• Journal of Korean Society for Atmospheric Environment
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• v.32 no.1
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• pp.82-99
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• 2016

This study was carried out to understand the regional contribution of Particulate Matter (PM) emissions from East Asia ($82^{\circ}{\sim}149^{\circ}E$, $18^{\circ}{\sim}53^{\circ}N$) to Seoul during high concentration period in February 2014. The Community Multi-scale Air Quality (CMAQ) version 5.0.2 with Decoupled Direct Method (DDM) was used to analyze levels of contributions over Seoul. In order to validate model performance of the CMAQ, predicted PM and its chemical species concentrations were compared to observations in China and Seoul. Model predictions could depict the daily and hourly variations of observed PM. The calculated PM concentrations, however, had a tendency of underestimation. The discrepancies are due to uncertainties of meteorological data, emission inventories and CMAQ model itself. The high PM concentration in Seoul was induced by stationary anticyclone over the West Coast of Korea during 24 to 27 February. The DDM in CMAQ was used to analyze the contributions of emissions from East Asia on Seoul during this PM episode. $PM_{10}$ concentration in Seoul is contributed by 39.77%~53.19% from China industrial and urban region, 15.37%~37.10% from South Korea, and 9.03%~18.05% North Korea. These indicate that $PM_{10}$ concentrations in Seoul during the episode period are dominated by long-range transport from China region as well as domestic sources. It was also found that the largest contribution region in China were Shandong peninsula during the PM event period.

• Journal of environmental and Sanitary engineering
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• v.19 no.4 s.54
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• pp.61-68
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• 2004

Hair driers and chemicals used in beauty shops generate a number of heavy metals and $PM_{10}$. Also many $PM_{10}$ are produced during hair cut. The pollutions raised health problems and uncomfortableness to hair dressers and customers in beauty shops. This study investigated to assess indoor, outdoor and personal particulate pollutants ($PM_{10}$ and Heavy metals) mean concentrations and the source of the pollutants in beauty shops. The results are summarized as follows: 1. The measured mean concentrations of respiratory particulates were $30.5ng/m^2$ in indoor, $30.5ng/m^2$ in outdoor and$44.0ng/m^2$ on personal levels. The personal concentration was found higher than indoor and outdoor concentrations. 2. The heavy metals mean concentrations were showed as indoor (Na>Zn>Cr), outdoor (Cr>Zn>Pb), and personal (Na>Cr>Zn) levels. 3. Chemicals and hair driers were regarded as the major sources of the pollutions. 4. Na was correlated with Mg, Zn and Cd, while Mg was correlated with Ni. Mn was correlated with Cu, Zn and AS, where as Cu was correlated with Zn, As and Cd. Zn and As, and Asand Cd were correlated each other. Na was inversely correlated with Cr.

• Atmosphere
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• v.27 no.1
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• pp.41-54
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• 2017

Organic carbon (OC) and elemental carbon (EC) in $PM_{2.5}$ were measured using Sunset OC/EC Field Analyzer at Seoul Hwangsa Monitoring Center from March to April, 2016. The mean concentrations of OC and EC during the entire period were $4.4{\pm}2.0{\mu}gC\;m^{-3}$ and $1.4{\pm}0.6{\mu}gC\;m^{-3}$, respectively. OC/EC ratio was $3.4{\pm}1.0$. The average concentrations of $PM_{10}$ and $PM_{2.5}$ were $57.4{\pm}25.9$ and $39.7{\pm}19.8{\mu}g\;m^{-3}$, respectively, which were detected by an optical particle counter. The OC and EC peaks were observed in the morning, which were impacted by vehicle emission, however, their diurnal variations were not noticeable. This is determined to be contributed by the long-range transported OC or secondary formation via photochemical reaction by volatile organic compounds at afternoon. A conditional probability function (CPF) model was used to identify the local source of pollution. High concentrations of $PM_{10}$ and $PM_{2.5}$ were observed from the westerly wind, regardless of wind speed. When wind velocity was high, a mixing plume of dust and pollution during long-range transport from China in spring was observed. In contrast, pollution in low wind velocity was from local source, regardless of direction. To know the effect of long-range transport on pollution, a concentration weighted trajectory (CWT) model was analyzed based on a potential source contribution function (PSCF) model in which 75 percentiles high concentration was picked out for CWT analysis. $PM_{10}$, $PM_{2.5}$, OC, and EC were dominantly contributed from China in spring, and EC results were similar in both PSCF and CWT. In conclusion, Seoul air quality in spring was mainly affected by a mixture of local pollution and anthropogenic pollutants originated in China than the Asian dust.

