• Journal of Korean Society for Atmospheric Environment
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• v.17 no.3
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• pp.251-258
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• 2001

Indoor and outdoor nitrogen dioxide(NO$_2$) concentrations of 122 houses were measured and compared with measurements of personal NO$_2$ exposure simultaneously . Time activity patterns were used to determine the impacts on NO$_2$ exposure assessment and time weighed average model to estimate the personal NO$_2$ exposure. Most people spent their times more than 80% of indoor and more than 50% in home, respectively. Personal NO$_2$ esposure was found to be significantly associated with both indoor NO$_2$ concentration(r=0.70) and outdoor NO$_2$ concentration (r=0.68). Using time weighted average model, personal NO$_2$ exposure was estimated with NO$_2$ measurements in indoor home, indoor workplace and outdoor home. The estimated NO$_2$ measurements were significantly correlated with measured personal exposures(r=0.69, N=122). For the difference between measured and estimated NO$_2$ exposures by multiple regression analysis showed that NO$_2$ concentrations in near workplace and other outdoors of no NO$_2$ measurements affected the personal NO$_2$ exposures(p=0.023).

• Safety and Health at Work
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• v.10 no.1
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• pp.103-108
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• 2019

Background: This study was designed to provide logical backgrounds for the revision of biological exposure indices (BEIs) for styrene exposure in Korea. In order to investigate the correlation between airborne styrene and biological exposure indices, we measured urinary mandelic acid (MA) and phenylglyoxylic acid (PGA) in workers exposed to styrene occupationally, as well as airborne styrene at workplaces. Methods: Surveys were conducted for 56 subjects. The concentrations of airborne styrene and urinary metabolites of styrene were measured in 36 workers who were occupationally exposed to styrene, and in 20 controls. Air samples were collected using personal air samplers and analyzed by gas chromatography. Urine samples were collected at the end of the shift and analyzed by high performance liquid chromatography. Results: The geometric mean concentration of airborne styrene was 9.6 ppm. The concentrations of urinary MA, PGA, and MA+PGA in the exposure group were 267.7, 143.3, and 416.8 mg/g creatinine, respectively. The correlation coefficients for correlation between airborne styrene and MA, PGA, and MA+PGA were 0.714, 0.604, and 0.769, respectively. The sum of urinary MA and PGA corresponding to an exposure of 20 ppm styrene was 603 mg/g creatinine. Conclusion: The correlation of the sum of urinary MA and PGA with airborne styrene was better than the correlation of each individual urinary determinant. It is considered appropriate to amend the concentration of urinary MA+PGA to 600 mg/g creatinine as a BEI, which corresponds to an airborne styrene concentration of 20 ppm in Korea.

• Korean Journal of Veterinary Research
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• v.63 no.4
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• pp.33.1-33.5
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• 2023

Many scolicidal agents have been used to destroy fertile protoscolices, but these scolicidal agents have side effects, highlighting the need for research on effective and non-toxic replacement scolicidal agents. Gold nanoparticles (AuNPs) are biocompatible and non-toxic. The current study examined the effects of AuNPs in killing the protoscolices of Echinococcus granulosus in vitro using eosin staining. The protoscolices were treated with 0.2, 0.4, 0.8, or 1.0 mg/mL of AuNPs for 15, 30, 45, or 60 minutes. A concentration of 1.0 mg/mL was the most efficient in killing the protoscolices after 60 minutes exposure, reaching 96%, followed by 0.8 mg/mL (84.5%), whereas 0.4 and 0.2 mg/mL of AuNPs achieved a death rate of 76.8% and 68.5%, respectively. The loss of the protoscolices was lower at shorter exposure times with the same concentration of AuNPs and increased as the AuNP concentration was increased at the same exposure time. Significant differences were found between the different groups compared to the control group.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.52-58
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• 2014

