• Korean journal of food and cookery science
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• v.31 no.2
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• pp.153-161
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• 2015

This study was conducted to investigate the consumption practices of ready-to-eat (RTE) foods and to analyze the microbiological hazard of kimbab, a Korean dish, and the most popular of the RTE foods eaten by participants in this study. A questionnaire was distributed to 230 university students who had previously purchased RTE foods, and 224 were collected (response rate: 97.4%). Statistical analyses were conducted on the questionnaires using the SPSS program, and a total of 135 kimbab products were sampled for aerobic plate counts, coliforms, E. coli, E. coli O157:H7, Staphylococcus aureus, Salmonella spp., and Listeria monocytogenes. The results of the analyses are as follows. Kimbab (87.0%), sandwich (86.4%), hamburger (89.8%), lunchbox (81.5%), and sushi (87.4%) were most often eaten immediately after purchasing. Additionally, the results of the microbiological hazards analysis of kimbab showed that the aerobic plate counts were significantly different according to the purchasing price (p<0.01). The coliform levels were significantly different according to the place of purchase (p<0.01) and the major ingredients of kimbab (p<0.05). In addition, Staphylococcus aureus and E. coli were detected in 5.9% and 5.2% of the tested samples, respectively. However, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes were not detected in any of the samples. In conclusion, the manufacturers of RTE foods should apply the HACCP system for food safety.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.2
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• pp.230-239
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• 2018

Objective: The purpose of this study is to identify the kinds and exposure levels of health hazards in the metalworking process in relation to acute poisoning accidents caused by methanol in 2016. Methods: The number of industries, workplaces, exposed workers, regional distribution, and exposure level of health hazards in metalworking process were investigated based on employee exposure assessment database provided by KOSHA (the Korea Occupational Safety and Health Agency), which was collected from workplace hazard evaluation programs in Korea. Exposure metrics for methanol were assessed by RCR (risk characterization ratio). Results: The numbers of processes, workplaces, and exposed workers of metalworking, which include CNC (computer numerical control) were 25, 14,405, and 169,102 respectively. The numbers of samples of chemical hazards including methanol were 91,325, and it was found that workers in metalworking were exposed to 249 kinds of chemical hazards. There were 16 kinds of special controlled substances including beryllium. It is estimated that the number of workplaces involving CNC process was 2,537, and the number of exposed workers was 27,976. In CNC process, the total number of workplaces handling methanol was 36, and 298 workers were estimated to be exposed. There was no exceeded that surpassed the OEL and 49% of samples were below the limit of detection. Methanol exposure concentrations in Gyeonggido Province were statistically significantly higher than in other areas (p <0.0001). Conclusions: In the metalworking process including CNC, there is exposure to a wide variety of health hazards. There was no sample exceeding the OEL for methanol. Therefore, it is necessary to recognize the limits of the employee exposure assessment system and urgently improve measures to prevent the occurrence of events like methanol poisoning.

• Preventive Nutrition and Food Science
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• v.18 no.2
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• pp.145-149
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• 2013

We tested for residual pesticide levels in dried vegetables in Seoul, Korea. A total of 100 samples of 13 different types of agricultural products were analyzed by a gas chromatography-nitrogen phosphate detector (GC-NPD), an electron capture detector (GC-${\mu}ECD$), a mass spectrometry detector (GC-MSD), and a high performance liquid chromatography- ultraviolet detector (HPLC-UV). We used multi-analysis methods to analyze for 253 different pesticide types. Among the selected agricultural products, residual pesticides were detected in 11 samples, of which 2 samples (2.0%) exceeded the Korea Maximum Residue limits (MRLs). We detected pesticide residue in 6 of 9 analyzed dried pepper leaves and 1 sample exceeded the Korea MRLs. Data obtained were then used for estimating the potential health risks associated with the exposures to these pesticides. The estimated daily intakes (EDIs) range from 0.1% of the acceptable daily intake (ADI) for bifenthrin to 8.4% of the ADI for cadusafos. The most critical commodity is cadusafos in chwinamul, contributing 8.4% to the hazard index (HI). This results show that the detected pesticides could not be considered a serious public health problem. Nevertheless, an investigation into continuous monitoring is recommended.

• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.19-26
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• 2009

It is becoming more and more important to develop safety-critical systems with special attention. Examples of the safety-critical systems include the mass transportation systems such as high speed trains, airplanes, ships and so forth. Safety critical issues can also exist in the development of atomic power plants that are attracting a great deal of attention recently as oil prices are sky-rocketing. Note that the safety-critical systems are in general large-scale and very complex for which case the effects of adopting the systems engineering (SE) approach has been quite phenomenal. Furthermore, safety-critical requirements should necessarily be realized in the design phase and be effectively maintained thereafter. In light of these comments, we have considered our approach to developing safety-critical systems to be based on the method combining the systems engineering and safety management processes. To do so, we have developed a design environment by constructing a whole life cycle model in two steps. In the first step, the integrated process model was developed by integrating the SE (ISO/IEC 15283) and systems safety (e.g., hazard analysis) activities and implemented in a computer-aided SE tool environment. The model was represented by three hierarchical levels: the life-cycle level, the process level, and the activity level. As a result, one can see from the model when and how the required SE and safety processes have to be carried out concurrently and iterately. Finally, the design environment was verified by the computer simulation.

• Safety and Health at Work
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• v.9 no.3
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• pp.290-295
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• 2018

Background: There is little information on the dose-response relationship between exposure to occupational carcinogenic agents and mesothelioma. This study aimed to investigate this association as well as the existence of agents other than asbestos that might cause mesothelioma. Methods: The Swedish component of the Nordic Occupational Cancer (NOCCA) study consists of 6.78 million individuals with detailed information on occupation. Mesothelioma diagnoses recorded in 1961-2009 were identified through linkage to the Swedish Cancer Registry. We determined cumulative exposure, time of first exposure, and maximum exposure intensity by linking data on occupation to the Swedish NOCCA job-exposure matrix, which includes 29 carcinogenic agents and corresponding exposure for 283 occupations. To assess the risk of mesothelioma, we used conditional logistic regression models to estimate hazard ratios and 95% confidence intervals. Results: 2,757 mesothelioma cases were identified in males, including 1,416 who were exposed to asbestos. Univariate analyses showed not only a significant excess risk for maximum exposure intensity, with a hazard ratio of 4.81 at exposure levels 1.25-2.0 fb/ml but also a clear dose-response effect for cumulative exposure with a 30-, 40-, and 50-year latency time. No convincing excess risk was revealed for any of the other carcinogenic agents included in the Swedish NOCCA job-exposure matrix. Conclusion: When considering asbestos exposure, past exposure, even for short periods, might be enough to cause mesothelioma of the pleura later in life.

• Journal of Preventive Medicine and Public Health
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• v.45 no.1
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• pp.21-28
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• 2012

Objectives: The aim of this study was to investigate whether a medium to high degree of total physical activity and indoor physical activity were associated with reduced all-cause and cardiovascular mortality among elderly Korean women. Methods: A prospective cohort study was done to evaluate the association between physical activity and mortality. The cohort was made up of elderly (${\geq}65$ years of age) subjects. Baseline information was collected with a self-administered questionnaire and linked to death certificates retrieved from a database. Cox proportional hazard models were used to estimate the hazard ratios (HRs) with 95% confidence interval (CI) levels. Results: Women who did not suffer from stroke, cancer, or ischemic heart disease were followed for a median of 8 years (n=5079). A total of 1798 all-cause deaths were recorded, of which 607 (33.8%) were due to cardiovascular disease. The group with the highest level of total physical activity and indoor physical activity was significantly associated to a reduced all-cause mortality (HR, 0.60; 95% CI, 0.51 to 0.71 and HR, 0.58; 95% CI, 0.50 to 0.67, respectively) compared to the group with the lowest level of total physical activity and indoor physical activity. Additionally, the group with the highest level of total physical activity and indoor physical activity was significantly associated to a lower cardiovascular disease mortality (HR, 0.53; 95% CI, 0.40 to 0.71 and HR, 0.51; 95% CI, 0.39 to 0.67, respectively) compared to the group with the lowest level of total physical activity and indoor physical activity. Conclusions: Our study showed that regular indoor physical activity among elderly Korean women has healthy benefits.

• Journal of Radiation Industry
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• v.11 no.1
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• pp.39-45
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• 2017

A cyclotron is a kind of particle accelerator that produces a beam of charged particles for the production of medical, industrial, and research radioisotopes. More than 30 cyclotrons are operated in Korea to produce $^{18}F$, an FDG synthesis at hospitals. A 30-MeV cyclotron was installed at ARTI (Advanced Radiation Technology Institute, KAERI) mainly for research regarding isotope production. In this study, we analyze and estimate the items of risk such as the problems in the main components of the cyclotron, the loss of radioactive materials, the leakage of coolant, and the malfunction of utilities, fires and earthquakes. To estimate the occurrence frequency in an accident risk assessment, five levels, i.e., Almost certain, Likely, Possible, Unlikely, and Rare, are applied. The accident consequence level is classified under four grades based on the annual permissible dose for radiation workers and the public in the nuclear safety law. The analysis of the accident effect is focused on the radioactive contamination caused by radioisotope leakage and radioactive material leakage of a ventilation filter due to a fire. To analyze the risks, Occupation Safety and Health Acts is applied. In addition, action plans against an accident were prepared after a deep discussion among relevant researchers. In this acts, we will search for hazard and introduce the risk assessment for the research 30-MeV cyclotron facilities of ARTI.

