• Molecular & Cellular Toxicology
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• v.4 no.3
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• pp.230-234
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• 2008

Epidemiological studies demonstrate an adverse effect of several environmental and occupational exposures on male sex hormone. Bisphenol A (BPA) is a weak estrogen and a widely used industrial chemical. Epoxy resin painters may be continuously exposed to BPA at high concentrations. The effect of occupational exposure of BPA on male reproduction was examined by measuring the urinary BPA, testosterone and gonadotropic hormones of epoxy resin painters in the shipyard. The painters had significantly higher concentrations of urinary BPA (2.61${\pm}$1.08 ${\mu}g$/g creatinine) than controls (1.38${\pm}$0.5 9 ${\mu}g$/g creatinine). In serum, the testosterone level of painters was significantly decreased but the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels of painters were significantly higher than controls. Occupational exposure to BPA influences testosterone and gonadotropic hormones in male workers.

• Journal of Environmental Health Sciences
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• v.42 no.2
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• pp.71-84
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• 2016

Objectives: Exposure assessment using questionnaires is effective in large-scale epidemiological studies. However, a limited number of studies have evaluated the questionnaires used in epidemiologic studies in terms of occupational and environmental exposure. The purpose of this study was to summarize and evaluate questionnaire items included in major epidemiological studies conducted in Korea with regard to occupational and environmental exposure. Methods: A total of 12 studies (four cohort studies, six large-scale cross-sectional surveys, and two panel studies) were selected for this study. Various questionnaire items related with occupational and environmental items were collected and summarized into tables. Results: Although job type and address were included in almost all of the studies, the information on occupational or environmental exposure to specific risk factors was collected in a limited number of studies. Moreover, questionnaire items were not standardized, warranting a continuous effort to develop questionnaires and evaluate their validity. Conclusion: Our results suggest that validated questionnaire items focusing on occupational and environmental exposure need to be developed in order to enhance the availability of the information collected from questions in epidemiological studies.

• Toxicological Research
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• v.18 no.1
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• pp.43-46
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• 2002

A 61 Year-old female patient was hospitalized for lung cancer. Her Occupational history indicated that she had worked for an asbestos company for 9 years from 1976. The histopathology of the lung revealed malignant bronchioalveolar adenocarcima (stage III) in the lower-left lobe, and a lung sample was found to cantion an unusually high level of asbestos, 218.9$\times$$10^6$ asbestos fibers/g of dry lung tissue. The majority of asbestos fibers found was chrusotile. yet no asbestos body was detected. When compared with Korean male (0.3$\times$$10^6$ fibers/g of dry lung tissue) and female subjects (0.15$\times$$10^6$ fibers/g of dry lung tissue) with no known history of occupational asbestos exposure, the apparent cause of the lung cancer in the current patient was occupational exposure to asbestos.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.10
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• pp.940-948
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• 2012

In Korea, researches on the exposure assessment of the hand-transmitted vibration started from the mid-90, however, they were performed in the limited industries such as auto-assembly plants and the evaluation of the vibration was mostly conducted by ISO 5349(1986). Therefore, it was necessary to assess hand-transmitted vibration levels of workplace such as ship building/repairing industry or mining industry where occupational injuries are largely occurred and to evaluate the vibration levels using revised ISO 5349(2001). The SVAN 948 Four Channels Sound & Vibration Analyser was used for the measurement. The workers using a chain saw were exposed to 1.7~2.8 $m/s^2$ of daily vibration level. Workers using a rock drill in a coal mining were exposed to the highest vibration acceleration among workers and the levels were 7.1~10.8 $m/s^2$. Vibration levels of grinders were different according to the types of grinders. The hand-transmitted vibration of 3 types of grinders were measured and the levels were 3.3~11.1 $m/s^2$. Workers using a impact wrench were exposed to 1.5~1.6 $m/s^2$ of vibration. Out of 20 kinds of machines, only 4 tools provided the information of vibration acceleration on the instructions. In addition, the current condition of workplace to control vibration was not much different from the past because there are no vibration exposure limit.

