• Journal of the Korean earth science society
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• v.25 no.6
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• pp.428-442
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• 2004

Dustfall samples were collected by the modified American dust jar (bulk type) at 5 sampling sites in the Nakdong river area from lune 2002 to May 2003. Nineteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Si, V, Zn, $Cl^-$, $NO_3^-$, $SO_4^{2-}$, and $NH_4^+$) were analyzed via the combination of ICP/AES, AAS, IC and UV. The purposes of this study were to qualitatively evaluate the chemical composition of dustfalls by examining their regional and seasonal distribution patterns. Computation of the enrichment factor showed that well-defined anthropogenic sources, particularly in Pb were found in the order Gamjeondong (industrial area), Wondong, Silla University, Samrangiin and Mulgum. The seasonal mean of soil contribution showed its highest value (16.3%) during the winter with an annual mean of 11.2%. The concentration ratio of [$SO_4^{2-}/NO_3^-$] was found to be highest (5.12) during the winter, while the lowest ratio value (3.30) was seen during the all. fall, Also regional equivalent ratios of [$SO_4^{2-}/NO_3^-$] were found in the order: Silla University (6.78), Gamjeondong (4.98), Mulgum (3.95), Wondong (3.85), and Samrangjin (2.87). Seasonal distribution of water soluble components for total dustfall were found in the order: spring (71.6%), summer (61.2%), fall (49.2%) and winter (48.6%) with a mean ratio of 57.6%. Regional contribution of sea salts of water soluble ions were found in the order: Silla university (34.5%), Gamjeondong (28.3%), Wondong (17.3%), Samrangiin (17.2%) and Mulgum (13.8%), the total mean contribution rate was 22.1%. As for the chemical composition of dustftll on the lower Nakdong river, there is a decreased influence of sea salt and artificial anthropogenic sources and increased influence of soil particle inland. Also, the total amount of deposition on the lower Nakdong river has decreased, with the river's surface serving as a confounding factor in resuspending dusts.

• Asian Journal of Atmospheric Environment
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• v.8 no.1
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• pp.35-47
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• 2014

The purpose of the study is to evaluate the pollution level (gaseous and particle phase) in the public facilities for the PAHs, non-regulated materials, forecast the risk level by the health risk assessment (HRA) and propose the guideline level. PAH assessments through sampling of particulate matter of diameter < 2.5 ${\mu}m$ ($PM_{2.5}$). The user and worker exposure scenario for the PAHs consists of 24-hour exposure scenario (WIES) assuming the worst case and the normal exposure scenario (MIES) based on the survey. This study investigated 20 PAH substances selected out of 32 substances known to be carcinogenic or potentially carcinogenic. The risk assessment applies major toxic equivalency factor (TEF) proposed from existing studies and estaimates individual Excess Cancer Risk (ECR). The study assesses the fine dusts ($PM_{2.5}$) and the exposure levels of the gaseous and particle PAH materials for 6 spots in each 8 facility, e.g. underground subway stations, child-care facilities, elderly care facilities, super market, indoor parking lot, terminal waiting room, internet caf$\acute{e}$ (PC-rooms), movie theater. For internet caf$\acute{e}$ (PC-rooms) in particular, that marks the highest $PM_{2.5}$ concentration and the average concentration of 10 spots (2 spots for each cafe) is 73.3 ${\mu}g/m^3$ (range: 6.8-185.2 ${\mu}g/m^3$). The high level of $PM_{2.5}$ seen in internet cafes was likely due to indoor smoking in most cases. For the gaseous PAHs, the detection frequency for 4-5 rings shows high and the elements with 6 rings shows low frequency. For the particle PAHs, the detection frequency for 2-3 rings shows low and the elements with 6 rings show high frequency. As a result, it is investigated that the most important PAHs are the naphthalene, acenaphthene and phenanthrene from the study of Kim et al. (2013) and this annual study. The health risk assessment demonstrates that each facility shows the level of $10^{-6}-10^{-4}$. Considering standards and local source of pollution levels, it is judged that the management standard of the benzo (a)pyrene, one of the PAHs, shall be managed with the range of 0.5-1.2 $ng/m^3$. Smoking and ventilation were considered as the most important PAHs exposure associated with public facility $PM_{2.5}$. This study only estimated for inhalation health risk of PAHs and focused on the associated cancer risk, while multiple measurements would be necessary for public health and policy.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.69-78
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• 2010

