• 한국지구과학회지
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• 제40권4호
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• pp.414-427
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• 2019

In East Asia, the long-range transport of dust storms originating from Mongolia and northern China affects airborne dust loadings over downwind areas in the southern Korean Peninsula. Since 1997, dust loading cases caused by dust storms have been observed using the thresholds of total suspended particles (TSP, ${\geq}250{\mu}g\;m^{-3}\;hr^{-1}$) and particulate matter less than $10{\mu}g$ ($PM_{10}$, ${\geq}190{\mu}g\;m^{-3}\;hr^{-1}$) in the central-southern Korean Peninsula. There were two dust loading cases that exceeded these thresholds in 2016 and three in 2017, which reflects the downward trend of the last twenty-one years in the central-southern Korean Peninsula. Furthermore, five other dust loading cases with mass concentrations lower than the thresholds were observed from 2016 to 2017. In the moderate dust loading cases exceeding the thresholds, a descending motion of cut-off lows below $45^{\circ}N$ and a southward trough at 500 hPa gpm isopleths intensified at the western ridge, and largely extended the surface high-pressure system over southeast China. Airborne dust loadings following pronounced north-westerlies in the forward side of the high-pressure system were transported to the surface of the central-southern Korean Peninsula. However, in slight dust loading cases lower than the thresholds, the restricted descending motion of cut-off lows over $45^{\circ}N$ and the southwestward trough at 500 hPa gpm isopleths intensified the zonal flow over the Korean Peninsula. Surface high- and low-pressure systems moved eastward from the source compared to moderate dust loading cases. Due to the zonal movement of dust storms traversing eastern China, slight dust loading cases were observed with relatively higher ratios of $PM_{2.5}/TSP$ and carbon monoxide (CO) in the central-southern Korean Peninsula.

• 대기
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• 제18권4호
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• pp.493-506
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• 2008

In order to examine the variational features of Asian dust outbreak in recent years, observed WMO synop data were employed for the period from 1996 to 2007. We first divided Asian dust source regions into four subregions; 1) Taklamakan, 2) Gobi, 3) Inner Mongolia-Manchuria and 4) Loess, and the meteorogical variables such as wind speed, precipitation and threshold wind speed observed during the Asian dust outbreak period were compared with those during non-Asian dust period. The results showed that temporal variation of occurrence frequency of dust outbreak had a strong positive correlation with the frequency of strong wind speed and low precipitation in each of the 4 source regions. Spatial distributions of frequency of dust occurrence after 2002 showed increasing trend in Gobi and Inner Mongolia-Manchuria but decreasing trend in Loess region. This is showing a shift in main source region toward Northwest, especially since 2003.

• 한국대기환경학회지
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• 제20권3호
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• pp.371-380
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• 2004

In the dust separation by using porous filter media, the structure of dust layer deposited on the filter surface of filter medium directly affects the effective filtration. The present study has investigated the specific resistance (K$_2$') of the dust layer and its porosity ($\varepsilon$$_{c}$) for three different filters; FA composite filter, metal fiber filter and stainless filter. The specific resistance (K$_2$') increased and at the same time the cake porosity ($\varepsilon$$_{c}$) decreased with the increase of filtration velocity, possibly due to the compressible effect of dust layer. However, under the low dust concentration, subsequent dust particles would block the open channels through the layer resulting in high specific resistance of the layer. The FA composite filter among three filters was shown to be the most effective filter for dust cake filtration at low filtration velocities less than 0.1 m/s for an approximate dust concentration of 5 g/㎥.

