• Journal of Preventive Medicine and Public Health
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• 제27권3호
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• pp.475-486
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• 1994

In order to provide necessary information for better health of workers through understanding the actual status of the industries adopting shift systems. The data were gathered from a stratified random sample of 347 (0.5%) firms selected out of about 70,000 manufacturing industries throughout the nation in 1993. Stratification during sampling was by industrial group and number of workers. The major findings obtained from 288 firms surveyed completely were as follows : 1. About 20.2% of the 288 firms were adopting shift systems and shirtworkers accounted for about 25.1% of the total work force in 288 firms. 2. The bigger number of workers was, the higher the adopting rate of shift system was. 3. The rate of having welfare facilities such as dining room, commuting bus, washing facilities, and health care room etc. was higher in the industries adopting shift systems. 4. The major industrial groups adopting shift systems were the rubber a: plastic goods manufacturing industry (54.1 per 100 firms) and the textile manufacturing industry (44.8 per 100 firms). However, the proportion of shiftworkers was higher in the textile manufacturing industry (70.5 per 100 firms) and the electronics industry (57.9 per 100 frms). 5. The most predominant work schedule was the weekly rotating, semi-continuos 2-crew 2-shift system (47.5%). 6. In the industries adopting shift systems, shiftworkers had an adjusted average of 0.29 spells per 100 workers ($0.14{\sim}0.45$ in 95% C.I.) compared to 0.23 spells per 100 nonshift dayworkers ($0.15{\sim}0.31$ in 95% C.I.) for 1 month. 7. Also, in the industries adopting shift systems, the adjusted average annuel turn-over rate of shiftworkers was 13.07 per 100 workers ($12.03{\sim}14.12$ in 95% C.I.) compared to 10.18 per 100 nonshift dayworkers ($9.53{\sim}10.82$ in 95% C.I.).

• Journal of Preventive Medicine and Public Health
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• 제35권4호
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• pp.282-286
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• 2002

Objectives : The level of 4-hydroxyproline (4-Hyp) in human urine was measured using high performance liquid chromatography (HPLC) with a fluorescence detector. This method is useful for medical examinations and investigating the radicals induced by physical, chemical, mental stresses. This method is superior to many published several methods in terms of its low cost and ability to analyze many samples. Methods : The urine from workers in a tire manufacturing company (22 male pre- and post-shift workers) and 18 office-workers as controls were analyzed. Data concerning age, the cumulative drinking amount and the cumulative smoking amount was collected with a questionnaire. The optimum applied amount of dansyl-Cl, the optimum reaction temperature and time, the recoveries and the optimum pH of the eluent and buffer were determined.4-Hyp from human urine was derivatized with dansyl-Cl (dimethylamino-naphthalene-1-sulfonyl chloride) after removing the a-amino acid by a treatment with phthalic dicarboxaldehyde (OPA) and cleaned with Bond Elut C18 column. The 4-Hyp derivatives were separated on a reversed phase column by gradient elution with a phosphate buffer (5 mmol, pH 8.0) and acetonitrile, and detected by fluorescence measurements at 340 nm (excitation) and 538 nm (emission). Results : The detection limit for the urinary free 4-Hyp was $0.364{\mu}mol/l$. The recovery rate of 4-Hyp was 99.7%, and the effective pH of the phosphate buffer and borate buffer were 3.0 and 8.0, respectively. From statistical analysis, age, drinking and smoking did not affect the urinary free 4-Hyp in both the controls and workers. The range of urinary 4-Hyp in the controls, pre-shift, and post-shift workers were 0.33-16.44, N.D-49.06, and $0.32-56.27{\mu}mol/l$. From the pared-sample t-test, the urinary 4-Hyp levels in post-shift workers ($11.82{\pm}6.73\;nmmol/mg\;Cre$) were 2-fold higher than in pre-shift workers ($5.36{\pm}5.53\;nmol;/mg\;Cre$) and controls ($4.91{\pm}4.89\;nmol;/mg\;Cre$). Conclusions : This method was developed with high sensitivity, accuracy, and precision. The present method was effectively applied to analyze the urinary free 4-Hyp in both controls and workers.

• 대한간호학회지
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• 제35권8호
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• pp.1500-1507
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• 2005

Purpose. The purpose of this study was to identify subgroups of the physical and behavioral risk profiles for cardiovascular disease among industrial workers, and to examine predicting factors for the subgroups. Sample and Method. Health records of 2,616 male and female workers aged 19-56 years who were employed in an airplane manufacturing industry were analyzed. Data were analyzed using the Latent class cluster analysis. Results. Four different clusters (two high-risk groups, one low-risk group, and one normal group) were found and these clusters were significantly different by age, gender, and work type (p < .05 ). The two high-risk groups had higher chances of drinking alcohol, elevated BMI, FBS, total cholesterol, having hypertension, and were significantly older, and had relatively high chances of being day workers rather than other groups. The low-risk group had higher chances of drinking alcohol, higher BMI and total cholesterols compared to normal group, and highest portions of current smokers and shift workers in the four clusters and their mean BP was within prehypertension criteria. Conclusion. Industrial nurses should guide the lifestyle behaviors and risk factors of the high risk groups for CVD and need to intervene early for behavioral change for the low-risk group who are young and shift workers. Age, and work environment should be considered in planning for targeted preventive interventions for industrial workers.