In order to investigate the degree of household dust contamination, 48 samples of household dust (24 from urban area and 24 from rural area) in Daegu city were collected in vacuum cleaner during January to February 2009. Samples were sieved below 100 ${\mu}m$, and 14 elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V, Zn) were analyzed using ICP after acid extraction. Results obtained from the source assessment of trace elements using enrichment factor showed that Ca, Fe, K, Mg, Mn, Na, and V were influenced by natural sources such as weathered rock and resuspended soil, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources such as fuel combustion and waste incineration. Concentrations were remarkably higher in components from natural sources than in components from urban anthropogenic sources. Household dust in urban area was more affected by anthropogenic sources compared with that of rural area. Pollution index of heavy metals revealed that urban area was 1.8 times more contaminated with heavy metal components than rural area. The correlation analysis among trace elements indicated that components were correlated with natural sources-natural sources (Al-Mg, Al-Mn, Fe-Mn) and natural sources-anthropogenic sources (Al-V, Fe-Cr, V-Mn) in both urban area and rural area. Trace element components of rural area were more correlated than those of urban area. Houses that use oil for heating fuel had relatively higher contents of heavy metals rather than those using gas or electricity for heating fuel. Houses with children also had higher contents of heavy metals. In addition, the age of houses was found to influence the heavy metal levels in household dusts, with older houses (>10years) having higher concentrations than newer houses (<10years) and houses located near the major road (<10 m) were found to have relatively higher heavy metal levels in household dust.

• Journal of the Korean earth science society
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• v.36 no.1
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• pp.90-108
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• 2015

The WRF-Chem model was applied to simulate the Asian dust event affecting the Korean Peninsula from 11 to 13 November 2010. GOCART dust emission schemes, RADM2 chemical mechanism, and MADE/SORGAM aerosol scheme were adopted within the WRF-Chem model to predict dust aerosol concentrations. The results in the model simulations were identified by comparing with the weather maps, satellite images, monitoring data of $PM_{10}$ concentration, and LIDAR images. The model results showed a good agreement with the long-range transport from the dust source area such as Northeastern China and Mongolia to the Korean Peninsula. Comparison of the time series of $PM_{10}$ concentration measured at Backnungdo showed that the correlation coefficient was 0.736, and the root mean square error was $192.73{\mu}g/m^3$. The spatial distribution of $PM_{10}$ concentration using the WRF-Chem model was similar to that of the $PM_{2.5}$ which were about a half of $PM_{10}$. Also, they were much alike in those of the UM-ADAM model simulated by the Korean Meteorological Administration. Meanwhile, the spatial distributions of $PM_{10}$ concentrations during the Asian dust events had relevance to those of both the wind speed of u component ($ms^{-1}$) and the PBL height (m). We performed a regressive analysis between $PM_{10}$ concentrations and two meteorological variables (u component and PBL) in the strong dust event in autumn (CASE 1, on 11 to 23 March 2010) and the weak dust event in spring (CASE 2, on 19 to 20 March 2011), respectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.1
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• pp.44-53
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• 2006

