Mixture of Kosa (Asian dust) and bioaerosols detected in the atmosphere over the Kosa particles source regions with balloon-borne measurements: possibility of long-range transport

Abstract

Long-range transport of atmospheric microbiota with Asian dust (Kosa) particles is of great concern in Northeast Asia in view of the health effect of Kosa particles on human being, disturbance of ecosystems caused through invasion of new microbe, contribution of microorganisms to biogeochemical cycle on global/regional scales, and others. Information on atmospheric microbes over the desert areas has been desired for a long time. Detection of atmospheric microbiota on the desert regions, on the base of balloon-borne measurements, has been made at Dunhuang, China (40°00′ N, 94°30′ E; east end of Taklamakan desert) in the summer of 2007. The measurements showed that microbiota mixed internally with Kosa particles were frequently floating from the ground to about 2-km heights (above sea level), and possible long-range transport of atmospheric microbiota with dust particles taking local circulations is strongly suggested, causing active mixing of atmospheric dust over the Taklamakan desert from the ground to the free troposphere where westerly jet dominates (Iwasaka et al. in J Geophys Res 108:8652, 2003a, J Geophys Res 108:8644, b). The concentration of the mixed particles of Kosa and microbiota having a size larger than about 1 μm in diameter is estimated to be about 1 particle/ cm 3 at those heights on the basis of measurements of particle concentration with an optical particle counter and analysis of particles having fluorescence light due to dye of DAPI (4′6-diamidino-2 phenylindole) with an epifluorescence microscope. The mixing situation of microbiota and Kosa particles is the important factor controlling atmospheric lifetime of floating microbiota, since the mixing state certainly can protect microbiota from stressful environments [dryness, solar ultraviolet (UV) radiation, low temperature] in the atmosphere, and therefore, it is useful to discuss the data of the first description of microbiota in the atmosphere on the Taklamakan desert.Keywords Dust particle . Microbiota (microorganism) . Desert areas in China . Balloon-borne measurement .

Vertical distribution of airborne bacterial communities in an Asian-dust downwind area, Noto Peninsula

“…Westerly winds blowing over Asian regions disperse airborne microorganisms to downwind environments (Iwasaka et al, 2009) and potentially influence ecosystem dynamics, human health, agricultural productivity, and climate change (Rodó et al, 2011;Brown andHovmøller, 2002, Liu et al 2014). The transport of particulate minerals by westerly winds has been reported to increase the amounts of airborne bacteria at the ground level (Hara and Zhang, 2012) and at high altitudes (Maki et al, 2013) during an Asian dust event.…”

“…Bioaerosols, which include bacteria, fungi, and viruses, are transported from ground environments to the free troposphere and account for a substantial proportion of the organic carbon fraction of atmospheric aerosols (Jaenicke, 2005;Iwasaka et al, 2009). Dust events are known to transport airborne microorganisms, thereby supporting the microbial immigration to downwind ecosystems (Griffin et al, 2007;Maki et al, 2010;Yamaguchi et al 2012).…”

NaCl-amendment assay targeting airborne bacteria in tropospheric bioaerosols transported by westerly wind over Noto Peninsula

“…The westerly wind at high altitudes over Asian region is known to carry Kosa mineral particles associated with microorganisms across hundreds and thousands of kilometers, and these airborne microorganisms are dispersed around the Asian downwind areas through the free troposphere (Griffin et al 2003;Iwasaka et al 2009). …”

“…Bioaerosol particles, which include microorganisms, are also transported from the continental areas to downwind regions through the free troposphere (Iwasaka et al 2009;Prospero et al 2005). Microorganisms in bioaerosols are significantly abundant in the organic carbon fraction of aerosol particles in the atmosphere and can remain viable in the free troposphere under extended UV exposure, low-moisture levels, and extremely oligotrophic conditions (Jones and Harrison 2004).…”

Distribution and Characteristics of Microorganisms Associated with Settled Particles During Asian Dust Events

“…기존 국내에서의 황사에 대한 연구는 modeling을 통한 이동 경로 분석, 미세먼지의 농도, 화학적 조성 및 입자의 크기 분포, 호흡기 질환과의 관계에 관한 역학 조사 등에 관한 것이 다수를 차지하고 있다 (Lee et al, 2007;Park et al, 2008;Yoo et al, 2008). 국제적으로는 황사 먼지를 통한 미생물의 장거리 이동에 대한 여러 연구가 있다 (Ichinose et al, 2008;Iwasaka et al, 2009 …”