• Korean Journal of Occupational Health Nursing
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• v.19 no.1
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• pp.88-96
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• 2010

Purpose: The aim of the present study was to clarify effects of long term, low-level monocyclic aromatic hydrocarbons exposure (MAHs) such as styrene, toluene and xylene on physiological levels of epinephrine (EP) and norepinephrine (NEP) and these hormones influences diagnosis indices of metabolic syndrome (MetS). Methods: Blood pressure and serum biochemical parameters were measured using digital sphygmomanometer and autochemical analyzer. EP and NEP were analyzed by using ELISA kit and exposure level of MAHs was measured by NIOSH method. Results: The differences of general characteristics such as age, smoking and drinking habits in both groups were not significantly different except working hours per day. In exposed workers, exposure levels of MAHs showed very low concentrations. Serum HDL-cholesterol concentration was significantly higher in exposed group, but concentration of NEP was significantly higher in control group. On multiple logistic regression analysis for the diagnosis indices of MetS, EP was WC (OR=0.970), NEP was blood pressure (OR=1.002) and MAHs exposure were significantly associated with HDL-cholesterol (OR=0.257), fasting glucose (OR=3.028) and MetS (OR=0.372). Conclusion: These findings suggest that the chronic exposure of low level MAHs maycontribute to glucose metabolism and induction of MetS. And also, changes of EP and NEP levels by exposure of MAHs affect blood pressure.

• Environmental Engineering Research
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• v.14 no.3
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• pp.180-185
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• 2009

Only limited information is available as regards to the exposure levels of naphthalene (polycyclic aromatic hydrocarbons, PAHs) and monocyclic aromatic hydrocarbons(MAHs) in the interiors of diesel-fueled passenger cars, while many studies investigated the exposure levels of various volatile organic compounds(VOCs) in the interiors of gasoline-fueled passenger cars or public buses. Present study was performed to supplement this deficiency by measuring naphthalene (as a representative of PAHs) and MAHs levels inside five diesel-fueled and five gasoline-fueled passenger cars while morning and evening commuting on real roadways. Each car was surveyed five times on different sampling days. The in-vehicle naphthalene levels were higher for the diesel-fueled cars as compared to gasoline-fueled cars, whereas the results were reversed for the in-vehicle MAH levels. The median cabin levels of diesel-fueled cars were 1.3, 7, 13, 4, and 6 ${\mu}g/m^3$ for naphthalene, benzene, toluene, ethyl benzene, and m,pxylene, respectively. With respect to gasoline-fueled cars, their respective levels were 0.7, 11, 21, 7, and 9 ${\mu}g/m^3$ . The median MAHs concentration ratios of gasoline-fueled cars to diesel-fueled cars ranged from 1.50 to 1.75, while the median naphthalene concentration ratio was estimated to be 0.54. In addition, there was no significant difference of both naphthalene and MAHs between the diesel-fueled cars, but the in-vehicle levels were significantly different between gasoline-fueled cars. The concentration levels of both naphthalene and MAHs were higher in the passenger cars than other non-industrial microenvironments. Consequently, it was confirmed that the cabins of both diesel-fueled and gasoline-fueled passenger cars are an important microenvironment associated with the exposure to naphthalene and MAHs.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.55-61
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• 2008

In this paper, we proposed a multi-agent based healthcare system (MAHS) which is the combination of medical sensor module and wireless communication technology. This MAHS provides wide services to mobile telemedicine, patient monitoring, emergency management, doctor's diagnosis and prescription, patients and doctors, information exchange between hospital workers in a long distance. Also, MAHS is connected to Body Area Network (BAN) and a doctor and hospital workers. In addition, we designed and implemented extended JADE based MAHS that reduces hospital server's burden. Agents gather, integrate, and deliver the collected patient's information from sensor, and provide presentation in healthcare environment. Proposed MAHS has advantage that can handle urgent situation in the far away area from hospital like Islands through PDA and mobile device. In addition, by monitoring condition of patient (old man) in a real time base, it shortens time and expense and supports medical service efficiently.

• Asian Journal of Atmospheric Environment
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• v.4 no.3
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• pp.177-188
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• 2010

The use of an activated carbon (AC) system alone has the limitation that the pollutants are not eliminated but only transferred to another phase with the consumed AC becoming hazardous waste itself. Therefore, the present study investigated the feasibility of using a combined system of granular AC (GAC) with S-doped visible-light-induced $TiO_2$ (GAC/S-doped $TiO_2$) to clean monocyclic aromatic hydrocarbons (MAHs) with concentrations at $\leq$ 3 mg $m^{-3}$, using a continuous air-flow reactor. This study conducted three different experiments: an adsorption test of pure GAC and GAC/S-doped $TiO_2$; a long-term adsorptional photocatalytic (AP) activity test of GAC/S-doped $TiO_2$; and an AP activity test of GAC/S-doped $TiO_2$ under different conditions. For the AP activity test, three parameters were evaluated: various weights of GAC/S-doped $TiO_2$ (0.9, 4.4, and 8.9 g); various flow rates (FRs) (0.5, 1 and 2 L $min^{-1}$); and various input concentrations (ICs) of the target MAHs (0.1, 1, 2 and 3 mg $m^{-3}$). The adsorption efficiencies were similar for the pure GAC and GAC/S-doped $TiO_2$ reactors, suggesting that S-doped $TiO_2$ particles on GAC surfaces do not significantly interfere with the adsorption capacity of GAC. Benzene exhibited a clear AP activity, whereas no other target MAHs did. In most cases, the AP efficiencies for the target MAHs did not significantly vary with an increase in weight, thereby suggesting that, under the weight range tested in this study, the weights or FRs are not important parameters for AP efficiency. However, ICs did influence the AP efficiencies.

• Safety and Health at Work
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• v.2 no.4
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• pp.365-374
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• 2011

Objectives: This study was designed to investigate whether long-term, low-level exposure to monocyclic aromatic hydrocarbons (MAHs) induced insulin resistance. Methods: The subjects were 110 male workers who were occupationally exposed to styrene, toluene, and xylene. One hundred and ten age-matched male workers who had never been occupationally exposed to organic solvents were selected as a control group. Cytokines, which have played a key role in the pathogenesis of insulin resistance, and oxidative stress indices were measured. Assessment of exposure to MAHs was performed by measuring their ambient levels and their urinary metabolites in exposed workers, and the resulting parameters between the exposed group and non-exposed control groups were compared. Results: There was no significant difference in general characteristics and anthropometric parameters between the two groups; however, total cholesterol, fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance levels were significantly higher in the exposed group. Phenylglyoxylic acid levels showed significant association with tumor necrosis factor-${\alpha}$, total oxidative status, and oxidative stress index via multiple linear regression analysis. Further, there was a negative correlation between methylhippuric acid levels and total anti-oxidative capacity, and there was a significant relationship between MAHs exposure and fasting glucose levels, as found by multiple logistic regression analysis (odds ratio = 3.95, 95% confidence interval = 1.074-14.530). Conclusion: This study indicated that MAHs increase fasting glucose level and insulin resistance. Furthermore, these results suggested that absorbing the organic solvent itself and active metabolic intermediates can increase oxidative stress and cytokine levels, resulting in the changes in glucose metabolism and the induction of insulin resistance.