Asian Dust Period Research Articles

Contributions of local pollution emissions to particle bioreactivity in downwind cities in China during Asian dust periods

This study investigated the effects of pollution emissions on the bioreactivity of PM2.5 during Asian dust periods. PM2.5 during the sampling period were 104.2 and 85.7 μg m−3 in Xi'an and Beijing, respectively, whereas PM2.5 which originated from the Tengger Desert was collected (dust background). Pollution conditions were classified as non-dust days, pollution episode (PE), dust storm (DS)-1, and DS-2 periods. We observed a significant decrease in cell viability and an increase in LDH that occurred in A549 cells after exposure to PM2.5 during a PE and DS-1 in Xi'an and Beijing compared to Tengger Desert PM2.5. Positive matrix factorization was used to identify pollution emission sources. PM2.5 from biomass and industrial sources contributed to alterations in cell viability and LDH in Xi'an, whereas vehicle emissions contributed to LDH in Beijing. OC, EC, Cl−, K+, Mg2+, Ca, Ti, Mn, Fe, Zn, and Pb were correlated with cell viability and LDH for industrial emissions in Xi'an during DS. OC, EC, SO42−, S, Ti, Mn, and Fe were correlated with LDH for vehicle emissions in Beijing during DS. In conclusion, the dust may carry pollutants on its surface to downwind areas, leading to increased risks of particle toxicity.

Detection of Pathogenic Viruses in the Ambient Air in Seoul, Korea.

The possible transport of pathogenic microorganisms during Asian dust events could be an important concern for health workers; however, this is still uncertain owing to a lack of supporting evidence. The present study aimed to investigate the presence of pathogenic microorganisms in air samples collected during the Asian and non-Asian dust periods. Between March and September 2016, air samples were collected at three weather observation stations in Seoul using a high-volume air sampler. Multiplex PCR was performed using the Allplex™ respiratory and gastrointestinal panel assay kits to detect 46 microorganisms. RT-PCR was performed for klassevirus, Aichivirus, and human parechovirus (HPeV) detection. In total, 71 air samples were collected during the Asian (8 samples) and non-Asian (63 samples) dust events. During an Asian dust event, only one human rhinovirus (HRV)-positive air sample was collected on April 23. During the non-Asian dust period, HRV, HPeV, norovirus (NoV), enteroaggregative Escherichia coli (EAEC), enterotoxigenic E. coli (ETEC), and Blastocystis hominis were detected in four, two, one, one, one, and one air samples, respectively. Pathogenic viruses were mostly detected in ambient air samples during the non-Asian dust period, which suggests a possible air-borne transmission of viral pathogens; however, the role of Asian dust in epidemics caused by pathogenic viruses is unclear.

Size distribution and sources of humic-like substances in particulate matter at an urban site during winter.

This study investigates the size distribution and possible sources of humic-like substances (HULIS) in ambient aerosol particles collected at an urban site in Gwangju, Korea during the winter of 2015. A total of 10 sets of size-segregated aerosol samples were collected using a 10-stage Micro-Orifice Uniform Deposit Impactor (MOUDI), and the samples were analyzed to determine the mass as well as the presence of ionic species (Na(+), NH4(+), K(+), Ca(2+), Mg(2+), Cl(-), NO3(-), and SO4(2-)), water-soluble organic carbon (WSOC) and HULIS. The separation and quantification of the size-resolved HULIS components from the MOUDI samples was accomplished using a Hydrophilic-Lipophilic Balanced (HLB) solid phase extraction method and a total organic carbon analyzer, respectively. The entire sampling period was divided into two periods: non-Asian dust (NAD) and Asian dust (AD) periods. The contributions of water-soluble organic mass (WSOM = 1.9 × WSOC) and HULIS (=1.9 × HULIS-C) to fine particles (PM1.8) were approximately two times higher in the NAD samples (23.2 and 8.0%) than in the AD samples (12.8 and 4.2%). However, the HULIS-C/WSOC ratio in PM1.8 showed little difference between the NAD (0.35 ± 0.07) and AD (0.35 ± 0.05) samples. The HULIS exhibited a uni-modal size distribution (@0.55 μm) during NAD and a bimodal distribution (@0.32 and 1.8 μm) during AD, which was quite similar to the mass size distributions of particulate matter, WSOC, NO3(-), SO4(2-), and NH4(+) in both the NAD and AD samples. The size distribution characteristics and the results of the correlation analyses indicate that the sources of HULIS varied according to the particle size. In the fine mode (≤1.8 μm), the HULIS composition during the NAD period was strongly associated with secondary organic aerosol (SOA) formation processes similar to those of secondary ionic species (cloud processing and/or heterogeneous reactions) and primary emissions during the biomass burning period, and during the AD period, it was only associated with SOA formation. In the coarse mode (3.1-10 μm), it was difficult to identify the HULIS sources during the NAD period, and during the AD period, the HULIS was most likely associated with soil-related particles [Ca(NO3]2 and CaSO4) and/or sea-salt particles (NaNO3 and Na2SO4).

