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Household garbage rooms release abundant bioaerosols and are an important source of pathogens; however, information on the distribution and survival patterns of pathogens in different waste components is limited. In this study, a culture method and 16S rRNA high-throughput sequencing were used to determine bacterial communities, culturable pathogens, and human bacterial pathogens (HBPs). The results showed that abundant culturable bacteria were detected in all waste types, and a large number of S. aureus was detected on the surface of recyclable wastes, whereas S. aureus , total coliforms, Salmonella , Enterococcus , and hemolytic bacteria were detected in food waste and other waste. The activities of these detected pathogenic bacteria decreased after 24 h of storage but re-activated within one week. Factors affecting the emergence of pathogens varied with different waste components. Sequencing results showed that Pseudomonas , Acinetobacter, and Burkholderia were abundant in the waste samples, whereas Achromobacter , Exiguobacteriums, Bordetella , and Corynebacterium were the primary pathogens in the bioaerosol and wall attachment. The results of traceability analysis showed that bioaerosol microbes were mainly derived from raw kitchen waste (5.98%) and plastic and paper contaminated with food waste (19.93%) in garbage rooms. In addition, bioaerosols were the main source of microflora in the wall attachment, which possessed high HBP diversity and required more attention. These findings will help in understanding the microbial hazards in different waste components and provide guidance for the control and risk reduction of bioaerosols during waste management and recycling. [Display omitted] • Abundant Staphylococcus aureus were detected on the surface of recyclable wastes. • Diverse pathogenic bacteria were detected in food wastes and other wastes. • The activities of pathogens decreased after 24 h but re-activated within one week. • Abundant and diverse human bacterial pathogens were detected in the wall attachment. • Raw kitchen waste and contaminated plastic and paper were main sources of bioaerosol. [ABSTRACT FROM AUTHOR]

Exposure to bioaerosol contamination has detrimental effects on human health. Recent advances in ATP bioluminescence provide more opportunities for the quantitative detection of bioaerosols. Since almost all active organisms can produce ATP, the amount of airborne microbes can be easily measured by detecting ATP-driven bioluminescence. The accurate evaluation of microorganisms mainly relies on following the four key steps: sampling and enrichment of airborne microbes, lysis for ATP extraction, enzymatic reaction, and measurement of luminescence intensity. To enhance the effectiveness of ATP bioluminescence, each step requires innovative strategies and continuous improvement. In this review, we summarized the recent advances in the quantitative detection of airborne microbes based on ATP bioluminescence, which focuses on the advanced strategies for improving sampling devices combined with ATP bioluminescence. Meanwhile, the optimized and innovative strategies for the remaining three key steps of the ATP bioluminescence assay are highlighted. The aim is to reawaken the prosperity of ATP bioluminescence and promote its wider utilization for efficient, real-time, and accurate detection of airborne microbes. [Display omitted] • Quantitative detection of airborne microbes is a critical prerequisite for avoiding associated risks from airborne pathogens. • Reviewed the current research progress of ATP bioluminescence in detection of airborne microbes. • Main challenges and perspectives of ATP bioluminescence in detecting airborne microbes are proposed and discussed. [ABSTRACT FROM AUTHOR]

Dust storms are known to be atmospheric phenomena that transport mineral dust but also airborne biological particles (bioaerosols) from desert areas to distant regions. These bioaerosols can influence atmospheric processes and they have the potential of changing the composition of the local aerobiome in urban areas, which, in recent years, have been associated with allergies and the exacerbation of respiratory syndromes. Here, we studied four dust events initiated in the Sahara Desert affecting the center of the Iberian Peninsula. The biological particles before and during the phenomena were analyzed by high-throughput DNA sequencing. The global composition of bioaerosols showed a marked seasonality. The relative abundances of the most predominant groups of bacteria and fungi were not significantly altered compared to the days prior the corresponding event. Nonetheless, we detected specific bacterial and fungal taxa associated with these events, whose composition and abundance were also related to the period of the year. Although a variety of plant and animal pathogens were identified both before and throughout the days influenced by dust storms, some were only detected during the latter, suggesting a long-range transport for these species. This work highlights the importance of analyzing the storm dust events separately, especially when they occur at different seasons, and the particular effect on an urban environment in the Iberian Peninsula as a model case, providing some recommendations for future studies. • Local aerobiome prevails over the changes in microbial communities caused by dust storms. • Foreign microorganisms contributed a low fraction to the local atmosphere. • Dust events may show particular features associated with intensity and seasonality. • The abundances of pathogenic species were not significantly altered by dust events. [ABSTRACT FROM AUTHOR]

The aerodynamic sizes of bioaerosols may significantly affect their behaviors, respiratory deposition and biodiversity. The respirable bacterial size, biodiversity, and human-associated bacteria (HAB) related bioaerosols were evaluated at three kindergartens in Taiwan. Kindergartens A, B, and C were in urban, semi-urban, and rural areas, respectively. A six-stage viable Andersen cascade impactor was used to collect bioaerosols and to determine their size distributions. The geometric mean diameter (GMD), geometric standard deviation (GSD), heat maps, and uniformity were used to evaluate the association of bacteria characteristics. A BD Phoenix-100 automated interpretation system was used to identify the airborne bacteria species. The results revealed that 1425 colonies of the sampled airborne bacteria contained 63 species in 29 genera, and overall, 63.0% were HABs. The most abundant phylum was Actinobacteria (56.6 ± 22.2%) and Firmicutes (31.6 ± 22.3%), and from the taxonomic analysis, both airborne Micrococcus and the Staphylococcus aureus are the dominant genus. All the bacteria aerodynamic particle size distributions were polydisperse distributions. The heat map and uniformity analysis had revealed most of the sampled bioaerosols distributed between 1.1–3.3 μm, and most of the polydisperse airborne Streptococcus spp. had a size in the respirable range, due to urbanization, they have potentially contributed to respiratory risk in the kindergartens. The Shannon diversity index (H) and inverse Simpson diversity index (D) of the bioaerosols in urban kindergarten were negatively correlated with GMD and GSD. The Pearson correlations revealed that the kindergarten in the rural area, with a higher temperature, a lower relative humidity, and a lower CO 2 concentration than the others, tended to have the largest H and D values (P < 0.05). Multiple and stepwise regression revealed that bioaerosol aerodynamic size was statistically significantly correlated with H (P = 0.001) and D values (P = 0.002). This study sheds light on the characteristics of bioaerosols and their associations with microbiome. [Display omitted] • Urbanized kindergarten had smaller bacterial size, lower biodiversity than others. • Actinobacteria, Firmicutes were easily airborne than Proteobacteria, Bacteroidetes. • Polydisperse airborne respirable-size Streptococcus spp. was hazardous for health. • Active sampling cultivates more airborne bacteria species than surface sampling. • Recirculated air, higher relative humidity, CO 2 , consequently had more bacteria. [ABSTRACT FROM AUTHOR]