• Journal of the Korea Safety Management & Science
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• v.15 no.3
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• pp.83-91
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• 2013

The purpose of this study was to compare the exposure levels to emotional labor, occupational and socio-psychological stress, and fatigue for workers engaged in the fields of beauty business (make-up, skin, nail, and hair). For this purpose, a survey was carried out and a statistical analysis was performed for 813 persons As a result, emotional labor was found to be linked with 3 factors of emotional control, emotional dissonance, and positive emotional expression. The exposure level of emotional control was found to be high in the area of hair care and that of positive emotional expression was high in the area of nail care. Based on evaluation of Occupational Stress Scale(KOSS), the stress were found to be highest among workers engaged in the field of make-up and lowest among those in the field of nail. The exposure level of psychosocial stress was found to be the highest in the area of make-up and the lowest in the area of nail care. The exposure level of fatigue was found to be the highest in the area of make-up and the lowest in the area of nail care, showing a difference in the exposure level of stress by area of beauty business. The study confirmed that there is a difference in the exposure level related to emotional labor, job stress, psychosocial stress, and fatigue by area of beauty business.

• Toxicological Research
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• v.28 no.4
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• pp.269-277
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• 2012

The purpose of this study was to understand the mechanism of cardiovascular disease (CVD) caused by exposure to hazardous chemicals. We investigated changes in the symptoms of metabolic syndrome, which is strongly related to CVD, and in levels of other CVD risk factors, with a special emphasis on the roles of catecholamines and oxidative stress. The results revealed that neither body mass index (BMI) nor waist and hip circumferences were associated with exposure to hazardous chemicals. Among metabolic syndrome criteria, only HDL-cholesterol level increased on exposure to hazardous chemicals. Levels of epinephrine (EP) and norepinephrine (NEP) were not influenced by exposure to hazardous chemicals; however, the total antioxidative capacity (TAC) reduced because of increased oxidative stress. Both hazardous chemical exposure level and metabolite excretion were related to EP, NEP, and the oxidative stress index (OSI). Logistic regression analysis with these factors as independent variables and metabolic syndrome criteria as dependent variables revealed that EP was associated with blood pressure, and NEP with metabolic syndrome in the chemical-exposed group. In conclusion, the results suggest that reactive oxygen species generated and oxidative stress due to exposure to hazardous chemicals act as mediators and cause changes in the physiological levels of EP and NEP to increase blood pressure. This ultimately leads to the development of CVD through increase in cholesterol, triglyceride, and blood glucose levels by lipid peroxidation.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.55-61
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• 1997

This study was executed for the purpose of investigation of the EMFs exposures of personal and electronic environment. This study examines ELF-EMFs of electric appliances, subways and occupational and non-occupational human exposures, using EMDEX II (for 40 - 800Hz, Enertech Consultant, Inc.), from October 1995 to March 1996. Among the electric appliances examined, a massage unit showed the highest mean value of 247.07 $\mu$T, followed by an electric blanket of 5.24 $\mu$T. Indoor levels of EMF in subways exceerlcd 0.2 $\mu$T of the Swedish Guideline. The mean personal exposure levels of occupational group were 0.18 $\mu$T, while the personal EMF level of non-occupational group were 0.07 $\mu$T. Occupational group were exposed more highly while at work. However, the EMF levels during nonwork and sleep exposures between occuptional group and nonoccupational group were about the same. Estimates of time-intergrated exposure indicated that utility-specipic job classifications received about one-half or more of their total exposure on the job. Finally, this study would provide significant data for future research for exposure to magnetic fields, and more detailed study and research are necessary.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.266-272
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• 2013

