Episodic Particulate Sulfate and Sulfur Dioxide on the Southwestern Japan Coast in March and April 2010

Tetsuji Nagatani,Maromu Yamada,Tomoko Kojima,Daizhou Zhang 한국대기환경학회 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.1

Particulate sulfate in PM2.5, sulfur dioxide (SO2) and size-segregated aerosol particle number concentrations were measured at a site (32° 9′N, 129° 59′E) on the southwestern Japan coast from 5 March to 10April, 2010. Results show frequent episodic increases of sulfate and SO2. Compared to the average concentration of sulfate 4.4±2.7 μg m-3 in the whole observation period, episodic sulfate reached 10.5-20.1 μg m-3. The variation of sulfate always synchronized with aerosol particles in the size range of 0.1-0.5 μm,indicating the episodic sulfate was a consequence of the increase of the sub-micron particles. SO2 did not have remarkable increase in any episodes of sulfate increase. During the passage of low pressure systems which loaded Asian dust in postfrontal air, concentrated sulfate appeared right behind the front but before dust arrival, suggesting the dominance of dustfree particulate sulfate. Weather and backward trajectory analyses revealed that air parcels with high sulfate passed eastern and northeastern China or Korean peninsula before arriving at the site. In contrast,those with high SO2 passed an active volcano,Mt. Sakurajima, about 100 km in the south, suggesting the SO2 was more likely from the volcanic emission. The ratio of sulfate to total sulfur compounds (SO42-)/(SO42-+SO2) was 0.31-0.89 in continentally originated air while was 0.25-0.43 in the air having passed the volcano, showing more efficient conversions of SO2 to sulfate in the air from the continent. The close dependence of the conversion on humidity in the continentally originated air was confirmed. Particulate sulfate in PM2.5, sulfur dioxide (SO2) and size-segregated aerosol particle number concentrations were measured at a site (32° 9′N, 129° 59′E) on the southwestern Japan coast from 5 March to 10April, 2010. Results show frequent episodic increases of sulfate and SO2. Compared to the average concentration of sulfate 4.4±2.7 μg m-3 in the whole observation period, episodic sulfate reached 10.5-20.1 μg m-3. The variation of sulfate always synchronized with aerosol particles in the size range of 0.1-0.5 μm,indicating the episodic sulfate was a consequence of the increase of the sub-micron particles. SO2 did not have remarkable increase in any episodes of sulfate increase. During the passage of low pressure systems which loaded Asian dust in postfrontal air, concentrated sulfate appeared right behind the front but before dust arrival, suggesting the dominance of dustfree particulate sulfate. Weather and backward trajectory analyses revealed that air parcels with high sulfate passed eastern and northeastern China or Korean peninsula before arriving at the site. In contrast,those with high SO2 passed an active volcano,Mt. Sakurajima, about 100 km in the south, suggesting the SO2 was more likely from the volcanic emission. The ratio of sulfate to total sulfur compounds (SO42-)/(SO42-+SO2) was 0.31-0.89 in continentally originated air while was 0.25-0.43 in the air having passed the volcano, showing more efficient conversions of SO2 to sulfate in the air from the continent. The close dependence of the conversion on humidity in the continentally originated air was confirmed.

A Detection of Airborne Particles Carrying Viable Bacteria in an Urban Atmosphere of Japan

Hara, Kazutaka,Zhang, Daizhou,Yamada, Maromu,Matsusaki, Hiromi,Arizono, Koji Korean Society for Atmospheric Environment 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.3

Viable bacteria on water-insoluble airborne particles were detected in the urban atmosphere of Kumamoto ($134^{\circ}45'E$, $32^{\circ}28'N$), Japan, in autumn 2008. Airborne particles were collected onto film-covered Cu meshes under clear weather conditions. The samples were stained by fluorescent stains, and then viewed and photographed with an epifluorescent microscope. Non-biological and bacterial parts in particles larger than 0.8 ${\mu}m$ were distinguished by their morphologies, fluorescent colors and fluorescent intensities. Bacterial viable statuses were discriminated according to cell membrane damage. In total, 2681 particles were investigated and it was found that 78 airborne particles were associated with bacteria. Viable bacteria were identified on 48 particles. A few particles carried multiple viable bacteria. These results provide the evidence that airborne particles act as carriers of viable bacteria in the atmosphere.

Identification of Culturable Bioaerosols Collected over Dryland in Northwest China: Observation using a Tethered Balloon

Chen, Bin,Kobayashi, Fumihisa,Yamada, Maromu,Kim, Yang-Hoon,Iwasaka, Yasunobu,Shi, Guang-Yu Korean Society for Atmospheric Environment 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.3

The transfer of microorganisms is important process for ecosystems. Microorganisms in dryland can transport itself to wetland through atmospheric diffusion, but only few papers reported about the atmospheric bioaerosol present over dryland. We carried out the direct sampling using a tethered balloon over Dunhuang City, China's northwestern dryland. Bioaerosols were collected using a tethered balloon with a bioaerosol collector at 820 m above the ground (1,960 m above the sea level) around noon on August 17, 2007. The bioaerosols were cultured after the collection at Dunhuang Meteorological observatory. Two strains of molds were isolated using the Nutrient agar medium. About 400-bp 18S rRNA partial sequences were amplified by PCR and determined afterwards. The results of a homology search by 18S rRNA sequences of isolates in DNA databases (GenBank, DDBJ, and EMBL) and an observation of the form revealed that two bioaerosols in the convective mixed layer over Dunhuang City were Cladosporium sp. and Aspergillus sp.