Vertical Resolved Dust Mass Concentration and Backscatter Coefficient Retrieval of Asian Dust Plume Using Quartz Raman Channel in Lidar Measurements

In this work, we present a method for estimating vertical resolved mass concentration of dust immersed in Asian dust plume using Raman scattering of quartz (silicon dioxide, silica). During the Asian dust period of March 15, 16, and 21 in 2010, Raman lidar measurements detected the presence of quartz, and successfully showed the vertical profiles of the quartz backscatter coefficient. Since the Raman backscatter coefficient was connected with the Raman backscatter differential cross section and the number density of quartz molecules, the mass concentration of quartz in the atmosphere can be estimated from the quartz backscatter coefficient. The weight percentage from 40 to 70 % for quartz in the Asian dust was estimated from references. The vertical resolved mass concentration of dust was estimated by quartz mass concentration and weight percentage. We also present a retrieval method to obtain dust backscatter coefficient from the mixed Asian dust and pollutant layer. OPAC (Optical Properties of Aerosol and Clouds) simulations were conducted to calculate dust backscatter coefficient. The retrieved dust mass concentration was used as an input parameter for the OPAC calculations. These approaches in the study will be useful for characterizing the quartz dominated in the atmospheric aerosols and estimating vertical resolved mass concentration of dust. It will be especially applicable for optically distinguishing the dust and non-dust aerosols in studies on the mixing state of Asian dust plume. Additionally, the presented method combined with satellite observations is enable qualitative and quantitative monitoring for Asian dust.

제주도 고산지역 대기 에어로졸의 입경별 산성화-중화 특성

제주도 고산지역에서 2010~2011년에 대기 에어로졸을 입경별로 채취하여 산성화와 중화 특성을 조사하였다. 인위적 기원의 <TEX>$NH_4{^+}$</TEX>와 nss-<TEX>$SO_4{^{2-}}$</TEX>은 일반적으로 <TEX>$0.7{\sim}1.1{\mu}m$</TEX>의 극미세 입자에서 높은 농도를 보였으나, 황사 시에는 <TEX>$4.7{\sim}5.8{\mu}m$</TEX>의 조대입자 범위에서도 함께 농도가 높은 이산형 분포를 나타내어 황사와 비황사 간에 서로 다른 분포 패턴을 보였다. nss-<TEX>$Ca^{2+}$</TEX>과 <TEX>$NO_3{^-}$</TEX>은 <TEX>$3.3{\sim}4.7{\mu}m$</TEX>의 조대입자에서 높은 농도를 보였으며, 특히 <TEX>$NO_3{^-}$</TEX>은 미세입자와 조대입자 영역에서 농도가 높은 이산형 분포를 나타내었다. 고산지역 대기 에어로졸의 산성화는 황산과 질산 등 무기산에 의한 영향이 대부분이며, 유기산인 포름산과 아세트산은 1.6~6.4% 정도 산성화에 기여하는 것으로 확인되었다. 또한 암모니아, 탄산칼슘, 탄산마그네슘 등이 대기 에어로졸의 산성 물질 중화에 주로 관여하고 있으며, 특히 암모니아에 의한 중화는 비황사와 황사 기간 모두 미세입자 영역에서 훨씬 더 높은 기여도를 보였으나, 탄산칼슘은 조대입자 영역에서 더 큰 중화 기여도를 보였다. The size fractionated atmospheric aerosols have been collected at Gosan site of Jeju Island during 2010~2011, and then their characteristics of acidification and neutralization have been investigated. The anthropogenic <TEX>$NH_4{^+}$</TEX> and nss-<TEX>$SO_4{^{2-}}$</TEX> showed high concentrations mostly at ultra-fine particle mode of <TEX>$0.7{\sim}1.1{\mu}m$</TEX>, but they also had a bimodal distribution showing high concentrations at coarse particle mode of <TEX>$4.7{\sim}5.8{\mu}m$</TEX> during Asian Dust periods. The concentrations of nss-<TEX>$Ca^{2+}$</TEX> and <TEX>$NO_3{^-}$</TEX> were relatively high at coarse particle mode of <TEX>$3.3{\sim}4.7{\mu}m$</TEX>, especially <TEX>$NO_3{^-}$</TEX> showed high concentrations with a bimodal pattern at both fine and coarse particle modes. The acidification of atmospheric aerosols at Gosan area was contributed mostly by inorganic sulfuric and nitric acids, while the contribution by organic formic and acetic acids was only 1.6~6.4%. Furthermore, the neutralization of acidic species among atmospheric aerosols was performed mostly by <TEX>$NH_3$</TEX>, <TEX>$CaCO_3$</TEX> and <TEX>$MgCO_3$</TEX>, especially the neutralization by <TEX>$NH_3$</TEX> was high in fine particle mode, while that by <TEX>$CaCO_3$</TEX> was relatively high in coarse particle mode.

