scholarly journals Fluorescent biological aerosol particle concentrations and size distributions measured with an Ultraviolet Aerodynamic Particle Sizer (UV-APS) in Central Europe

2010 ◽  
Vol 10 (7) ◽  
pp. 3215-3233 ◽  
Author(s):  
J. A. Huffman ◽  
B. Treutlein ◽  
U. Pöschl
Keyword(s):  
Particle Number ◽  
Fungal Spores ◽  
Number Concentration ◽  
Size Distributions ◽  
Bacterial Cells ◽  
Spores And Pollen ◽  
Measurement Results ◽  
The Mean ◽  
Particle Sizer ◽  
Biological Aerosol Particles

Abstract. Primary Biological Aerosol Particles (PBAPs), including bacteria, spores and pollen, are essential for the spread of organisms and disease in the biosphere, and numerous studies have suggested that they may be important for atmospheric processes, including the formation of clouds and precipitation. The atmospheric abundance and size distribution of PBAPs, however, are largely unknown. At a semi-urban site in Mainz, Germany we used an Ultraviolet Aerodynamic Particle Sizer (UV-APS) to measure Fluorescent Biological Aerosol Particles (FBAPs), which provide an estimate of viable bioaerosol particles and can be regarded as an approximate lower limit for the actual abundance of PBAPs. Fluorescence of non-biological aerosol components are likely to influence the measurement results obtained for fine particles (<1 μm), but not for coarse particles (1–20 μm). Averaged over the four-month measurement period (August–December 2006), the mean number concentration of coarse FBAPs was ~3×10−2 cm−3, corresponding to ~4% of total coarse particle number. The mean mass concentration of FBAPs was ~1μg m−3, corresponding to ~20% of total coarse particle mass. The FBAP number size distributions exhibited alternating patterns with peaks at various diameters. A pronounced peak at ~3 μm was essentially always observed and can be described by the following campaign-average lognormal fit parameters: geometric mean diameter 3.2 μm, geometric standard deviation 1.3, number concentration 1.6×10−2 cm−3. This peak is likely due to fungal spores or agglomerated bacteria, and it exhibited a pronounced diel cycle (24-h) with maximum intensity during early/mid-morning. FBAP peaks around ~1.5 μm, ~5 μm, and ~13 μm were also observed, but less pronounced and less frequent. These may be single bacterial cells, larger fungal spores, and pollen grains, respectively. The observed number concentrations and characteristic sizes of FBAPs are consistent with microscopic, biological and chemical analyses of PBAPs in aerosol filter samples. To our knowledge, however, this is the first exploratory study reporting continuous online measurements of bioaerosol particles over several months and a range of characteristic size distribution patterns with a persistent bioaerosol peak at ~3 μm. The measurement results confirm that PBAPs account for a substantial proportion of coarse aerosol particle number and mass in continental boundary layer air. Moreover, they suggest that the number concentration of viable bioparticles is dominated by fungal spores or agglomerated bacteria with aerodynamic diameters around 3 μm rather than single bacterial cells with diameters around 1 μm.

scholarly journals Fluorescent biological aerosol particle concentrations and size distributions measured with an ultraviolet aerodynamic particle sizer (UV-APS) in Central Europe

2009 ◽  
Vol 9 (4) ◽  
pp. 17705-17751 ◽  
Author(s):  
J. A. Huffman ◽  
B. Treutlein ◽  
U. Pöschl
Keyword(s):  
Particle Number ◽  
Fungal Spores ◽  
Number Concentration ◽  
Size Distributions ◽  
Bacterial Cells ◽  
Spores And Pollen ◽  
Measurement Results ◽  
The Mean ◽  
Particle Sizer ◽  
Biological Aerosol Particles

