• Safety and Health at Work
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• 제2권2호
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• pp.135-147
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• 2011

Objectives: The purpose of this study was to evaluate cancer risks in the Korean semiconductor industry. Methods: A retrospective cohort study was performed in eight semiconductor factories between 1998 and 2008. The number of subjects was 113,443 for mortality and 108,443 for incidence. Standardized mortality ratios (SMR) and standardized incidence ratios (SIR) were calculated. Results: The SMR of leukemia was 0.39 (95% Confidence Interval 0.08-1.14) in males (2 cases) and 1.37 (0.55-2.81) in females (7 cases). The SMR of non-Hodgkin's lymphoma (NHL) was 1.33 (0.43-3.09, 5 cases) in males and 2.5 (0.68-6.40, 4 cases) in females. The SIR of leukemia was 0.69 (0.30-1.37, 8 cases) in males and 1.28 (0.61-2.36, 10 cases) in females. The SIR of NHL in females was 2.31 (1.23-3.95, 13 cases) and that of thyroid cancer in males was 2.11 (1.49-2.89, 38 cases). The excess incidence of NHL was significant in female assembly operators [SIR=3.15 (1.02-7.36, 5 cases)], but not significant in fabrication workers. The SIR of NHL in the group working for 1-5 years was higher than the SIR of NHL for those working for more than five years. The excess incidence of male thyroid cancer was observed in both office and manufacturing workers. Conclusion: There was no significant increase of leukemia in the Korean semiconductor industry. However, the incidence of NHL in females and thyroid cancer in males were significantly increased even though there was no definite association between work and those diseases in subgroup analysis according to work duration. This result should be interpreted cautiously, because the majority of the cohort was young and the number of cases was small.

• Safety and Health at Work
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• 제15권1호
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• pp.53-58
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• 2024

Background: As social distancing persists and interest in work-life balance grows, more companies are adopting flexible work policies. While there have been studies on sleep disorders associated with different types of work, such as shift work, research exploring the relationship between flexible work schedules and sleep disorders is still limited, particularly among Korean workers. Methods: We performed a secondary analysis of the 6th Korean Working Conditions Survey, focusing on 31,243 paid workers out of a total of 50,538 participants. We defined flexible workers as those who set their own working hours. Sleep disorders were divided into three categories: 'difficulty falling asleep,' 'frequent waking during sleep,' and 'waking up feeling exhausted and fatigued.' Using scores derived from three specific symptoms, the Minimal Insomnia Symptoms Scale (MISS) was calculated to assess the prevalence of insomnia. We used chi-square tests to analyze demographic and job-related differences. A multivariate logistic regression analysis was employed to identify any relationship between flexible work schedules and sleep disorders. Results: Significant differences were found between flexible and non-flexible workers regarding age, income level, education level, and job type. Flexible workers reported sleep-related symptoms significantly more often. The odds ratio for insomnia was 1.40 (95% CI 1.21-1.61). For males, the odds ratio was 1.68 (1.36-2.08). Conclusion: This study establishes a correlation between flexible work schedules and sleep disorders among Korean salaried workers. Potential causes could include changes in circadian rhythm, increased work demands, and extended working hours. To precisely determine causality and associated diseases, further research is required.

• Journal of Preventive Medicine and Public Health
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• 제42권5호
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• pp.323-330
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• 2009

Objectives : The aim of this study was to investigate whether working married women in different occupational classes affected diverse health outcomes. Methods : We used data for married women aged 25-59 (N=2,273) from the 2005 National Health and Nutritional Examination Survey. Outcome measures included physical/mental and subjective/objective indicators (selfrated poor health, chronic diseases, depression, and suicidal ideation from reported results; metabolic syndrome dyslipidemia from health examination results). Agestandardized prevalence and logistic regression were employed to assess health status according to three types working groups (housewives, married women in manual jobs, married women in non-manual jobs). Sociodemographic factors (age, numbers of children under 7, education, household income) and health behaviors (health examination, sleep, rest, exercise, smoking, drinking) and a psychological factor (stress) were considered as covariates. Results : Non-manual married female workers in Korea showed better health status in all five health outcomes than housewives. The positive health effect for the non-manual group persisted in absolute (age-adjusted prevalence) and relative (odds ratio) measures, but multivariate analyses showed an insignificant association of the non-manual group with dyslipidemia. Manual female workers showed significantly higher age-adjusted prevalence of almost all health outcomes than housewives except chronic disease, but the associations disappeared after further adjustment for covariates regarding sleep, rest, and stress. Conclusions : Our results suggest that examining the health impact of work on married women requires the consideration of occupational class.