Influence of regional biomass burning on the highly elevated organic carbon concentrations observed at Gosan, South Korea during a strong Asian dust period.

PM2.5 carbonaceous particles were measured at Gosan, South Korea during 29 March-11 April 2002 which includes a pollution period (30 March-01 April) when the highest concentrations of major anthropogenic species (nss-SO4 (2-), NO3 (-), and NH4 (+)) were observed and a strong Asian dust (AD) period (08-10 April) when the highest concentrations of mainly dust-originated trace elements (Al, Ca, Mg, and Fe) were seen. The concentrations of elemental carbon (EC) measured in the pollution period were higher than those measured in the strong AD period, whereas an inverse variation in the concentrations of organic carbon (OC) was observed. Based on the OC/EC ratios, the possible source that mainly contributed to the highly elevated OC concentrations measured in the strong AD period was biomass burning. The influence of the long-range transport of smoke plumes emitted from regional biomass burning sources was evaluated by using MODIS (Moderate Resolution Imaging Spectroradiometer) satellite data for fire locations and the potential source contribution function analysis. The most potential source regions of biomass burning were the Primorsky and Amur regions in Far Eastern Russia and southeastern and southwestern Siberia, Russia. Further discussion on the source characteristics suggested that the high OC concentrations measured in the strong AD period were significantly affected by the smoldering phase of biomass burning. In addition to biomass burning, secondary OC (SOC) formed during atmospheric long-range transport should be also considered as an important source of OC concentration measured at Gosan. Although this study dealt with the episodic case of the concurrent increase of dust and biomass burning particles, understanding the characteristics of heterogeneous mixing aerosol is essential in assessing the radiative forcing of aerosol.

황사와 연무 시 PM10및 PM2.5미세먼지 조성 비교: 2010-2011년 고산지역 측정

제주도 고산측정소에서 <TEX>$PM_{10}$</TEX>, <TEX>$PM_{2.5}$</TEX> 미세먼지를 채취하여 주요 성분을 분석한 결과로부터 입경분포 및 오염 특성을 조사하였다. <TEX>$NH{_4}{^+}$</TEX>, nss-<TEX>$SO{_4}^{2-}$</TEX>, <TEX>$K^+$</TEX>, <TEX>$CH_3COO^-$</TEX>은 대체적으로 미세입자 분포하고, <TEX>$NO{_3}{^-}$</TEX>은 조대와 미세입자에 고루 분포하였으나 <TEX>$Na^+$</TEX>, <TEX>$Cl^-$</TEX>, <TEX>$Mg^{2+}$</TEX>, nss-<TEX>$Ca^{2+}$</TEX>은 대부분 조대입자에 분포되는 경향을 보였다. 황사 시에 조대입자와 미세입자에서 nss-<TEX>$Ca^{2+}$</TEX>이 36.7배, 15.0배 증가하고, <TEX>$NO{_3}{^-}$</TEX>은 조대입자에서 3.2배, 미세입자에서 3.1 배 높았다. 또 Al, Fe, Ca, K, Mg, Ti, Mn, Sr, Ba의 농도도 크게 증가하였다. 연무 시에는 nss-<TEX>$SO{_4}^{2-}$</TEX>, <TEX>$NO{_3}{^-}$</TEX>, <TEX>$NH{_4}{^+}$</TEX> 농도가 조대입자에서 1.3~2.6배, 미세입자에서 1.5~4.2배 상승하였고, 특히 미세입자에서 <TEX>$NO{_3}{^-}$</TEX> 농도가 크게 상승하였다. 고산지역 미세입자의 오염원 특성을 조사한 결과, 조대입자는 해염 영향이 가장 크고, 다음으로 토양, 인위적 오염원 순으로 영향을 많이 받았으나 미세입자는 인위적인 오염원 영향이 더 크고, 다음으로 해양과 토양 유입의 영향을 많이 받고 있는 것으로 나타났다. The <TEX>$PM_{10}$</TEX> and <TEX>$PM_{2.5}$</TEX> samples were collected at Gosan Site of Jeju Island, and analyzed, in order to investigate the size distribution and pollution characteristics of their components. <TEX>$NH{_4}{^+}$</TEX>, nss-<TEX>$SO{_4}^{2-}$</TEX>, <TEX>$K^+$</TEX>, and <TEX>$CH_3COO^-$</TEX> were mostly existed in fine particles. Meanwhile, <TEX>$NO{_3}{^-}$</TEX> was distributed in both fine and coarse particles, and <TEX>$Na^+$</TEX>, <TEX>$Cl^-$</TEX>, <TEX>$Mg^{2+}$</TEX>, nss-<TEX>$Ca^{2+}$</TEX> were rich in coarse particle mode. The concentrations of nss-<TEX>$Ca^{2+}$</TEX> and <TEX>$NO{_3}{^-}$</TEX> were increased 36.7 and 3.2 times in coarse particles, and 15.0 and 3.1 times in fine particles during the Asian Dust periods. Especially, the concentrations of crustal elemental species such as Al, Fe, Ca, K, Mg, Ti, Mn, Sr, Ba were highly increased for those periods. In the haze events, the concentrations of secondary air pollutants were increased 1.3~2.6 and 1.5~4.2 times in coarse and fine particles, respectively. Moreover, the remarkable increase of <TEX>$NO{_3}{^-}$</TEX> concentration was also observed in fine particle mode. The factor analysis showed that the composition of coarse particles was influenced mainly by marine sources, followed by soil and anthropogenic sources. On the other hand, the fine particles were influenced by anthropogenic sources, followed by marine and soil sources.