Abstract. Primary biological aerosol particles (PBAPs), including bacteria, spores and pollen, are essential for the spread of organisms and disease in the biosphere, and numerous studies have suggested that they may be important for atmospheric processes, including the formation of clouds and precipitation. The atmospheric abundance and size distribution of PBAPs, however, are largely unknown. At a semi-urban site in Mainz, Germany, we used an ultraviolet aerodynamic particle sizer (UV-APS) to measure fluorescent biological aerosol particles (FBAPs), which can be regarded as viable bioaerosol particles representing a lower limit for the actual abundance of PBAPs. Fluorescence of non-biological aerosol components are likely to influence the measurement results obtained for fine particles (<1 μm), but not for coarse particles (1–20 μm). Averaged over the four-month measurement period (August–December 2006), the mean number concentration of coarse FBAPs was ~3×10−2 cm−3, corresponding to ~4% of total coarse particle number. The mean mass concentration of FBAPs was ~1 μg m−3, corresponding to ~20% of total coarse particle mass. The FBAP number size distributions exhibited alternating patterns with peaks at various diameters. A pronounced peak at ~3 μm was essentially always observed and can be described by the following campaign-average lognormal fit parameters: geometric mean diameter 3.2 μm, geometric standard deviation 1.3, number concentration 1.6×10−2 cm−3. This peak is likely due to fungal spores or agglomerated bacteria, and it exhibited a pronounced diel cycle with maximum intensity during early/mid-morning. FBAP peaks around ~1.5 μm, ~5 μm, and ~13 μm were also observed, but less pronounced and less frequent. These may be explained by single bacterial cells, larger fungal spores, and pollen grains, respectively. The observed number concentrations and characteristic sizes of FBAPs are consistent with microscopic, biological and chemical analyses of PBAPs in aerosol filter samples. To our knowledge, however, this study reporting: continuous online measurements of bioaerosol particles over several months, a range of characteristic size distribution patterns, and a persistent bioaerosol peak at ~3 μm. The measurement results confirm that PBAPs account for a substantial proportion of coarse aerosol particle number and mass in continental boundary layer air. Moreover, they suggest that the number concentration of viable bioparticles is dominated by fungal spores or agglomerated bacteria with aerodynamic diameters around 3 μm rather than single bacterial cells with diameters around 1 μm.

scholarly journals Using flow cytometry and light-induced fluorescence technique to characterizethe variability and characteristics of bioaerosols in springtime at Metro Atlanta, Georgia

2018 ◽  
Author(s):  
Arnaldo Negron ◽  
Natasha DeLeon-Rodriguez ◽  
Samantha M. Waters ◽  
Luke D. Ziemba ◽  
Bruce Anderson ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Nucleic Acid ◽  
Acid Content ◽  
Fungal Spores ◽  
Epifluorescence Microscopy ◽  
Nucleic Acid Content ◽  
Rain Event ◽  
Bacterial Cells ◽  
Sampling System ◽  
Spores And Pollen

Abstract. The abundance and speciation of primary biological aerosol particles (PBAP) is important for understanding their impacts on human health, cloud formation and ecosystems. Towards this, we have developed a protocol for quantifying PBAP collected from large volumes of air with a portable wet-walled cyclone bioaerosol sampler. A flow cytometry (FCM) protocol was then developed to quantify and characterize the PBAP populations from the sampler, which were confirmed against epifluorescence microscopy. The sampling system and FCM analysis were used to study PBAP in Atlanta, GA over a two-month period and showed clearly defined populations of DNA-containing particles: Low Nucleic Acid-content particles (bioLNA), High Nucleic Acid-content particles (HNA) being fungal spores and pollen. We find that daily-average springtime PBAP concentration (1 to 5 μm diameter) ranged between 1.4 × 104 and 1.1 × 105 m−3. The BioLNA population dominated PBAP during dry days (72 ± 18 %); HNA dominated the PBAP during humid days and following rain events, where HNA (e.g., wet-ejected fungal spores) comprised up to 92 % of the PBAP number. Concurrent measurements with a Wideband Integrated Bioaerosol Sensor (WIBS-4A) showed that FBAP and total FCM counts are similar; HNA (from FCM) significantly correlated with ABC type FBAP concentrations throughout the sampling period (and for the same particle size range, 1–5 μm diameter). However, the FCM bioLNA population, possibly containing bacterial cells, did not correlate to any FBAP type. The lack of correlation of any WIBS FBAP type with the bioLNA suggest bacterial cells may be more difficult to detect with autofluorescence than previously thought. Ιdentification of bacterial cells even in the FCM (bioLNA population) is challenging, given that the fluorescence level of stained cells at times may be comparable to that seen from abiotic particles. HNA and ABC displayed highest concentration on a humid and warm day after a rain event (4/14), suggesting that both populations correspond to wet-ejected fungal spores. Overall, information from both instruments combined reveals a highly dynamic airborne bioaerosol community over Atlanta, with a considerable presence of fungal spores during humid days, and a bioLNA population dominating bioaerosol community during dry days.

scholarly journals Measurement of nonvolatile particle number size distribution

2016 ◽  
Vol 9 (1) ◽  
pp. 103-114 ◽  
Author(s):  
G. I. Gkatzelis ◽  
D. K. Papanastasiou ◽  
K. Florou ◽  
C. Kaltsonoudis ◽  
E. Louvaris ◽  
...  
Keyword(s):  
Size Distribution ◽  
Black Carbon ◽  
Biomass Burning ◽  
Particle Number ◽  
Number Concentration ◽  
Experimental Methodology ◽  
Particle Number Concentration ◽  
Scanning Mobility Particle Sizer ◽  
Number Size Distribution ◽  
Particle Sizer