• 한국직업건강간호학회지
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• 제6권2호
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• pp.79-95
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• 1997

The purposes of this study were to develop a job stress measurement tool and to identify the job stress according to the characteristics of worker and work condition at the small and medium-sized plants. Data were collected through face-to-face survey for April-May, 1997. Subjects were 180 workers at 36 small and medium-sized plants located near Seoul. Data were analyzed by item analysis, factor analysis, and ANOVA. The results were as follow : 1, Number of items of job stress measurement were 33 and Cronbach's $\alpha$ was .9262 except 13 items with low values of Cronbach's coefficient. Factor analysis was done in order for construct validity and 8 factors were extracted and cumulative percent of variance was 65.6%. 2. The job stress scores of male, the younger, 2-shift workers, and over-time workers were significantly higher than those of female, the older, 1-shift workers, and 48 hour workers per week. 3. There were no significant difference between job stress scores and the groups by number of worker, and the types of manufacturing. The stress measurement tool is valid and very reliable to measure worker's stress. Furthermore, the job stress managent program for health promotion of the workers at the vulnerable work condition is needed more and more.

• Safety and Health at Work
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• 제10권1호
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• pp.109-113
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• 2019

Background: In both developed and developing countries, noise is regarded as the most common occupational hazard in various industries. The present study aimed to examine the effect of sound pressure level (SPL) on serum cortisol concentration in three different times during the night shift. Methods: This case-control study was conducted among 75 workers of an industrial and mining firm in 2017. The participants were assigned to one of the three groups (one control and two case groups), with an equal number of workers (25 participants) in each group. Following the ISO 9612 standard, dosimetry was adopted to evaluate equivalent SPL using a TES-1345 dosimeter. The influence of SPL on serum cortisol concentration was measured during the night shift. The serum cortisol concentration was measured using a radioimmunoassay (RIA) test in the laboratory. Repeated measure analysis of variance and linear mixed models were used with ${\alpha}=0.05$. Results: The results indicated a downward trend in the serum cortisol concentration of the three groups during the night shift. Both SPL and exposure time significantly affected cortisol concentration (p < 0.0001, p < 0.0001). Conversely, age and body mass index had no significant influence on cortisol concentration (p = 0.360, p = 0.62). Conclusion: Based on the obtained results, increasing SPL will lead to enhancement of serum cortisol concentration. Given that cortisol concentration varies while workers are exposed to different SPLs, this hormone can be used as a biomarker to study the effect of noise-induced stress.

• Safety and Health at Work
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• 제13권2호
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• pp.240-247
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• 2022

Background: Although insomnia and constipation are highly prevalent worldwide, studies examining a possible association between them are lacking. We examined the relationship between insomnia and constipation in shift workers who have a high prevalence of insomnia and other diseases. Methods: This study had a multicenter cross-sectional design and conducted using health examination data including self-reported questionnaires. In total, 12,879 and 4,650 shift workers were enrolled in Severance Hospital and Wonju Severance Hospital, respectively, during 2015-2017. Multivariate logistic regression models and subgroup analysis were performed in each center with the same protocol, using a common data model. Results: The mean age of the total population was 44.35 (standard deviation = 8.75); the proportion of males was 56.9%. Female sex, being underweight and non-smoker were strongly associated with an increased risk of constipation symptom (p < 0.001). Pooled odds ratios (ORs) were calculated using ORs of both centers with weights; there was a significant dose-response relationship (sub-threshold 1.76 [95% confidence interval [CI] 1.62-1.91]; moderate 2.28 [95% CI 2.01-2.60]; severe 4.15 [95% CI 3.18-5.41] in the final model, p for trend < 0.001). Subgroup analysis performed by stratifying sex and pooled ORs showed a similar trend to that of the entire group. Conclusion: We observed a strong correlation between insomnia and constipation in this population. Our findings may help in formulating guidelines and policies to improve quality of life in shift workers through the management of sleep quality and proper bowel function. This study is the first to report this relationship among people working in shifts.

