• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.236-243
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• 2022

Background: In the case of multiple exposures to different types of heavy metals, such as the conditions faced by residents living near a smelter, it would be preferable to group hazardous substances with similar characteristics rather than individually related substances and evaluate the effects of each group on the human body. Objectives: The purpose of this study is to evaluate the utility of factor analysis in the assessment of health effects caused by exposure to two or more hazardous substances with similar characteristics, such as in the case of residents living near a smelter. Methods: Heavy metal concentration data for 572 people living in the vicinity of the Janghang smelter area were grouped based on several subfactors according to their characteristics using factor analysis. Using these factor scores as an independent variable, multiple regression analysis was performed on health effect markers. Results: Through factor analysis, three subfactors were extracted. Factor 1 contained copper and zinc in serum and revealed a common characteristic of the enzyme co-factor in the human body. Factor 2 involved urinary cadmium and arsenic, which are harmful metals related to kidney damage. Factor 3 encompassed blood mercury and lead, which are classified as related to cardiovascular disease. As a result of multiple linear regression analysis, it was found that using the factor index derived through factor analysis as an independent variable is more advantageous in assessing the relevance to health effects than when analyzing the two heavy metals by including them in a single regression model. Conclusions: The results of this study suggest that regression analysis linked with factor analysis is a good alternative in that it can simultaneously identify the effects of heavy metals with similar properties while overcoming multicollinearity that may occur in environmental epidemiologic studies on exposure to various types of heavy metals.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.845-846
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• 2011

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.235-247
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• 1999

This study was performed to investigate what was the most serious occupational factors in small scale industries. Twenty-three occupatonally hazardous substances were measured at the five workplaces in the Eastern Seoul during 1995∼1996. Total of 2,020 samples were analyzed by either GC/FID for organic vapors or AAS for heavy metals. From the results of this study noise was the most serious factor at the selected workplaces. Noise level in the metal processing, the printing, and the auto repairing industries exceeded the 8 hr PEL by 19.7%, 13.6%, and 11.6%, respectively. Mean concentrations of toluene in the shoe making and the printing industries exceeded the assessment crieterion by 6.0% and 3.8%, respectively. Further study of risk assessment of occupational exposure may be required to protect workers from hazardous working conditons.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.3
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• pp.401-417
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• 2011

The purpose of this study was to investigate consumer concerns about hazardous elements on foods and recognition of the roles of government, food producers, and consumers in securing food safety. The data were collected from the 443 adult consumers living in Seoul, Busan, Daegu, Incheon, Kwangju and Daejeon through a self-administered questionnaire. Frequencies, t tests, analysis of variance and Duncan's multiple range tests were conducted using SPSS Windows. The results of the survey were as follows: (1) the respondents were worried about health risks related to hazardous elements on foods, (2) many respondents were more worried about preservatives of imported foods than those of domestic foods, and (3) most respondents mentioned that observance of enforcement regulations by producers was the most important factor for ensuring food safety in the future. These results imply that regulations regarding the safety of imported foods should be increased.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.1
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• pp.73-79
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• 2009

Hazardous materials (HazMats) are substances that are flammable, explosive, toxic, or harmful, if released into the environment. Since the transportation of HazMats increases in many developed countries, HazMat transportation has the key function in the process of HazMat usage to trace information of production, storage, shipment, usage, and waste disposal. The Korean Ministry of Environment (KMOE) and the National Emergency Management Agency (NEMA) have developed many laws, regulations, and standards for hazardous materials. However, the Korean HazMat laws, regulations, and standards do not guarantee accurate information of HazMat origin-destination (O-D) shipments, though the HazMat O-D movement is the critical information in safety and security of HazMat transportation. The objectives of this research are: (1) to investigate emerging and recurrent issues in Korean HazMat transportation, and (2) to develop the estimation method of O-D matrices for hazardous materials under limited data sets. The sodium hydroxide waste shipment among forty candidate HazMats is selected as the sample research case. The growth-factor method is applied to estimate the 2005 O-D matrix of sodium-hydroxide waste shipment. The column-and-row factoring process is used to calibrate the estimated sodium-hydroxide O-D matrix. The result shows the applicability of the O-D estimation process for hazardous materials. The Sodium Hydroxide Waste Origin-Destination Matrix is obtained to trace routes and paths of the Sodium Hydroxide transportation.