Abstract. An experimental methodology was developed to measure the nonvolatile particle number concentration using a thermodenuder (TD). The TD was coupled with a high-resolution time-of-flight aerosol mass spectrometer, measuring the chemical composition and mass size distribution of the submicrometer aerosol and a scanning mobility particle sizer (SMPS) that provided the number size distribution of the aerosol in the range from 10 to 500 nm. The method was evaluated with a set of smog chamber experiments and achieved almost complete evaporation (> 98 %) of secondary organic as well as freshly nucleated particles, using a TD temperature of 400 °C and a centerline residence time of 15 s. This experimental approach was applied in a winter field campaign in Athens and provided a direct measurement of number concentration and size distribution for particles emitted from major pollution sources. During periods in which the contribution of biomass burning sources was dominant, more than 80 % of particle number concentration remained after passing through the thermodenuder, suggesting that nearly all biomass burning particles had a nonvolatile core. These remaining particles consisted mostly of black carbon (60 % mass contribution) and organic aerosol (OA; 40 %). Organics that had not evaporated through the TD were mostly biomass burning OA (BBOA) and oxygenated OA (OOA) as determined from AMS source apportionment analysis. For periods during which traffic contribution was dominant 50–60 % of the particles had a nonvolatile core while the rest evaporated at 400 °C. The remaining particle mass consisted mostly of black carbon with an 80 % contribution, while OA was responsible for another 15–20 %. Organics were mostly hydrocarbon-like OA (HOA) and OOA. These results suggest that even at 400 °C some fraction of the OA does not evaporate from particles emitted from common combustion processes, such as biomass burning and car engines, indicating that a fraction of this type of OA is of extremely low volatility.

scholarly journals Urban aerosol size distributions over the Mediterranean city of Barcelona, NE Spain

2012 ◽  
Vol 12 (7) ◽  
pp. 16457-16492 ◽  
Author(s):  
M. Dall'Osto ◽  
D.C.S. Beddows ◽  
J. Pey ◽  
S. Rodriguez ◽  
A. Alastuey ◽  
...  
Keyword(s):  
Particle Number ◽  
Number Concentration ◽  
Aerosol Size Distribution ◽  
Time Variability ◽  
Small Contribution ◽  
Particle Number Concentration ◽  
Size Distributions ◽  
Total Particle Number ◽  
Total Particle ◽  
One Year

Abstract. Differential mobility particle sizer (DMPS) aerosol concentrations (N13–800) were collected over a one-year-period (2004) at an urban background site in Barcelona, North-Eastern Spain. Quantitative contributions to particle number concentrations of the nucleation (33–38%), Aitken (39–49%) and accumulation mode (18–22%) were estimated. We examined the source and time variability of atmospheric aerosol particles by using both K-means clustering and Positive Matrix Factorization (PMF) analysis. Performing clustering analysis on hourly size distributions, nine K-means DMPS clusters were identified and, by directional association, diurnal variation and relationship to meteorological and pollution variables, four typical aerosol size distribution scenarios were identified: traffic (69% of the time), dilution (15% of the time), summer background conditions (4% of the time) and regional pollution (12% of the time). According to the results of PMF, vehicle exhausts are estimated to contribute at least to 62–66% of the total particle number concentration, with a slightly higher proportion distributed towards the nucleation mode (34%) relative to the Aitken mode (28–32%). Photochemically induced nucleation particles make only a small contribution to the total particle number concentration (2–3% of the total), although only particles larger than 13 nm were considered in this study. Overall the combination of the two statistical methods is successful at separating components and quantifying relative contributions to the particle number population.

scholarly journals Comparison between summertime and wintertime Arctic Ocean primary marine aerosol properties

2013 ◽  
Vol 13 (9) ◽  
pp. 4783-4799 ◽  
Author(s):  
J. Zábori ◽  
R. Krejci ◽  
J. Ström ◽  
P. Vaattovaara ◽  
A. M. L. Ekman ◽  
...  
Keyword(s):  
Sea Ice ◽  
Water Temperature ◽  
Arctic Ocean ◽  
Particle Number ◽  
Number Concentration ◽  
The Arctic ◽  
Particle Number Concentration ◽  
Size Distributions ◽  
Total Particle Number ◽  
Total Particle

