The effects of volcanic ashes on human health differ in distance and time. It was found that indirect and long-term damages are significant in remote areas from the volcanoes, while the direct and physical damages in adjacent areas are observed. In general, the minute polluted particles of volcano ashes are diffused to remote area from the volcanoes after staying over atmosphere. As a result, those particles have indirect and significant effects on human health such as eye disease, atopic dermatitis and PTSD, as similar as previous research results on Asian dust. This presentation presents the effects of volcano ashes and similar situation such as Asian dusts on human health based on indirect and long-term damage factors in remote areas from volcanoes. Further, this study provides a fundamental reference for medical hazard mitigation through examining the factors that affect health hazards in similar situation such as Asian dust.

Hourly concentrations of PM1, PM2.5 and PM10, were investigated at Gangneung city in the Korean east coast on 0000LST October 26~1800LST October 29, 2003. Before the intrusion of Yellow dust from Gobi Desert, PM10(PM2.5, PM1) concentration was generally low, more or less than 20 (10, 5) μg/m3, and higher PM concentration was found at 0900LST at the beginning time of office hour and their maximum ones at 1700LST around its ending time. As correlation coefficient of PM10 and PM2.5(PM2.5 and PM1, and PM10 and PM1) was very high with 0.90(0.99, 0.84), and fractional ratios of (PM10-PM2.5)/PM2.5((PM2.5-PM1)/PM1) were 1.37~3.39(0.23~0.54), respectively. It implied that local PM10 concentration could be greatly affected by particulate matters of sizes larger than 2.5 μm, and PM2.5 concentration could be by particulate matters of sizes smaller than 2.5 μm. During the dust intrusion, maximum concentration of PM10(PM2.5, PM1) reached 154.57(93.19, 76.05) μg/m3 with 3.8(3.4, 14.1) times higher concentration than before the dust intrusion. As correlation coefficient of PM10 and PM2.5(vice verse, PM2.5, PM1) was almost perfect high with 0.98(1.00, 0.97) and fractional ratios of (PM10-PM2.5)/PM2.5((PM2.5-PM1)/PM1) were 0.48~1.25(0.16~0.37), local PM10 concentration could be major affected by particulates smaller than both 2.5 μm and 1 μm (fine particulate), opposite to ones before the dust intrusion. After the ending of dust intrusion, as its coefficient of 0.23(0.81, - 0.36) was very low, except the case of PM2.5 and PM1 and (PM10-PM2.5)/PM2.5((PM2.5-PM1)/PM1) were 1.13~1.91(0.29~1.90), concentrations of coarse particulates larger than 2.5 μm greatly contributed to PM10 concentration, again. For a whole period, as the correlation coefficients of PM10, PM2.5, PM1 were very high with 0.94, 1.00 and 0.92, reliable regression equations among PM concentrations were suggested.

2009년 3월 17일 채집된 황사 총시료(TSP)의 개별 입자에 대하여, 고분해 주사전자현미경 및 에너지분산 X선 분광분석을 이용한 광물학적 특성 및 혼합상태 분석을 실시하였다. 황사 입자들 중, 석영, 사장석, K-장석, 각섬석, 흑운모, 백운모, 녹니석, 방해석 등은 비교적 조립질 입자로 산출되며, 이들 입자는 앓은 극미립 일라이트질 점토광물 층으로 피복되어 있다. 극미립 점토광물 입자들은 또한 개별 점토 덩어리를 형성한다. 조립질 방해석 외에 나노섬유 방해석들이 개별적으로 또는 집합체로 큰 입자를 피복하거나 점토광물과 함께 덩어리를 형성한다. 입자의 주 광물에 따라 광물학적 분류를 실시하고 빈도를 구하였다. 이번 TSP의 단일입자 광물학적 특성 및 혼합상태는 기존의 PM10 분석 결과와 거의 차이가 없었다.

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.