Biological particles are ubiquitous in nature and can transmit diseases to humans, animals and plants. Moreover, they play a significant role in influencing both regional and global climates and hydrological cycles by serving as nuclei for water droplets or ice crystals. Fluorescent biological aerosol particles (FBAPs) were observed by a wideband integrated bioaerosol spectrometer (WIBS) at an urban site in Beijing, China during spring season with highly variable weather conditions. The average of number (N F), surface area (S F) and mass concentrations (M F) of FBAPs over the spring was 0.34 cm−3, 2.0 μm2 cm−3, 1.56 μg m−3, respectively. N F was barely fluctuated throughout the clean and haze periods, but revealed pronounced variations during rain period. During the dusty period, FBAPs size distributions shifted towards larger sizes (∼ 4.0 μm), suggesting that dust-storms may introduce biological particles with larger sizes. Different from total particles, FBAPs size distribution during rain period, all exhibited a unique undulant tail on the right side, which obviously increased when D a > 10.0 μm, indicating that there should be external biological particles with large size were emitted during the rain event. Overall, these results furthered our understanding on characteristic changes of FBAPs in Beijing during distinct weather conditions. [Display omitted] • Fluorescent biological aerosol particles constitute a significant proportion of total aerosol loading in Beijing. • Air quality conditions affect the size distribution of fluorescent biological aerosol particles. • Dust events contribute more significantly to the mass of FBAPs than to their number concentration. • Rain events caused most pronounced variations in FBAPs characteristics. [ABSTRACT FROM AUTHOR]

Among the components of fine particulate matter (PM 2.5), the contributions of airborne microorganisms and antibiotic resistance genes (ARGs) to health risks have been overlooked. Airborne microbial dynamics exhibit a unique diurnal cycle due to environmental influences. However, the specific roles of PM 2.5 chemical properties resulting from fossil fuel combustion in driving circadian fluctuations in microbial populations and ARGs remain unclear. This study explored the interactions between toxic components and microbial communities during the heating period to understand the variations in ARGs. Bacterial and fungal communities showed a higher susceptibility to diel variations in PM 2.5 compared to their chemical properties. Mantel tests revealed that chemical properties and microbial community interactions contribute differently to ARG variations, both directly and indirectly, during circadian fluctuations. Our findings highlight that, during the daytime, the enrichment of pathogenic microorganisms and ARGs increases the risk of PM 2.5 toxicity. Conversely, during the nighttime, the utilization of water-soluble ions by the fungal community increased, leading to a significant increase in fungal biomass. Notably, Aspergillus exhibited a significant correlation with mobile genetic elements and ARGs, implying that this genus is a crucial driver of airborne ARGs. This study provides novel insights into the interplay between the chemical composition, microbial communities, and ARGs in PM, underscoring the urgent need for a comprehensive understanding of effective air pollution control strategies. [Display omitted] • The diurnal enriching of antibiotic resistance genes (ARGs) elevated PM 2.5 toxicity. • The nocturnal fungal community was positively correlated with NH 4 + and NO 3 −. • The fungal community emerges as a crucial driver of ARG patterns in PM 2.5. [ABSTRACT FROM AUTHOR]

This investigation used portable air cleaners (PACs) and quantitative filter forensics (QFF) to assess week-long average airborne concentrations of SARS-CoV-2 RNA in homes occupied with COVID-symptomatic individuals, classrooms, and dining locations throughout Toronto, Canada. PACs were deployed for one week each, and dust from filters was collected via vacuuming. SARS-CoV-2 RNA from filter dust was quantified using reverse transcription-polymerase chain reaction (RT-PCR). RNA quantities and PAC metadata were used to estimate airborne concentrations of SARS-CoV-2 RNA. The highest concentrations of RNA were found in isolation rooms (median concentration = 8.68 RNA copies/m3). Classrooms had lower concentrations during summer than in fall and winter (median concentration of sampling weeks when RNA was present = 0.02 RNA copies/m3 and 0.11 RNA copies/m3, respectively), which may be attributed to differences in classroom occupancy among other factors. Limitations include unknown recovery efficiency of RNA from filters and the dynamics of concentrations due to the temporal averaging of QFF. Our results are consistent with previous research highlighting the effectiveness of isolation in preventing distribution of high concentrations of SARS-CoV-2 RNA throughout a home. Overall, QFF is a beneficial tool for environmental sampling of respiratory airborne viral RNA such as SARS-CoV-2 RNA, that can be implemented for long-term sampling in mixed-occupancy environments. [Display omitted] • Quantitative filter forensics provides week-long estimates of airborne SARS-CoV-2 RNA. • Isolation rooms have the highest SARS-CoV-2 RNA concentrations in homes. • Classrooms have seasonal differences in concentrations of SARS-CoV-2 RNA. • No significant difference in RNA quantification between RT-dPCR and RT-dPCR. [ABSTRACT FROM AUTHOR]

• 31 years of Birch pollen records in the northwestern Iberian Peninsula. • Precipitation in early spring delays the onset of the pollen period. • Pollen intensity in the last decades is increasing. • Temperature during the pollen period affects each locality differently. • Pre-summer temperature increases pollen intensity at all studies locations We studied the relationship between the occurrence of airborne pollen of Betula spp. and climate, during the main pollination season, as well as before the pollen season and in the preceding year. Our aim was to understand how environmental conditions could influence the main pollen season and the intensity of airborne pollen presence at the meridional boundary of the Betula forest distribution in Europe. For this purpose, pollen monitoring was conducted using Lanzoni VPPS 2000 volumetric trap and weather data from the nearest meteorological station. The study area was located in the northwest of the Iberian Peninsula, specifically in three areas with diverse mesoclimate: Vigo (Atlantic), Ourense (Mediterranean) and Lugo (Cantabrian), which had a distinct oceanic influence. Aerobiological analysis was conducted based on the Spanish aerobiology network protocol. Data on precipitation, maximum, minimum and mean temperature were selected for three time windows: 1st the main pollen season period, 2nd from 5 to 90 days before the onset of pollen presence, with a cumulative five-day interval, and 3rd the average monthly climate of the previous year. Precipitation delays the onset of the main pollination season as well as the end of the season, increasing pollen counts in the post-peak interval at all three sites. Temperature during the pollen season affects duration and pollen integral differently among sites. The pollen integral shows an increasing trend over the last decade's at all three areas. The rise trend detected in the minimum temperature of the previous summer explains these increases in the three sites. In conclusion, the effect of climate prior to and during the main pollen season have varied effects on date-related data across mesoclimates, while temperature during bud floral primordia development can be considered as a timeframe for predicting pollen intensity in the following year through the entire area. [ABSTRACT FROM AUTHOR]