This study purposed to investigate air pollution in car shipping yards and, for this purpose, we selected an outdoor open-air yard and an indoor ramp into the ship and measured the concentrations of sulfur dioxide, nitrogen dioxide, carbon monoxide, PM10, PM2.5 and heavy metals in the air. The results of this study are as follows. No significant difference was observed in temperature and humidity between the outdoor and indoor workshop, and the average air flow was 0.52 m/s in the indoor workshop, which is higher than 0.19 m/s in the outdoor workshop(p<0.01). The average concentrations of sulfur dioxide, nitrogen dioxide, carbon monoxide, PM10 and PM2.5 according to workplace were 0.03 ppm(${\pm}0.01$), 0.03 ppm(${\pm}0.01$), 0.46 ppm(${\pm}0.22$), $39.44{\mu}g/m^3$(${\pm}2.45$) and $5.45{\mu}g/m^3$(${\pm}1.15$) respectively in the outdoor workshop, and 0.15 ppm(${\pm}0.05$), 0.22 ppm(${\pm}0.06$), 8.85 ppm(${\pm}3.35$), $236.39{\mu}g/m^3$(${\pm}58.21$) and $152.43{\mu}g/m^3$(${\pm}35.42$) respectively in the indoor workshop. Thus, the concentrations of gaseous substances in the indoor workshop were 4.9-19.2 times higher than those in the outdoor workshop, and the concentrations of fine dusts were 5.9-27.9 times higher(p<0.01). In addition, according to the result of investigating pollutant concentrations according to displacement and the number of car loaded when shipping gasoline cars into the ship, no significant relation between the number of cars loaded and pollutants was observed in shipping passenger cars, but the concentrations of nitrogen dioxide and carbon monoxide got somewhat higher with the increase of the number of cars loaded(p<0.05). In addition, the concentrations of nitrogen dioxide, carbon monoxide, PM10 and PM2.5 in the air were significantly higher when shipping recreational vehicles, the displacement of which is larger than passenger cars, than when shipping passenger cars(p<0.01). On the other hand, the average heavy metal concentrations of the air in indoor workshop were: lead $-0.05{\mu}g/m^3$(${\pm}0.10$); chromium $-0.90{\mu}g/m^3$(${\pm}0.18$); zinc $-0.38{\mu}g/m^3$(${\pm}0.24$); copper $-0.18{\mu}g/m^3$(${\pm}0.22$); and manganese and cadmium not detected. In addition, the complaining rates of 'asthma,' a major symptom of chronic respiratory diseases, were 18.5% and 22.5% respectively in indoor workers and outdoor workers. Thus the rate was somewhat higher in indoor workers but the difference was not statistically significant. The complaining rates of 'chronic cough' and 'chronic phlegm' were very low and little different between indoor and outdoor workers. The results of this study show that the reason for the higher air pollution in indoor than in outdoor workshop is incomplete combustion of fuel due to sudden start and over-speed when cars are driven inside the ship. In order to prevent high air pollution, efficient management measures should be taken including the observance of the optimal speed, the improvement of old ships and the installation of efficient ventilation system.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.720-725
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• 2013

When highly shrinkable materials such as coir dust are major component of root media, the degrees of compaction during container filling of root media severely influences the physical properties of root media. It results in the changes in total porosity (TP), container capacity (CC) and air-filled porosity (AFP). This research was conducted to secure the fundamental information in changes of soil physical properties as influenced by the compaction of root media during container filling. To achieve this, three root media were formulated by blending coir dust (CD) with expanded rice hull (CD + ERH, 8:2, v/v), carbonized rice hull (CD + CRH, 6:4) and ground and raw pine bark (CD + GRPB, 8:2). Based on the optimum bulk density, the amount of root media filled into 6.0, 7.5, 8.5, 10.5 and 12.5 cm were adjusted to 90, 100, 110, 120 and 130% based on the weight of root media. Then the changes in TP, CC, and AFP were measured. Elevation of the packing amount of root media in all sizes of pot resulted in the decrease of TP. But the decrease was more severe in CD + ERH and CD + CRH than those in CD + GRPB. The CC also decreased gradually as the packing amounts were elevated in three root media, but the decreases were severe as the container sizes became larger. The AFP decreased drastically by the elevation of the packing amount of root media in all sizes of pot. The AFP was the highest in CD + CRH medium when pot sizes were smaller than 7 cm, but that was the highest in CD + ERH when the pot sizes were larger than 8.5 cm among the 3 root media tested. In this research, the elevation of packing amount of three root media influenced more severely the AFP rather than CC. This result indicates that the packing amount should be controlled to maintain appropriate level of AFP because AFP rather than CC influence severely crop growth. The results obtained through this study can be used to predict the changes in physical properties of root media as influenced by packing amount in various sizes of pots.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.301-306
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• 2005