In order to investigate the variations and corelation among PM10, PM2.5 and PM1 concentrations, the hourly concentrations of each particle sizes of 300 ηm to 20 μm at a city, Gangneung in the eastern mountainous coast of Korean peninsula have been measured by GRIMM aerosol sampler-1107 from March 7 to 17, 2004. Before the influence of the Yellow Dust event from China toward the city, PM10, PM2.5 and PM1 concentrations near the ground of the city were very low less than 35.97 μg/m3, 22.33 μg/m3 and 16.77 μg/m3, with little variations. Under the partial influence of the dust transport from the China on March 9, they increased to 87.08 μg/m3, 56.55 μg/m3 and 51.62 μg/m3. PM10 concentration was 1.5 times higher than PM2.5 and 1.85 times higher than PM1. Ratio of (PM10-PM2.5)/PM2.5 had a maximum value of 1.49 with an averaged 0.5 and one of (PM2.5-PM1)/PM1 had a maximum value of 0.4 with an averaged 0.25. PM10 and PM2.5 concentrations were largely influenced by particles smaller than 2.5 μm and 1 μm particle sizes, respectively. During the dust event from the afternoon of March 10 until 1200 LST, March 14, PM10, PM2.5 and PM1 concentrations reached 343.53 μg/m3, 105 μg/m3 and 60 μg/m3, indicating the PM10 concentration being 3.3 times higher than PM2.5 and 5.97 times higher than PM1. Ratio of (PM10-PM2.5)/PM2.5 had a maximum value of 7.82 with an averaged 3.5 and one of (PM2.5-PM1)/PM1 had a maximum value of 2.8 with an averaged 1.5, showing PM10 and PM2.5 concentrations largely influenced by particles greater than 2.5 μm and 1 μm particle sizes, respectively. After the dust event, the most of PM concentrations became below 100 μg/m3, except of 0900LST, March 15, showing the gradual decrease of their concentrations. Ratio of (PM10-PM2.5)/PM2.5 had a maximum value of 3.75 with an averaged 1.6 and one of (PM2.5-PM1)/PM1 had a maximum value of 1.5 with an averaged 0.8, showing the PM10 concentration largely influenced by corse particles than 2.5 μm and the PM2.5 by fine particles smaller than 1 μm, respectively. Before the dust event, correlation coefficients between PM10, PM2.5 and PM1 were 0.89, 0.99 and 0.82, respectively, and during the dust event, the coefficients were 0.71, 0.94 and 0.44. After the dust event, the coefficients were 0.90, 0.99 and 0.85. For whole period, the coefficients were 0.54, 0.95 and 0.28, respectively.

The research was conducted to simulate and interpret the change of PM10 profile by Asian dust using the CALPUFF modeling system for the period April 6 through 18, 2001. The results, which are represented a daily variation of PM10 concentration before and after Asian dust, was located between a minimum concentration of 50 μg/㎥ and a maximum concentration of 100 μg/㎥. Most concentration peaks in the PM10 profile were shown within a level below 500 m and had a pattern that rapidly increased up the peak and decreased after the peak to 1000 m. Even though the shapes of the vertical profile during Asian dust days were similar to non-Asian dust days, no rapid change vertically was observed. In particular, the vertical profile on 1200 LST and 1800 LST was noticeably shifted to the higher concentrations, which means PM10 in the atmosphere was changed into a vertically and horizontally heterogeneous form under the Asian dust event. Finally, it is confirmed that the simulation result from CALPUFF might schematically sketched atmospheric PM10 profiles and their change by Asian dust throughout the comparison with profiles of aerosol extinction coefficients, which were acquired from Lidar measurement at KGAWO.

The characteristics of meteorological conditions relevant to Asian dust (AD) outbreaks and their occurrence frequencies were analyzed in four source regions (R1 to R4) during spring months (March to May) of 1998-2002. Moreover, the concentration variations of AD (e.g., PM10) observed in Korea were investigated during the study period. In the relationship between AD outbreaks and three meteorological parameters (i.e., air temperature, wind speed, and aridity), the largest AD outbreaks in April (～250 observations) mostly occurred in R2 when air temperature ranging from 10.0 to 15.0℃ and surface wind speed from 7 to 9 m s-1 were recorded. Moreover, the aridity (≥ 4) in April was significantly high in R2 with the maximum frequency of AD outbreaks (i.e., 206 observations). On the other hand, the number (percentage) of days belonging to AD events observed in five Korean cities were found to be 116 (44%), 121 (46%), and 26 days (10%) in March, April, and May, respectively. The mean PM10 concentrations were found to range from 150 to 220, 150 to 200, and 95 to 120 ㎍ m-3 in March, April, and May, respectively. Consequently, this implied that the AD events in Korea were found to be gradually frequent in early spring and to be affected from the large AD outbreaks observed in the source regions.