Bioaerosols produced during animal production have potential adverse effects on the health of workers and animals. Our objective was to investigate characteristics, antibiotic-resistance genes (ARGs), and health risks of bioaerosols in various animal barns. Poultry and swine barns had high concentrations of airborne bacteria (11156 and 10917 CFU/m3, respectively). Acinetobacter , Clostridium sensu stricto , Corynebacterium , Pseudomonas , Psychrobacter , Streptococcus , and Staphylococcus were dominant pathogenic bacteria in animal barns, with Firmicutes being the most abundant bacterial phylum. Based on linear discriminant analysis effect size (LEfSe), there were more discriminative biomarkers in cattle barns than in poultry or swine barns, although the latter had the highest abundance of bacterial pathogens and high abundances of ARGs (including tet M, tet O, tet Q, tet W sul 1, sul 2, erm A, erm B) and intI 1). Based on network analyses, there were higher co-occurrence patterns between bacteria and ARGs in bioaerosol from swine barns. Furthermore, in these barns, relative abundance of bacteria in bioaerosol samples was greatly affected by environmental factors, mainly temperature, relative humidity, and concentrations of CO 2 , NH 3 , and PM 2.5. This study provided novel data regarding airborne bio-contaminants in animal enclosures and an impetus to improve management to reduce potential health impacts on humans and animals. [Display omitted] • Bioaerosol types and levels differ by barn species: poultry, swine, cattle. • Identified 24 pathogen genera vary across barn bioaerosols. • Swine barns had high ARGs and pathogen levels. • Environmental conditions drive bioaerosol diversity in barns. • Health risks in cattle barns were lower than in poultry and swine barns. [ABSTRACT FROM AUTHOR]

Airborne Staphylococcus aureus is detected in various locations and linked to human infection. Reliable quantification of viable S. aureus bioaerosols by filter-based samplers helps characterize personal exposure, requiring efficient sampling and post-sampling processing. However, the efficiencies of filtration sampling and cell extraction are undetermined for viable S. aureus. In coupled with quantitative PCR and propidium monoazide, the performance of three widely-used samplers (IOM, Button, and Cassette) loaded with polycarbonate (PC) or gelatin filters was evaluated over 30–270 min of sampling and compared to that of BioSampler containing deionized water (DW). Effects of sampler type, filter type, and sampling time on cell recovery efficiency of sampling methods were assessed. Methods to extract cells from filters were also studied. The 1.5-min vortexing in peptone-Tween mixture and 10-min heating in DW were respectively granted optimal for cell extraction from PC and gelatin filters with extraction efficiencies averaged 1.0–1.76 (n = 4). Both Button and IOM with 3-μm gelatin filter performed best to capture S. aureus , significantly greater than Button with 0.8-μm PC by a factor of 9–11 (P < 0.05) and Cassette or IOM with 0.2-μm PC by a factor of 15–79 (P < 0.05). Cassette and IOM with 0.2-μm PC also showed less efficiencies than BioSampler/DW by a factor of 4–16 (P < 0.05). Cell recovery efficiency was not affected by sampling time except for the Button with 0.8-μm PC. Overall, filter type is the most critical factor governing cell recovery efficiency. Button and IOM with gelatin filter and 10-min heating in DW are considered the most efficient filtration sampling and extraction methods for viable S. aureus. • Filtration sampling and extraction were assessed for viable Staphylococcus aureus. • Effects of sampler type, filter type, and sampling time were demonstrated. • Filter type was the most important factor affecting recovery efficiency. • 10-min heating in deionized water was optimal to extract cells from gelatin filter. • Button and IOM samplers with gelatin filter are suitable to sample viable S. aureus. [ABSTRACT FROM AUTHOR]

• Bioaerosol characteristics and risks under different rural sewage treatment models were studied. • Highest bioaerosol emission concentration was found in open channel discharge. • Many pathogenic microorganisms were detected in bioaerosols in different modes. • Adult males had the highest exposure risk based on respiratory rate. • Risks of elderly, children, and the infirm, who were with long exposure time, cannot be ignored. Sewage treatment processes are a critical anthropogenic source of bioaerosols and may present significant health risks to plant workers. Compared with the specialization and scale of urban sewage treatment, many decentralized treatment models are flexible and extensive. These treatment facilities are usually close to residential areas owing to the pipe network layout and other restrictions. Bioaerosols generated by these facilities may present a serious and widespread occupational and non-occupational exposure risk to nearby residents, particularly the elderly and children. An understanding of the characteristics and exposure risks of bioaerosols produced during decentralized sewage treatment is lacking. We compared bioaerosol emission characteristics and potential exposure risks under four decentralized sewage discharge methods and treatment models: small container collection (SCC), open-channel discharge (OCD), single household/combined treatment (SHCT), and centralized treatment (CT) in northwest China. The OCD mode had the highest bioaerosol production, whereas the CT mode had the lowest. The OCD model contained the most pathogenic bacterial species, up to 43 species, including Sphingomonas, Pseudomonas, Cladosporium, and Alternaria. Risk assessments indicated bioaerosol exposure was lower in the models with sewage treatment (SHCT and CT) than in those without (SCC and OCD). Different populations exhibited large variations in potential risks owing to differences in time spent indoors and outdoors. The highest risk was observed in males exposed to the SCC model. This study provides a theoretical basis and theories for the future joint prevention and control of the bioaerosol exposure risk from decentralized sewage treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