• 한국안전학회지
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• 제18권4호
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• pp.85-91
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• 2003

In this study, We have investigated leaching characteristics of heavy metals for recycled plastic composites containing EAF(Electric Arc Furnace) dust & EAF slag. EAF dust & EAF slag used that is generated in the 3 steel-making compaines in domestic. The physical and chemical properties of EAF dust & slag was examined by measuring specific surface area. porosity, oil absorption test and chemical wetting analysis etc. Results of total analysis indicated that EAF dust, slag contained significant amount of hazardous metals such as Cu, Pb, Cd and Cr. But, In the leaching test of the recycled plastic composites containing EAF dust, slag by Korean Standard Leaching Procedure, composites shows much lower leaching concentration of heavy metals. It was concluded that the recycled plastic composites containing EAF dust, slag showed good physical and chemical characteristics. This means that the EAF dust, slag can be effectively used as a functional filler.

• 한국환경보건학회지
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• 제45권6호
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• pp.630-637
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• 2019

Objectives: This study was performed to evaluate the secular changes in indoor airborne dust or endotoxin levels in the dust from swine confinement buildings. Indoor levels were compared with the level at the exhaust outlet in order to examine the contribution potential of indoor dust to nearby ambient air dust. Methods: Comparisons were made on inhalable and respirable dust levels reported in 2002, 2012, and 2017 from 14, 10, and 36 swine fattening confinement buildings in Korea, respectively. This data was produced by the same research group. Levels of endotoxin adsorbed into inhalable or respirable dust were also compared. Samples of inhalable or respirable dust were collected indoors and at exhaust outlets from 17 swine fattening confinement buildings in 2019, and dust levels were compared between the indoor and the outlet. Results: The outlet inhalable dust level (0.111 mg/㎥) was approximately 19% of that from indoors, and the respirable dust level (0.033 mg/㎥) was approximately 74% of that from indoors. The outlet respirable dust levels were lower than the airborne fine dust levels in the towns where those farms are located. No significant difference was observed in the inhalable dust levels among the years examined, but the respirable dust level in 2017 (0.143 mg/㎥) was significantly lower than in 2002 (0.328 mg/㎥). The level of endotoxin in inhalable dust was significantly higher in 2017 (722 EU/㎥) than in both 2002 (75 EU/㎥) and 2012 (171 EU/㎥). Conclusion: Even though no apparent contribution from swine farm indoor dust to nearby ambient air dust was observed in terms of amount, a certain control strategy to reduce the production of airborne dust and endotoxin from swine farms is merited.

• 한국환경과학회지
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• 제20권4호
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• pp.493-500
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• 2011

This study investigates the relationship between Asian dust and asthma disease in Seoul, using data of Asian dust occurrences and the number of treatments for asthma between 2005 and 2008. The data include the number of treatments for asthma on the basic day paired with the average number of treatments for asthma on the compared days. The compared day is defined by the day of no Asian dust in same month and day of the week as the basic day, when Asian dust occurs. Also, the basic day is expanded to the day after three days from the day of Asian dust. The paired two sample t-test for the number of treatments for asthma on the basic day and the compared days revealed that the Asian dust occurrences are correlated with the asthma disease. The number of treatments for asthma is significantly increased on the one and two days after Asian dust occurs. On the other hand, there's no significant difference in the number of treatments for asthma between the days of Asian dust occurrence and the days of no Asian dust, which implies that people usually try not to go out when Asian dust occurs.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.9-18
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• 2001

1. EAF Dust in Japan - Generation and Characteristics. The quantity of dust generated from EAF shops in Japan was estimated to be 520,000 tons/year in 1999. Extremely fine dust (or fume) is formed in the EAF by metal vaporization. Its characteristics such as chemical compositions, phases, particle size, leaching of heavy metal are mentioned. 2. EAF Dust Treatment Methods in Japan. In 1999, 61% of EAF dust was treated by regional zinc recovery processing routes, 25% went to landfill disposal, 4% was reused as cement material, and 10% was treated by on-site processing routes. The problems of EAF dust treatment methods in Japan are: (1) very high treatment cost, and (2) heavy environmental load (leaching of heavy metal, emission of dioxins, depletion of disposal sites, etc). It has been much hoped for that new dust management technology would be developed. 3. New technology of EAF dust treatment in Japan. In Japan, some new technologies of EAF dust treatment have been developed, and some others are in the developing stages. Following five processes are mentioned:. (1) Smelting reduction process by Kawasaki Steel, (2) DSM process by Daido Steel, (3) VHR process by Aichi Steel, (4) On-site dust direct recycling technology, and (5) Process technology of direct separation and recovery of iron and zinc metals contained in high temperature EAF off gas by the Japan Research and Development Center fur Metals.

