• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.1
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• pp.42-51
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• 2012

Objectives: To compare the exposure level of extremely low frequency (ELF) magnetic fields among semiconductor workers, shipyard welders and office workers. Methods: To measure the ELF magnetic field concentration, EMDEX LITE (Enertech, USA) were used and monitored for eight hours continuously. Five companies handling the electric and magnetic field (EMF) source were investigated, which the exposure groups were classified into three groups: semiconductor workers, welders, and office workers. Welder group was chosen as a high exposed group and office group as a low exposed group. Results: The arithmetic mean (${\pm}SD$) and geometric mean (GSD) of personal exposure level of semiconductor workers were 0.73 (${\pm}1.33$) ${\mu}T$, 0.43 (2.88) ${\mu}T$, respectively. The ceiling value ranged between 0.18 and 123.2 ${\mu}T$. Welders were exposed high with the arithmetic mean value of 3.46 (${\pm}\;13.46$) ${\mu}T$ and geometric mean value of 0.45 (4.70) ${\mu}T$, respectively, and ceiling value range of 75.5~129.6 ${\mu}T$. The exposure levels of office workers were low compared to other exposed groups; the arithmetic mean 0.05 (${\pm}0.13$) ${\mu}T$, geometric mean 0.03 (2.38) ${\mu}T$ and ceiling value range 0.37~3.35 ${\mu}T$. This study revealed statistically significant differences of the mean ELF magnetic field exposure doses among three groups (p < 0.01). Conclusions: The average ELF magnetic field exposure doses of semiconductor workers were much higher than those of office workers in control group, but were lower than those of welders in high exposure group.

• The Korean Journal of Health Service Management
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• v.9 no.2
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• pp.33-46
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• 2015

This study was done on the basis that IT convergence-contents can help the elderly. The effects of IT convergence-contents were analyzed on the occupational performance of the elderly. This investigation was done with 100 elderly people above 65 years of age who lived in local community and two senior welfare centers in Busan and Kyeongbuk. The 100 elderly people were split into two groups of 50: the one group who has experience with IT convergence-contents was the experiment group, and the other group with no experience was the control group. In both groups, body functions, cognitive functions, activities of daily living and community participation were tested. The experimental group had higher scores for cognitive function, and activities of daily living than that of the control group. In conclusion, future studies can support continued IT convergence-contents at the local business community level rather than with smaller samples. This work lays the groundwork for follow-up studies to evaluate the effectiveness of IT convergence-contents.

• Therapeutic Science for Rehabilitation
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• v.10 no.1
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• pp.115-127
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• 2021

Objective : The purpose of this study was to investigate the effect of telerehabilitation on executive function, activities of daily living, instrumental activities of daily living, and occupational performance in stroke patients. Methods : The participants of this study were 30 outpatients with stroke residing in community. Both groups underwent the intervention 3 times a week for a total of 18 sessions. For the experimental group telerehabilitation was administered at home to only fifteen participants in the experimental group schedule, and it was supervised by the caregiver. Fifteen people in the control group underwent only the traditional occupational therapy. Executive function and instrumental activities of daily living were evaluated using the Korean version of the Executive Function Performance Test (EFPT-K). The basic daily activities of living were assessed using the Modified Barthel Index (MBI). The Canadian Occupational Performance Measure (COPM) was used to evaluate the client-centered occupational performance. Results : After the intervention, the experimental and control groups showed improvements in executive function, instrumental activities of daily living and occupational performance. Occupational performance improved more significantly in the experimental group than in the control group. Conclusion : Telerehabilitation and occupational therapy positively affect executive function, instrumental activities of daily living and occupational performance of patients with stroke. We suggest that telerehabilitation combined with occupational therapy is more effective in improving the occupational performance of stroke patients.