Asian dust was collected in Korea and soils in the arid area of northern China were analysed for its physical and chemical properties, and mineral compositions for in order to interpret the origin of Aeolian soils and estimate the effect of dust wind on the soil environment in Korea. Asian dust was collected at Suwon in Korea from 2002 to 2004. Soil samples were collected from the desert and Loess plateaus around Gobi desert in China. As a result of analysis of desert soil distributed on northern region and Loess soils in China, it was observed that soil pH was about 9, organic matter 11 to $23g\;kg^{-1}$, and CEC 7.1 to $18.4cmolc\;kg^{-1}$, showing a high spatial variation among different sampling locations. About 62 to 80% of particles were composed of quartz and feldspars, 2 to 14% calcite ($CaCO_3$) and dolomite [$Ca{\cdot}Mg(CO_3)_2$], and trace other clay minerals. All the dust particles in Korea were below 50 m in diameter, and the mineral compositions were quartz, mica, feldspar and some clay minerals. Major components of clay mineral of Asian dust was mainly illite as compared to the kaolin of soils in Korea. The base saturation of exchangeable Ca, Mg, K and Na in the Asian dust was above 250% due to the high content calcite. Most of upland soil in Suwon was thin and sharp type, but Asian dust in Korea was the spherical shape. Asian dusts in Suwon, Korea, did not show a definite mineralogical variation of the dust during the collection period. Difference between the Asian dust collected in Korea and the soils in arid area of China was observed in the physical and chemical properties, especially for particle size distribution, cations such as Ca, Mg, K and Na. However, some similarities were found on the mineral compositions and chemical properties between Asian dust collected in Korea and the loess of China.

• Resources Recycling
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• v.2 no.2
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• pp.27-38
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• 1993

In this study, we investigated the grinding and sedimentation(elutriation) process of the dusts for the effective separation of high purity iron and iron oxides. For characterization of the dust, particle size distribution and chemical composition, were examined. The results obtained in this study may be summarized as follows : 1. The converter CF(clarifier) dust of the Pohang 1st, 2nd steel making factory and EC(Evaporation Cooler), EP(Eltrostatic precititator) dust of the Kwangyang 2nd steel making factory are composed $\alpha$-Fe(21~50%), FeO(wustite)$Fe_3$$O_4$(magnetite), $Fe_2$$O_3$, CaO, $Al_2$$O_3$, $SiO_2$, and etc. 2. Pure iron has ductile characteristic in nature, particle size of the pure iron increase by increasing the grinding time. On the other hand, it is conformed that bo고 particles of hematite and magnetite become less than 325 mesh after 10 minutes grinding. 3. By applying the elutriation technique for the EC dust of the Kwangyang 2nd steel making factory, the iron powder of high content more than 99.17% of pure Fe was recovered with 37.8% yield at grinding time for 40 minutes. 4. By applying the elutriation technique for the CF dust of the Pohang 2nd steel making factory, the iron powder of high content more than 98.38% of pure Fe was recovered with 44.42% yield at grinding time for 40 minutes. 5. When magnetic separation was performed using plastic bonding magnet of 70 gauss, more than 98% Fe grade of iron powder was recovered in the size range +65 -200 mesh but the recovery of it was low.