• 한국대기환경학회지
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• 제28권1호
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• pp.86-93
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• 2012

We present a retrieval method to obtain dust backscatter coefficient from the mixed Asian dust and pollutant layer. In the present study, vertically resolved quartz (silicon dioxide, silica) concentration was calculated using Raman scattering signals from quartz at 546 nm. Dust concentration was obtained based on typical mass percentage of quartz in Asian dust. The highest value of dust concentration at 3.7 km in March 21, 2010 was 22.3 and 10.9 ${\mu}gm^{-3}$ according to the quartz percentage in Asian dust as 65 and 30% based on literature survey, respectively. OPAC (Optical Properties of Aerosol and Clouds) simulations were conducted to calculate dust backscatter coefficient. The retrieved dust concentration was used as an input parameter for the OPAC calculations. Utilization of quartz Raman channel in Lidar measurements is considered useful for distinguishing optical properties of dust and nondust aerosol in the mixing state of Asian dust.

• 환경영향평가
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• 제21권4호
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• pp.581-591
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• 2012

The purpose of this study was to analyze the characteristics of fine particles concentration and meteorological parameters, and long range transport of wintertime Asian dust at Busan. Also we studied occurrence frequency and tendency of wintertime Asian dust from 1961 to 2010 in Korea. Asian dust occurred most frequently in the spring, the next to winter in Korea. Wintertime Asian dust is steadily increasing recently. Asian dust in Busan was the most occurred in 2001 with 21 days, followed by 12 days in 2002, and 10 days in 2006. The annual mean frequency during the past 12 years(1999~2010) was 7.5 days, and it was two times more than that during the past 50 years(3.8 days). Wintertime Asian dust in Busan has occurred 6 episodes since 2008, and it all occurred in December except for 20 Feb. 2009. The highest concentration of wintertime Asian dust was recorded mostly at Hakjangdong and Jangrimdong which are industrial area. Maintenance time of Asian dust at Busan was from 1hr 30min to 9hr 20min, it was shorter than in the spring. It took from 10 to 15 hours move to Busan after Asian dust was first detected in Korea. Wintertime Asian dust originated from Gobi desert in Mongolia and inner Mongolia near China, except for 9 Dec. 2008 at Busan.

• 한국대기환경학회지
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• 제22권5호
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• pp.719-723
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• 2006

House dust mite was the most important cause of allergic asthma and rhinitis. More than 70% of Korean children and about 50% of adult with respiratory allergy were sensitive to house dust mite. This experiment was indoor environment in house and house dust mite existence inquiry. From 23rd December 2005 to 28th February 2006, dust samples were collected from the bedclothes by a vacuum cleaner and air sampler And the levels of Der f1 and Der p1 were determined by ELISA((Enzyme-Linked Immunosorbent Assay). The results were as follows : 1 The dust mites allergy contaminations of bedclothes in house were higher than international standards(2000 ng/g). 2. In type of dust mite, the Korean house the almost have the D. farinae other than D. pteronyeeinus of mite. 3. The Der f1 and Der p1 levels per gram of dust from the bedclothes were 2074.99 ng on average, but they did not exist in air. The concentrations of house dust mite were significantly high in the bedclothes. This results suggest that the bedclothes have enough concentrations of dust mites to develop the sensitization. The control of indoor environment should be emphasized to prevent the sensitization by the repeated exposure to dust mite.