Exacerbation of daily cough and allergic symptoms in adult patients with chronic cough by Asian dust: A hospital-based study in Kanazawa

The health effects associated with Asian dust have attracted attention due to the rapid increase in the number of Asian dust events in East Asia in recent years. The aim of this study was to investigate the associations between Asian dust and daily cough, as well as allergic symptoms, in adult patients who suffer from chronic cough. We enrolled 86 adult patients from Kanazawa University Hospital, Japan, who were diagnosed with asthma, cough variant asthma, atopic cough or a combination of these conditions. From January to June 2011, subjects recorded their symptoms in a diary every day. Asian dust and non-Asian dust periods were defined according to the dust extinction coefficient, measured using the light detection and ranging (LIDAR). The daily levels of total suspended particulates, polycyclic aromatic hydrocarbons (PAHs) and coexisting factors related to allergies, such as the Japanese cedar pollen count, were measured. McNemar's test showed that there were significantly more cough-positive patients during Asian dust periods than during the non-Asian dust period (p = 0.022). In addition, during Asian dust periods when the daily levels of Japanese cedar pollen, Japanese cypress pollen and PAHs were elevated, there were significantly more patients who experienced itchy eyes than during the non-Asian dust period (p < 0.05). On the other hand, there were no significant differences in the allergic symptoms, including sneezing or a runny nose and nasal congestion. This is the first report to show that Asian dust triggers cough and allergic symptoms in adult patients with chronic cough.

2009년 봄철 부산지역 황사 기간 중 에어로솔 농도 분포

동아시아 지역 봄철에 주로 발생하는 황사의 물리적 특성을 알아보기 위하여 부산지역에서 발생한 2009년 황사 기간의 종관 일기도와 자동기상관측장비(AWS)를 이용한 기상해석, <TEX>$PM_{10}$</TEX> 샘플러와 레이저입자계수기(LPC)를 이용한 대기입자상 물질농도 분석, 위성영상과 역궤적분석 모델을 이용한 발생원을 조사하였다. 2009년 2월 20일의 경우 (사례 1), <TEX>$PM_{10}$</TEX> 농도가 급격히 증가할 때 <TEX>$0.3-1.0{\mu}m$</TEX>의 작은 입자의 에어로솔 체적 농도 분포가 감소한 반면 <TEX>$1.0-10.0{\mu}m$</TEX>의 큰 입자의 농도는 증가하였다. 그 후 <TEX>$PM_{10}$</TEX> 농도가 감소할 때 지상의 풍향은 북풍에서 남서풍으로 변하였으며, 전체 에어로솔 농도는 감소하였다. <TEX>$PM_{10}$</TEX>과 <TEX>$1.0-10.0{\mu}m$</TEX>의 큰 입자 농도의 상관계수는 0.9 이상으로 높은 양의 상관관계를 나타내었다. 이는 내몽골 지역에서 발달된 황사가 중국 고비 사막을 통과하여 한반도로 유입된 것으로 추측할 수 있었다. 2009년 4월 25일의 경우 (사례 2), <TEX>$PM_{10}$</TEX> 농도가 급격히 증가할 때 <TEX>$0.3-0.5{\mu}m$</TEX>의 작은 입자의 에어로솔 체적 농도 분포가 감소한 반면 <TEX>$0.5-10.0{\mu}m$</TEX>의 큰 입자의 농도는 증가하였다. 그 후 <TEX>$PM_{10}$</TEX> 농도가 감소할 때 <TEX>$0.3-0.5{\mu}m$</TEX>의 작은 입자의 농도는 증가한 반면 <TEX>$0.5-10.0{\mu}m$</TEX>의 큰 입자의 농도는 감소하였다. 이 때 지상의 풍향은 북동풍에서 남서풍으로 변한 후 다시 북동풍으로 변하였다. <TEX>$PM_{10}$</TEX>과 <TEX>$1.0-10.0{\mu}m$</TEX>의 큰 입자의 농도의 상관계수는 약 0.9에 가까운 높은 양의 상관관계를 나타내었다. 입자의 역궤적 수송 모델 분석 결과, 만주지역과 중국 동쪽 해안으로부터 한반도로 유입된 것으로 추측할 수 있었다. This study investigates the distribution of suspended particulates during the Asian dust period in Busan, Korea in the spring of 2009. Weather map and automatic weather system (AWS) data were used to analyze the synoptic weather conditions during the period. Particulate matter 10, laser particle counter data, satellite images and a backward trajectories model were used to analyze the aerosol particles distribution and their origins. In Case 1 (20 February 2009), when the <TEX>$PM_{10}$</TEX> concentration increased, the aerosol volume distribution of small (<TEX>$0.3-1.0{\mu}m$</TEX>) particles decreased, while the concentration of large (<TEX>$1.0-10</TEX><TEX>.0{\mu}m$</TEX>) particles increased. When the <TEX>$PM_{10}$</TEX> concentration decreased, the aerosol volume distribution was observed to decrease as well. The prevailing winds changed from weak northerly winds to strong southwesterly winds when the concentration of the large particles increased. The correlation coefficient between the <TEX>$PM_{10}$</TEX> concentration and aerosol volume distribution of large particles showed a high positive value of over 0.9. The results from the trajectory model show that the Asian dust originated in the Gobi desert and the Nei Mongol plateau. In Case 2 (25 April 2009), when the <TEX>$PM_{10}$</TEX> concentration increased, the aerosol volume concentration of small (<TEX>$0.3-0.5{\mu}m$</TEX>) particles decreased, but the concentration of large (<TEX>$0.5-10.0{\mu}m$</TEX>) particles increased. The opposite was observed when the <TEX>$PM_{10}$</TEX> concentration decreased. The prevailing winds changed from northeasterly winds to southwesterly and northeasterly winds. The correlation coefficient between the <TEX>$PM_{10}$</TEX> concentration and aerosol volume distribution of large particles (<TEX>$1.0-10.0{\mu}m$</TEX>) showed a high positive value of about 0.9. The results from the trajectory model show that the Asian dust originated in Manchuria and the eastern coast of China.