• 한국산업보건학회지
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• 제18권4호
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• pp.310-317
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• 2008

The objective of the survey is to define and judge exposure profiles semi-qualitative data in high risk processes using styrene. The survey was conducted on 98 factories out of 229 factories based on data from periodic working environment monitoring for styrene. Styrene is widely utilized as a raw material for PS and co-polymers such as ABS, SAN, SBR, SBL, unsaturated polyester resins(UPR) and others. An approximate breakdown of styrene's markets in Korea is PS 30%, expandable PS 17%, ABS 33%, SAN 5%, SBL 4%, SBR 3%, UPR 1% and other 7%. Although UPR accounts for 1% of total amount of styrene, workers dealing with it are exposed to very high concentrations up to 64 ppm. Especially styrene is widely used in the laminating process of fiberglass reinforced plastics(FRP) manufacturing industry. The Applications using styrene are largely classified into two sections which are applied to styrene monomer(SM) and UPR. SM is utilized for a raw material of resins, surfactant and adhesive. UPR is employed for FRP and non-FRP. For SM control targets are mixing colors and packing in the gelcoat resins manufacturing industry(MI), for UPR control targets out of works using UPR are 1) laminating in the MI of plastics, automobile parts and boats, 2) mixing and packing in the SMC/BMC MI, 3) molding and cutting in the other specific plastics MI, 4) mixing and coating in artificial marble product MI, 5) dipping in the electric motors & transformers MI, 6) molding in the button MI, 7) painting in the musical instrument MI. Findings from the study have given the information for the high risk processes and working practices so that occupational health professionals could focus on targeted workplaces to prevent occupational diseases. It is also useful to develop a control strategies and specific controls for high risk processes and facilities using styrene.

• Safety and Health at Work
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• 제13권3호
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• pp.326-335
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• 2022

Background: One of the important actions for enhancing human reliability in any industry is assessing human error probability (HEP). The HEART technique is a robust tool for calculating HEP in various industries. The traditional HEART has some weaknesses due to expert judgment. For these reasons, a hybrid model is presented in this study to integrate HEART with Best-Worst Method. Materials Method: In this study, the blasting process in an iron ore mine was investigated as a case study. The proposed HEART-BWM was used to increase the sensitivity of APOA calculation. Then the HEP was calculated using conventional HEART formula. A consistency ratio was calculated using BWM. Finally, for verification of the HEART-BWM, HEP calculation was done by traditional HEART and HEART-BWM. Results: In the view of determined HEPs, the results showed that the mean of HEP in the blasting of the iron ore process was 2.57E-01. Checking the full blast of all the holes after the blasting sub-task was the most dangerous task due to the highest HEP value, and it was found 9.646E-01. On the other side, obtaining a permit to receive and transport materials was the most reliable task, and the HEP was 8.54E-04. Conclusion: The results showed a good consistency for the proposed technique. Comparing the two techniques confirmed that the BWM makes the traditional HEART faster and more reliable by performing the basic comparisons.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.39.1-39.14
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• 2023

Background: Diseases affecting the lungs and airways contribute significantly to the global burden of disease. The problem in low- and middle-income countries appears to be exacerbated by a shift in global manufacturing base to these countries and inadequate enforcement of environmental and safety standards. In Ghana, the potential adverse effects on respiratory function associated with occupational wood dust exposure have not been thoroughly investigated. Methods: Sixty-four male sawmill workers and 64 non-woodworkers participated in this study. The concentration of wood dust exposure, prevalence and likelihood of association of respiratory symptoms with wood dust exposure and changes in pulmonary function test (PFT) parameters in association with wood dust exposure were determined from dust concentration measurements, symptoms questionnaire and lung function test parameters. Results: Sawmill workers were exposed to inhalable dust concentration of 3.09 ± 0.04 mg/m³ but did not use respirators and engaged in personal grooming habits that are known to increase dust inhalation. The sawmill operators also showed higher prevalence and likelihoods of association with respiratory symptoms, a significant cross-shift decline in some PFT parameters and a shift towards a restrictive pattern of lung dysfunction by end of daily shift. The before-shift PFT parameters of woodworkers were comparable to those of non-woodworkers, indicating a lack of chronic effects of wood dust exposure. Conclusions: Wood dust exposure at the study site was associated with acute respiratory symptoms and acute changes in some PFT parameters. This calls for institution and enforcement of workplace and environmental safety policies to minimise exposure at sawmill operating sites, and ultimately, decrease the burden of respiratory diseases.

