• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.3
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• pp.214-221
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• 2024

Objectives: People using pedestrian walkways within tunnels may be exposed to environmental hazards that can have adverse effects on their health. This study aimed to measure changes in the levels of particulate matter (PM10), black carbon (BC), and noise after the installation of safety walls on pedestrian walkways within tunnels. Methods: Measurements were taken at the entrances on both sides of a tunnel and at the central point, both before and after the installation of pedestrian safety walls. Additionally, measurements were conducted by distinguishing between non-rush hour and rush hour periods to account for variations in the number of vehicles using the tunnel. A SidePak was used for PM10 measurements, an aethalometer for BC, and a sound level meter for noise. Results: PM10 showed the highest concentrations at the center of the tunnel at both pre- and post-installation of safety walls, as well as during rush hour periods. After the installation, the concentration at the center was 31.09 ± 14.02 ㎍/m³ (19.44 ± 8.02% increase). During rush hour, BC concentration reached 2.28 ± 1.55 ㎍/m³, indicating a 26.71 ± 13.19% increase compared to non-rush hour. As for noise, installation of safety walls reduced noise levels about 3 - 6 dB (8.10 ± 3.31% decrease). Conclusions: It was confirmed that installing safety walls on pedestrian walkways within the tunnel can reduce noise levels. However, the interior of a tunnel is a poorly ventilated environment, and exposure levels vary depending on the length of the tunnel. Therefore, the development of safety measures related to this issue is warranted, and further research on harmful substances within the tunnel should be conducted.

• Korean Journal of Occupational Health Nursing
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• v.23 no.4
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• pp.245-253
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• 2014

Purpose: School foodservice employees (SFEs) could be exposed to the risk of musculoskeletal disease and of job stress due to their job characteristics. This study was to evaluate the level of job stress and the prevalence of work-related musculoskeletal symptoms (WRMS) in Seoul city's SFEs, and to determine associations between job stress and WRMS. Methods: The study design was cross-sectional, and 975 SFEs were recruited. Self-administered questionnaire included the 'Korean occupational stress scale-short form' and the 'KOSHA GUIDE H-9-2012' instrument to evaluate the job stress and WRMS, respectively. SFEs' medians of job stress were compared to the reference values of published study in Korean workers. Results: The participants reported greater levels of job demand and physical environment than the general Korean population. WRMS were reported in 89.0% of participants at any body part, and 41.1% were presumed to need for medical intervention. High levels of job demand and of physical environment were significantly associated with WRMS. Conclusion: Subscales of job demand and physical environment were relatively high in SFEs and those were related to the occurrence of WRMS. To reduce the WRMS prevalence, a job stress management program focused on job demand and physical environment may be required.

• Safety and Health at Work
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• v.10 no.3
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• pp.341-346
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• 2019

Background: Although the concept of workload is important to nursing practice, only a few nursing researchers have focused on the issue of workload within the nursing context. Knowledge of how the dynamics of workload affects the job stress of nurses working in a specific unit or department in a hospital setting, and the influence of coworker support on this relationship, still remains limited. This study, therefore examined the effect of workload on job stress of Ghanaian outpatient department nurses and the moderating effect of coworker support on this relationship. Methods: A cross-sectional survey design was used, and questionnaire was used to collect data from a sample of 216 outpatient department nurses from four major hospitals in Ghana. The data collected measured workload, job stress, and coworker support using National Aeronautics and Space Administration (NASA) Task Load Index, job stress scale, and coworker support scale, respectively. Data were analysed using descriptive statistics, correlation, and hierarchical regression. Results: High levels of workload were associated with high levels of job stress of the nurses. Also, higher levels of workload were related to higher levels of job stress for nurses who received high levels of coworker support, but this was not the case for those who received low levels of coworker support (reserve buffering effect). Conclusion: The finding reiterates the adverse effect of workloads on employees' health, and the reverse buffering effect implies that supporting a colleague at work should be conveyed in a positive manner devoid of negative appraisal.

