• 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.

• 월간산업보건
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• 통권266호
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• pp.26-32
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• 2010

• 한국융합학회논문지
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• 제8권12호
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• pp.199-208
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• 2017

본 연구의 목적은 한국의 소규모 산업장에 근무하는 생산직 근로자의 초과근무가 건강관련 삶의 질에 미치는 영향을 분석하기 위함이다. 본 서술적 조사연구는 2015년 10월부터 11월까지 6개의 소규모 사업장에서 근무하는 생산직 근로자 229명을 대상으로 하였다. 융합적 관점으로 다양한 변수들의 영향을 고려한 상태에서 생산직 근로자의 건강관련 삶의 질에 영향을 미치는 초과근무의 영향을 파악하기 위하여 위계적 회귀분석을 실시하였다. 그 결과 초과근무를 투입하였을 때 설명력 변화가 유의하게 증가하였으며, 생산직 근로자의 건강관련 삶의 질에 영향을 미치는 요인은 초과근무(${\beta}=.152$, p=.025), 우울(${\beta}=-.192$, p=.003), 야간근무(${\beta}=-.201$, p=.032)였다. 본 연구 결과는 향후 한국의 생산직 근로자의 건강관련 삶의 질을 높이기 위한 최적 근로시간 기준을 마련하는데 기초자료로 활용될 수 있을 것이다.

• 한국직업건강간호학회지
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• 제16권1호
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• pp.37-47
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• 2007

Purpose: To find out the relationship between the shift work, and disrupted sleep and consequent fatigue symptoms. Methods: The questionnaires were given to 345 nurses of 4 hospitals with over 400 beds in Daejeon. Results: The shift workers showed worse subjective quality of sleep than the daytime workers, and had significantly higher frequency of "cannot get to sleep within 30 minutes", "wake up in the middle of the night" and "wake up in the early morning". The shift workers had significantly higher scores of subjective symptoms of fatigue than the daytime workers, and the fatigue was found to be the mental type. The subjective symptoms of fatigue scores were significantly higher in the group who had "cannot get to sleep within 30 minutes", "wake up in the middle of the night" and "wake up in the early morning". Conclusion: The study results indicated that the shift workers had the higher level of subjective symptoms of physical fatigue as well as the worse quality of sleep than the daytime workers. It is speculated that the factors attributable to the poor quality of sleep or sleep induction disorders of nurses of hospitals could be due in major part to adaptational difficulties resulting from frequent night shifts.

• Journal of Preventive Medicine and Public Health
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• 제27권1호
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• pp.74-83
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• 1994

To investigate the sleeping patterns and gastrointestinal disorders of shift workers, the author studied 434 female workers who worked at textile industry ill Taejon city from September 1,1992 to September 31,1992. Shift pattern were divided into 3 categories ; 3 shift(shifts per 8 hours), 2 shift(day and night shift) and day work. The results obtained were as follows : 1 The average sleeping hours when adjusted for the education level of the total study subjects was 6.1 hours. That of 3 shift workers was 6.1 hours, 2 shift workers was 6.0 hours, but that of day workers was 6.5 hours. There were no significant difference among the shift workers. 2. For the 3 shift workers, the average physiologic adjusted duration in day shift (2.2 days) was shorter than that of night shift(2.7 days) and there were significant difference among the rotating shift works (p<0.001). The sleeping problems in day shift was less than those of night shift (p<0.001). 3. 44.9% of 3 shift workers, 39.3% of 2 shift workers and 33.1% of day workers complained gastrointestinal symptoms when adjusted for the age, education level, job tenure, work post. And the rates of gastrointestinal symptoms complained increase with job tenures (p<0.001). 4. The most frequent gastrointestinal diseases were gastitis and gastric ulcer with 14.2% , Irritable bowel syndrome with 3.1 %, duodenitis and duodenal ulcer with 2.1% and combined gastrointestinal disease with 2.1%. Age, eating habit, amount of coffee per day, job tenure, work post and shift pattern showed no significant difference with the gastrointestinal diseases when adjusted for the age. According to the above results, the author suggested that the shift pattern and job tenure can affect to the sleeping problem and gastrointestinal symptoms.

• 간호행정학회지
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• 제13권1호
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• pp.32-39
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• 2007

Purpose: This study is conducted to compare and analyse the health status and job satisfaction of nurses. Method: The subjects were a group of 90 nurses on fixed day nurse and the other group of 100nurses on night nurse. The collected data were analysed by using the SPSS WIN(10.0) program for descriptive statistics, t-test, ${\chi}^2-test$, ANOVA, and Pearson correlation coefficient. Result: There was a significant difference according to years in services. In nurses on day shift, there was a inverse correlation between the health status and job satisfaction. And in nurses on day shift, job satisfaction levels differed significantly depending on personality, satisfaction to pay, and current health status. In nurses on night shift, nurses' job satisfaction levels differed significantly depending satisfaction to pay. Conclusion: It was confirmed that health of nurses is greatly affected by shift work. so, it is very important to maintain and promote their health status in nurses on night shift. We must find out the factors that greatly affect health of nurses, and continuously make an effort to improve the working environment.

