• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.1
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• pp.85-91
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• 2001

Background : It goes without saying that cumulative trauma disorders is spreading to various types of occupation in many advanced countries including America, and it forms considerable rate of total occupational disorders already. and as the result of it, the seriousness of worker health problem and economic loss owing to production loss, recuperation expense, etc. are on the increasing trend through whole society. In case of Korea, the related measures as well as accurate fact-finding survey data on cumulative trauma disorders aren't prepared in detail, so it implies forward problem would be serious. Purpose : The purpose of this study is to draw the risk factor of cumulative trauma disorders in production factory, to forecast the rate of occurrence of cumulative trauma disorders on the basis of subjective symptoms, and to present forward realistic and effective prevention measures by showing the risk of cumulative trauma disorders, objecting the production factory of a domestic riding automobile assembly shop, by estimating in the aspect of human-engineering through the analysis of risk factor being a cause of cumulative trauma disorders. Methods : For this study, I investigated work type and on-duty hours, breathing time, and subjective symptoms of cumulative trauma disorders through questionnaire, objecting the workers in press. car body, coating, and outfit factory. Results : As a result of research, 81.2% of workers were in the physical burden due to present working, and the highest prevalence by part of body is an waist. The higher a rule score, The higher the number of workers complaind for working intensity, and the higher age work duration, tool used time, the higher prevalence of subjective symptoms by part of body. The number of workers complaind subjective symptom for treatment is the highest in drugstore.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.2
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• pp.152-159
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• 2014

Objectives: This study aims to investigate the excretion aspect of urinary t, t-MA and hippuric acid by measuring concentrations of urinary metabolites according to the use of gasoline vapor recovery system. Materials:In order to analyze urinary metabolites, samples from the 23 gas station workers ten gas stations in the Seoul and Gyeonggi Province area were collected once daily after work. In addition, a survey was conducted on work factors and lifestyle habits as factors affecting the concentration of urinary metabolites. Results: The average concentrations of t, t-MA and hippuric acid after work were $0.124{\pm}0.177mg/g$ creatinine and $0.557{\pm}0.251g/g$ creatinine among workers at gas stations where gasoline vapor recovery systems were installed. The average concentrations of t, t-MA and hippuric acid were $0.160{\pm}0.113mg/g$ creatinine and $0.682{\pm}0.619g/g$ creatinine among workes at gas stations where gasoline vapor recovery systems were not installed. Average concentrations were higher at gas stations where a gasoline vapor recovery system was not installed, but the differences were not statistically significant differences. Urinary t, t-MA and hippuric acid average concentrations of smokers and non-smokers were higher in the gas stations where gasoline a vapor recovery system was not installed. T, t-MA as a factor evaluation affecting the concentration of urinary metabolites was not statistically significant in all factors, while hippuric acid was statistically significant only for age(p=0.024). Conclusions: The average concentrations of urinary t, t-MA and hippuric acid were higher in gas stations where gasoline vapor recovery systems were not installed compared to gas stations where such a system was installed. There needs to be an assessment of biological monitoring according to refueling activity considering skin absorption of benzene and toluene and presence of gasoline vapor recovery system.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.1-9
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• 2020