• Safety and Health at Work
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• v.5 no.3
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• pp.113-117
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• 2014

The mechanisms by which iron is absorbed are similar to those of divalent metals, particularly manganese, lead, and cadmium. These metals, however, show different toxicokinetics in relation to menarche or menopause, although their interaction with iron is the same. This review focuses on the kinetics of these three toxic metals (manganese, lead, and cadmium) in relation to menarche, pregnancy, and menopause. The iron-manganese interaction is the major factor determining sex-specific differences in blood manganese levels throughout the whole life cycle. The effects of estrogen overshadow the association between iron deficiency and increased blood lead concentrations, explaining why women, despite having lower ferritin concentrations, have lower blood lead concentrations than men. Iron deficiency is associated with elevated cadmium levels in premenopausal women, but not in postmenopausal women or men; these findings indicate that sex-specific differences in cadmium levels at older ages are not due to iron-cadmium interactions, and that further studies are required to identify the source of these differences. In summary, the potential causes of sex-specific differences in the blood levels of manganese, lead, and cadmium differ from each other, although all these three metals are associated with iron deficiency. Therefore, other factors such as estrogen effects, or absorption rate as well as iron deficiency, should be considered when addressing environmental exposure to toxic metals and sex-specific differences in the blood levels of these metals.

• Journal of Preventive Medicine and Public Health
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• v.32 no.1
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• pp.17-29
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• 1999

Objectives. This study was carried out to analyze the hearingthreshold levels and relating factors of 1,048 workers with noiseinduced hearing loss$(D_1)$. Methods. We analyzed the hearing-threshold levels and relating factors of 1,048 workers with noise-induced hearing loss$(D_1)$ examined by the summary reports of specific health examination results of industries and personal reports of specific health examination results reported by 58 specific health examination institutes and 8 secondary pneumoconiosis examination institutes in 1996. Results. Among 1,048 workers at 510 workplaces, male workers were 1,009 (96.3%) and female workers were 39 (3.7%). The mean ages of workers initially exposed to noise and at present were 28.7 and 47.2, respectively. The duration of total exposure was 16.5 years. Average hearing-threshold levels analyzed by three-divided classification of the study subjects were 43.7dB(Lt) and 42.6dB(Rt). Those analyzed by six-divided classification were 50.5dB(Lt) and 48.6d8(Rt). Among workers with noise-induced shearing loss$(D_1)$, 16.3% was unilateral hearing loss and 84.6% was classified to compensation case. 8.8%(Rt) and 10.2%(Lt) of them were suspected to be conductive hearing loss by differences of air-bone hearing-threshold levels. Hearing-threshold levels of workers in manufacturing industry were significantly increased during the short exposure compared with the levels in mining industry. Among manufacturing industries, hearing-threshold levels of workers in trailer and other transportation equipment manufacturing industry were significantly increased. Age and duration of total noise exposure were not significantly related to the average hearing-threshold levels analyzed by three-divided classification. Hearing-threshold levels of female workers were significantly increased during the short exposure compared with those of male workers. Hearing-threshold levels of workers at the high risk group, ages of 20s, 30s and total exposure duration of less than 10 years, were not significantly increased compared with those of the other groups. However, they were exposed at young ages. The 3 leading industries of workers at high risk group were trailer and other transportation equipment manufacturing, automobile manufacturing and assemble-metal manufacturing industries. Conclusions. This study was the first nationwide analysis of the hearing-threshold levels and relating factors of workers with noise. induced hearing loss$(D_1)$. We found the differences of the real number by the statistics of the department of labour and the expected number of worker' s compensations for occupationally-induced hearing loss estimated by this study. According to the results of this study, we should carefully examine the methods to narrow this difference.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.102-107
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• 2022