Objectives: Using laborers participating in the petrochemical factory turnaround process as subjects, this study aims to identify exposure to benzene in the air and examine the relationship between exposure and the excretion of urinary metabolites by measuring concentrations of urinary trans, trans-muconic acid (t,t-MA). Methods: A passive sampler was used to measure the level of benzene in the air. In order to analyze urinary metabolites, the urine of laborers participating in the turnaround process was collected twice daily, both before and after work. In addition, a survey was conducted on work factors and lifestyle habits as factors affecting the concentration of urinary metabolites. Results: During the survey period, benzene was detected in the samples from all workers, and its average concentration was $0.16{\pm}0.22ppm$. The average concentration of t,t-MA after work was $1.20{\pm}1.86mg/g$ creatinine, and the results of analyzing urinary metabolites concentration before and after work showed statistically significant differences(p=0.003). There was also a statistically significant correlation (r=0.52, p=0.002) between benzene in the air and the concentration of after-work urinary t,t-MA. Conclusions: During the turnaround process, the average benzene concentration in workers was $0.16{\pm}0.22ppm$, which was below the exposure limit. However, their average t,t-MA concentration was $1.20{\pm}1.86mg/g$ creatinine, which exceeded the exposure limit of 1mg/g creatinine. The characteristics of turnaround process work require considerations such as underestimating the passive sampler being used and the skin absorption of benzene, and there needs to be a simultaneous assessment of working environment measurements and biological monitoring.

• Journal of Environmental Health Sciences
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• v.26 no.3
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• pp.25-31
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• 2000

In order to assess the accumulation levels of cadmium and other metals(Zn, Cu, Ca and Fe) in fish bodies, an experimental study was performed by raising fry of "Oryzias latipes" in the water containing cadmium 0.03 ppm, cadmium 0.03 ppm + zinc 0.03 ppm and in the tap water(control group) were made. In the results the concentration of Cd in fish bodies were increased with advancing exposure time in Cd 0.03 ppm treated group and 0.03 ppm + Zn 0.03 ppm treated group, but there was no significantly different between both groups with Cd concentration in each week. The concentration of Zn in fish bodies was no changed with advancing exposure time in control group and Cd 0.03 ppm + Zn 0.03 ppm treated group were significantly different from control and Cd 0.03 ppm treated group. The concentration of Cu, Ca and Fe in fish bodies were increased with advancing exposure time, and control group was higher than any other groups. Simple correlation analysis showed that the positive correlation between Cd and Zn, Cu and Ca, Fe, Ca and Fe, but Cd was negative correlation with Cu, Ca and Fe. In conclusion, we investigated a tendency that the concentration of Cd and Zn in fish bodies tended to increase with the lapse of time, but Cu was unchanged and those of Ca and Fe were decreased in administrating the trace dose of Cd and Zn in water. in water.

• Journal of the Korean Society of Safety
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• v.10 no.2
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• pp.105-112
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• 1995

The concentrations of $NO_2$ were measured to estimate a new developed long term exposure $NO_2$ sampler at Pusan City considering the meteorological factors from May to July, in 1994. The monthly mean concentration of $NO_2$ was 15.9 PPb and 36.2 ${\mu}\ell$/day $NO_2$ and their high values were shown in the downtown of Pusan City which show potential pollution due to the increase of traffic activities and micrometeorological factors In and around the City. As a result of statistical correlation between $NO_2$ concentration by new sampling method and $NO_2$ concentration by the handy air sampler and chemiluminescent nitrogen oxides analyzer, 1994, correlation coefficients were high(r=0.93) and showed more than 0.88 value in the high concentration data set, which was arbitrarily divided into 30${\mu}\ell$ $NO_2$ concentration in an attempt to further investigate these relationships. Therefore, use of new developed long term exposure $NO_2$ sampler is good for $NO_2$ measurement and valuable for estimation of air quality in the urban and Industrial area.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.2
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• pp.107-113
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• 2011

This study was performed for the application of the exposure limit in work field and the relative noxious gas concentration was estimated by using a miniature ship. The noxious gas concentration about light and shade number distribution of measuring subject field was estimated by using floating visualization image from a miniature ship in a large wind tunnel. About the concentration estimation, the correlation of concentration distribution drawn from the existing experimental results was used, the estimation result satisfied LTEL standard.

