• Journal of the Korean Home Economics Association
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• v.46 no.1
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• pp.39-45
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• 2008

We analyzed the effects of regular Jjimjilbang(Korean sauna) exposure on the physiological responses in seven elderly farmers(Male=3, Female=4). Jjimjil training group took a bath in Jjimjilbang 8 times twice a week. Jjimjibang exposure was limited three times per day. Rectal temperature, total sweat rate, body fat (%), blood pressure, pulse, $Na^+$ concentration in sweat, and subjective sensation were measured during Jjimjil training exposure. The results are as follow: During Jjimjil exposure, changes of rectal temperature in male farmers were more stabilized than female farmers. The gradual decrease in total sweat rate and Na+ concentration in sweat was observed in both sexes. After Jjimjil exposure, the decrease in blood pressure was observed in both sexes, but not observed changes according to regular Jjimjil exposure. Subjective thermal comfort sensation was changed positively. In conclusion, the regular Jjimjil exposure has positive effects upon improvement in regulation of body temperature, blood pressure, and $Na^+$ concentration especially in heat tolerance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1085-1092
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• 2010

This paper describes the development of estimating equation for under 16 aged children's exposure to habitat's magnetic field for 24 hours by using particle swarm optimization(PSO) algorithm, which was carried out by using the measured database collected from the exposure survey to Korean habitat's magnetic field as to under 16 aged Korean students such as preschooler, children in elementary school, and children in middle school. Sex, age, residence type, size of habitation site, distance from power line, and power transmission voltage are used as the input data of estimating 24 hour's personal exposure to magnetic field. And distribution of 24 hour's personal exposure to magnetic field, exposure characteristic to magnetic field, and exposure characteristic to magnetic field according to special conditions, are analyzed for under 16 aged children.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.1
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• pp.100-107
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• 2018

Objectives: This study examines exposure to hazardous substances in the working environment caused by exposure to toxic substances produced in the aluminum die casting process in the automobile manufacturing industry. Materials and Methods: The exposure concentration levels, detection rates and time-trend of 15 hazardous factors in the aluminum die casting process over 10 years(from 2006 to 2016) were used as a database. Results: The study found that hazardous factors in the aluminum die casting process were mostly metals. The rate for detected samples was 70.6%(405 samples), and that for not detected samples was 29.4%. The noise for an eight-hour work shift showed a 49.7% exceedance rate for TLV-TWA. Average noise exposure was 89.0 dB. The maximum exposure level was 105.1 dB. Conclusion: The high numbers of no-detection rates for hazardous substance exposure shows that there is no need to do a work environment measurement. Therefore, alternatives are necessary for improving the efficiency and reliability of the work environment measurement. Moreover, to prevent noise damage, reducing noise sources from automation, shielding, or sound absorbents are necessary.

• Journal of Preventive Medicine and Public Health
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• v.19 no.2 s.20
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• pp.177-183
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• 1986

Subjective symptoms, counts of blood cells and liver function test were conducted on 198 male workers who were exposed to toluene in Kyungin area from September to November, 1986. According to the level of urinary hippuric acid concentration, the total sample was classified into the high exposure group ($concentration{\geqq}3g/1$) and the low exposure group(concentration<3g/1). The following findings were obtained by comparing the two group: 1) Contrary to the previous findings. the urinary hippuric acid concentration of toluene exposed workers showed bimodal distribution. It meant that the toluene exposed workers were mixed with the non-exposed or minimal exposed workers. 2) The high exposure group showed a lower level of leucocytes counts ($6,630{\pm}1,860{\mu}l$) than the low exposure group ($6,340{\pm}1,960/{\mu}l$). 3) The high exposure group showed a higher level of SGOT, SGPT and r-GTP than the low exposure group (p<0.05). 4) The high exposure group complained much more subjective symptoms (e. g. skin rash, loss of appetite, palpitation) than the low exposure group.

• Journal of Sensor Science and Technology
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• v.27 no.6
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• pp.368-373
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• 2018

The effects of long-term exposure of high and low humidity on thin-film humidity sensors are investigated. Five commercially available thin-film humidity sensors are initially calibrated in a humidity chamber as a reference before longterm exposure to high and low humidity. Then, the sensors are kept in a high-humidity environment (~95 %rh) for four months. After the exposure, the sensors are calibrated in the same manner as the initial calibration. Consequently, the device reading values from the humidity sensors are elevated up to about 5 %rh. Interestingly, the degree of elevation by the high-humidity exposure shows a negative correlation with the price of the humidity sensors. Humidity sensors are then kept in a low-humidity environment (~10 %rh) for another four months. After the exposure, a calibration similar to the initial calibration is performed. As a result, the device reading from humidity sensors is decreased, indicating a recovery from the effect of high-humidity exposure. The durability test conducted in this study provides experimental evidence for the use of thin-film humidity sensors in high-humidity environments such as greenhouses and food factories for a long period of time.