• Journal of Preventive Medicine and Public Health
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• v.23 no.3 s.31
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• pp.275-284
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• 1990

To obtain the useful information for the status of working environment and health management of workers in manufacturing industries, comparision of results on the status of working environmental and health management of workers for 32 manufacturing industries in Chunan area from 1988 to 1989 was carried out. The results were as follows : 1. The rate of over-PEL (Permissible Exposure Limit) to for hazardous factors decreased significantly 23.5% in 1988, 18.3% in 1989 (p<0.05) and, the highest rate of over-PEL was the stone and sand handling industry, the highest rate of over-PEL was the dusty workplace as 38.5% in 1988, 35.2% in 1989. 2. The rate of workers exposed to hazardous factors in 1988 and in 1989 was 22.4% respectively, the rate of workers checked up special health examination was 40.1% in 1988, 75.3% in 1989. In stone and sand handling and medicochemical industries, none of workers exposed to hazardous factors was subjected to special health examination in 1988, but 75% of workers exposed to hazardous factors had checked up in 1989. 3. The 6 industries appointed as part-time factory physician among 17 industries which were supposed to have factory physician according to the Safety and Healthy Act of Korea, 6 out of 24 industries only appointed industrial hygienist, furthermore 4 out of 6 hygienists had another duty in addition to occupational hygiene itself.

• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.81-85
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• 2002

This paper presents the calculation methods of liquid release rate in the transition region when hazardous materials leak from the pipeline due to an unwanted accident. For the laminar and turbulent flow region, liquid release rate from a pipeline can be calculated by using a commercial software or by using calculator based on the models(equations) suggested by Crowl and Louvar et al. However, there has been no corresponding model for the transition flow region. In this paper. we showed that the turbulent model may be used as an equation generally used in the transition region for conservative hazard analysis if safety factor $30\%$ is added to the value calculated by the turbulent model. In this regard, we first calculated the release rate from liquid pipeline in the transition region by using experimental data on Fanning friction factor depending on Reynolds number which Lap-Mou Tam et al. had introduced, then compared it with that of the laminar and turbulent models in transition region.

• Journal of Environmental Science International
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• v.13 no.7
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• pp.703-710
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• 2004

Petroleum refineries have been considered as an important emission source for atmospheric volatile hazardous air pollutants(HAPs). The emission source includes petroleum refinery processes and process equipment. The control strategy for volatile HAPs requires emission estimations of these pollutants. However, systematic methods of volatile HAPs emission from petroleum refineries have not yet been established. Accordingly, present study surveyed the estimation method of volatile HAPs emitted from the petroleum refinery processes and process equipment. The emission estimation methods for the petroleum refinery processes are applied for 11 petroleum refining facilities: fluidized catalytic cracking, thermal cracking, moving bed catalytic cracking, compressed engine, blowdown system, vacuum distilled column condensator, natural gas or distilled boiler, natural gas or distilled heater, oil boiler, oil heater and flare. Four emission estimation methods applied for the petroleum refinery process equipment are as follows: average emission factor approach, screening ranges approach, EPA correlation approach and unit-specific correlation approach. The process equipment for which emission factors are available are valves, pump seals, connectors, flanges and open-ended lines.

• Korean Journal of Health Education and Promotion
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• v.22 no.4
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• pp.203-213
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• 2005

Purpose: To assess the environmental hazards of falling accident in the homes of the elderly. Method: 222 homes of the elderly were assessed by the home environmental Checklist from May to July in 2003. Results: The mean score of home environmental hazards for fall were 13.19 with the highest score being 49, ranging from 4 to 24. The bathroom was the most hazardous place in the home, porch came next bedroom, kitchen, living room and stair followed them. The floor surface such as finishes and non-skid mats was the most hazardous interior factor in the home, using bathroom came next furniture and illumination followed them. The floor surface such as finishes and non-skid mats in the bathroom, kitchen, living room and porch, illumination of bedroom and stair were the most prevalent hazards in the home of interior. Of the 49 potential hazards, bathroom grab bar was the most prevalent one with 89.9%, and non-skid rugs in the porch, bathroom and kitchen, safety of dinner table, the threshold and furniture of porch, and illumination of bedroom were prevalent more than half of the home under assessing. Men, living in the separate house or villa with stairs were in more hazardous environments. Conclusion: To reduce the potential hazards of fall accident in the home, improving hazards relating to floor surface such as slip resistance surface and mats is important specially those of the separate house or villa with stairs.

• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.21-29
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• 2018

In many companies handling flammable liquids, explosion-proof electrical equipment have been installed according to the Korean Industrial Standards (KS C IEC 60079-10-1). In these standards, hazardous area for explosive gas atmospheres has to be classified by the evaluation of the evaporation rate of flammable liquid leakage. The evaporation rate is an important factor to determine the zones classification and hazardous area distance. However, there is no systematic method or rule for the estimation of evaporation rate in these standards and the first principle equations of a evaporation rate are very difficult. Thus, it is really hard for industrial workplaces to employ these equations. Thus, this problem can trigger inaccurate results for evaluating evaporation range. In this study, empirical models for estimating an evaporation rate of flammable liquid have been developed to tackle this problem. Throughout the sensitivity analysis of the first principle equations, it can be found that main factors for the evaporation rate are wind speed and temperature and empirical models have to be nonlinear. Polynomial regression is employed to build empirical models. Methanol, benzene, para-xylene and toluene are selected as case studies to verify the accuracy of empirical models.