• Journal of Environmental Health Sciences
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• v.37 no.1
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• pp.73-79
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• 2011

The growing interest in nanotechnology has resulted in increasing concern and a number of published environmental and workplace measurements for assessing occupational exposure to engineered nanomaterials. However, the amount of previous exposure data remains limited. Furthermore the data available was collected with extensive variation in terms of exposure measurement strategy, which limits the ability to pool the data in the future. In response, this paper reviewed several pertinent issues related to exposure measurement strategy to suggest a harmonized measurement strategy which would make exposure data more useful in the future, e.g. correlation between exposure metrics, relationship between activity and exposure, task-based or shift-based assessment, background concentration, limitation of personal exposure monitoring and other determinants of exposure/modeling. An improved sampling strategy for nanomaterial exposure assessment should be considered in order to maximize the use of the data from various real time monitoring instruments.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.1
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• pp.78-88
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• 2002

Experimental animals were divided into 5 groups; normal, cadmium control, and 3 experimental groups. Cadmium control and experimental groups were exposed to 1 mg/㎥ of cadmium aerosol in air by inhalation exposure for 6 hours/day, 5 days/week during 4 weeks. Dosages of 20, 40, and 80mg/kg of extracts of persimmon leaves were intraperitoneally injected to experimental groups respectively and several toxicological parameters and induction of metallothionein were measured from the rats that inhaled cadmium aerosol in air. The results of this study were as follows. Cadmium concentration that cadmium control and experimental groups were inhaled was 0.980±0.061 mg/㎥. Mass median diameter of cadmium aerosol for inhalation exposure was 4.93±0.483㎛. Cadmium content of normal group in lung was 0.088㎍/g and the highest cadmium content in lung, 55.492㎍/g was from 80mg/kg dose group. Cadmium concentration of normal group in blood was 0.348㎍/100㎖ and the highest cadmium concentration in blood, 2.642㎍/100㎖ was from cadmium control. Cadmium concentration of normal group in liver was 0.010㎍/g and the highest cadmium concentration in liver, 31.100㎍/g was from 20mg/kg dose group. Cadmium concentration of normal group in kidney was 0.030㎍/g and the highest cadmium concentration in kidney, 2.526㎍/g was from cadmium control. Cadmium concentration of normal group in intestine was O.064㎍/g and the highest cadmium concentration in intestine, 0.300㎍/g was from 80mg/kg dose group. The highest cadmium concentration in urine by week was 6.080㎍/day from 20mg/kg dose group in the fouth week and the highest cadmium concentration in feces by week was 341.731㎍/day from 20mg/kg dose group in the fouth week. Metallothionein concentration of normal group in lung was 5.769㎍/g and the highest in lung, 30.986㎍/g was from 80mg/kg dose group. Metallothionein concentration of normal group in liver was 38.856㎍/g and the highest in liver, 169.378㎍/g was from 40mg/kg dose group. Metallothionein concentration of normal group in kidney was 22.228㎍/g and the highest in kidney, 47.898㎍/g was from 80mg/kg dose group. Metallothionein concentration of normal group in intestine was 2.170㎍/g and the highest in intestine, 13.642㎍/g was from 80mg dose group.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.360-365
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• 2008

In the last several years, studies on the association of oxidative stress damage with exposure in the work place have been conducted. Xenobiotics create an imbalance of the homeostasis between oxidant molecules and antioxidant defense. By monitoring oxidative stress biomarkers, information was obtained on damages induced by oxidative stress and the toxicity of xenobiotics. In the present study, a Job Exposure Matrix (JEM) was constructed using the data from the Working Environment Measurement (WEM) of painters in the shipyard industry from the past 3 years to assess the exposure status. Additionally, by measuring the concentration of urinary malondialdehyde (MDA), the effect of lipid peroxidation was examined. The subjects consisted of 68 workers who were exposed to mixed organic solvents in the painting process and 25 non-exposure controls. The exposure indices of the exposure groups were significantly different (sprayer: 0.83, touchup: 0.54, assistant: 0.13, P<0.05). The urinary MDA concentration of the exposure group was 48.60${\pm}$ 39.23 ${\mu}mol$/mol creatinine, which was significantly higher than 18.03${\pm}$16.33 ${\mu}mol$/mol creatinine of the control group (P<0.05). From the multiple regression analysis of urinary MDA, the regression coefficient for exposure grade was statistically significant. In future studies, evaluation of the antioxidant levels of subjects should be performed simultaneously with quantitative exposure measurements.