• 한국산업보건학회지
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• 제25권4호
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• pp.566-572
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• 2015

Objectives: The major objective of this study was to analyze insomnia after the change to consecutive day shift from day and night shift in a motor assembly factory. Materials: Data were collected at before and after shift system change through a survey conducted by a labor union. We analyzed transition of PSQI(Pittsburgh Sleep Quality Index) among 222 workers by separating the day shift week and night shift week. The cut-off point of insomnia was 8.5 on the PSQI. Results: Mean PSQI in the day shift week significantly did not decrease, going from $6.36{\pm}3.23$ to $6.46{\pm}3.00$(p=0.612 by paired t-test), Mean PSQI for night shift week significantly decreased from $8.31{\pm}3.36$ to $6.19{\pm}3.18$(p<0.001 by paired t-test). However, mean PSQI in the day shift week increased from $6.33{\pm}3.83$ to $7.11{\pm}2.86$ in ${\geq}50$ years(p=0.085, by repeated measured ANOVA). Mean PSQI score in the night shift week improved more in the married group(from $8.38{\pm}3.27$ to $6.12{\pm}3.18$) than in the non-married group(from $7.82{\pm}3.27$ to $6.12{\pm}3.18$)(p=0.038, by repeated measured ANOVA). Conclusions: The change to consecutive day shift improved insomnia in night shift. However, insomnia in the day shift week was worsened among those more than 50 years old.

• 한국보건간호학회지
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• 제30권3호
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• pp.495-511
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• 2016

Purpose: The present study was performed to describe the prevalence of various types of smoking statuses and to identify factors associated with different types among Korean wageworkers. Methods: The prevalence of hardcore smoking, daily smoking, and intermittent smoking was assessed in 2,126 wage workers from the Sixth Korea National Health and Nutrition Examination Survey. The associations of these three types of smoking statuses with sociodemographic characteristics, health conditions, and occupation-related characteristics were also examined in a multinomial logistic regression. Results: In men, the prevalence of hardcore smoking and daily smoking were 11.4% and 30.2%, respectively; and in women, the daily smoking prevalence was 5.6%. The education level was strongly associated with men's hardcore smoking and women's daily smoking. The household income and marital status were associated with women's daily smoking. Among occupation-related characteristics, the regularity of work and night work were associated with men's intermittent smoking. Night work was also associated with women's daily smoking. Employment condition was associated with women's intermittent smoking. Conclusion: The socioeconomic status and health conditions, compared with occupation-related factors, were found to have more influence on smoking. Therefore, antismoking programs that focus on individual characteristics should be developed for Korean wageworkers.

• Safety and Health at Work
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• 제15권1호
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• pp.102-109
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• 2024

Background: In today's modern world, longer working hours, shift work, and working at night have become major causes of the disruption of our natural circadian rhythms. This study aimed to investigate the effects of the type of shift work (rotating vs. fixed day), duty period (on-duty vs. off-duty), and working period within each shift (nighttime vs. daytime) on the circadian rhythm characteristics of nurses who provide direct patient care. Methods: This cross-sectional study used a purposive sampling method. Cosinor analysis was applied to analyze the actigraphy data of nurses providing direct patient care for seven consecutive days. The linear mixed effects model was then used to determine any variances between shift type, duty period, and working period within each shift for the nurses. Results: The mesor value did not differ according to nurses' shift type, duty period, and working period within each shift. The amplitude was statistically higher in on-duty nurses and in daytime working hours. The acrophase was significantly delayed in nighttime working hours. As well as nurses in rotating shift had experience. Conclusion: Our findings revealed that the peak activity of nurses occurs significantly later at night while working and nurses working during nighttime hours may have a weaker or less distinct circadian rhythm. Thus, this study suggests that limits be placed on the number of rotating nighttime shifts for nurses.

• 천문학회보
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• 제41권1호
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• pp.54.1-54.1
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• 2016

Multi-wavelength variability is a staple of active galactic nuclei (AGN). Optical variability probes the nature of the central engine of AGN at smaller linear scales than conventional imaging and spectroscopic techniques. Previous studies have shown that optical variability is more prevalent at longer timescales and at shorter wavelengths. Intra-night variability can be explained through the damped random walk model but small samples and inhomogeneous data have made constraining this model hard. To understand the properties and physical mechanism of intra-night optical variability, we are performing the KMTNet Active Nuclei Variability Survey (KANVaS). Using KMTNet, we aim to study the intra-night variability of ~1000 AGN at a magnitude depth of ~19mag in R band over a total area of ${\sim}24deg^2$ on the sky. Test data in the COSMOS, XMM-LSS, and S82-2 fields was obtained over 4, 6, and 8 nights respectively during 2015, in B, V, R, and I bands. Each night was composed of 5-13 epoch with ~30 min cadence and 80-120 sec exposure times. As a pilot study, we analyzed data in the COSMOS field where we reach a magnitude depth of ~19.5 in R band (at S/N~100) with seeing varying between 1.5-2.0 arcsec. We used the Chandra-COSMOS catalog to identify 166 AGNs among 549 AGNs at B<23. We performed differential photometry between the selected AGN and nearby stars, achieving photometric uncertainty ~0.01mag. We employ various standard time-series analysis tools to identify variable AGN, including the chi-square test. Preliminarily results indicate that intra-night variability is found for ~17%, 17%, 8% and 7% of all X-ray selected AGN in the B, V, R, and I band, respectively. The majority of the identified variable AGN are classified as Type 1 AGN, with only a handful of Type 2 AGN showing evidence for variability. The work done so far confirms there are more variable AGN at shorter wavelengths and that intra-night variability most likely originates in the accretion disk of these objects. We will briefly discuss the quality of the data, challenges we encountered, solutions we employed for this work, and our updated future plans.