Characteristics of atmospheric dust deposition in snow on Glacier No. 4, Mt Bogeda, China

Wind-blown mineral dust derived from the crustal surface is an important atmospheric component affecting the Earth’s radiation budget. Deposition of dust particles was measured in snow on the Glacier No. 4, Mt Bogeda, in the eastern Tian Shan, China. The mean number concentration of dust particles with 0.57 < d < 26 μm in the snowpack is 279 × 103 mL−1, with a mean mass concentration of 1,480 μg kg−1. Dust number size distribution showed the dominant particles with d < 2 μm, while volume size distribution showed single-modal structures having volume median diameters from 3 to 25 μm. Results were compared with the data from other sites in the Tian Shan and various northern hemisphere sites. A backward trajectory model was also employed to examine the transport process of dust particles in this region. Most of the air mass originated from the southern and northwestern regions, e.g., the Taklimakan and Gurbantunggut deserts in springtime, during the Asian dust period, which may bring plentiful aerosol dust particles from the sandy deserts. Transport of dust from western Chinese deserts to adjacent mountains is in agreement with a growing body of evidence on the importance of dust inputs to alpine regions.

The comparison of two severe Hwangsa (Asian dust) cases of spring and winter in Seoul, Korea

This study investigated meteorological, physical, and chemical characteristics of 2 severe Hwangsa (Asian dust, maximum average of PM10 above 1000 μg m−3) observed in Seoul, the capital city of Korea, during 30∼31st May, 2008 (DSS2008) and 25∼26th December, 2009 (DSS2009). DSS2008 and DSS2009 had a same source region and route. However, they have different meteorological conditions. DSS2009 had a shorter travel time from the source region to Korea and shorter duration time in Korea than DSS2008 due to a strong winter Siberian anticyclone. One of DSS2008 sample was affected by not only Asian dust but also a long-range transported haze due to consecutive influx after low pressure passed while DSS2009 sample collected only dust aerosol. For both cases, the mass concentration of coarse particles (PM10-1) increased by 3∼14 times compared to that during non Asian dust period, however, that of fine particles (PM1) increased only in DSS2008. For DSS2008 water-soluble ion balance between anions and cations in fine mode was close to 1:1 while cations were higher than anions in coarse mode. NH4 + and Ca2+ were found to be the main contributing factors for the neutralization. Cl− loss was observed about 60% indicating an active interaction of Na+ with pollutants. Reconstruction of chemical compositions showed relatively high concentrations of secondary pollutants (NH4NO3 and (NH4)2SO4), CaCO3, and Ca(NO3)2 compared to that during non Asian dust period. DSS2009 exhibited the typical characteristics of Asian dust having a high concentration of Ca2+ with higher equivalent concentration of cations than anions in all size bins. Cl− loss was hardly observed. The secondary pollutants were lower than that of non Asian dust cases. The result of reconstruction of ionic components indicated the CaCO3 derived from soil particle, CaSO4, and Ca (NO3)2 were dominant in DSS2009.