The characteristics for the aerosol number distribution was studied during spring, 2004 in Incheon. Optical Particle Counter (OPC, HIAC/ROYCO 5230) was used in order to measure the number concentration of aerosol in the range of 0.3～25㎛. The obtained results were compared with PM2.5 and PM10 data during Asian dust events. The results show that the size resolved aerosol number concentration from OPC measurement has a similar tendency with PM10 and PM2.5 mass concentration. During Asian dust periods, the number concentrations in large particle (CH5～CH8) increase more than small particles which diameter is less than 2.23㎛(CH5) and the same results were shown when PM10 was compared with PM2.5 data compared with non-dust days, Consequently, this study shows that size resolved aerosol number concentration from OPC measurement can be used as a useful tool in comparison of mass concentration data.

Dust phenomenon is a critical thing in the East Asian countries. However, it is quite recent that Asian dust has drawn much attention and the scientific investigation of dust particles began. In this study, the recognition for Asian-dust in Northeast Asia region was analyzed. The survey results show that the people generally recognize the origins and seriousness of Asian dust and understand the difficulty in solving the dust related problems. However, approaches to figure out Asian dust have many difficulties and limits in scientific, economic and political points of view and more detailed road map is needed based on government policy.

최근 정확한 대기오염 및 황사이동예보를 위하여, 대기역학모형과 확산모형의 결합을 통한 수치실험이 실시되고 있다. 본 연구에서는 3차원 대기역학모형( RAMS)과, 확산모형(PDAS)에 사용되는 기상장의 시간분해능이 대기확산장에 미치는 영향을 조사하였다. 그리고 여러 가지 시간분해능의 기상자료를 확산모형에 적용하여 황사입자의 분포 특성과 차이를 수치실험을 통하여 비교분석하였다. 수치실험 결과 다음과 같은 결론을 얻을 수 있었다. 1) RAMS에 의한 바람장 예측결과, 지면과 상층의 바람장이 동조될 수도 있고, 그렇지 않을 수도 있다. 상하층의 바람장이 동조되지 않을 경우 황사의 예측은 황사의 상승고도예측과 밀접하게 관련된다. 2) 황사의 연직분포에서 초기에는 상층의 황사가 먼저 이동을 하게 되며, 시간이 지남에 따라 하층의 황사도 이동을 시작한다. 본 연구에서는 최고 고도 3.9km 까지 도달한다. 3) 수치실험에서 초기(24시)의 경우, 시간해상도에 따른 확산의 차이는 크지 않다. 그러나 시간이 경과함에 따라 입자확산분포의 차이가 크게 나타난다. 4) 3시간 이하의 높은 시간해상도의 경우, 입자분포의 차이가 크지 않다. 그러나 6시간보다 간격이 큰 자료를 이용할 경우, 황사입자분포의 양적측면에서 큰 차이를 나타내며, 밀도 분포의 차이에 일정한 경향성을 가진다 5) 입력 바람장의 시간분해능이 작은 경우 즉 입력시간 간격이 큰 경우, 황사입자는 지역의 주풍성분(동아시아의 경우 편서풍)을 따라 분포한다. 그러나 시간분해능이 큰 경우, 중규모적인 기상현상을 잘 재현되며, 여기에 의하여 주풍의 직각성분인 남북성분의 효과가 크게 나타난다. 이상의 결과에서 확산모형의 입력자료로 사용되어지는 바람장은 보고자하는 기상현상을 잘 표현할 수 있는 시간분해능 내의 자료를 이용하여야하며, 이를 무시할 경우 입자의 농도예측에 많은 오차를 발생시킬 수 있다. 그러므로 확산예보에 앞서 시간분해능에 관한 검증이 필요하다고 판단된다.

On the basis of the distribution of particle size measured by laser diffraction spectrometers, this research was carried out to investigate the characteristics of mist removal with the change of operating condition in the plasma reactor of impulse streamer corona. The operating parameters in this experiment were power of impulse streamer corona, gas velocity, impulse generation time, gas temperature, and SOx/NOx concentration. The collection efficiency T(d) was estimated by the distribution of particle size in the collection zone through the advanced model.