The concentration of bioaerosols, thus measured, is widely represented in colony forming units (C... more The concentration of bioaerosols, thus measured, is widely represented in colony forming units (CFU/m3). Each specific agar mediums viz. Mannitol Salt (11.10 %; w/v), MacConkey (5.15 %; w/v) and Sabouroud Dextrose (6.50 %; w/v) were boiled for ~ 1 h with double distilled water in a sterilized pressure-cooker. The prepared stuffs were allowed to cool and then poured into petri dishes. The lids of petri dishes (3 required on each sampling day) were closed and allowed to cool down to normal temperature in a bio-safety cabinet equipped with ultraviolet (UV) lamp. The concentrations of each agar medium mentioned above and incubation at 35 °C temperature were considered to be optimal for the bioaerosols culture. In regional scenario, a large variability in weather conditions (on a seasonal basis) and associated anthropogenic emissions has been witnessed. Therefore, the number of viable bioaerosols colonies was expected to vary in orders of magnitude over a period of 1 year in this study. Thus, the only critical parameter that could affect significantly on our observations of colony counting is the time-period of incubation. Towards this, about 40% of the total collected bioaerosols samples were incubated for different time-periods (24, 48, 72, 96 and 120 h). Subsequently their colonies counting were performed. All other conditions including specific agar medium strength and incubation temperature were kept identical. The observations of colony counting for GPB, GNB and Fungi for different incubation periods are shown in Figures (S2a, b, c). The results shown in figure S2 suggest that 48 h of incubation is the optimum culture period for GPB and GNB, whereas 72 h is optimum period for Fungi culture. Thus, finally for these 50 samples we have considered the colony counting data pertaining to 48 h of incubation for GPB and GNB, whereas 72 h incubated counting data for Fungi was considered. For rest of the sampling, GPB and GNB colony counting was performed post to 48 h of incubation, whereas 72 h of incubation was strictly followed for Fungi colony counting.
Previous studies worldwide have suggested the potential role of bioaerosols as ice-nuclei and clo... more Previous studies worldwide have suggested the potential role of bioaerosols as ice-nuclei and cloud-condensation nuclei. Furthermore, their participation in regulating the global carbon cycle urges systematic studies from different environmental conditions throughout the globe. Towards this through one-year study, conducted from June 2015‒May 2016, we report on atmospheric abundance and variability of viable bioaerosols, organic carbon (OC) and particles number and deduced mass concentrations from Indo-Gangetic Plain (IGP; at Kanpur). Among viable bioaerosols, the highest concentrations of Gram-positive bacteria (GPB), Gram-negative bacteria (GNB) and Fungi were recorded during December‒January (Avg.: 189 CFU/m3), November (244 CFU/m3) and September months (188 CFU/m3), respectively. Annual average concentration of GPB, GNB and Fungi are 105 ± 58, 144 ± 82 and 116 ± 51 CFU/m3. Particle number concentration (PNC) associated with fine-fraction aerosols (FFA) predominates throughout the year. However, mineral dust (coarser particle) remains a perennial constituent of atmospheric aerosols over the IGP. Temporal variability records and significant linear positive correlation (p < 0.05) of GPB and GNB with OC and biomass burning derived potassium (K+BB) indicates their association with massive emissions from paddy-residue burning (PRB) and bio-fuel burning. Influence of meteorological parameters on viable bioaerosols abundance has been rigorously investigated herein. Accordingly, ambient temperature seems to be more affecting the bacteria (anti-correlation), whereas wet-precipitation (1‒4 mm) relates to higher abundance of Fungi. High abundance of GNB from large-scale biomass burning emissions has implications to endotoxin exposure on human health. Thus, field-based data-set of bioaerosols, OC, PNC and deduced mass concentrations reported herein could serve to better constraint their role in human health and climate relevance.
The concentration of bioaerosols, thus measured, is widely represented in colony forming units (C... more The concentration of bioaerosols, thus measured, is widely represented in colony forming units (CFU/m3). Each specific agar mediums viz. Mannitol Salt (11.10 %; w/v), MacConkey (5.15 %; w/v) and Sabouroud Dextrose (6.50 %; w/v) were boiled for ~ 1 h with double distilled water in a sterilized pressure-cooker. The prepared stuffs were allowed to cool and then poured into petri dishes. The lids of petri dishes (3 required on each sampling day) were closed and allowed to cool down to normal temperature in a bio-safety cabinet equipped with ultraviolet (UV) lamp. The concentrations of each agar medium mentioned above and incubation at 35 °C temperature were considered to be optimal for the bioaerosols culture. In regional scenario, a large variability in weather conditions (on a seasonal basis) and associated anthropogenic emissions has been witnessed. Therefore, the number of viable bioaerosols colonies was expected to vary in orders of magnitude over a period of 1 year in this study. Thus, the only critical parameter that could affect significantly on our observations of colony counting is the time-period of incubation. Towards this, about 40% of the total collected bioaerosols samples were incubated for different time-periods (24, 48, 72, 96 and 120 h). Subsequently their colonies counting were performed. All other conditions including specific agar medium strength and incubation temperature were kept identical. The observations of colony counting for GPB, GNB and Fungi for different incubation periods are shown in Figures (S2a, b, c). The results shown in figure S2 suggest that 48 h of incubation is the optimum culture period for GPB and GNB, whereas 72 h is optimum period for Fungi culture. Thus, finally for these 50 samples we have considered the colony counting data pertaining to 48 h of incubation for GPB and GNB, whereas 72 h incubated counting data for Fungi was considered. For rest of the sampling, GPB and GNB colony counting was performed post to 48 h of incubation, whereas 72 h of incubation was strictly followed for Fungi colony counting.
Previous studies worldwide have suggested the potential role of bioaerosols as ice-nuclei and clo... more Previous studies worldwide have suggested the potential role of bioaerosols as ice-nuclei and cloud-condensation nuclei. Furthermore, their participation in regulating the global carbon cycle urges systematic studies from different environmental conditions throughout the globe. Towards this through one-year study, conducted from June 2015‒May 2016, we report on atmospheric abundance and variability of viable bioaerosols, organic carbon (OC) and particles number and deduced mass concentrations from Indo-Gangetic Plain (IGP; at Kanpur). Among viable bioaerosols, the highest concentrations of Gram-positive bacteria (GPB), Gram-negative bacteria (GNB) and Fungi were recorded during December‒January (Avg.: 189 CFU/m3), November (244 CFU/m3) and September months (188 CFU/m3), respectively. Annual average concentration of GPB, GNB and Fungi are 105 ± 58, 144 ± 82 and 116 ± 51 CFU/m3. Particle number concentration (PNC) associated with fine-fraction aerosols (FFA) predominates throughout the year. However, mineral dust (coarser particle) remains a perennial constituent of atmospheric aerosols over the IGP. Temporal variability records and significant linear positive correlation (p < 0.05) of GPB and GNB with OC and biomass burning derived potassium (K+BB) indicates their association with massive emissions from paddy-residue burning (PRB) and bio-fuel burning. Influence of meteorological parameters on viable bioaerosols abundance has been rigorously investigated herein. Accordingly, ambient temperature seems to be more affecting the bacteria (anti-correlation), whereas wet-precipitation (1‒4 mm) relates to higher abundance of Fungi. High abundance of GNB from large-scale biomass burning emissions has implications to endotoxin exposure on human health. Thus, field-based data-set of bioaerosols, OC, PNC and deduced mass concentrations reported herein could serve to better constraint their role in human health and climate relevance.
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