A Detection of Airborne Particles Carrying Viable Bacteria in an Urban Atmosphere of Japan

Kazutaka Hara,Daizhou Zhang,Maromu Yamada,Hiromi Matsusaki,Koji Arizono 한국대기환경학회 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.3

Viable bacteria on water-insoluble airborne particles were detected in the urban atmosphere of Kumamoto (134^ㅇ45′E, 32^ㅇ28′N), Japan, in autumn 2008. Airborne particles were collected onto film-covered Cu meshes under clear weather conditions. The samples were stained by fluorescent stains, and then viewed and photographed with an epifluorescent microscope. Non-biological and bacterial parts in particles larger than 0.8 μm were distinguished by their morphologies,fluorescent colors and fluorescent intensities. Bacterial viable statuses were discriminated according to cell membrane damage. In total, 2681 particles were investigated and it was found that 78 airborne particles were associated with bacteria. Viable bacteria were identified on 48 particles. A few particles carried multiple viable bacteria. These results provide the evidence that airborne particles act as carriers of viable bacteria in the atmosphere.

Identification of Culturable Bioaerosols Collected over Dryland in Northwest China: Observation using a Tethered Balloon

Bin Chen,Fumihisa Kobayashi,Maromu Yamada,Yang-Hoon Kim,Yasunobu Iwasaka,Guang-Yu Shi 한국대기환경학회 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.3

The transfer of microorganisms is important process for ecosystems. Microorganisms in dryland can transport itself to wetland through atmospheric diffusion,but only few papers reported about the atmospheric bioaerosol present over dryland. We carried out the direct sampling using a tethered balloon over Dunhuang City, China’s northwestern dryland. Bioaerosols were collected using a tethered balloon with a bioaerosol collector at 820 m above the ground (1,960m above the sea level) around noon on August 17,2007. The bioaerosols were cultured after the collection at Dunhuang Meteorological observatory. Two strains of molds were isolated using the Nutrient agar medium. About 400-bp 18S rRNA partial sequences were amplified by PCR and determined afterwards. The results of a homology search by 18S rRNA sequences of isolates in DNA databases (GenBank,DDBJ, and EMBL) and an observation of the form revealed that two bioaerosols in the convective mixed layer over Dunhuang City were Cladosporium sp. and Aspergillus sp.

Atmospheric Bioaerosol, Bacillus sp., at an Altitude of 3,500 m over the Noto Peninsula: Direct Sampling via Aircraft

Fumihisa Kobayashi,Shinji Morosawa,Teruya Maki,Makiko Kakikawa,Maromu Yamada,Yutaka Tobo,Chun-Sang Hon,Atsushi Matsuki,Yasunobu Iwasaka 한국대기환경학회 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.3

This work focuses on the analysis of bioaerosols in the atmosphere at higher altitudes over Noto Peninsula,Japan. We carried out direct sampling via aircraft,separated cultures, and identified present isolates. Atmospheric bioaerosols at higher altitudes were collected using a Cessna 404 aircraft for an hour at an altitude of 3,500 m over the Noto Peninsula. The aircraft-based direct sampling system was devised to improve upon the system of balloon-based sampling. In order to examine pre-existing microorganism contamination on the surface of the aircraft body, bioaerosol sampling was carried out just before takeoff using the same method as atmospheric sampling. Identification was carried out by a homology search for 16S or 18S rDNA isolate sequences in DNA databases (GenBank). Isolate sampling just before takeoff revealed Stretpomyces sp., Micrococcus sp., and Cladosporium sp. One additional strain,Bacillus sp., was isolated from the sample after bioaerosol collection at high altitude. As the microorganism contamination on the aircraft body before takeoff differed from that while in the air, the presence of additional, higher atmosphere-based microorganisms was confirmed. It was found that Bacillus sp. was floating at an altitude of 3,500 m over Noto Peninsula.

Atmospheric Bioaerosol, Bacillus sp., at an Altitude of 3,500 m over the Noto Peninsula: Direct Sampling via Aircraft

Kobayashi, Fumihisa,Morosawa, Shinji,Maki, Teruya,Kakikawa, Makiko,Yamada, Maromu,Tobo, Yutaka,Hon, Chun-Sang,Matsuki, Atsushi,Iwasaka, Yasunobu Korean Society for Atmospheric Environment 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.3

This work focuses on the analysis of bioaerosols in the atmosphere at higher altitudes over Noto Peninsula, Japan. We carried out direct sampling via aircraft, separated cultures, and identified present isolates. Atmospheric bioaerosols at higher altitudes were collected using a Cessna 404 aircraft for an hour at an altitude of 3,500 m over the Noto Peninsula. The aircraft-based direct sampling system was devised to improve upon the system of balloon-based sampling. In order to examine pre-existing microorganism contamination on the surface of the aircraft body, bioaerosol sampling was carried out just before takeoff using the same method as atmospheric sampling. Identification was carried out by a homology search for 16S or 18S rDNA isolate sequences in DNA databases (GenBank). Isolate sampling just before takeoff revealed Stretpomyces sp., Micrococcus sp., and Cladosporium sp. One additional strain, Bacillus sp., was isolated from the sample after bioaerosol collection at high altitude. As the microorganism contamination on the aircraft body before takeoff differed from that while in the air, the presence of additional, higher atmosphere-based microorganisms was confirmed. It was found that Bacillus sp. was floating at an altitude of 3,500 m over Noto Peninsula.