Objectives: The purpose of this case study is to assess workers' exposure to carbon nanotubes(CNTs) and characterize particles aerosolized during the process of producing CNT-enabled polytetrafuoroethylene(PTFE) composites at a worksite in Korea. Methods: Personal breathing zone and area samples were collected for determining respirable concentrations of elemental carbon(EC) using NIOSH(National Institute for Occupational Safety and Health) Method 5040. Personal exposure to nano-sized particles was measured as the number concentration and mean diameter using personal ultrafine particle monitors. The number concentration by particle size was measured using optical particle sizers(OPS) and scanning mobility particle sizers(SMPS). Transmission electron microscopy (TEM) area samples were collected on TEM grids and analyzed to characterize the size, morphology, and chemistry of the particles. Results: Respirable EC concentrations ranged from 0.04 to 0.24 ㎍/㎥, which were below 23% of the exposure limit recommended by NIOSH and lower than background concentrations. Number concentrations by particle size measured using OPS and SMPS were not noticeably elevated during CNT-PTFE composite work. Instant increase of number concentrations of nano-sized particles was observed during manual sanding of CNT-PTFE composites. Both number concentrations and mean diameters did not show a statistically significant difference between workers handing CNT-added and not-added materials. TEM analyses revealed the emission of free-standing CNTs and CNT-PTFE aggregate particles from the powder supply task and composite particles embedded with CNTs from the computer numerical control(CNC) machining task with more than tens of micrometers in diameter. No free-standing CNT particles were observed from the CNC machining task. Conclusions: Significant worker exposure to respirable CNTs was not found, but the aerosolization of CNTs and CNT-embedded composite particles were observed during handing of CNT-PTFE powders and CNC machining of CNT-PTFE composites. Considering the limited knowledge on the toxicity of CNTs and CNT composite particles to date, it seems prudent to take a precautionary approach for the protection of workers' health.

• Industry Promotion Research
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• v.3 no.2
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• pp.33-40
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• 2018

The purpose of this study is to analyze the effect of flexible working system for work - family connection on job satisfaction. A total of 73 questionnaires were analyzed for workers. The results of this study are as follows: First, flexible work system for work and home affairs has a statistically insignificant relationship with job satisfaction, flexible work system, work satisfaction, work status, flexible work system, organizational satisfaction, But the correlation between job satisfaction and organizational satisfaction showed a low correlation of .313, p <.01. Second, according to the regression analysis on the job satisfaction of the flexible work system, it was analyzed that the flexible work system for work and home affair did not have a statistically significant effect on the job satisfaction. Third, there was a significant relationship between the number of employees and average years of service. The average number of years of service was below 5 years. No child (38.4%), 1 person (15.1%), 2 children (11% ). & Lt; / RTI & gt; The purpose of this study is to examine the effect of the flexible work system on the job satisfaction of the worker and the family, and to verify the effectiveness of the flexible work system by increasing the flexible work system and the job satisfaction by activating the flexible work system.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.1
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• pp.19-26
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• 2005

In previous report, we presented that petroleum based solvents used in dry cleaning shop was almost similar to stoddard solvent defined by ACGIH and NIOSH, and the occupational exposure standard of stoddard solvent could be used in total exposure assessment of those solvents. The specific aim of the this study was to evaluate of the solvent exposure used in commercial dry cleaning shops by using occupational exposure standard of stoddard solvent. We conducted first survey of 8 self-employed dry cleaning shops and 5 factory type dry cleaning shops from July to August, and second survey of the same shops from October to November in 2002. The exposure concentration to the solvent during loading and unloading activity of vented dry cleaning machine was 489.2ppm(GM), 270.3ppm(GM), respectively, which was almost excursion limit(500ppm) of ACGIH, and exceed the ceiling limit(312ppm) of NIOSH. The time-weighted average (TWA) worker exposure to the solvent was 21.3ppm(GM) at self-employed shops, 20.7ppm(GM) at factory type shops on first survey, and 31.1ppm(GM), 33.7ppm(GM), respectively on second survey. The TWA exposure concentration of workers with spotting and cleaning machine operating job was 25.4ppm(GM), which was 2.9 times higher than the TWA exposure concentration, 8.8ppm(GM) of press workers. All TWA exposure concentrations was lower than OEL(100ppm) of stoddard solvent. We found that the most heavy exposure process at dry cleaning was loading, unloading process, and the vent of dry cleaning machine was the main emission source for workers exposure to petroleum based solvent.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.4
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• pp.402-411
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• 2013