• Toxicological Research
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• v.31 no.4
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• pp.393-402
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• 2015

This study was conducted to measure toxicity of 1-chloropropane (CAS No. : 540-54-5). According to the OECD Test Guideline 413 (Subchronic inhalation toxicity: 90-day study), SD rats were exposed to 0, 310, 1,250, and 5,000 ppm of 1-chloropropane for 6 h/day, 5 day/week for 13 weeks via whole-body inhalation. Mortality, clinical signs, body weights, food consumption, motor activity, ophthalmoscopy, hematology, serum chemistry, urinalysis, organ weights, gross and histopathological findings were compared between control and all tested groups. No mortality or remarkable clinical signs were examined during the study. No gross lesions or adverse effects on body weight, food consumption, motor activity, ophthalmoscopy, urinalysis, hematology, organ weights were observed in any of male or female rats in all tested groups. In serum biochemistry, glucose was significantly decreased in males of 1,250 and 5,000 ppm groups compared to control group in dose-dependent relationship. In histopathological examination, vacuolation of acinar cells was observed in pancreas of all male and female groups exposed to 1-chloropropane. In conclusion, no observable adverse effect level (NOAEL) was considered to be below 310 ppm/6 h/day, 5 day/week for rats.

• Toxicological Research
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• v.32 no.3
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• pp.245-250
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• 2016

3-Methylpentane ($C_6H_{14}$, CAS No. 96-14-0), isomer of hexane, is a colorless liquid originating naturally from petroleum or natural gas liquids. 3-Methylpentane has been used as a solvent in organic synthesis, as a lubricant, and as a raw material for producing carbon black. There is limited information available on the inhalation toxicity of 3-methylpentane, and the aim of this study was to determine its subacute inhalation toxicity. According to OECD Test Guideline 412 (subacute inhalation toxicity: 28-day study), Sprague Dawley rats were exposed to 0, 284, 1,135, and 4,540 ppm of 3-methylpentane for 6 hr/day, 5 days/week for 4 weeks via whole-body inhalation. Mortality, clinical signs, body weights, food consumption, hematology, serum chemistry, organ weights, and gross and histopathological findings were compared between control and all exposure groups. No mortality or remarkable clinical signs were observed during the study. No gross or histopathological lesions, or adverse effects on body weight, food consumption, hematology, serum chemistry, and organ weights were observed in any male or female rats in all exposure groups, although some statistically significant changes were observed in food consumption, serum chemistry, and organ weights. In conclusion, the results of this study indicate that no observable adverse effect level (NOAEL) for 3-methylpentane above 4,540 ppm/6 hr/day, 5 days/week for rats.

• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.211-217
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• 2008

To clarify the DNA damage from reactive oxygen species, we measured the DNA damage through Fpg/Endo III FLARE (Fragment Length Analysis with Repair Enzyme) assay and real time RT-PCR. The 80 SD rats assigned to 4 dose groups exposed to cumene vapor for 90 days. With Fpg/Endo III FLARE assay in hepatocytes, we found the OTM (Olive Tail Moment) and TL (Tail Length) significantly increased in no-enzyme treated and Fpg-treated control and 8 ppm groups with 28 days exposure. In Endo III-treated 8 ppm group, significantly increased the values with 90 days exposure. With lymphocytes, it was founded the values significantly increased in no-enzyme treated 800 ppm group in 28 and 90 days. It was significantly increased in Endo III-treated 80 ppm for 28 days and 800 ppm for 90 days. From the above findings, FLARE assay was suggested as being available as a biological marker for DNA damage induced by cumene exposure in SD rats. And we used real time RT-PCR for the OGG1 mRNA expression, it had dose-dependent biologic effects in 1 day exposure, but decrease the levels of rOGG1 mRNA. Our findings provide evidence that cumene exposure may cause suppression of rOGG1 in the rat hepatocytes or lymphocytes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.3
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• pp.297-306
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• 2009

The purposes of this study were to investigate whether the program of health promotion and follow up feedback by periods could improve physical fitness related to work ability of the middle-aged and aged workers. Subjects were composed of two groups; workers aged below forty five and forty five and over who had measured their health-related physical fitness twice for 2 years (2006 & 2007) through the program of health promotion operated by Korea Occupational Safety & Health Agency. Paired t-test was used to evaluate the difference between the first measurement and re-measurement of health-related fitness which was operated after six to twelve months from the first one. We used 0.05 level for statistical significance. The results of this study were as follows. All measurement items including body fat ratio(%), $VO_2max$, grip strength, sit-up, and trunk flexion were significantly improved in both groups. The improvement(%) of $VO_2max$, grip strength of workers of forty five and above was lower than those of workers of below forty five. Servicing the program of health promotion and follow up feedback by periods may help workers' improvement of health-related physical fitness related to work ability.