• 한국환경보건학회지
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• 제38권3호
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• pp.204-212
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• 2012

Objectives: The purpose of this study was to determine house dust mite concentrations in living rooms and bedding materials in atopic case-control groups. Methods: Fifty four homes with children suffering atopic diseases as cases and fifty one homes without atopic diseases as controls were selected after diagnosis at three elementary schools in Ulsan City. Dust samples were collected from the living rooms and bedding materials in each home during summer and winter with a vacuum cleaner and analyzed for house dust mites using enzyme-linked immunosorbent assay (ELISA). Environmental factors and family history were surveyed during sampling. Results: Both species of house dust mite Dermatophagoides farina (Der f 1) and Dermatophagoides pteronyssinus (Der p 1) were found in all homes. Derf1 concentrations were much higher than Der P1 concentrations, both in atopic homes (1518.9 vs. 27.0 ng/g. dust, respectively) and non-atopic homes (810.8 vs. 44.3 ng/g. dust, respectively). Der f 1 concentrations were significantly higher in the atopic group than in the non-atopic group (atopic: 1518.9 ng/g.dust, non-atopic: 810.8 ng/g.dust, p = 0.035). However, total house dust mite Der p 1 concentrations were significantly higher in the non-atopic group than in the atopic group (atopic: 27.0 ng/g.dust, non-atopic: 44.3 ng/g.dust, p = 0.035). Multiple regression implied that mothers with family history of atopic diseases (OR = 4.79, 95% CI = 1.81-12.69), Der f 1 concentrations (OR = 1.74, 95% CI = 1.07-2.81), and air freshener use (OR = 4.60, 95% CI = 1.72-12.34) had significant associations with atopic children. Conclusion: House dust mite Der f 1 concentrations were associated with atopic children. This study suggests that parents should reduce house dust mite Der f 1 concentrations through environmental controls.

• 보건행정학회지
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• 제24권3호
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• pp.219-227
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• 2014

Background: Current trends in Korea population aging with advances in public health and clinical medicine foretell rises in the prevalence of not only chronic diseases but also patients with multimorbidity. One important aspect in analyzing multimorbidity is to define the list of chronic diseases included when calculating multimorbidity index. The objective of this study is to describing the effect of multimorbidity on healthcare cost in Korea using US Office of the Assistant Secretary of Health (OASH) list. Methods: We analyzed the Korea Health Panel Data representing non-institutionalized Korean adult populations aged 20 and more. We calculated multimorbidity index based on OASH list and estimated the prevalence and healthcare cost for each OASH chronic disease. Results: In 2011, 15.2 million (39.6%) Koreans aged 20 and more were living with chronic condition. The health care cost due to chronic diseases, accounted for 80.2% of the overall healthcare costs and the prevalence of chronic conditions, the prevalence of multimorbidity and healthcare cost increased with ages. In the analysis using OASH list, 40% of the adult population over the age of 20 and 66.7% of the population over the age of 65 was affected with multimorbidity. In most of diseases in OASH list, prevalence of mulitmorbidity was high and healthcare cost increased with multimorbidity. Conclusion: OASH chronic disease list that accounts for 72.4% of prevalence and 86.7% of healthcare cost of persons with chronic conditions in Korea. OASH chronic disease list would be a useful and representative indicator for studying multimorbidity.

• Journal of Preventive Medicine and Public Health
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• 제14권1호
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• pp.75-80
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• 1981

Due to rapid industrialization and economic development, the occupational diseases have appeared as one of the social problems in Korea. Up until now little has been known about the prevalence rate, predisposing factors and symptomatology of the occupational disease due to localized vibration in Korea. The researcher intends to investigate the prevalence rate and affecting factors of the occupational disease due to localized vibration among rock-drillers in the anthracite mines. A total of 135 rock-drillers were interviewed and examined from May 15th to 31th, 1980. The results were revealed as follows; 1. The prevalence rate of the vibration syndrome among rock-drillers was 12.6%. 2. The latent period of the vibration syndrome was 6.8 years. 3. The prevalence rate of the vibration syndrome was not significantly different between smokers and non-smokers. 4. With the increase of total vibration exposure time, the prevalence rate of the vibration syndrome increased also. 5. The average vibration sensation threshold was high (6.4dB) in stage 1 of the vibration syndrome and low (-0.6dB) in stage 0. 6. The average pain sensation threshold was high (4.4g) in stage 1 of the vibration syndrome and low (2.5g) in stage 0.

• Toxicological Research
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• 제21권2호
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• pp.121-128
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• 2005

Economic animal husbandry workers exposed to organic dust can be suffered from immunologic disorders. Our study was to determine immunological parameters related with occurrence of respiratory allergic diseases to animal husbandry workers in Korea for the first time. Peripheral blood were obtained from twenty-five pig barn workers, forty-nine chicken farming workers and fifty-one non-agricultural control workers. Significantly upregulated plasma IgE level was observed with pig-barn workers than that of chicken farming workers or healthy community control subjects. Furthermore, level of histamine, a hallmark of allergy induction, was upregulated in the pig and chicken farming workers in comparison with that of the control subjects. Downregulation of $IFN_\gamma$ and $TNF_{\alpha}$ production from T cells was apparent in the animal husbandry workers compared with the control subjects. Meanwhile, T cells collected from the pig barn workers demonstrated significantly higher production of IL-4 and IL-10 than the other groups. There were also alterations in IgG subclass distribution. In conclusion, immunological modulation probably leading to occupational allergic diseases can be occurred in the economic animal husbandry workers and the pig barn workers could be the most risky group to the work-related allergic disease.