• Journal of the Korean earth science society
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• v.23 no.6
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• pp.514-525
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• 2002

The analysis of heavy metals associated with both PM2.5 and PM10 fraction of aerosols was made from a northeast region of Seoul during the spring period of 2001. The mean concentrations of fine (PM2.5), coarse (PM10-PM2.5), and PM10 fraction were observed as 49.3${\pm}$29.2, 50.5${\pm}$35.0, and 95.5${\pm}$46.1 ${\mu}g$/m$^3$, respectively during this study period. According to the results of enrichment factor (EF) analysis between different particle fractions, major elements (including Fe, Ca, Na, and K) were found to exhibit EF values of less than 10. However, heavy metal components (like Zn and Pb) showed very high EF values. Comparison of fine/coarse (F/C) concentration ratio showed that Zn, Cr, Pb, and Ni have higher ratio values than others. The metallic composition of particles was also compared on both absolute and relative terms. The results of our analysis showed an evidence that the increase in the total metallic contents is prominent during the spring period due mostly to the Asian Dust event.

• Atmosphere
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• v.32 no.2
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• pp.119-133
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• 2022

From 2015 to 2021, high-concentration fine dust episodes with a daily average PM_2.5 concentration of 50 ㎍ m^-3 or higher were selected and classified into 3 types [long range transport (LRT), mixed (MIX) and Local emission and stagnant (LES)] using synoptic chart and backward trajectory analysis. And relationships between the fine particle data (PM_2.5 and PM₁₀ concentration and PM_2.5/PM₁₀ ratio) and meteorological data (PBLH, Ta, WS, U-wind, and Rainfall) were analyzed using hourly observation for the classification episodes on the Korean Peninsula and the Seoul metropolitan area (SMA). In LRT, relatively large particles such as dust are usually included, and in LES, fine particle is abundant. In the Korean peninsula, the rainfall was relatively increased centered on the middle and western coasts in MIX and LES. In the SMA, wind speed was rather strong in LRT and weak in LES. In LRT, rainfall was centered in Seoul, and in MIX and LES, rainfall appeared around Seoul. However, when the dust cases were excluded, the difference between the LRT and other types of air quality was decreased, but the meteorological variables (Ta, RH, Pa, PBLH, etc.) were further strengthened. In the case of the Korean Peninsula, it is difficult to find a clear relationship because regional influences (topographical elevation, cities and coasts, etc.) are complexly included in a rather wide area. In the SMA, it is analyzed that the effects of urbanization such as the urban heat island centered on Seoul coincide with the sea and land winds, resulting in a combination of high concentrations and meteorological phenomena.

• Journal of Environmental Impact Assessment
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• v.16 no.5
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• pp.351-361
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• 2007

To evaluate dominant synoptic classes which affect on $PM_{10}$ concentration in Seoul, 64 synoptic classes are classified from four seasons, 850hPa geopotential wind and lower level stability Index. In this study, we used air monitoring and meteorological data in Seoul for five years from 2001 to 2005. The results indicate that the highest occurrence frequency of synoptic class is under a strong westerly geopotential wind and stable lower atmosphere in spring. The highest $PM_{10}$ concentration of synoptic class is associated with a weak geopotential wind speed and high lower level stability. In that class, not only $PM_{10}$ but $SO_2$, $NO_2$ and CO concentrations are also higher than other classes. The analysis of spacial distribution of $PM_{10}$ concentration in each class are indicate that the influence of synoptic class are similar in the Metropolitan area in Korea. But $PM_{10}$ concentration in some areas in Kyoung-Gi are more higher than in Seoul. The relationship between $PM_{10}$ concentration and Meteorological indicator (relative humidity, temperature, surface wind speed) under same synoptic class is more correlative in Winter than other season.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1813-1821
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• 2002