Comparison of Chemical Compositions of Size-segregated Atmospheric Aerosols between Asian Dust and Non-Asian Dust Periods at Background Area of Korea

diameter). As well in the elemental analysis of aerosols, the major soil-originated Al, Fe, Ca, and others showed prominently high concentrations in the coarse particle fraction, whereas the anthropogenic S and Pb were relatively high in the fine particle fraction. From the comparison of aerosol compositions between Asian dust and non-Asian dust periods, the concentrations of the soil-originated species such as nss-Ca 2+ , Al, Ca, Fe, Ti, Mn, Ba, Sr have increased as 2.7-4.2 times during the Asian dust periods. Meanwhile the concentrations of nssSO4 2� and NO3 � have increased as 1.4 and 2.0 times, and on the contrary NH4 + concentrations have a little bit decreased during the Asian dust periods. Especially the concentrations of both soil-originated ionic and elemental species increased noticeably in the coarse particle mode during the dust storm periods.

2007년 봄철 대전지역에서 발생한 황사 및 대기부유물의 지구화학적 특성 및 중 금속의 오염도

본 연구에서는 2007년도 봄철 대전 지역에서 발생한 황사(황사 기간) 및 대기부유물(비황사 기간)의 미량원소의 지구화학적 특성과 정량적 오염정도를 평가하였다. 황사 내 미량원소의 함량은 황사발원지 토양의 평균 함량에 비하여 수십에서 수백 배 높은 함량을 보여주고 있으며, 비황사 시기의 대기부유물에서도 유사한 특성을 보이고 있어, 황사 시기뿐만 아니라 비황사 시기에도 중국으로부터 이동되는 오염물질의 영향을 받고 있음을 지시하고 있다. 입도별 미량원소의 함량은 <TEX>$PM_{2.5}$</TEX>에서 Cr, Cu, Pb, Zn, V, S, As, Cd, Co, Ni, Mo, Sb, Cs, Rb, Th, Sc, Y 등이, 그리고 TSP에서는 Zr, Sr, Ba, Li, Th, U 등의 함량이 가장 높은 것으로 나타났다. 황사의 S, Cd, Mo, Zn, Pb, Sb, Cu 및 Zr 함량은대기부유물과 큰 차이를 보이지 않으나, 대기오염으로 부화가 발생하지 않는 Li, Cs, Co, U, Cr, Ni, Rb, V, Th, Y, Sr, Sc 등은 황사에서 2-4.2배 높아졌다. 그러므로 이들 원소들을 황사발생의 지시원소로 사용할 수 있으며, 특히 Sr, V, Cr 및 Li 등은 황사 발생을 판단하기 위한 지시원소로 사용하기에 적합한 것으로 보인다. 한편 황사의 이동경로에 따른 미량원소의 함량을 살펴본 결과, 중국의 대도시 및 산업단지를 경유하여 국내 유입된 황사가, 북한을 경유하여 국내에 도달한 황사에 비해서, S, Cd, Zn, Pb, Cu, Mo 및 As 함량이 높게 나타나, 황사의 이동경로가 이들 미량원소 오염 여부 및 오염도를 결정하는데 중요한 역할을 하는 것으로 판단된다. 황사 및 대기부유물 내 미량원소의 부화지수(Enrichment factor)을 기준으로 오염정도를 분류한 결과, 환경재해 측면에서 가장 문제가 되는 미량원소는 S, Zn, Cu, Pb, As, Mo, Cd이며, 이들은 인간의 건강 뿐만 아니라, 오랜 기간 토양과 수계환경에 퇴적될 경우 환경오염으로 인한 주변 생태계에 해로운 영향을 미치게 될 것으로 판단된다. We evaluated the geochemical characteristics and their potential pollution of Asian Dusts in Daejeon, Korea during spring 2007. Compared with the chemical compositions of soils in source area of Asian Dust, those of aerosols in Daejeon were enriched with trace elements (ten to hundred fold), inferring that pollutants from China have affected on local environment in adjoining country such as Korea. Chemical analysis of aerosols during Asian dust showed that fine particles (<TEX>$PM_{2.5}$</TEX>) contained high contents of trace elements such as Cr, Cu, Pb, Zn, V, S, As, Cd, Co, Ni, Mo, Sb, Cs, Rb, Th, Sc and Y. In the case of TSP (Total Suspended Particle), Zr, Sr, Ba, Li, Th and U were contained much more than other trace elements. The contents of some elements (i.e. Li, Cs, Co, U, Cr, Ni, Rb, V, Th, Y, Sr and Sc) in aerosols collected in Asian Dust period, which are not likely enriched by air pollutants, were higher (2 - 4.2 fold) than those in Non Asian Dust period, indicating that these elements could be used as indicator elements for determining the occurrence of Asian Dust phenomena (especially, Sr, V, Cr & Li). In the case of Asian Dust coming through the big cities and/or industrial areas of China, the domestic aerosols had higher contents of trace elements (such as S, Cd, Zn, Pb, Cu, Mo and As) than those from Northeastern China via North Korea, indicating that the transportation courses of air mass are very important to determine the pollution degrees. Using the enrichment factors of trace elements in aerosols during Asian Dust and Non Asian Dust, we identified that some elements (i.e. S, Zn, Cu, Pb, As, Mo and Cd) were most problematic in terms of environmental hazard aspects, and these elements could affect adverse effects on human health as well as ecosystem and surface environment (soil and water) through long-lived precipitation.