• Journal of Biomedical Engineering Research
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• v.39 no.6
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• pp.243-249
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• 2018

The indoor radon concentration was measured in the lecture room of the university and the radon concentration was converted to the amount related to the radon exposure using the dose conversion convention and compared with the reference levels for the radon concentration control. The effect of indoor radon inhalation was evaluated by estimating the life effective dose and the risk of exposure. To measure the radon concentration, measurements were made with a radon meter and a dedicated analysis Capture Ver. 5.5 program in a university lecture room from January to February 2018. The radon concentration measurement was carried out for 5 consecutive hours for 24 hours after keeping the airtight condition for 12 hours before the measurement. Radon exposure risk was calculated using the radon dose and dose conversion factor. Indoor radon concentration, radon exposure risk, and annual effective dose were found within the 95% confidence interval as the minimum and maximum boundary ranges. The radon concentration in the lecture room was $43.1-79.1Bq/m^3$, and the maximum boundary range within the 95% confidence interval was $77.7Bq/m^3$. The annual effective dose was estimated to be 0.20-0.36 mSv/y (mean 0.28 mSv/y). The life-time effective dose was estimated to be 0.66-1.18 mSv (mean $0.93{\pm}0.08mSv$). Life effective doses were estimated to be 0.88-0.99 mSv and radon exposure risk was estimated to be 12.4 out of 10.9 per 100,000. Radon concentration was measured, dose effective dose was evaluated using dose conversion convention, and degree of health hazard by indoor radon exposure was evaluated by predicting radon exposure risk using nominal hazard coefficient. It was concluded that indoor living environment could be applied to other specific exposure situations.

• Journal of Korean Academy of Nursing
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• v.50 no.6
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• pp.837-847
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• 2020

Purpose: The purpose of this study was to investigate the effects of hospital characteristics on employment rate, working period, and retirement of ward nurses in Korea through a retrospective cohort study based on HIRAS data. Methods: Data were obtained from a report on medical care institutions of Health Insurance Review & Assessment Service (HIRAS). Data from 259,941 nurses who were working for a day or more from January 1, 2012, to December 31, 2016, at 2,942 medical care institutions were analyzed. Life table method analysis, Kaplan-Meier analysis, and Cox proportional hazard regression analysis were conducted. Results: The employment rates of 5 yeas and 10 years for the total sample were 38% and 28%, respectively. The estimated mean value of the working period was 3,642.7 days (SE: 17.4 days). Cox proportional hazard regression analyses revealed that nurses who were working at the general hospital/hospital, clinic, and nursing hospital were more likely to leave the hospital compared to those who were working at the 3rd general hospital. Nurses who were working at the medical institutions which were located in cities and countries, established by the private foundation, rated lower levels of nursing, and owned an insufficient number of beds, nurses and doctors were more likely to leave their workplace compared to those of the counterparts. Conclusion: This study indicates that hospital characteristics may play a significant role in retirement and working period of ward nurses in Korea. The improvement of hospital conditions to reduce ward nurses' retirement are needed.

• Korean Journal of Radiology
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• v.24 no.6
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• pp.590-598
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• 2023

Objective: To investigate whether the levels of inflammation detected by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) can predict disease relapse in immunoglobulin G4-related disease (IgG4-RD) patients receiving standard induction steroid therapy. Materials and Methods: This prospective study analyzed pretherapy FDG PET/CT images from 48 patients (mean age, 63 ± 12.9 years; 45 males and 3 females) diagnosed with IgG4-RD between September 2008 and February 2018, who subsequently received standard induction steroid therapy as the first-line treatment. Multivariable Cox proportional hazards models were used to identify the potential prognostic factors associated with relapse-free survival (RFS). Results: The median follow-up time for the entire cohort was 1913 days (interquartile range [IQR], 803-2929 days). Relapse occurred in 81.3% (39/48) patients during the follow-up period. The median time to relapse was 210 days (IQR, 140-308 days) after completion of standardized induction steroid therapy. Among the 17 parameters analyzed, Cox proportional hazard analysis identified whole-body total lesion glycolysis (WTLG) > 600 on FDG-PET as an independent risk factor for disease relapse (median RFS, 175 vs. 308 days; adjusted hazard ratio, 2.196 [95% confidence interval: 1.080-4.374]; P = 0.030). Conclusion: WTLG on pretherapy FDG PET/CT was the only significant factor associated with RFS in IgG-RD patients receiving standard steroid induction therapy.