The development of a rapid and sensitive method for the enrichment and direct detection of airborne viruses has become urgently needed to prevent their spread. We have developed a dual-functional, label-free platform for the enrichment and optical identification of airborne viruses. This platform allows for the on-site enrichment and identification of airborne viruses through a virus enrichment component combined with surface-enhanced Raman scattering (SERS). In this work, we created an Au-porous anodic alumina (PAA) composite film, by ion sputtering Au nanoparticles (Au NPs) on a porous structure. The Au-PAA serves as a dual-functional sensor: it combines ultrafiltration through the vertical nanopores in the PAA for virus enrichment and constitutes a plasmonic substrate due to the surface plasmon near-field enhancements within the nanochannel structure. This sensor demonstrates an extraordinary enrichment efficiency (about 98 %) of obtained bioaerosols and enables simultaneous, sensitive detection at the single-virus level. Finite-difference time-domain (FDTD) simulations evidenced the electric field intensity and charge distribution of the Au-PAA. This Au-PAA composite film offers a powerful system for on-site, label-free viral particle enrichment and SERS detection. Contaminated air containing viruses can be collected in a few minutes and analyzed immediately by our platform, which is particularly beneficial for timely monitoring of viruses in the air of large public spaces. Additionally, this platform can be applied to evaluate the indoor air quality. • A potential system for enrichment and label-free on-site detection of airborne virus was designed. • Comprehensive explanation of electromagnetic enhancement mechanism. • The mechanism of the enrichment and detection of virus is demonstrated. [ABSTRACT FROM AUTHOR]

This study aimed to assess the markers of chemical and microbiological contamination of the air at sport centers (e.g., the fitness center in Poland) including the determination of particulate matter, CO2, formaldehyde (DustTrak™ DRX Aerosol Monitor; Multi-functional Air Quality Detector), volatile organic compound (VOC) concentration (headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry), the number of microorganisms in the air (culture methods), and microbial biodiversity (high-throughput sequencing on the Illumina platform). Additionally the number of microorganisms and the presence of SARS-CoV-2 (PCR) on the surfaces was determined. Total particle concentration varied between 0.0445 mg m−3 and 0.0841 mg m−3 with the dominance (99.65–99.99%) of the PM2.5 fraction. The CO2 concentration ranged from 800 ppm to 2198 ppm, while the formaldehyde concentration was from 0.005 mg/m3 to 0.049 mg m−3. A total of 84 VOCs were identified in the air collected from the gym. Phenol, D-limonene, toluene, and 2-ethyl-1-hexanol dominated in the air at the tested facilities. The average daily number of bacteria was 7.17 × 102 CFU m−3–1.68 × 103 CFU m−3, while the number of fungi was 3.03 × 103 CFU m−3–7.34 × 103 CFU m−3. In total, 422 genera of bacteria and 408 genera of fungi representing 21 and 11 phyla, respectively, were detected in the gym. The most abundant bacteria and fungi (>1%) that belonged to the second and third groups of health hazards were: Escherichia-Shigella, Corynebacterium, Bacillus, Staphylococcus, Cladosporium, Aspergillus, and Penicillium. In addition, other species that may be allergenic (Epicoccum) or infectious (Acinetobacter, Sphingomonas, Sporobolomyces) were present in the air. Moreover, the SARS-CoV-2 virus was detected on surfaces in the gym. The monitoring proposal for the assessment of the air quality at a sport center includes the following markers: total particle concentration with the PM2.5 fraction, CO2 concentration, VOCs (phenol, toluene, and 2-ethyl-1-hexanol), and the number of bacteria and fungi.

The article presents the history of the development and the current state of the apparatus for the detection of interferents and biological warfare simulants in the air with the laser-induced fluorescence (LIF) method. The LIF method is the most sensitive spectroscopic method and also enables the measurement of single particles of biological aerosols and their concentration in the air. The overview covers both the on-site measuring instruments and remote methods. The spectral characteristics of the biological agents, steady-state spectra, excitation–emission matrices, and their fluorescence lifetimes are presented. In addition to the literature, we also present our own detection systems for military applications.

Diurnal variations in the concentrations of culturable fungal and bacterial bioaerosols were measured during winter and spring. Significant variations in concentrations of bacterial bioaerosols were observed during the day in this measurement campaign. The bacterial bioaerosol concentration exhibited two peaks during the morning and evening periods in the winter season. Diurnal variation in bacterial bioaerosols was greater in spring than that in winter. However, fungal bioaerosol concentrations were not affected by diurnal and seasonal changes. Environmental properties such as temperature, relative humidity, and ultraviolet irradiation intensity were measured, and their relationship with bioaerosol concentrations was analyzed. The surrounding temperature was suspected as a significant factor. This diurnal variation in culturable bioaerosols can explain various public health phenomena. Variations in the concentrations of non-biological aerosol particles were also analyzed.

With urbanization, municipal solid waste (MSW) transfer station as an important link in the process of refuse collection and transportation is closer to residents' living areas. At present, studies on airborne antibiotic resistance genes (ARGs) generated during MSW management are still few and not comprehensive enough. In this study, metagenomics and high-throughput sequencing methods were used to analyze the composition and content of bioaerosol and airborne ARGs in the waste reception hall and the top vent of three MSW transfer stations. 265 ARG subtypes were detected. The main subtypes were bacA, multidrug_transporter, mexW, sul2 and macB, and the main types were multidrug resistance genes and bacitracin resistance genes. Different microbes and ARGs showed diverse release characteristics, but in general, the concentration of bacteria and ARGs at the top vent of the transfer station was higher than that in the waste reception hall, and fungi were more sensitive than bacteria when passing through the odor treatment system connecting between the top vent and the waste reception hall. For ARGs, daily intake of a worker was calculated to be 1.08 × 1010–2.79 × 1010 copies d− 1 and environmental release was 2.88 × 109–9.49 × 109 copies m− 3. Therefore, control measures for airborne ARGs and pathogenic microorganisms are urgently needed to ensure the health of workers and surrounding residents. [ABSTRACT FROM AUTHOR]

Summary: Covid‐19 has triggered an unprecedented global health crisis. The highly contagious nature and airborne transmission route of SARS‐CoV‐2 virus requires extraordinary measures for its containment. It is necessary to know the behaviour of aerosols carrying the virus to avoid this contagion. This paper describes the behaviour of aerosols and their role in the transmission of SARS‐CoV‐2 according to published models using a scoping review based on the PubMed, Scopus, and WOS databases. From an initial 530 references, 9 papers were selected after applying defined inclusion criteria. The results reinforce the airborne transmission route as a means of contagion of the virus and recommend the use of face masks, extending social distance to more than 2 metres, and natural ventilation of enclosed spaces as preventive measures. These results contribute to a better understanding of SARS‐CoV‐2 and help design effective strategies to prevent its spread. [ABSTRACT FROM AUTHOR]