Objectives: This study aims to assess the concentrations of ammonia and hydrogen sulfide according to task unit area at swine farms. Methods: A total of six swine farms were selected for this study. Ammonia and hydrogen sulfide were monitored using a real-time multi-gas monitor which could sample the gases simultaneously. The sampling was done in the pig building, manure storage facility and composting facility of each farm. Results: The concentration of ammonia in the pig buildings(GM 22.6 ppm, GSD 2.3) was significantly higher(p<0.0001) than in the manure storage facilities(GM 10.4 ppm, GSD 2.7) and composting facilities(GM 8.6 ppm, GSD 2.8). The concentration of hydrogen sulfide in the manure storage facilities(GM 9.8 ppm, GSD 3.2) was higher(p<0.0001) than in the pig buildings(GM 2.3 ppm, GSD 2.3) and composting facilities(GM 1.9 ppm, GSD 2.5). In particular, the levels of hydrogen sulfide in the confined manure storage facilities were higher than those in open-type facilities and the peak concentration(98 ppm) in the confined facilities was approximate to 100 ppm, at the value of Immediately Dangerous to Life or Health(IDLH). Conclusions: Suffocation accidents caused by hazardous gases at a swine farm have occurred annually. Real-time monitoring of the hazards should be done in order to protect farm workers and livestock from the sudden accidents.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.2
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• pp.138-148
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• 2017

Objectives: Sleep quality is directly related to the health, quality of life and working capacity and is affected by age, gender, exercise, life habits. Gender dissimilarities in sleep quality are acknowledged. However, the gender difference in the quality of sleep in shift workers was not well known. Our aim was to study the less known gender differences in the quality of sleep of shift workers. Methods: 1,008 study subjects aged between 21 and 57 years among these, 637(525 male and 112 female workers) were daytime workers and 371(253 males and 118 female workers) were shift workers. Sleep quality was measured by self-report through the Pittsburg Sleep Quality Index(PSQI) and fatigue was measured by using the Chalder Fatigue Scale(CFS). All data was analyzed using SPSS version 19.0 program. The study was approved by the Institutional Review Board of the Occupational Safety and Health Research Institute. Results: Overall, sleep quality was found to be worse in shift workers than in daytime workers and in female than in male. Fatigue in shift female workers was significantly higher than in daytime female workers and shift male workers. In Spearman correlation analysis results, fatigue were significantly associated with gender, drink habit, regular exercise, working hours and sleep quality. With group male workers as the reference, the odds ratio(OR) for having a CFS was 2.115(${\beta}$ value=0.749, p<0.01), and subjective sleep quality, sleep latency, daytime dysfunction and PSQI were 1.541(${\beta}$ value=0.432, p<0.05), 2.297(${\beta}$ value=0.831, p<0.001), 1.798(${\beta}$ value=0.587, p<0.01) and 2.224(${\beta}$ value=0.799, p<0.01), respectively. Conclusions: Shift work played an important role in lowering the quality of sleep, and the effect was more pronounced in female workers than in male workers. Sleep quality was related to fatigue, especially sleep quality, sleep duration, sleep disturbances and daytime dysfunction were significantly related. Therefore, to improve fatigue and sleep quality of shift worker, it is necessary to improve healthy habits such as regular exercise, smoking cessation, and limited drinking. In particular, it is urgent to develop and implement a regular exercise program to reduce fatigue and improve the quality of sleep in workplace.

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.279-286
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• 1991

Much of the working population in developing countries are engaged in shift work now and the number of shift workers is not expected to decrease in the future mostly because the need for continuity of production is increasing. Therefore, the possible effects of shift work on health are of particular interest, and in fact, there have been many epidemiological studies on shift work since the first world war. However, no studies on health effects of shift work have been reported in Korea, and the existing studies in western world have arrived at quite different conclusions mainly because the conditions of work other than shift work, such as age and selection of workers, work environment, and labor conditions also influence the health of workers. This study was firstly carried out in Korea to investigate the health risks related to shift work with 2,093 female workers randomly selected from three major manufacturing industries in proportion to total number of female workers in those industries. Differences of work conditions other than shift work in this study were adjusted by multivariate analysis. Ma findings obtained from this study are as follows : 1. There were significant differences between shift and day workers in the distribution of age, type of industry, condition of noise and dust, regularity of mealtime, working position, and working duration. Shift workers tended to be younger, to have shorter working duration, to have more irregular mealtime, to work in standing position, and to work under more noisy and dusty environment than day workers. 2. Univariate analysis showed that shift work increased the Todai Health Index (THI) scores of digestive tract, respiratory tract, and mental instability symptom categories. Shift work also increased days of sickness absence and number of industrial accident per 100 workers per month. 3. Multivariate analysis that adjusted the differences of demographic, occupational and non-occupational health-related working conditions showed that digestive tract symptom and mental instability symptom scores were significantly higher in shift workers than those in day workers. Based on these study results, it is concluded that the shift work has significant effects on some psychophysiological conditions of the workers and the effects are also influenced by several other personal and working conditions.

