Characterization of microbial community during Asian dust events in Korea

This study explores the effects of an Asian dust storm (ADS) and Southeast Asian biomass burning on the composition of atmospheric aerosols in the coastal area of southern Taiwan in spring 2010. Coarse and fine particles were collected using two manual dichotomous samplers (Dichots) that were equipped with Teflon and Quartz filters. The results reveal that the concentrations of PM 10 and PM 2.5 in the ADS period were about twice those before and after this. More than half of water-soluble ions in coarse particles (PM 2.5-10 ) were Cl -and Na + (sea salt), while 70% of water-soluble ions of fine particles were SO 4 2-and NH 4 + (secondary aerosols). The OC/EC ratios of PM 2.5 and PM 2.5-10 were all above 2.0. Over 98% of the metals in coarse and fine particles were crustal elements (98.1-99.1%), and over 60% of the metals in PM 10 were in coarse particles (PM 2.5-10 ). The water-soluble ion, EC, OC, and metal contents in PM 2.5 all exceeded those in PM 2.5-10 . The ADS was associated with higher concentrations of water-soluble ions in PM 2.5 and PM 2.5-10 than was the non-ADS period, except for K + in PM 2.5-10 . ADS most increased the Ca 2+ content and concentration, causing a rise in the average concentrations of Ca 2+ in coarse and fine particles by factors of 3.0 and 3.2, respectively. In the ADS period, although the OC and EC concentrations of coarse and fine particles increased, the OC and EC contents in these particles decreased. The ADS period was associated with higher metal contents in coarse and fine particles than the non-ADS period, and the increase in PM 2.5-10 (more than 2%) exceeded that in PM 2.5 . In PM 2.5-10 and PM 2.5 , the Ca and Ni contents increased the most, respectively. In addition, the concentrations of the water-soluble ions, EC, OC, and metals in PM 2.5-10 and PM 2.5 increased, but their contents decreased, while the contents of the other constituents (= total -(water-soluble ions + EC + OC + metals)) in PM 2.5-10 and PM 2.5 increased. It is also found that Southeast Asian biomass burning is related to the deterioration of the air quality of southern Taiwan.

Section: Metal Analysis and Quality Controlsupporting

confidence: 44%

Influence of an Asian Dust Storm and Southeast Asian Biomass Burning on the Characteristics of Seashore Atmospheric Aerosols in Southern Taiwan

Tsai

Huang

Lin

et al. 2012

“…The comparison of PM 2.5 and PM 10 concentrations between the present study and other related studies is shown in Table 2. All these studies revealed that the concentrations of PM 2.5 and PM 10 in DS periods were significantly higher than those in non-DS periods (Mori et al, 2003;Chen et al, 2004;Lee et al, 2009;Hong et al, 2010;Bian et al, 2011;Li et al, 2011;Wang et al, 2011;Zhao et al, 2011;Tsai et al, 2012;Chuang et al, 2013). In the present study, the average concentrations of PM 10 and PM 2.5 in non-DS and DS (Table 1) were clearly much higher than the World Health Organization (WHO) PM 10 (50 µg/m 3 for 24 h) and PM 2.5 (25 µg/m 3 for 24 h) (WHO, 2006).…”

Section: Pm Fractions Temporal Trends Of Different Particle Sizes Conmentioning

confidence: 98%

Characterization and Elemental Composition of Atmospheric Aerosol Loads during Springtime Dust Storm in Western Saudi Arabia