Membrane bioreactors (MBRs) have become one of the most promising technologies in wastewater treat - ment. This study aimed to investigate the emission characteristics, source analysis and health risk of bioaerosols generated from a wastewater treatment plant (WWTP) with an MBR throughout the entire process. The results suggested that tile MBR exhibited a high concentration of bacterial bioaerosols 2921-6173 CFU/mt and fungal bioaerosols (77-673 CFU/mt and a high proportion of the respiratory fraction (RF) of bioaerosols. In the MBR, Holomonas, Microvirga, and Geodermatophilus and Rubellimicrobium were the dominant bacteria, and the predominant fungi were Acidea, Neophaeosphaeria, and Cryptotrichosporon. Water soluble ions (WS[s) in the bioaerosols were mainly 5042: N03-, Cl-, Ca2+1 Na+ and NH4*, with concentrations ranging from 18.68 to 183.41 tig/m3. Temperature, relative humidity (RH) and wind speed (WS) all had different influences on bacterial bioaerosols and fungal bioaerosols. Air was the major source of bioaerosols from the MBR. Bioaerosols in the fine grid (FG) and sludge dewatering room SDR) were from wastewater, sludge and air. Furthermore, inhalation was the greatest pathway of bioaerosol exposure. The SDR, aeration tank (AerT) and MBR showed the highest risks of bioaerosols. Thus, bioaerosols from MBRs should be sufficiently investigated, and effective controls should be set up to protect workers and residents around plants. [ABSTRACT FROM AUTHOR]

The Covid-19 pandemia increased the attention of the world community to air biocontamination. Sewage treatment plants (STPs) generate a bioaerosol during different technological operations. Research aimed to estimate the range of bioaerosol emission from different technological objects of 5 small STPs. Such knowledge is very important for risk assessment, monitoring programs and pollution limitation. The sedimentation method was used for the detection of mesophiles, psychrophiles, Escherichia coli, pigmented bacteria, Streptococcus faecalis, Pseudomonas fluorescens, and mold fungi. The highest level of psychrophiles and mold fungi (> 1000 cfu/m³) was detected in points located near activated sludge chambers, sludge thickening tanks, and secondary clarifiers. The mesophiles (>500 cfu/m3) and E. coli aren't a normal component of air microflora, but were detected in all measurement points, especially near a pomp station (inflow), grit, activated sludge, sludge thickening chambers. At the points located at the leeward, the number of microorganisms was higher than in the windward. The research results indicate the necessity of constant monitoring of the STP impact on the air quality. [ABSTRACT FROM AUTHOR]

The results of microscopic analysis for the presence of bioaerosols of 114 samples of precipitation (snow) taken during two cold periods (2015–2016 and 2016–2017) in the south of Western Siberia are presented. With the use of trajectory, synoptic, and map analyzes, the main regions were identified from which pollen grains and algae arrived with air masses and precipitated with atmospheric precipitation. [ABSTRACT FROM AUTHOR]

Dust events impose negative socio-economic, health, and environmental impacts on vulnerable areas and reflect their sources' physiochemical and biological characteristics. This study aimed to assess the impact of two dust sources on the concentration and diversity of airborne fungi in one of the dustiest areas in the world. This study is the first attempt to investigate the relationship between dust sources fungal community and those in airborne dust. Also, the contribution of dust sources to airborne fungi was estimated. Air masses arriving at the study area were assessed using local wind rose and the HYSPLIT model. Sampling was carried out from airborne dust at the Arvand Free Zone as target areas and soil in the dried parts of the Hor al-Azim and Shadegan wetlands as source areas to explore the relationship between fungi in the dust sources and the downwind area. The samples were analyzed in the lab to extract DNA. The internal transcribed spacer (ITS) regions of the rDNA gene were amplified using the primers ITS1F and ITS4, and then PCR products were sent to the lab for sequencing. The raw DNA data were processed using the QIIME virtual box to pick operational taxonomic units and taxonomy assignments. The most common fungi at the genus level were in the order of Penicillium > Aspergillus > Alternaria > Fusarium > Paradendryphiella > Talaromyces. The similarity between air and soil fungal genera was investigated using richness and diversity indices, the phylogenetic tree, and principal component analysis. The results showed that the community structures of ambient fungi in the Hor al-Azim and Shadegan dust sources were more similar to those on dusty days than non-dusty days. The source tracker model was used to quantify the contributions of known dust sources to airborne fungi. The results showed that the main source of airborne fungi was Hor al-Azim on dusty and non-dusty days. This study's results can help managers identify and prioritize dust sources regarding fungal species. [ABSTRACT FROM AUTHOR]

Bioaerosols (aerosolized particles with biological origin) are strongly suspected to play a significant role in the transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‐CoV‐2), especially in closed indoor environments. Thus, control technologies capable of effectively inactivating bioaerosols are urgently needed. In this regard, cold atmospheric pressure plasma (CAP) can represent a suitable option, thanks to its ability to produce reactive species, which can exert antimicrobial action. In this study, results; on the total inactivation of SARS‐CoV‐2 contained in bioaerosols treated using CAP generated in air are reported, demonstrating the possible use of CAP systems for the control of SARS‐CoV‐2 diffusion through bioaerosols. [ABSTRACT FROM AUTHOR]

[Display omitted] The COVID-19 pandemic affected universities and institutions and caused campus shutdowns with a transition to online teaching models. To detect infections that might spread on campus, we pursued research towards detecting SARS-CoV-2 in air samples inside student dorms. We sampled air in 2 large dormitories for 3.5 months and a separate isolation suite containing a student who had tested positive for COVID-19. We developed novel techniques employing 4 methods to collect air samples: Filter Cassettes, Button Sampler, BioSampler, and AerosolSense sampler combined with direct qRT-PCR SARS-CoV-2 analysis. For the 2 large dorms with the normal student population, we detected SARS-CoV-2 in 11 samples. When compared with student nasal swab qRT-PCR testing, we detected SARS-CoV-2 in air samples when a PCR positive COVID-19 student was living on the same floor of the sampling location with a detection rate of 75%. For the isolation dorm, we had a 100% SARS-CoV-2 detection rate with AerosolSense sampler. Our data suggest air sampling may be an important SARS-CoV-2 surveillance technique, especially for buildings with congregant living settings (dorms, correctional facilities, barracks). Future building designs and public health policies should consider implementation of Heating, Ventilation, and Air Conditioning surveillance. [ABSTRACT FROM AUTHOR]