Objectives: This study aimed to evaluate the effects of low-level exposure to toluene on T lymphocytes subpopulations.s. Methods: The study lasted from April to October 2010. The subjects were 390 male workers, among whom 137 were chronically exposed to toluene in video-tape manufacturing factories and 253 were controls had never been occupationally exposed to hazardous chemicals. The subpoupulations of CD4+, CD8+, CD16+ (natural killer cells) and total (CD3+) T lymphocytes were examined by two-color staining using monoclonal antibodies. The general and job characteristics of subjects were assessed through a self-administered questionnaire. Results: There was no significant difference in general and job characteristics between both groups. No significant difference in lipid peroxide level was observed between the control and exposed workers, but the concentration of hydrogen peroxide was significantly higher in the exposed workers. The numbers of CD16+ T lymphocytes in controls were significantly higher than those in exposed workers, but no significant differences were found in CD4+, CD8+ and CD3+ T lymphocytes. Hydrogen peroxide levels showed a significantly negative correlation with CD8+ (r = -0.29, p < 0.01), CD16+ (r = -0.56, p < 0.01) and CD3+(r = -0.22. p < 0.01), and toluene levels was significantly negative correlated with CD3+ (r = -0.29, p < 0.05). Conclusions: Our results suggest that chronic low-level exposure to toluene affects cell-mediated immunity and the effects might mediate through ROSs (Reactive Oxygen Species) such as hydrogen peroxide.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.29 no.1
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• pp.57-68
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• 2019

Objective: The purpose of this study is to propose the benefits of reduction measures according to the occupational radon reference level in order to present basic data for radon management guidelines considering domestic circumstances. Methods: This study uses radon data measured in the subway stations from 2015 to 2016. Of the total of 4,643 cases, 4,231 cases were analyzed excluding the 412 cases where the values were below $300Bq/m^3$. Results: Cost-Benefit analysis was done on the results of the field survey on subway work sites. At the exposure level of $400Bq/m^3$, the ratio between the cost and the benefit was highest at 1 : 1.81(the cost was KRW 1,398,568,032, while the benefit KRW 2,5248,772,841). At the exposure level of $600Bq/m^3$, the ratio of cost and benefit was 1: 1.80, at $300Bq/m^3$ it was 1.72, at $800Bq/m^3$ it was 1.71, at $200Bq/m^3$ it was 1.54, and at $100Bq/m^3$ it was 1.40. Conclusions: Radon management in the workplace provides economic benefits and appropriate reduction strategies are needed. In addition, it is necessary to establish and distribute radon exposure assessment procedures and guidelines for the safety and health of employees when exceeding the exposure standard, and guidelines for radon management in the workplace should be established.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.1
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• pp.87-98
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• 1999

The objectives of this study were to evaluate exposures to airborne methylene chloride and postshift carboxyhemoglobin (COHb) in blood of workers engaged in processes using blowing or cleaning agents, and to investigate correlation between methylene chloride concentrations and the blood COHb levels of workers. The geometric mean (GM) of workers' exposures (8 hour-time weighted averages, TWA) to airborne methylene chloride during cleaning molds using rags wetted with the solvent in the manufacture of flexible polyurethane foam (GM = 61.4 ppm), during operating the dip tank for cleaning molds in the manufacture of lens (GM = 61.0 ppm), and during cleaning the blowing nozzles by spraying the solvent in the manufacture of shoes (GM = 117.2 ppm) were exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value ($TLV^{(R)}$)-Time Weighted Average (TWA) (50 ppm). The COHb levels were significantly different among groups (p<0.05). The average COHh levels in blood of non-smoking workers were 2.0% in. low-level (<50 ppm) exposure group, and 3.9 % in high-level (>50ppm) exposure group. The average COHb levels in smoking workers were 3.1% in low-level exposure group, and 4.8% in high-level exposure group. The blood COHb levels of no-exposed workers to methylene chloride were 1.8% in non-smoking group, and 2.8% in smoking group. It was found that the COHb level dependeds on the methylene chloride concentration and smoking habit, and was highly correlated with methylene chloride concentration in air. The correlation coefficient was 0.81 among non-smoking workers. The estimated COHb level (3.6%) and 95% upper confidence limit (4.0%) corresponding to TLV-TWA of methylene chloride exceeded the current ACGIH Biological Exposure Index (COHb 3.5%) for carbon monoxide. The estimated COHb level (5.4%) at 100 ppm exceeded the standard (5%) recommended by National Institute for Occupational Safety and Health (NIOSH) for preventing adverse cardiovascular effect. The estimated COHb value and 95% upper confidence limit at 25 ppm of the Occupational Safety and Health. Adminstration (OSHA) Permissible Exposure Limit-TWA (PEL-TWA) were 2.6% and 3.0%, respectively. It is suggested that COHb in blood be kept below 3.0% to comply with OSHA PEL-TWA.