazard spectra are then used to derive probabilistic site coefficients. Comparison of probabilistic and deterministically site coefficients demonstrate that there is a distinct discrepancy between two coefficients.

• Wind and Structures
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• v.35 no.4
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• pp.287-296
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• 2022

Analyzing the typhoon wind hazards is crucial to determine the extreme wind load on engineering structures in the typhoon prone region. In essence, the typhoon hazard analysis is a high-dimensional problem with randomness arising from the typhoon genesis, environmental variables and the boundary layer wind field. This study suggests a dimension reduction approach by decoupling the original typhoon hazard analysis into two stages. At the first stage, the randomness of the typhoon genesis and environmental variables are propagated through the typhoon track model and intensity model into the randomness of the key typhoon parameters. At the second stage, the probability distribution information of the key typhoon parameters, combined with the randomness of the boundary layer wind field, could be used to estimate the extreme wind hazard. The Chinese southeast coastline is taken as an example to demonstrate the adequacy and efficiency of the suggested decoupling approach.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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• pp.1-10
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• 2007

This study accomplished to grasp the present condition of HAPs and to examine efficiently carcinogenic and non-carcinogenic health effects through health risk assessment in new apartments from June, 2004 to May,2005. Moreover, we performed uncertainty analysis by Monte-Carlo analysis to control uncertainty of exposure factors. The major results obtained from this study were as follows. Firstly, cancer risk of formaldehyde for male was $1.67{\times}10^{-5}$ in CTE in point estimation. Cancer risk of formaldehyde was showed $2.94{\times}10^{-3}$ in RME that applied worst case used results of 95 percentile in point estimation. It exceeds $10^{-6}$ of guide line in US EPA. Moreover, cancer risks of formaldehyde for female were $3.98{\times}10^{-5}$ in CTE and $3.93{\times}10^{-3}$ RME. Secondly, every hazard index for non-carcinogenic pollutants was less than 1 of permitted standards in CTE. However, in RME of male, hazard indexes of 1,2-Dichloropropane and Toluene were 1.3 and 2.0, respectively. Hazard indexes of 1,2-Dichloropropane and Totuene for female in RME were 1.7 and 2.6, respectively.

• Journal of Environmental Health Sciences
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• v.46 no.4
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• pp.410-422
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• 2020

Objectives: According to the Act on Registration, Evaluation, Etc. of Chemicals, new and existing chemicals must be registered by 2030. In addition, industries need to submit hazard data as an attachment during the registration process. Therefore, we constructed a nationwide chemical database to support small industry by providing hazard data and original sources. During the process, we developed a new standard procedure for minimizing errors and increasing reliability. Methods: We analyzed the categories of errors and the cause of the errors through the verification results of the 2019 project. We present an improved database construction methodology and system. Results: Errors are categorized according to their causative factors into simple, technical, and structural type errors. Simple errors arise simply because of decreased concentration or negligence in following the instructions. Technical errors are caused by a discrepancy between the professional field and the type of data. Structural errors indicate systemic errors such as incomplete forms on the excel database or ambiguity in the guidelines. Lessons from the errors collected in the 2019 project are used to update the procedures for database authorization and technical guidelines. The main update points are as follows; 'supplementation of review process', 'giving regular training to external reviewers', 'giving additional information to authors, like physico-chemical properties of substances, degradability, etc.', 'amendment of excel form', and 'guideline upgrades'. Conclusions: We conducted this study with the aim of improving the accuracy and reliability of the database of hazard information for chemical substances. The new procedures and guidelines are now being used in the 2020 project for construction of a hazard information database for Korea.