Primary biological aerosol particles (PBAPs) are involved in multiple phenomena ranging from seasonal allergies to pandemic diseases. Furthermore, PBAPs that act as ice nuclei, might interact with cloud physics affecting the formation of hail and, potentially, causing damage to agriculture. These latter dynamics are still unclear, especially due to the lack of knowledge about PBAPs concentration and emission rates. Here we characterized the fungal aerobiology of Arceburgo, Minas Gerais State, Brazil, through ground level and airborne sampling of PBAPs via a hot-air balloon. Total and cultivable fungal spores were collected using personal portable Burkard and a MAS100 sampler respectively during the summer and winter of 2019. In the latter season, daily dynamics were resolved by repeating flights and sampling in the morning and in the afternoon. Both samplers identified a core fungal community (Penicillum/Aspergillus and Cladosporium spp.) that are coupled with local meteorological dynamics and are able to undergo atmospheric transport as indicated by their survival in the night-time residual boundary layer. These results are invaluable in identifying a core set of aerobiological indicators that can be used in future works to unravel PBAPs emission rates on the area of Arceburgo and form a basis to close the gap in knowledge in the interplay between PBAPs and hail formation. [ABSTRACT FROM AUTHOR]

Bioaerosols in commercial livestock barns threaten the health of animals and humans. To better understand microbial dynamics in the layer house, we characterized and compared the size-segregated bacterial community of the manure cleaning process in a typical commercial laying hen house equipped with an H-type manure removal belt and negative pressure tunnel ventilation system in Ningbo, China by using full-length 16S rRNA gene sequences. The third-generation single-molecule real-time sequencing (SMRT Cell) based on the Pacific BioSciences (PacBio) RS II platform was performed for capturing sequence information of the microbial aerosol samples. The results showed that the concentrations of total airborne bacteria in the layer house were in the range of 0.35 × 103 CFU/m3 to 0.70 × 103 CFU/m3, 2.76 × 103 CFU/m3 to 2.88 × 103 CFU/m3, and 2.10 × 103 CFU/m3 to 2.54 × 103 CFU/m3 before, during, and after manure removal, respectively. The airborne bacteria concentrations were significantly increased by the manure removal process. According to LEfSe analysis results, g_Escherichia_Shigella, s_Escherichia_coli, o_Enterobacteriales, f_Enterobacteriaceae could be suggested as biomarkers during manure removal. The dominant bacterial phyla in the layer house monitored were Proteobacteria, Bacteroidetes, Firmicutes, and genera were Pseudomonas, Escherichia-Shigella, Comamonas. The predominant potential pathogenic bacteria in the layer house were Pseudomonas, Escherichia, Enterobacter, and Acinetobacter. [ABSTRACT FROM AUTHOR]

Aerosols are produced during dental procedures. An airborne route has long been said to be involved in transmission of infections. The recent COVID-19 has also been considered to spread by respiratory droplets or by the contact of contaminated surfaces. The nature of the dental practice hence poses threat to dentists, dental team, and patients owing to the accompanied aerosol-generating procedures. A thorough knowledge about the dental aerosol originated from various dental procedure needs to be present for suitable prevention of infectious hazards like the COVID-19. Hence, this review aims to throw light on literature related to mechanism and source of production, composition, microbial load, and potential diseases transmitted by dental aerosol.

Respiratory infectious disease outbreaks such as those caused by coronaviruses and influenza, necessitate the use of specialized aerosol test chambers to study aspects of these causative agents including detection, efficacy of countermeasures, and aerosol survivability. The anthrax attacks from 2001 and earlier biowarfare and biodefense also influenced the study of biological aerosols to learn about how certain pathogens transmit either naturally or through artificial means. Some high containment biological laboratories, which work with Risk Group 3 and 4 agents in biosafety level -3, biosafety level-4 containment, are equipped with aerosol test chambers to enable the study of high-risk organisms in aerosolized form. Consequently, the biomedical, military and environmental sectors have specific applications when studying bioaerosols which may overlap while being different. There are countless aerosol test chambers worldwide and this number along with numerous high containment biological laboratories underscores the need for technical standards, regulatory and dual-use compliance. Here we survey common aerosol test chambers and their history, current use, and practice. Our findings reinforce the importance and need for continued collaboration among the multi-disciplinary fields studying aerobiology and biological aerosols.

Pathogenic bacteria and antibiotic resistance genes (ARGs) in bioaerosols are major threats to human health. In this study, the microbial community structure and ARG distribution characteristics of airborne bacteria in total suspended particulates (TSP) and PM2.5 were investigated under different air quality levels in Xinxiang, Central China. The results revealed that with the deterioration of air quality, the concentrations of airborne bacteria in both TSP and PM2.5 decreased; however, the relative amounts of pathogenic bacteria increased. The predominant genera in pathogenic bacteria of Bacillus, Sphingomonas, Corynebacterium, Rhodococcus, and Staphylococcus were identified in both TSP and PM2.5. Although the airborne bacteria concentrations and absolute abundances of ARGs in TSP were higher than those in PM2.5 under identical air quality conditions, the bacterial community structure and relative amounts of pathogenic bacteria were similar. In addition, the relationship between environmental factors of ions, metal elements, and meteorological parameters and the community structures of airborne bacteria and pathogenic bacteria were also analyzed. The effects of soluble ions and metal elements on several dominant genera of total bacteria and pathogenic bacteria differed, probably due to the strong tolerance of pathogenic bacteria to harsh atmospheric environments Different subtypes of ARGs showed various distribution characteristics with variations in air quality. The deterioration of air quality can inhibit the dissemination of ARGs, as the minimum values of all ARGs and class 1 integrase intI1 were observed under Severely Polluted conditions. This study provides a comprehensive understanding of the effect of air pollution levels on the airborne bacteria community composition and ARG distribution.

In this work, we propose a high-throughput online identification method of bioaerosols based on multi-angle polarization index system (MAPIS). In the study, four categories and 10 subclasses of aerosol samples from biological and non-biological sources are detected under three incident polarization mode. Then their measured MAPIS shows that bioaerosols like pollen can be easily distinguished from other types of aerosols. Not only that, experimental results also indicate the feasibility of fine identification between different kinds of bioaerosols based on MAPIS in P and R modes. To further extract simple and optimized polarization characterization parameters suitable for bioaerosols, we analyze the multidimensional data of MAPIS by PCA then validate the aerosol recognition accuracy using the first two principal components by multiple groups of randomly mixed aerosol datasets. The comparison with PCA components based on only scattering intensity demonstrate that MAPIS can be not only applied in the specific identification of bioaerosols but also suitable for the distinction between different kinds of bioaerosols.