Analysis of Impact Factors on the Variation of PM10 Concentration in Seoul, Korea

To identify the primary factor affected the decreased PM 10 concentration in Seoul which is the capital city of Korea, wind speed and emissions in 2003 and 2004 were analyzed. The level of air pollution is intense in Seoul and continually increased since the late 1990s. However the concentration of PM 10 has been greatly declined recently. In particular, the concentration of PM 10 decreased 14% in 2003 and 2004 excluding the Asian dust periods. It is suggested that the major factors for the decrease are differences in wind speed between the two years and the period of constant breeze. In 2003, intense Asian dust events happened frequently and it increased the concentration of total PM 10 . The intense dust events were influence by the speed and duration of the wind. It is considered that the meteorological condition was the primary drive for the change of the concentration of PM 10 . The decreased emissions seem to be the additional factor for the change in the concentration of PM 10 .

Characteristics of Atmospheric Dust Deposition in Snow on Glacier No. 72, Mount Tuomuer, China

Wind-blown mineral dust derived from the crustal surface is an important atmospheric component affecting the Earth’s radiation budget. Deposition of dust particles was measured in snow on Glacier No. 72, Mount Tuomuer, in the western Tian Shan, China. The mean concentration of dust particles (measured as the number of particles) with 0.57 < d < 26 µm in the snow pack is 706 × 103 mL−1, with a mean mass concentration of 3806 µg kg−1. Dust number size distribution showed the dominant particles with d < 2 µm, while volume size distribution showed single-modal structures having volume median diameters from 3 to 25? µm. Results were compared with data from other sites in the Tian Shan and various Northern Hemisphere sites. A backward trajectory model was also employed to examine the transport process of dust particles in this region. Most of the air mass originated from southern China, e.g., the Taklimakan Deserts in springtime, during the Asian dust period. Transport of dust from southern Chinese deserts to adjacent mountains is in agreement with a growing body of evidence on the importance of dust inputs to alpine regions.

라만 라이다의 석영 채널을 이용한 고도별 황사 농도 산출

The Light Detection and Ranging (Lidar) observation provides a specific knowledge of the temporal and vertical distribution and the optical properties of the aerosols. Unlike typical Mie scattering Lidars, which can measure backscattering and depolarization, the Raman Lidar can measure the quartz signal at the ultra violet (360 nm) and the visible (546 nm) wavelengths. In this work, we developed a method for estimating mineral quartz concentration immersed in Asian dust using Raman scattering of quartz (silicon dioxide, silica). During the Asian dust period of March 15, 16, and 21 in 2010, Raman lidar measurements detected the presence of quartz, and successfully showed the vertical profile of the dust concentrations. The satellite observations such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) confirmed spatial distribution of Asian dust. This approach will be useful for characterizing the quartz dominated in the atmospheric aerosols and the investigations of mineral dust. It will be especially applicable for distinguishing the dust and non-dust aerosols in studies on the mixing state of Asian aerosols. Additionally, the presented method combined with satellite observations is enable qualitative and quantitative monitoring for Asian dust.

Physico-chemical characteristics and environmental significance of snow deposition on Haxilegen glacier No.51 in Tian Shan, China

Snow chemistry on the glaciers of alpine regions is a good indicator of atmospheric environmental change. We examine snow chemistry in three snowpits at different altitudes on the Haxilegen Glacier No. 51, in the Kuitun River source, Tian Shan, China, during July-September 2004 to 2007. We use correlation analysis, factor analysis and sea-salt tracing methods to examine the characteristics and sources of major ions and mineral dust particles in the snow. Results show that mineral dust particles and major ions in the snow pits vary seasonally. During the Asian dust period in springtime, the concentration of mineral dust particles and major ions deposited in snow is high, while the concentration is relatively low during the non-dust period of summer and autumn. This may be caused by dust storm activity in central Asia. The order of major ionic concentrations in the snow packs was determined to be Ca2+ > SO4 2− > NH4 + > NO3 − > Cl−> Na+ > Mg2+ > K+. Ca2+ was the dominant cation; SO4 2− was the dominant anion. We find, with the exception of NO3 −, that the variabilities of ionic concentrations are highly correlated. Results show that the glacier region was significantly affected by dust activity and anthropogenic source. The major ions, especially Na+, originate from dust sources of central Asia and from the Ocean, transported by the westerly winds.