The aim of this study was to identify useful secondary traits for estimating genetic ability of milk production traits. We investigated the value of using plasma metabolites concentrations. Two hundred and nineteen cattle out of 271 had only milk production traits records (G1), 33 had only metabolites records (G2), and 19 had both milk production traits and metabolites records (G3). Fifty two calves with metabolites records (G2 and G3) were born from 1992 to 1997. Forty three calves (29 females, 14 males) were used from 10 to 90 d of age and the others (3 females, 6 males) from 10 to 60 d of age. A total of 566 records of milk yield, fat yield and protein yield for 240 to 305 d on 238 heads (G1 and G2) were collected The collected blood samples were divided into three age groups: AG1, 10 to 30 d; AG2, 40 to 60 d; and AG3, 70 to 90 d. Heritabilities of milk yield, fat yield and protein yield were $0.45{\pm}0.04$, $0.50{\pm}0.04$ and $0.38{\pm}0.04$, respectively. Heritability of plasma glucose concentration at AG1 was $0.45{\pm}0.08$. Genetic correlations between plasma glucose concentration and milk yield, fat yield and protein yield were -$0.35{\pm}0.28$, $0.64{\pm}0.24$ and $0.36{\pm}0.35$, respectively. When the plasma glucose concentration at AG1 was used to estimate genetic ability of these milk production traits, reliability of milk yield of animals without milk record increased 8.2%, fat yield increased 24.2% and protein yield increased 9.5%. Heritability of plasma total cholesterol concentration at AG3 was $0.83{\pm}0.04$. Genetic correlation between plasma total cholesterol concentration and milk yield, fat yield and protein yield were $0.58{\pm}0.21$, $0.42{\pm}0.20$ and $0.45{\pm}0.22$, respectively. When the plasma total cholesterol concentration at AG3 was using to estimate genetic ability of these milk production traits, reliability of milk yield of animals without milk record increased 19.0%, fat yield increased 9.6%, and protein yield increased 13.5%. The annual genetic gain is in proportion to the reliability of selection. These results show that the plasma metabolite concentrations would be useful for improvement of genetic ability for milk production traits in the genetic improvement in herd of cows, where half of the animals selected are from a herd without its own milk record.

• Biomolecules & Therapeutics
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• v.22 no.1
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• pp.78-81
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• 2014

Irinotecan suppository was prepared using the moulding method with a homogeneous blend. A sensitive and specific fluorescence method was developed and validated for the determination of irinotecan in plasma using HPLC. The pharmacokinetics of intravenous administered and rectal administered in rabbits was investigated. Following a single intravenous dose of irinotecan (50 mg/kg), the plasma irinotecan concentration demonstrated a bi-exponential decay, with a rapid decline over 15 min. $C_{max}$, $t_{1/2}$, $AUC_{0-30h}$ and $AUC_{0-{\infty}}$ were $16.1{\pm}2.7g/ml$, $7.6{\pm}1.2h$, $71.3{\pm}8.8{\mu}g{\cdot}h/ml$ and $82.3{\pm}9.5{\mu}g{\cdot}h/ml$, respectively. Following rectal administration of 100 mg/kg irinotecan, the plasma irinotecan concentration reached a peak of $5.3{\pm}2.5{\mu}g/ml$ at 4 h. The $AUC_{0-30h}$ and $AUC_{0-{\infty}}$ were $32.2{\pm}6.2{\mu}g{\cdot}h/ml$ and $41.6{\pm}7.2{\mu}g{\cdot}h/ml$, respectively. It representing ~50.6% of the absolute bioavailability.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.1
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• pp.65-73
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• 2014