Not only coughing and sneezing, but even normal breathing can produce aerosols, because rupture of liquid plugs forms microdroplets during pulmonary airway reopening. Aerosols are important carriers of various viruses, such as influenza, SARS, MERS, and COVID-19. To control airborne disease transmission, it is important to understand aerosol formation, which is related to the pressure drop, liquid plug, and film. In addition, the detrimental pressure and shear stress at the airway wall produced in the process of airway reopening have also attracted a lot of attention. In this paper, we proposed a multiphase lattice Boltzmann method to numerically simulate pulmonary airway reopening, in which the gas-liquid transition is directly driven by the equation of state. After validating the numerical model, two rupture cases with and without aerosol formation were compared and analyzed. We found that injury of the epithelium in the case with aerosol formation was almost the same as that without aerosol formation, even though the pressure drop in the airway increased by about 50%. Further investigation showed that the aerosol size and maximum differences of the wall pressure and shear stress increased with pressure drop in the pulmonary airway. A similar trend was observed when the thickness of the liquid plug became larger, while an opposite trend occurred when the thickness of the liquid film increased. The model can be extended to study generation and transmission of bioaerosols carrying the influenza or coronavirus. [ABSTRACT FROM AUTHOR]

Background: Bacillus Calmette–Guérin (BCG) is a vaccine used to protect against tuberculosis primarily in infants to stop early infection in areas of the world where the disease is endemic. Normally administered as a percutaneous injection, BCG is a live significantly attenuated bacteria that is now being investigated for its potential within an inhalable vaccine formulation. This study investigates the feasibility and performance of two jet and two vibrating mesh nebulizers aerosolizing BCG and the resulting particle characteristics and residual viability of the bacteria postaerosolization. Methods: A jet nebulizer (Collison), outfitted either with a 3- or 6-jet head, was compared with two clinical nebulizers, the vibrating mesh Omron MicroAir and Aerogen Solo devices. Particle characteristics, including aerodynamic particle sizing, was performed on all devices within a common aerosol chamber configuration and comparable BCG innocula concentrations. Integrated aerosol samples were collected for each generator and assayed for bacterial viability using conventional microbiological technique. Results: A batch lot of BCG (Danish) was grown to titer and used in all generator assessments. Aerosol particles within the respirable range were generated from all nebulizers at four different concentrations of BCG. The jet nebulizers produced a uniformly smaller particle size than the vibrating mesh devices, although particle concentrations by mass were similar across all devices tested with the exception of the Aerogen Solo, which resulted in a low concentration of BCG aerosols. Conclusions: The resulting measured viable BCG aerosol concentration fraction produced by each device approximated one another; however, a measurable decrease of efficiency and overall viability reduction in the jet nebulizer was observed in higher BCG inoculum starting concentrations, whereas the vibrating mesh nebulizer returned a remarkably stable viable aerosol fraction irrespective of inoculum concentration. [ABSTRACT FROM AUTHOR]

The airborne route is the dominant form of COVID‐19 transmission, and therefore, the development of methodologies to quantify SARS‐CoV‐2 in bioaerosols is needed. We aimed to identify SARS‐CoV‐2 in bioaerosols by using a highly efficient sampler for the collection of 1–3 µm particles, followed by a highly sensitive detection method. 65 bioaerosol samples were collected in hospital rooms in the presence of a COVID‐19 patient using a liquid impinger sampler. The SARS‐CoV‐2 genome was detected by ddPCR using different primer/probe sets. 44.6% of the samples resulted positive for SARS‐CoV‐2 following this protocol. By increasing the sampled air volume from 339 to 650 L, the percentage of positive samples went from 41% to 50%. We detected five times less positives with a commercial one‐step RT‐PCR assay. However, the selection of primer/probe sets might be one of the most determining factor for bioaerosol SARS‐CoV‐2 detection since with the ORF1ab set more than 40% of the samples were positive, compared to <10% with other sets. In conclusion, the use of a liquid impinger collector and ddPCR is an adequate strategy to detect SARS‐CoV‐2 in bioaerosols. However, there are still some methodological aspects that must be adjusted to optimize and standardize a definitive protocol. [ABSTRACT FROM AUTHOR]

Background and Objective: Bioaerosols as small particles enter the body by inhalation and lead to respiratory diseases based on type, concentration, and exposure time. In sensitive workplaces such as medical centers, it is necessary to pay attention to the type and population of these pollutants and the possibility of nosocomial infections. In the present study, the population and type of bioaerosols (bacteria and fungi) in the air of different hospital wards under normal conditions, visiting hours, and Covid-19 pandemic was evaluated. Materials and Methods: Air sampling was carried out in different wards and ambient air of Valiasr Hospital of Zanjan during September 2019 (morning and visiting hours) and October 2020 (Corona pandemic) using an air sampling pump (Flite 3- SKC Ltd) with a flow of 14.1 L/min and then cultured in Sabaroud dextrose agar and nutrient agar. Results: The results showed that air pollution in wards such as infectious diseases and clinics in both periods was more than other wards. The microbial density during visiting hours (before the coronavirus outbreak) was almost 30% higher than normal conditions. In October 2020, due to the coronavirus outbreak and reduced traffic, microbial air pollution in the hospital decreased. In both periods of study, the frequency of gram-positive bacteria, especially Staphylococcus species (49%) was higher than other bacteria and among fungal species the frequency of Aspergillus (47%) was higher than others. Conclusion: This study showed that traffic restrictions caused by the coronavirus pandemic reduce microbial density in hospital space and this achievement can be used in the future with the aim of improving air quality and controlling nosocomial infections. [ABSTRACT FROM AUTHOR]