• Nuclear Engineering and Technology
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• v.50 no.7
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• pp.1088-1098
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• 2018

Kori unit #1, which is the first commercial nuclear power plant in Korea, was permanently shutdown in June 2017, and it is about to be decommissioned. Currently in Korea, researches on the decommissioning technology are actively conducted, but there are few researches on workers internal exposure to radioactive aerosol that is generated in the process of decommissioning nuclear power plants. As a result, the over-exposure of decommissioning workers is feared, and the optimal working time needs to be revised in consideration of radioactive aerosol. This study investigated the annual exposure limits of various countries, which can be used as an indicator in evaluating workers' internal exposure to radioactive aerosol during pipe cutting in the process of decommissioning nuclear power plants, and the growth and dynamics of aerosol. Also, to evaluate it, the authors compared/analyzed the cases of aerosol generated when activated pipes are cut in the process of nuclear power plants and the codes for evaluating internal exposure. The evaluation codes and analyzed data conform to ALARA, and they are believed to be used as an important indicator in deriving an optimal working time that does not excess the annual exposure limit.

• Safety and Health at Work
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• v.12 no.2
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• pp.230-237
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• 2021

Background: Noise-induced hearing loss is a well-known occupational disease that affects many fish harvesters from many fisheries worldwide, whose risk factor is prolonged exposure to hazardous noise levels. To date, academic research activities and regulatory bodies have not provided any comparative analysis among the existing methods to assess noise exposure levels of fish harvesters. This paper provides a comparison of four relevant assessment methods of noise exposure, examining the results of a measurement campaign performed onboard small fishing vessels from Newfoundland and Labrador. Methods: We traveled onboard 11 vessels engaged in multiple fisheries from Newfoundland and Labrador and performed extensive noise exposure surveys using the simplified International Maritime Organization method, the full-day measurement method, and the two methods provided by ISO 9612:2009, the task-based method and job-based method (JBM). Results: The results showed that the four methods yield similar values when the noise components are dominated by the engine and auxiliaries (steady-state sources); when noise components are dominated by the fishing gear, task-based method and the simplified International Maritime Organization method estimates are less accurate than JBM, using full-day measurements as baseline. Conclusion: The JBM better assesses noise exposure in small-scale fisheries, where noise exposure has significant variance and uncertainties on the exposure levels are higher.

• Journal of Information Science Theory and Practice
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• v.10 no.2
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• pp.86-101
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• 2022

This research aimed at studying the factors that influence new media exposure of political news by youths in Isan society in Thailand. The target group comprised 1,200 individuals, obtained from multi-stage sampling from undergraduate students in Isan's autonomous universities, governmental universities, and private institutions. The data collection tool was a questionnaire, the content of which was validated by experts. The reliability of the tool was tested by the formula for Cronbach's alpha coefficient, which yielded a reliability of 0.83. Multiple regression analysis was applied to analyze the data. The results, regarding factors influencing the channels for political news exposure, showed that channels for political news exposure were mostly influenced by inner drives, followed by importance in political news exposure, influence from social networks, and specific characteristics of the Internet. This could explain the variation of channels for political news exposure at 46.5%. In terms of factors influencing political news selection, it was found that political news selection was influenced mostly from social networks, followed by inner drives, benefits from political news exposure, specific characteristics of the Internet, and the field of study. The variation of the political news selection could be explained at 44.6%. These results elaborate on the current situation in Thailand, especially in Isan region, where youths in higher education are playing an increasing role in demonstrating their political stance through various political activities.

• Korean Journal of Environmental Biology
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• v.42 no.1
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• pp.1-14
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• 2024

This study evaluated the risk of single and combined exposure to microplastics in zebrafish (Danio rerio) through biomarkers, such as survival rate, excretion rate, and histological alterations of organ systems. The experimental groups were the control(Cont.), single microplastics exposure group(MPs, 1.83%/fish total weight(g)), the copper group(Cu, 21.6 ㎍ L^-1), and a group with combined exposure to MPs and copper (MPs^*Cu). The experiment was conducted with individual exposure (7 days) for MP excretion rate analysis and group exposure (14 days) for biomarker analysis. The daily excretion rate of MPs tended to decrease in a time-dependent manner. The copper concentration in the body was not significantly different between single and combined copper exposure. The degeneration of mucous cells in the skin, capillary dilation of the gill lamella, increased intestinal mucous, hepatocyte hypertrophy, and the degeneration of glomeruli and renal tubules were observed in all exposure groups. These histological alterations showed the highest tendency in the MPs^*Cu group. In this study, the changes in biomarkers were attributed to the single effect of copper or the combined effect of copper and MPs rather than being solely influenced by MPs.

• Journal of The Korean Society of Clinical Toxicology
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• v.12 no.1
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• pp.1-7
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• 2014

Purpose: The purpose of this study is to find differences in the demographics of toxic exposed patients and substance between call based poison information data and hospital based poison information data. Methods: Seoul 1339 call-response data were used as call based poison data and toxic related injury surveillance data of the Korean center for disease control and prevention (KCDC) were used as hospital based poison data. Age, sex, the kind of exposed substance, reasons for exposure, and exposure routes were compared between two data sets. We analyzed the presence or not of documentation on the name and amount of exposed substance, symptoms after exposure in call based poison data. Results: Seoul1339 poison data included a total of 2260 information related to toxic exposure and KCDC poison data included 5650 poison cases. There was no difference in sexual distribution. Pediatric exposure and accidental exposure were more common in call based poison data. The most common exposed substances were household products in call based poison data and medicines in hospital based poison data, respectively. Documents regarding amount and time of toxic exposure and symptoms after toxic exposure were not recorded exactly in call based poison data. Conclusion: There were significant differences in age, reasons for toxic exposure, and the kinds of exposed substances. Poison information data from both pre-hospital and hospital must be considered.