• Journal of the Korean earth science society
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• v.39 no.6
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• pp.519-532
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• 2018

We investigated the effect of galactic plane toward molecular motion and kinematics in the northern filament (NF) of Orion Molecular Clouds Complex (OMC) using $^{12}CO$ (J=1-0) line. Observed data were from three areas including NF1, NF2, and NF3 in far-out order from galactic plane, for a total 270 hours by Seoul National University Radio Astronomy Observatory (SRAO) 6m telescope, with 2arcmin spatial resolution. galactic plane and OMC NF were connected to each other along the magnetic field at a density of 3% for $^{12}CO$ (J=2-1) and 9% for the case of dust. $^{12}CO$ (J=1-0), $^{12}CO$ (J=2-1), and interstellar dusts were distributed uniformly in NF3, but only in certain regions with relatively high density in NF1 and NF2. NF showed a single structure, partial shrinking motion in NF1, and rotational motion at the bottom of NF2, and spiral rotation associated with magnetic field only in NF3. The position-velocity analysis showed that the materials including $^{12}CO$ (J=1-0) could flow toward galactic plane along NF2 and NF3. However, there was no clear cause for the material to flow toward galactic plane in this result. Further detailed observation for rotational motion at the top of NF1 and NF2 might help to confirm it.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.510-522
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• 1999

The air pollutants ; $SO_2$, $SO{_4}^{-2}$, $NO{_3}^-$, $Cl^-$ are absorbed into soils through falling with dusts and rain from the atmosphere. The sources of heavy metal contaminants in the environments are agricultural and horticultural materials, sewage sludges, fossil fuel combustion, metallurgical industries, electronics and waste disposal etc.. The soils and hydrosphere can be polluted on the way of the circulation of these heavy metals. Studied pollutant anions are $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ and heavy metals are Se, Mo, Zn, Cd, Pb, Mn, Cr, Co, V, As, Cu and Ni which are the elements to be concerned with the essentials for plants, with animal and human health. This study is with the aim of selecting the species of roadside trees and green space trees which have excellent absorption of air pollutants and heavy metals from the atmosphere and the soils in the urban area. Two areas are designated to carry out this study : urban area ; Kwangju city and rural area ; the yard of Forest Environment Institute of Chollanam-do, at Sanje-ri, Sampo-myum, Naju city, Chollanam-do (23km away from Kwangju). This study is carried out to understand the movement of anions and heavy metals from the soils to the trees in both areas, the absorption of anions and heavy metals from atmosphere into leaves and the amounts of anions and heavy metals in leaves and fine roots(< 1mm dia.) of roadside trees and green space trees in Kwangju and trees in the yard of Forest Environment Institute of Chollanam-do. The tree species selected for this study in both areas are Ginkgo biloba, Quercus acutissima, Cedrus deodara, Platanus occidentalis, Robinia pseudoacacia, Alnus japonica. Metasequoia glyptostroboides. Zekova serrata. Prunus serrulata var. spontanea, and Pinus densiflora. The results of the study are as follows : 1. $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ concentrations are higher in the soils of the urban area than in those of the rural area, and $NO{_3}^-$ and $SO{_4}^{-2}$ are higher in the leaves than in the roots due to the absorption of the these pollutants through the stomata. 2. Ginkgo biloba, Robinia pseudoacacia. Zekova serrata, Quercus acutissima, and Platanus occidentalis can be adequated to the roadside trees and the environmental trees due to their good absorption of $NO{_3}^-$ and $SO{_4}^{-2}$. 3. Heavy metals in the soils of both areas are in the order of Mn > Zn > V > Cr > Pb > Ni > Cu > Mo> Cd, and in the leaves and roots of the trees in the both areas are in the order of Mn>Zn>Cr>Cu>V>Ni. Both orders are similar ones except V. There are more in the urban soils than in the rural soils in amount of Mn, Zn, Pb, V, Cu. 4. It is supposed that there is no antagonism between Mn and Zn in this study. 5. Se, Co and As are not detected in the soils, the leaves and the roots in both areas. Sn, Mo, Cd and Pb are also not detected in the leaves and roots in spite of considerable amount in the soils of both areas.