• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.326-335
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• 2015

Background: Asian dust is known to have harmful effects on the respiratory system. Respiratory conditions are also influenced by environmental conditions regardless of the presence of pollutants. The same pollutant can have different effects on the airway when the air is dry compared with when it is humid. We investigated hospital visits for chronic obstructive pulmonary disease (COPD) and asthma in relation to the environmental conditions. Methods: We conducted a retrospective study using the Korean National Health Insurance Service claims database of patients who visited hospitals in Chuncheon between January 2006 and April 2012. Asian dust, haze, mist, and fog days were determined using reports from the Korea Meteorological Administration. Hospital visits for asthma or COPD on the index days were compared with the comparison days. We used two-way case-crossover techniques with one to two matching. Results: The mean hospital visits for asthma and COPD were $59.37{\pm}34.01$ and $10.04{\pm}6.18$ per day, respectively. Hospital visits for asthma significantly increased at lag0 and lag1 for Asian dust (relative risk [RR], 1.10; 95% confidence interval [CI], 1.01-1.19; p<0.05) and haze (RR, 1.13; 95% CI, 1.06-1.22; p<0.05), but were significantly lower on misty (RR, 0.89; 95% CI, 0.80-0.99; p<0.05) and foggy (RR, 0.89; 95% CI, 0.84-0.93; p<0.05) days than on control days. The hospital visits for COPD also significantly increased on days with Asian dust (RR, 1.29; 95% CI, 1.05-1.59; p<0.05), and were significantly lower at lag4 for foggy days, compared with days without fog (RR, 0.85; 95% CI, 0.75-0.97; p<0.05). Conclusion: Asian dust showed an association with airway diseases and had effects for several days after the exposure. In contrast to Asian dust, mist and fog, which occur in humid air conditions, showed the opposite effects on airway diseases, after adjusting to the pollutants. It would require more research to investigate the effects of various air conditions on airway diseases.

• Journal of the Mineralogical Society of Korea
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• v.29 no.2
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• pp.79-87
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• 2016

Asian dust (Hwangsa) interacts with light, atmospheric gas, aerosol, and marine ecosystem, affecting Earth climate. Mineralogical properties are essential to understand the interaction between the dust and environments. In this study, we examined the mineralogical properties of Asian dust collected at Deokjeok Island, Incheon, Korea in February 22, 2015. X-ray diffraction (XRD) analyses showed that phyllosilicate minerals (62 wt%) dominate the Asian dust. Illite-smectite series clay minerals (55%) were common with minor chlorite (5%) and kaolinite (2%). Non-phyllosilicate minerals were quartz (18%), plagioclase (10%), K-feldspar (4%), calcite (4%), and gypsum (1%). Similar results were obtained by mineral quantification using scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). Transmission electron microscopy combined with EDS confirmed illite-smectite series clay minerals as the dominant phyllosilicate type. Morphological analyses using SEM showed clay agglomerates, clay-coated quartz, feldspars, and micas. Gypsum grains were common on the particle surface, while calcite nanofibers, previously reported as common on the surface, were rare, indicating the reaction of calcite and acidic atmospheric pollutants to form gypsum. The analytical result of 2015 Asian dust would contribute to the establishment of mineralogical base for the modeling of the interaction between Asian dust and environments.

• 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.

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.279-285
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• 2005

Background : Ambient particles during Asian dust events are usually less than $10{\mu}m$ in size, and known to be associated with the adverse effects on the general population. There is little evidence linking Asian dust to adverse effects on the airways. In 2002, the authors found that particulate matter during Asian dust events had an effect on the symptoms and pulmonary function of patients with bronchial asthma. An aggravating factor might be that of a viral infection, but this remains unclear. Conversely, it has been speculated that African dust may carry the virus responsible for foot and mouth disease. Asian dust events are also likely to be responsible for transporting viruses, some of which are pathogenic, and common in many environments. Therefore, in this study, air samples were screened for the presence of viruses. Methods : Air samples were collected 20 times each during Asian dust events and under non-dust conditions, for at least 6 hours per sample, using a high volume air sampler (Sibata Model HV500F), with an airflow rate of 500L/min, between April and August 2003, and between April and August 2004. The samples were then screened for the presence of targeted viruses (Influenza A, B, Hog cholera virus, and Aphthovirus) using a polymerase chain reaction method. Results : One Asian dust event occurred between April and August 2003, and 3 between April and August 2004, with a 24 hour average PM10 level of $148.0{\mu}g/m^3$. The 24 hour average PM10 level was $57{\mu}g/m^3$. There was a significant difference in the PM10 concentration between dusty and clear days. No viruses (Influenza virus, Aphthovirus, and Hog cholera virus) were identified in the air samples obtained during the dusty days. Conclusions : Although no virus was detected in this study, further studies will be needed to identify suspected viruses carried during Asian dust events, employing more appropriate virus detection conditions.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.531-546
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• 2018

Air quality forecasting system with Asian dust emissions was developed in East Asia, and $PM_{10}$ forecasting performance of chemical transport model with Asian dust emissions was validated and evaluated. The chemical transport model (CTM) with Asian dust emission was found to supplement $PM_{10}$ concentrations that had been under-estimated in China regions and improved statistics for performance of CTM, although the model were overestimated during some periods in China. In Korea, the prediction model adequately simulated inflow of Asian dust events on February 22~24 and March 16~17, but the model is found to be overestimated during no Asian dust event periods on April. However, the model supplemented $PM_{10}$ concentrations, which was underestimated in most regions in Korea and the statistics for performance of the models were improved. The $PM_{10}$ forecasting performance of air quality forecasting model with Asian dust emissions tends to improve POD (Probability of Detection) compared to basic model without Asian dust emissions, but A (Accuracy) has shown similar or decreased, and FAR (False Alarms) have increased during 2017.Therefore, the developed air quality forecasting model with Asian dust emission was not proposed as a representative $PM_{10}$ forecast model in South Korea.