• Industry Promotion Research
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• v.2 no.1
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• pp.45-50
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• 2017

This study analyzed the effect of on - the - job training of workers in Chungnam western area on productivity improvement. A total of 76 questionnaires were analyzed for workers in the western part of Chungcheongnam-do that completed the training course of the Korea Polytechnic University Education and Labor Ministry. The results of this study are as follows: First, the higher the motivation to receive the on - the - job training for the improvement of the productivity, the higher the satisfaction of the training of the worker, but the effect on the job productivity was not significant. Second, the correlation between training experience and job productivity was not statistically significant. Third, as for the effect on the productivity improvement according to the rank, the temporary workers showed higher education satisfaction than the regular workers (agency), and the job productivity was higher than the manager (manager level). Results of ANOVA analysis showed that there was a significant effect on educational satisfaction and job satisfaction according to years of work, career, and rank. The purpose of this study is to analyze the effects of on - the - job training of workers in the western part of Chungnam, on the productivity improvement, The validity of the study is significant.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.1
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• pp.36-43
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• 2006

The principal aim of this field study was to determine the concentrations and emissions of gaseous contaminants such as ammonia and hydrogen sulfide in the different types of pig buildings in Korea and allow objective comparison between Korea and the other countries in terms of pig housing types. This field study was performed from May to June and from September to October in 2002. Pig buildings investigated in this research were selected in terms of three criteria; manure removal system, ventilation mode and growth stage of pig. Measurements of concentration and emission of ammonia and hydrogen sulfide in the pig buildings were done in 5 housing types and the visited farms were 15 sites per each housing type. Concentrations of ammonia and hydrogen sulfide were measured at three locations of the central alley in the pig building and emission rates of them were estimated by multiplying the average concentration($mg/m^3$) measured near the air outlet by the mean ventilation rate($m^3/h$) and expressed either per pig of liveweight 75kg(mg/h/pig) or per area($mg/h/m^2$). Concentrations of ammonia and hydrogen sulfide in the pig buildings were averaged to 7.5 ppm and 286.5 ppb and ranged from 0.8 to 21.4 ppm and from 45.8 to 1,235 ppb, respectively. The highest concentrations of ammonia and hydrogen sulfide were found in the mechanically ventilated buildings with slats; 12.1 ppm and 612.8 ppb, while the lowest concentrations of ammonia and hydrogen sulfide were found in the pig buildings with deep-litter bed system(2.2 ppm) and the naturally ventilated pig buildings with manure removal system by scraper(115.2 ppb), respectively(p<0.05). All the pig buildings were investigated not to exceed the threshold limit values(TLVs) of ammonia(25 ppm) and hydrogen sulfide(10 ppm). The mean emissions of ammonia and hydrogen sulfide per pig(75kg in terms of liveweight) and area($m^2$) from pig buildings were 250.2 mg/h/pig and 37.8 mg/h/pig and $336.3mg/h/m^2$ and $50.9mg/h/m^2$, respectively. The pig buildings with deep-litter bed system showed the lowest emissions of ammonia and hydrogen sulfide(p<0.05). However, the emissions of ammonia and hydrogen sulfide from the other pig buildings were not significantly different(p>0.05). Concentrations and emissions of ammonia and hydrogen sulfide were relatively higher in the pig buildings managed with deep-pit manure system with slats and mechanical ventilation mode than the different pig housing types. In order to prevent pig farm workers from adverse health effect caused by exposure to ammonia and hydrogen sulfide in pig buildings, they should wear the respirators during shift and be educated sustainably for the guideline related to occupational safety.