Abstract. Primary marine aerosols (PMAs) are an important source of cloud condensation nuclei, and one of the key elements of the remote marine radiative budget. Changes occurring in the rapidly warming Arctic, most importantly the decreasing sea ice extent, will alter PMA production and hence the Arctic climate through a set of feedback processes. In light of this, laboratory experiments with Arctic Ocean water during both Arctic winter and summer were conducted and focused on PMA emissions as a function of season and water properties. Total particle number concentrations and particle number size distributions were used to characterize the PMA population. A comprehensive data set from the Arctic summer and winter showed a decrease in PMA concentrations for the covered water temperature (Tw) range between −1°C and 15°C. A sharp decrease in PMA emissions for a Tw increase from −1°C to 4°C was followed by a lower rate of change in PMA emissions for Tw up to about 6°C. Near constant number concentrations for water temperatures between 6°C to 10°C and higher were recorded. Even though the total particle number concentration changes for overlapping Tw ranges were consistent between the summer and winter measurements, the distribution of particle number concentrations among the different sizes varied between the seasons. Median particle number concentrations for a dry diameter (Dp< 0.125μm measured during winter conditions were similar (deviation of up to 3%), or lower (up to 70%) than the ones measured during summer conditions (for the same water temperature range). For Dp > 0.125μm, the particle number concentrations during winter were mostly higher than in summer (up to 50%). The normalized particle number size distribution as a function of water temperature was examined for both winter and summer measurements. An increase in Tw from −1°C to 10°C during winter measurements showed a decrease in the peak of relative particle number concentration at about a Dp of 0.180μm, while an increase was observed for particles with Dp > 1μm. Summer measurements exhibited a relative shift to smaller particle sizes for an increase of Tw in the range 7–11°C. The differences in the shape of the number size distributions between winter and summer may be caused by different production of organic material in water, different local processes modifying the water masses within the fjord (for example sea ice production in winter and increased glacial meltwater inflow during summer) and different origin of the dominant sea water mass. Further research is needed regarding the contribution of these factors to the PMA production.

scholarly journals Evaluation of the Particle Aerosolization from n-TiO2Photocatalytic Nanocoatings under Abrasion

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Neeraj Shandilya ◽  
Olivier Le Bihan ◽  
Christophe Bressot ◽  
Martin Morgeneyer
Keyword(s):  
Particle Number ◽  
Number Concentration ◽  
Particle Number Concentration ◽  
Size Distributions ◽  
Irregular Shapes ◽  
Opposite Behavior ◽  
Stress Application ◽  
Ti Content ◽  
Evolution With Time ◽  
Concentration Evolution

A parametric study on the release of titanium dioxide (TiO2) nanoparticles from two commercial photocatalytic nanocoatings is carried out. For this, abrasion tests are performed on them. The formed aerosols are characterized by their number concentration, particle size distribution, individual particle shape, size, and chemical composition. The two nanocoatings appear to exhibit contrastingly opposite behavior with respect to the number concentration of the released particles. Having irregular shapes, the released particles are found to have unimodal size distributions with 1.5–3.5% (in mass) of Ti content. However, no free nanoparticles of TiO2were found. Distinct phases during the particle number concentration evolution with time are also discussed and evaluated. Two quantities—(ΔC/Δt)IandTII—are identified as the important indicators to qualitatively measure the resistance strength and hence the concentration of the released particles from a nanocoating during stress application.

scholarly journals Using flow cytometry and light-induced fluorescence to characterize the variability and characteristics of bioaerosols in springtime in Metro Atlanta, Georgia

2020 ◽  
Vol 20 (3) ◽  
pp. 1817-1838 ◽  
Author(s):  
Arnaldo Negron ◽  
Natasha DeLeon-Rodriguez ◽  
Samantha M. Waters ◽  
Luke D. Ziemba ◽  
Bruce Anderson ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Nucleic Acid ◽  
Acid Content ◽  
Aerosol Particles ◽  
Fungal Spores ◽  
Epifluorescence Microscopy ◽  
Nucleic Acid Content ◽  
Rain Event ◽  
Bacterial Cells ◽  
Biological Aerosol Particles