• Asian Journal of Atmospheric Environment
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• v.7 no.2
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• pp.114-119
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• 2013

The characteristics of Asian dust (AD) in Korea between 1997 and 2005 were investigated, focusing on peak 1-hour $PM_{10}$ concentrations during AD events at seven cities over the Korean Peninsula. The frequency of AD events decreased from Seoul to Busan, indicating the major pathway of AD in Korea was from northwest to southeast. AD events were most frequent in 2001 while peak concentrations during AD events were much higher in 2002. Recent works show that the trajectories from northerly directions increased during the 2000s and later (Chun, 2009; Kim, 2008). In this work, the fraction of trajectories from the northwest was the largest on the whole, although trajectories from each direction varied by city and year. It is presumed that high concentrations of $PM_{10}$ during AD events are generally associated with trajectories from the northwest rather than from the source region.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.518-519
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• 2003

Many studies of Asian dust have been undertaken to investigate dust sources, their transport and deposition mechanisms, their optical and chemical properties, and their physical characteristics. These studies have used meteorological parameters, optical thickness, and mineral compositions derived from satellite images, lidar, sunphotometer, and other ground-based instruments in East Asia (Chun et al., 2001; Murayama et al., 2001). (omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.574-579
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• 2005

Optimal management of indoor air quality in a confined pig house, especially in winter, is indispensable for preventing infectious respiratory disease to workers and animals. This study was performed to elucidate the correlation of aerial contaminants and climate factors in a confinement. It was observed that indoor air contaminants ion in the confinement was the highest at 2:00-5:00 pm in a day, followed by 8:00-11:00 pm and 8:00-11:00 am. This was attributed to the increase of pig activities in the afternoon. The concentration of total dust and total airborne bacteria was found to have a significant correlation with temperature and relative humidity (p<0.05). Correlation of total dust and total airborne bacteria, total dust and ammonia, and total dust and odor were shown statistically significant at 95% confidence level. In conclusion, temperature and total dust concentration correlated significantly with all the parameters except for hydrogen sulfide ($H_2S$). This could be explained by the fact the dryness of pig feces by increase of interior temperature and resuspension of feed deposited on the floor by the pig activity, resulted in high generation of dust which adsorbed and carried the airborne bacteria and odor compounds in a confined pig house. It was proved that the adsorptive capacity of dust with ammonia ($NH_3$) was higher than that with hydrogen sulfide ($H_2S$).

• Atmosphere
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• v.17 no.3
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• pp.299-314
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• 2007

The purpose of this study is to summarize tropical cyclone activity in 2006. Twenty three tropical cyclones of tropical storm (TS) intensity or higher formed in the western North Pacific and the South China Sea in 2006. The total number is less than the thirty-year (1971~2000) average frequency of 26.7. Out of twenty three tropical cyclones, fifteen cyclones reached typhoon (TY) intensity, while the rest eight cyclones only reached severe tropical storm (STS) and tropical storm (TS) intensity - three STS and five TS storms. The tropical cyclone season in 2006 began in May with the formation of CHANCHU (0601). The convective activity was slightly inactive around the Philippines from late June to early August. In addition, subtropical high was more enhanced than normal over the south of Japan from May to early August. Consequently, most tropical cyclones formed over the sea east of the Philippines after late June, and many of them moved westwards to China. CHANCHU (0601), BILIS (0604), KAEMI (0605), PRAPIROON (0606) and SAOMI (0608) brought damage to China, the Philippines, and Vietnam. On the other hand, EWINIAR (0603) moved northwards and hit the Republic of Korea, causing damage to the country. From late August to early September, convective activity was temporarily inactive over the sea east of the Philippines. However, it turned active again after late September. Subtropical high was weak over the south of Japan after late August. Therefore, most tropical cyclones formed over the sea east of the Philippines and moved northwards. WUKONG (0610) and SHANSHAN (0613) hit Japan to bring damage to the country. On the other hand, XANGSANE (0615) and CIMARON (0619) moved westwards in the South China Sea, causing damage to the Philippines, Thailand, and Vietnam. Another special feature in 2006 tropical cyclone activity is that IOKE (0612) formed in the central North Pacific crossed 180 degree longitude and moved into the western North Pacific. It has been four years since HUKO (0224) in 2002.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.E1
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• pp.1-14
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• 2004

Meteorological mechanisms in association with long-range transport of Asian dust in April 2001 have been investigated using weather maps, satellite images, TOMS and surface $PM_{10}$ data, backward trajectories, plus modeling output results (geopotential heights, horizontal wind vectors, potential temperatures, and streamlines). The results indicated that long -range transport of Asian dust to the west coast of North America was associated with strong westerlies between the Aleutian low and the Pacific high acting as a conveyor belt. Accelerating westerly flows due to cyclogenesis at the source regions over East Asia transported pollution from the continent to the central Pacific. When the system reached the Aleutian Islands, the intensity of troughs and the westerlies were amplified in the North Pacific. Thereafter the winds between the Aleutian Islands and the Pacific Ocean were more intensified from the air flow transport of the conveyor belt. Consequently, the strong wind in the conveyor belt enhanced the dust transport from the Pacific Ocean to the west coast of North America. This was evidenced by $PM_{10}$ concentration (maximum of about $100{\mu}g\;m^{-3}$) observed In California. Further evidence of the dust transport was found through the observation of satellite images, the distribution of TOMS aerosol index, and the analyses of streamlines and backward trajectories.