Objectives: The purposes of this study are to investigate workers' exposures to respirable particles generated in taconite mines and to compare two metric methods for mass concentrations using direct-reading instruments. Methods: Air monitorings were conducted at six mines where subjects have been exposed primarily to particulate matters in crushing, concentrating, and pelletizing processes. Air samples were collected during 4 hours of the entire work shift for similarly exposure groups(SEGs) of nine jobs(N=37). Following instruments were employed to evaluate the workplace: a nanoparticle aerosol monitor(particle size range; 10-1000 nm, unit: ${\mu}m^2/cc$, Model 9000, TSI Inc.); DustTrak air monitors($PM_{10}$, $PM_{2.5}$, unit: $mg/m^3$, Model 8520, TSI Inc.); a condensation particle counter(size range; 20-1000 nm, unit: #/cc, P-Trak 8525, TSI Inc.); and an optical particle counter(particle number by size range $0.3-25{\mu}m$, unit: #/cc, Aerotrak 9306, TSI Inc.). Results: The highest airborne concentration among SEGs was for furnace operator followed by pelletizing maintenance workers in number of particle and surface area, but not in mass concentrations. The geometric means of $PM_{2.5}$ by the DustTrak and the Ptrak/Aerotrak were $0.04{\mu}m$(GSD 2.52) and $0.07{\mu}m$(GSD 2.60), respectively. Also, the geometric means of RPM by the DustTrak and the Ptrak/Aerotrak were $0.16{\mu}m$(GSD 2.24) and $0.32{\mu}m$(GSD 3.24), respectively. The Pearson correlation coefficient for DustTrak $PM_{2.5}$ and Ptrak/Aerotrak $PM_{2.5}$ was 0.56, and that of DustTrak RPM and Ptrak/Aerotrak RPM was 0.65, indicating a moderate positive association between the two sampling methods. Surface area and number concentration were highly correlated($R^2$ = 0.80), while $PM_{2.5}$ and RPM were also statistically correlated each other($R^2$ = 0.79). Conclusions: The results suggest that it is possible to measure airborne particulates by mass concentrations or particle number concentrations using real-time instruments instead of using the DustTrak Aerosol monitor that monitor mass concentrations only.

• Korean Journal of Veterinary Research
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• v.30 no.1
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• pp.65-71
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• 1990

Rabbits were experimentally infected with rabbit hemorrhagic disease virs and the viral pathogenicity, hemagglutinability, and the effect of physicochemical factors were studied. The experimental results were summariaed as follows: 1. Mean rectal temperature of 11 infected rabbits was $40.0{\pm}0.47^{\circ}C$ prior to the virus inoculation, and $39.9{\pm}0.75^{\circ}C$ after 12hrs., $40.2{\pm}0.65^{\circ}C$ after 24hrs., $40.1{\pm}0.77^{\circ}C$ after 36hurs, and $40.6{\pm}0.56^{\circ}C$ just before the death. 2. Mean death time of infected rabbits was $40.3{\pm}22.0$ honrs and its range was 24 to 93 hours. 3. O, B, AB and A type of human erythrocytes were shown their HA in the order, but rabbit and chicken erythrocytes were not hemagglutinated by the virus. 4. In the hemagglutination, less than 0.25 per cent of a final concentration of erythrocytes and 0.2 per cent of BSA in PBS resulted in the best hemagglutination. Phosphate concentration in a range of 0.01M to 0.10M in PBS was not influenced on the hemagglutination reaction, and its pH 7.0 resulted in a better HA. 5. The hemagglutinating titers, in log 2 scale, of organs and tissues of the virus infected rabbits were $9.3{\pm}3.8$ (liver), $9.1{\pm}3.9$ (blood), $6.2{\pm}2.6$ (spleen) and $5.0{\pm}2.5$ (kidney). 6. The physicochemical factors such as heating ($50^{\circ}C$, 10 min.), trypsin treatment (0.05 pre cent, 5 min.), acid treatment (pH 3.0, 20 min.) and ether extraction (3 times) were not affective to the stability of virus and viral HA activities.