Abstract. The abundance and speciation of primary biological aerosol particles (PBAP) is important for understanding their impacts on human health, cloud formation, and ecosystems. Towards this, we have developed a protocol for quantifying PBAP collected from large volumes of air with a portable wet-walled cyclone bioaerosol sampler. A flow cytometry (FCM) protocol was then developed to quantify and characterize the PBAP populations from the sampler, which were confirmed against epifluorescence microscopy. The sampling system and FCM analysis were used to study PBAP in Atlanta, GA, over a 2-month period and showed clearly defined populations of nucleic-acid-containing particles: low nucleic acid-content particles above threshold (LNA-AT) and high nucleic acid-content particles (HNA) likely containing wet-ejected fungal spores and pollen. We find that the daily-average springtime PBAP concentration (1 to 5 µm diameter) ranged between 1.4×104 and 1.1×105 m−3. The LNA-AT population dominated PBAP during dry days (72±18 %); HNA dominated the PBAP during humid days and following rain events, where HNA comprised up to 92 % of the PBAP number. Concurrent measurements with a Wideband Integrated Bioaerosol Sensor (WIBS-4A) showed that fluorescent biological aerosol particles (FBAP) and total FCM counts are similar; HNA (from FCM) moderately correlated with ABC-type FBAP concentrations throughout the sampling period (and for the same particle size range, 1–5 µm diameter). However, the FCM LNA-AT population, possibly containing bacterial cells, did not correlate with any FBAP type. The lack of correlation of any WIBS FBAP type with the LNA-AT suggests that airborne bacterial cells may be more difficult to unambiguously detect with autofluorescence than currently thought. Identification of bacterial cells even in the FCM (LNA-AT population) is challenging, given that the fluorescence level of stained cells at times may be comparable to that seen from abiotic particles. HNA and ABC displayed the highest concentration on a humid and warm day after a rain event (14 April 2015), suggesting that both populations correspond to wet-ejected fungal spores. Overall, information from both instruments combined reveals a highly dynamic airborne bioaerosol community over Atlanta, with a considerable presence of fungal spores during humid days and an LNA-AT population dominating the bioaerosol community during dry days.

scholarly journals On the seasonal variation in observed size distributions in northern Europe and their changes with decreasing anthropogenic emissions in Europe: climatology and trend analysis based on 17 years of data from Aspvreten, Sweden

2019 ◽  
Vol 19 (23) ◽  
pp. 14849-14873 ◽  
Author(s):  
Peter Tunved ◽  
Johan Ström
Keyword(s):  
Particle Number ◽  
Particle Formation ◽  
Number Concentration ◽  
Northern Europe ◽  
Anthropogenic Emissions ◽  
Particle Number Concentration ◽  
Size Distributions ◽  
Modal Number ◽  
Accumulation Mode ◽  
Aitken Mode

Abstract. Size-resolved aerosol trends were investigated based on a 17-year data set (2000–2017) from the rural background site Aspvreten located in southern Sweden (58.8∘ N, 17.4∘ E). Cluster analysis of the size distributions was performed to aid in the interpretation of the data. The results confirm previous findings of decreasing aerosol mass and number during the last decades as a result of reduced anthropogenic emissions in Europe. We show that both particle modal number concentration and size have substantially been reduced during the last 17 years. Negative trends in particle number concentration of about 10 cm−3 yr−1 are present for nuclei, Aitken, and accumulation modes. In total, integral particle number concentration has decreased by 30 %, from 1860 to ca. 1300 cm−3. The reduction in modal number concentration is accompanied by a decrease in modal size, and this decrease is largest for the accumulation mode (2 nm yr−1 or about 17 % for the whole period). These reductions have resulted in a decrease in submicron particle mass (< 390 nm) by more than 50 % over the period 2000–2017. These decreases are similar to observations found at other stations in northern Europe. Although all size classes show a downward trend as annual averages, we also show that observed trends are not evenly distributed over the year and that a rather complex picture emerges where both sign and magnitude of trends vary with season and size. The strongest negative trends are present during spring (accumulation mode) and autumn (Aitken mode). The strongest positive trends are present during summer months (Aitken mode). The combined trajectory and data analyses do not present evidence for an increase in new particle formation formed locally, although some evidence of increased new particle formation some distance away from the receptor is present. Observed aerosol size distribution data, together with an adiabatic cloud parcel model, were further used to estimate the change in cloud droplet concentration for various assumptions of updraught velocities and aerosol chemical composition. The results indicate a substantial increase in the atmospheric brightening effect due to a reduction in cloud reflectivity corresponding to 10 %–12 % reduction in cloud albedo over the period 2000–2017.

Variation of particle number concentration and size distributions at the urban environment in Vilnius (Lithuania)

2013 ◽  
Author(s):  
Vidmantas Ulevicius ◽  
Steigvilė Byčenkienė ◽  
Kristina Plauškaitė ◽  
Vadimas Dudoitis
Keyword(s):  
Urban Environment ◽  
Particle Number ◽  
Number Concentration ◽  
Particle Number Concentration ◽  
Size Distributions
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