짙은 황사와 연무가 공존한 대기의 에어러솔 특성 - 2009년 3월 15~17일 -

The variation of the physicochemical properties of atmospheric aerosols in coexistence of the heavy Asian Dust and Haze observed from <TEX>$15^{th}$</TEX> to <TEX>$17^{th}$</TEX> March 2009 in Seoul was scrutinized through the mass and ion concentration observations and synoptic weather analysis. Although the ratio of PM1.0/PM10 was constant at 0.3 (which is typical during Asian Dust period in Korea) during the measurement period, both PM10 and PM1.0 mass concentrations were 3~6 times and 2~4 times higher than that of clear days, respectively. Water-soluble ion components accounted for 30~50% of PM10 and 50~70% of PM1.0 mass concentration. One of the secondary pollutants, <TEX>$NO_3^-$</TEX> was found to be associated with <TEX>$Ca^{2+}$</TEX> and <TEX>$Na^+$</TEX> in coarse mode indicating that the aerosol derived from natural source was affected by anthropogenic pollutants. While the acidity of the aerosols increased in fine mode when the stagnation of weather patterns was the strongest (March <TEX>$16^{th}$</TEX>), the alkalinity increased in coarse mode when new air masses arrived with a southwestern wind after ending a period of stagnation (March <TEX>$17^{th}$</TEX>). In the selected case, SOR (Sulfur Oxidation Ratio, <TEX>$nSO_4^{2-}/[nSO_4^{2-}+nSO_2]$</TEX>) and NOR (Nitrogen Oxidation Ratio, <TEX>$nNO_3^-/[nNO_3^-+nNO_2]$</TEX>) values of ion components were higher than the general values during Asian Dust period. These results imply that dust aerosols could be mixed with pollutants transported from China even in heavy Asian Dust cases in Korea.

Temporal characteristics of mineral dust particles in precipitation of Urumqi River Valley in Tian Shan, China: A comparison of alpine site and rural site

Physico-chemical characteristics of mineral dust particles in the precipitation at both an alpine site and a rural site were determined in the Urumqi River Valley, Tian Shan, China. Results showed that the concentration, size distribution and chemical constitutes of dust particles in the precipitation varied seasonally at both two sites, though there existed obvious differences between them. Dust particle concentration in the precipitation increased during winter and springtime, but it decreased during summer and autumn, which had a positive correlation with strengthened wind speed and Asian dust activity, but a negative correlation with the seasonal variation of the precipitation amount, implying that aerosol dust in the precipitation of Urumqi River Valley in Tian Shan was very sensitive to the seasonal change of regional atmospheric environment in central Asia. Volume-size distribution of mineral dust particles showed larger modal size in Asian dust period of winter–spring, but relatively smaller modal size in non-dust period of summer–autumn. Moreover, the average modal size and mass concentration of dust particles at the rural site are larger than that of the alpine site. Chemical constitutes of dust indicated that the precipitation chemistry was mainly controlled by regional dust storms, local dust and anthropogenic activities in central Asia. HYSPLIT Model was also employed to examine the transport process of air mass and mineral dust particles in this region.

The effects of transported Asian dust on the composition and concentration of ambient fungi in Taiwan

This study was conducted to evaluate the effects of transported Asian dust and other environmental parameters on the levels and compositions of ambient fungi in the atmosphere of northern Taiwan. We monitored Asian dust events in Taipei County, Taiwan from January 2003 to June 2004. We used duplicate Burkard portable air samplers to collect ambient fungi before, during, and after dust events. Six transported Asian dust events were monitored during the study period. Elevated concentrations of Aspergillus (A. niger, specifically), Coelomycetes, Rhinocladiella, Sporothrix and Verticillium were noted (p < 0.05) during Asian dust periods. Botryosporium and Trichothecium were only recovered during dust event days. Multiple regression analysis showed that fungal levels were positively associated with temperature, wind speed, rainfall, non-methane hydrocarbons and particulates with aerodynamic diameters ≤10 μm (PM(10)), and negatively correlated with relative humidity and ozone. Our results demonstrated that Asian dust events affected ambient fungal concentrations and compositions in northern Taiwan. Ambient fungi also had complex dynamics with air pollutants and meteorological factors. Future studies should explore the health impacts of ambient fungi during Asian dust events, adjusting for the synergistic/antagonistic effects of weather and air pollutants.