Alghamdi

Almazroui

Shamy

et al. 2015

Dust storm is a common phenomenonand, a severe environmental hazard in western Saudi Arabia. In this study, simultaneous measurement of PM 10 , PM 2.5 and PM 1.0 and elemental compositions analysis of PM 2.5 in Jeddah city during springtime (March 2012) dust storm (DS) and non-dust storm (non-DS) periods were carried out to investigate the impact of DS on the levels, characterization and elemental compositions of atmospheric particles. Results indicate that PM fractions concentrations were higher in DS environment compared to non-DS. The diurnal variation of PM fractions concentrations was uni-modal in non-DS environment and bimodal in DS. PM 1.0 /PM 10 , PM 2.5 /PM 10 and PM 2.5 /PM 2.5-10 ratios were relatively lower in DS, indicating that sand-dust events in spring carry much more coarse than fine particles to Jeddah. PM 10 , PM 2.5 and PM 1.0 in DS and PM 10 and PM 2.5 in non-DS might originate from similar sources. PM 10 , PM 2.5 , PM 1.0 in DS and PM 10 in non-DS were correlated negatively with relative humidity and positively with wind speed. PM 2.5 and PM 1.0 in non-DS were correlated positively with relative humidity and negatively with wind speed. The crustal elements accounted for 44.62 and 67.53% of the total concentrations of elements in non-DS and DS, respectively. The elements concentrations increased in DS, with highest DS/non-DS ratios for Ca, Si, Al and Fe. This indicates that the soil originating species contributed mainly in DS particles.The enrichment factors values and non-crustal fractions in both non-DS and DS indicate that the main sources of Na, Mg, Si, K, Ca, Ti, Cr, Mn, Fe, Rb and Sr are of a crustal type, whereas S, Cl, Co, Cu, Zn, Ga, As, Pb and Cd are anthropogenic. V and Ni in DS only are emitted from anthropogenic sources. The enrichment factors of these anthropogenic elements were lower in DS. They might originate mainly from local sources in Jeddah.

“…Bacilli are spore-forming bacteria that are more resistant against environmental stress than other nonsporeforming ones (Roszak and Colwell, 1987). Similar bacterial strains are frequently present as the dominant species among culturable bacterial fraction in the atmosphere (Fang et al, 2007) and have been well detected in surface and elevated air in East Asia with cultural method and DNA analysis (Harrison et al, 2005;Fang et al, 2007;Hua et al, 2007;Maki et al, 2008;Lee et al, 2009;Yukimura et al, 2009;Maki et al, 2010;Smith et al, 2010;Womack et al, 2010;Kobayashi et al, 2011).…”

Section: Bacterial Samplesmentioning

confidence: 85%

Applicability of LIVE/DEAD BacLight Stain with Glutaraldehyde Fixation for the Measurement of Bacterial Cell Concentration and Viability in the Air

Murata

Zhang

2013

Data on the concentration and viability of microorganisms in the atmosphere provide crucial information with regard to their dispersion, roles in environmental changes, and effects on ecosystems. In this study, we investigated the application of the LIVE/DEAD ® BacLight™ Bacterial Viability Kit (BacLight stain) with regard to the enumeration of viable and non-viable bacterial cells in the air, with the 4',6-diamidino-2-phenylindole (DAPI) stain used as the control of total cell counts. Two cultured bacterial strains isolated from an air sample, Bacillus subtilis and Micrococcus sp., were used in laboratory experiments. The results of BacLight staining agreed well with those of DAPI staining in detecting total cell counts, and the detection efficiency of Bacillus subtilis was 76-112%. Bacterial viability (number ratio of viable cells to total cells) showed consistency among repeated experiments with the same sample replicates, indicating the high confidence of counting viable cells, as well as total cells with the stain. Fixation of samples with glutaraldehyde prevented fluorescence bleaching at the exposure to fluorescence and increased detection accuracy. Application of the BacLight stain with and without fixation to air samples that were collected with a bio-sampler at an urban site proved the effectiveness of this approach in determining the cell concentration and viability of airborne bacteria at a 1-hour time resolution. A combination of BacLight staining and glutaraldehyde fixation treatment, in parallel with experiments without this treatment in field measurements, is proposed to ensure the detection accuracy. The method described here is able to measure the concentration and viability of bacterial cells in the air, and their variation with weather conditions.