South Korea will soon be a super-aged society, as more than 20.6% of its population will be 65 years and older by 2025. As of 2022, 17.5% of the total population in South Korea is 65 years and older, which exceeds the set threshold for an aged society, where more than 14% of the population is 65 years and older. The proportion of older subway construction workers has increased. Aging workers and their work stress negatively impact their workability. A previous study demonstrated that the stress index measured using the uBioMacpa measurement device (Macpa stress index) had a significant correlation with work stress in South Korea. The device tests vascular health and measures stress levels via Macpa signal analysis. In this study, the pulse waves of subway construction workers were measured using uBioMacpa to identify their stress levels. The stress levels were analyzed by age, years of service, job position, employment type, and work type. Herein, these statistics could not be easily represented by a normal distribution; therefore, the Kruskal-Wallis test, a nonparametric statistical method, was used for the analysis of data. The results showed that age, job position, employment type, and working type affected the Macpa stress index and the stress levels of workers increased with age. In terms of job position, technical engineers were more stressed than other workers because of their poor working environment. In terms of employment type, daily-wage workers were more stressed than other workers. In terms of working type, tunneling, waterproofing, and construction scored the highest Macpa stress indexes without any significant difference, whereas earthworks scored the lowest. Based on the analysis of Macpa stress index, safety and health management plans were proposed to reduce the stress levels of workers. Moreover, a manual for efficient stress management must be developed for subway construction workers.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.1
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• pp.63-69
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• 2010

This study was conducted to compare the concentration of various air contaminants in nine different laboratories during routine activities. Volatile organic compounds (VOC) were sampled and analyzed using NIOSH Method 1500 and asbestos fibers were sampled and analyzed using NIOSH Method 9002 and 7400. Detectable levels of acetone, toluene and ethanol were found in all the laboratories and xylene and n-hexane were detected in eight of the nine laboratories. All the VOC concentrations were well below the Korean Ministry of Labor's Exposure Limit and American Conference of Governmental Industrial Hygienists' (ACGIH) Threshold Limit Values (TLVs). Total VOC concentrations at the university laboratories were significantly higher than those at governmental agency laboratories. Airborne fiber concentrations were below 0.01 fibers/cc, while the concentration of chrysotile was 2% in insulation materials sprayed on the ceiling of one laboratory. While all the governmental agency laboratories (n=4) had fume hoods, two out of the five university laboratories did not have fume hoods. The capture velocity of half of the fume hoods were below the maintenance standard(0.4 m/sec). In conclusion, the study suggests that the current controls in place at both university and government agency laboratories are not sufficient in limiting exposure to harmful chemicals to non-detectable levels, though they appear to be adequate in protecting workers to levels below applicable occupational exposure limits. The study also suggests that researchers working in university laboratories may be exposed to greater levels of contaminant than those working in government agency laboratories.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.12a
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• pp.85-86
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• 2005

To investigate the association between blood lead level (Pb-B) and neurobehavioral performance of school age children in Korea.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.65-74
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• 2013

Objectives: This study attempted to develop a method to measure ultra-trace lead concentrations in plasma using Inductively Coupled Plasma Mass Spectrometry(ICP-MS) and to test whether plasma lead can be used as a biomarker for the biological monitoring of exposure to lead. Methods: Lead concentrations in 160 plasma samples of field workers and 42 plasma samples from the control group were measured by ICP-MS. Blood zinc protophorphyrin(ZPP) concentrations and urinary ${\delta}$-aminolevulinic acid${\delta}-ALA$) were measured for correlation analysis with plasma lead. Results: The mean lead level in the plasma of the workers exposed to lead at work were 786.1 ng/L. Plasma lead levels were not correlated with blood ZPP or urinary ${\delta}-ALA$ concentrations. Otherwise, plasma lead levels showed a good correlation coefficient of 0.400 with blood lead levels, and their correlation coefficient had a better value of 0.552 for the non-smoking and drinking group. In the general population group which was not exposed to lead in the workplace and was considered the control group, the mean concentration of plasma lead was 123.1 ng/L. The plasma lead levels for the general population group showed a good correlation coefficient of 0.520 with blood ZPP and urinary ${\delta}-ALA$ concentrations.

• 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.