• Journal of Preventive Medicine and Public Health
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• 제39권2호
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• pp.171-176
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• 2006

Objectives : The objective of this study is to assess the factors influencing biological monitoring of textile coating factory workers exposed to N,N-dimethylformamide(DMF). Methods : We studied 35 workers who were occupationally exposed to DMF from 9 textile coating factories. The study was carried out in two phases; summer and winter. While air concentration of DMF, temperature and humidity were assessed in order to monitor the atmospheric conditions, biological monitoring was done to determine the internal dose by analyzing the N-methylformamide(NMF) collected from urine at the beginning and end of the shift. Questionnaires and medical surveillance were also obtained during the two phases. Results : Median air concentrations of DMF in winter and summer were 1.85 ppm and 2.78 ppm respectively. Also the difference between the urinary NMF concentration at the beginning and end of the shift $({\Delta}NMF)$ was always significant in each season (P < 0.001). The correlations between log DMF in air, log end-of-shift urinary NMF (r=0.555, P < 0.001) and log ${\Delta}NMF$ (r = 0.444, P < 0.001) was statistically significant in summer. The temperature, humidity, a shift system and different styles of clothing worn were significantly different during the two phases. In a multivariate analysis, temperature and the concentration of DMF in the air were the main factors influencing biological monitoring of textile coating factory workers. Conclusions : Concerning more comprehensive prevention measures to reduce exposure for those workers occupationally exposed to DMF, dermal exposure conditions such as temperature and humidity together with the air concentration of DMF should be assessed and biological monitoring is necessary to reduce adverse health effects, especially during the summer.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.12.1-12.12
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• 2023

Background: The purpose of this study is to investigate the relationship between job stress and impaired fasting glycemia (IFG) of male workers in a manufacturing industry. Methods: Data were collected from 5,886 male workers in a manufacturing industry who participated in the medical examination from June 19 to August 14, 2020 through self-reported questionnaires. The general characteristics of the subjects, shift work, high blood pressure, dyslipidemia, and job stress were included. Job stress was measured using the Korean Occupational Stress Scale (KOSS) consisting of 8 items and 43 questions. Multivariable logistic regression analysis was used to investigate the IFG association with job stress. Results: Among the various factors that can cause job stress, only high job demand was associated with a risk of IFG (odds ratio, 1.43; 95% confidence interval, 1.13-1.82) especially in non-shift worker. For all other factors, no statistically significant results were obtained. Conclusions: In this study of male workers engaged in the Korean steel manufacturing industry, the 'job demand' item among job stress of non-shift worker was related to IFG.

• 한국산학기술학회논문지
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• 제22권1호
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• pp.178-187
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• 2021

본 연구는 교대근무 서비스 종사자를 대상으로 생활만족도에 영향을 미치는 요인을 파악하기 위하여 제5차 근로 환경조사 원시자료를 이용한 2차 자료분석연구이다. 연구대상자는 총 577명으로 20세 이상의 교대근무 서비스 종사자 중 조사 당시 근무 직장의 경력이 1년 이상이며, 주 40시간이상 근로를 하는 상용근로자만 선택하였다. 자료의 분석은 t-test, One-way ANOVA, Scheffe test, Person's correlation coefficients, Hierarchical multiple regression analysis을 SPSS 23.0 WIN을 이용하여 분석하였다. 연구결과, 대상자의 일반적 특성에서 연령, 교육정도, 산업업종, 주관적 건강상태에 따라 생활만족도의 차이가 있는 것으로 나타났다. 교대근무 서비스 종사자의 일과 생활 균형과 근무 만족도가 높을수록 생활만족도가 높은 것으로 나타났다. 또한, 교대근무 서비스 종사자의 일과 생활균형, 근무만족도간의 관계에서 사회적 지지가 조절효과가 나타났다. 본 연구를 토대로 생활만족의 영향요인을 고려한 교대근무 서비스 종사자에 대한 적극적인 사회적 지지와 근무만족, 일과 생활균형 증진증진 프로그램 개발 및 적용을 하여 교대근무 서비스 종사자의 생활만족도을 향상시켜 개인의 행복뿐만 아니라 기업의 생산성 향상을 기대해 본다.

• Safety and Health at Work
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• 제8권2호
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• pp.212-219
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• 2017

Background: Low back pain (LBP) is a major problem for office workers. Individuals adopting poor postures during prolonged sitting have a considerably increased risk of experiencing LBP. This study aimed to investigate seat pressure distribution characteristics, i.e., average pressure, peak pressure ratio, frequency of postural shift, and body perceived discomfort (BPD), during 1 hour of sitting among office workers with and without chronic LBP. Methods: Forty-six participants (chronic LBP = 23, control = 23) typed a standardized text passage at a computer work station for an hour. A seat pressure mat device was used to collect the seat pressure distribution data. Body discomfort was assessed using the Body Perceived Discomfort scale. Results: Office workers with chronic LBP sat significantly more asymmetrically than their healthy counterparts. During 1-hour sitting, all workers appeared to assume slumped sitting postures after 20 minutes of sitting. Healthy workers had significantly more frequent postural shifts than chronic LBP workers during prolonged sitting. Conclusion: Different sitting characteristics between healthy and chronic LBP participants during 1 hour of sitting were found, including symmetry of sitting posture and frequency of postural shift. Further research should examine the roles of these sitting characteristics on the development of LBP.