• Toxicological Research
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• v.33 no.2
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• pp.165-171
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• 2017

Bisphenol A (BPA) is a monomer used in a polymerization reaction in the production of polycarbonate plastics. It has been used in many consumer products, including plastics, polyvinyl chloride, food packaging, dental sealants, and thermal receipts. However, there is little information available on the inhalation toxicity of BPA. Therefore, the aim of this study was to determine its inhalation toxicity and effects on the estrous cycle, spatial learning, and memory. Sprague-Dawley rats were exposed to 0, 10, 30, and $90mg/m^3$ BPA, 6 hr/day, 5 days/week for 8 weeks via whole-body inhalation. Mortality, clinical signs, body weight, hematology, serum chemistry, estrous cycle parameters, performance in the Morris water maze test, and organ weights, as well as gross and histopathological findings, were compared between the control and BPA exposure groups. Statistically significant changes were observed in serum chemistry and organ weights upon exposure to BPA. However, there was no BPA-related toxic effect on the body weight, food consumption, hematology, serum chemistry, organ weights, estrous cycle, performance in the Morris water maze test, or gross or histopathological lesions in any male or female rats in the BPA exposure groups. In conclusion, the results of this study suggested that the no observable adverse effect level (NOAEL) for BPA in rats is above $90mg/m^3$/6 hr/day, 5 days/week upon 8-week exposure. Furthermore, BPA did not affect the estrous cycle, spatial learning, or memory in rats.

• Korean Journal of Occupational Health Nursing
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• v.16 no.2
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• pp.158-167
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• 2007

Propose: To identify the effects of job stress for depression in clinical nurses. Method: The subjects were 304 clinical nurses in Busan Metropolitan City. Data was collected by questionnaire surveys using convenience sampling. The instruments used in this study were the short form of the Korean Occupational Stress Scale(KOSS-SF) and the Beck Depression Inventory-Korean Version Standard Ten(K-BDI STEN). Result: After adjusting potential confounders, we found that the group of 50~75% job stress score for interpersonal conflict was more likely to have depression than the group of less than 25%(OR=3.522, 95% CI 1.06~20.25). The group of equal or more than 75% job stress score for job insecurity was more likely to have depression than the groups of less than 25%(OR=9.413, 95% CI 4.00~71.03). The groups of equal or more than 75% and 50~ 75% job stress score for lack of reward was more likely to have depression than the group of less than 25%, respectively(OR=19.302, 95% CI 2.50~244.25; OR=38.201, 95% CI=6.25~344.45). Conclusion: To prevent depression in clinical nurses, we need to intervene job stress for insufficient job control, interpersonal conflict, job insecurity and lack of reward.

• Safety and Health at Work
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• v.12 no.1
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• pp.114-118
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• 2021

Background: Exposure to particulate matter (PM) emitted from vehicle exhaust might disrupt systemic function and elevate the risk of cardiovascular disease. In this study, we examined the changes of cardiometabolic biomarkers among vehicle inspectors exposed daily to PM0.25 and components. Methods: This cross-sectional study was conducted at two vehicle inspection centers, Pulogadung and Ujung Menteng, located in East Jakarta, Indonesia. The exposed respondents were 43 workers from vehicle inspection centers, and the unexposed group consisted of 22 staff officers working in the same locations. Vehicle exhaust particulate matter was measured for eight hours using a Leland Legacy personal pump attached to a Sioutas Cascade Impactor. The used filters were 25 and 37-mm quartz filters. The particulate matter concentration was analyzed using a gravimetric method, whereas trace elements were analyzed using energy dispersive X-ray fluorescence. An EEL Smoke Stain Reflectometer analyzed black carbon. Results: The personal exposure concentrations of PM0.25 were 10.4-fold higher than those in unexposed groups. Calcium and sulfur were the major components in the obtained dust, and their levels were 3.3- and 7.2-fold higher, respectively, in the exposed group. Based on an independent-samples t-test, high-density lipoprotein, triglyceride, HbA1c, total immunoglobulin E, high-sensitivity C-reactive protein, tumor necrosis factor-alpha, and nitric oxide levels were significantly different between the groups. Conclusions: In summary, it was suggested that PM0.25 exposure from vehicle exhaust might affect cardiometabolic biomarkers change.