Introduction: In recent decades, with the emergence of new industrial activities and an increase in waste production, industries require the existence of treatment equipment and sanitation. The equipment sometimes spreads infectious microorganisms into the air. These industries include waste recycling industries and wastewater treatment plants. Bioaerosols are produced at different stages of the wastewater treatment process, especially in processes, such as mobile mechanisms and aeration. This study aimed to investigate the bacterial bioaerosols in the air of the wastewater treatment plant in Jahanabad industrial town of Meybod. Methods: In this study, air sampling was performed from different units of the treatment plant and indoor air. The plates were placed in an incubator for 24-48 hours at a temperature of 35-37 °C. Then the number of bacterial colonies grown on the culture media was counted and recorded as CFU/m³. Results: The results showed that the mean population of bacterial aerosols was higher in summer than in spring. Moreover, the highest bacterial population was observed in spring in indoor air with mean value of 187.58±13.41 CFU/m³ and in summer in an equalization unit with mean value of 202.89±12.11 CFU/m³. Conclusion: The study indicated that the number of bacterial bioaerosols increases in warm seasons. Also, the equalization unit has a high ability to produce bacterial bioaerosols. Moreover, increasing the distance from the source of contamination causes a significant reduction in the number of bacterial bioaerosols. [ABSTRACT FROM AUTHOR]

Bioaerosol has been increasingly recognized as a hazardous factor, possibly leading to environmental issues and health risks. However, the driving factors were rarely investigated, which impeded comprehensive assessment of environmental quality. Herein ambient trace metals and bacterial community in PM2.5 and their interactions during severe pollution were characterized in high time resolution. The results showed that the mass concentrations of total trace elements in PM2.5 were 1.4–9.4 μg m−3, with As and Cr exceeding the national standard, which might pose health risks to humans, especially children with frequently hand‐to‐mouth activity. The airborne bacterial community structure responded to the changing environmental and meteorological variables including PM2.5, related water‐soluble ions, SO2, O3, temperature, relative humidity, and wind speed. Our results suggested that the trace metal was an overlooked factor in shaping the bacterial community compared to PM2.5, related water‐soluble inorganic ions, trace gases, and meteorological variables based on the aggregated boosted tree. Cd, Ga, and Nb were main trace metals factors affecting the bacterial community. The better knowledge of airborne bacterial diversity in high‐time resolution were essential to assess the environmental quality and help to explore the interactions of bioaerosols and atmospheric pollutants in PM2.5. The synergistic toxicity effects for the combination of trace metals and bioaerosol should be considered in future studies when evaluating their health effects. [ABSTRACT FROM AUTHOR]

Exposure to bioaerosols in enclosed livestock facilities have been reported to pose health risks to workers and animals. Environment-friendly methods for reducing bioaerosol levels in enclosed animal production units could provide important environmental control options. In this study, laboratory-scale electrospray modules were developed to generate engineered water nanostructures (EWNS) to inactivate microbes. The EWNS were generated using three spray liquids (reverse osmosis (RO) water, saline water, and NaOH solution). The physicochemical properties (size, lifetime, reactive oxygen species (ROS) content) of the generated EWNS were characterised. Results showed that the average diameter of the EWNS droplets ranged from 40 to 45 nm. It was found that approximately 17% of the generated EWNS was still present after 4.5 h, and that the most predominant ROS generated was OH·. Furthermore, the efficacy of the generated EWNS in inactivating Escherichia coli was assessed under conditions relevant to livestock facilities. The electrospray modules were installed in an acrylic chamber, which was used to simulate the airspace in an animal barn. After 60-min treatment, reductions in E. coli concentrations inside the chamber were 69%, 64%, and 50% using RO water, saline water, and NaOH solution, respectively, at a ventilation rate of seven air changes per hour (ACH). At 15 ACH, the efficacy of the EWNS generated using RO water was 37%. The results show the potential of the EWNS technology as a microbial decontamination method for animal confinement buildings; however, in-barn tests are necessary before it can be fully implemented in commercial livestock barns. • An electrospray system was developed to generate nanosized EWNS. • The generated EWNS could remain airborne for hours. • The EWNS was found effective in inactivating Escherichia coli. [ABSTRACT FROM AUTHOR]

Bioaerosols have gained importance in atmospheric sciences in the past few decades. Their exposure upsurges the health problems in sensitive population and is also known to participate in atmospheric chemistry. The present study assesses the monthly distribution of bioaerosol load at four different microenvironments inside an academic institute in Kanpur situated in Indo-Gangetic Plain (IGP). The study duration was from November 2017 to April 2018. The measured total bioaerosol concentrations were highest during April (418–610 CFU/m3) at all sites followed by the post-monsoon month of November (369–577 CFU/m3). The winter period showed low concentrations with lowest concentration obtained in January (251–419 CFU/m3). The indoor–outdoor (I/O) bioaerosol ratio was mostly less than one for bacteria depending on microenvironment, but for fungi it was always less than one. The Gram-positive bacteria (GPB) comprised 70–80% of total bacterial concentration, while Gram-negative bacteria (GNB) contributed 20–30% to bacterial concentration in ambient air. The bacterial genera were mostly dominated by Bacillus, Staphylococcus, Micrococcus, Streptococcus, and Enterococcus, while the fungal genera of Aspergillus, Penicillium, Rhizopus, Cladosporium, Basidiobolus, and Epidermophyton were seen in the campus. The statistical analysis showed a weak positive correlation of bioaerosol concentration with meteorological parameters: temperature and relative humidity (RH). [ABSTRACT FROM AUTHOR]

Limiting infection transmission is central to the safety of all in dentistry, particularly during the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Aerosol-generating procedures (AGPs) are crucial to the practice of dentistry; it is imperative to understand the inherent risks of viral dispersion associated with AGPs and the efficacy of available mitigation strategies. In a dental surgery setting, crown preparation and root canal access procedures were performed with an air turbine or high-speed contra-angle handpiece (HSCAH), with mitigation via rubber dam or high-volume aspiration and a no-mitigation control. A phantom head was used with a 1.5-mL min−1 flow of artificial saliva infected with Φ6-bacteriophage (a surrogate virus for SARS-CoV-2) at ~108 plaque-forming units mL−1, reflecting the upper limits of reported salivary SARS-CoV-2 levels. Bioaerosol dispersal was measured using agar settle plates lawned with the Φ6-bacteriophage host, Pseudomonas syringae. Viral air concentrations were assessed using MicroBio MB2 air sampling and particle quantities using Kanomax 3889 GEOα counters. Compared to an air turbine, the HSCAH reduced settled bioaerosols by 99.72%, 100.00%, and 100.00% for no mitigation, aspiration, and rubber dam, respectively. Bacteriophage concentrations in the air were reduced by 99.98%, 100.00%, and 100.00% with the same mitigations. Use of the HSCAH with high-volume aspiration resulted in no detectable bacteriophage, both on nonsplatter settle plates and in air samples taken 6 to 10 min postprocedure. To our knowledge, this study is the first to report the aerosolization in a dental clinic of active virus as a marker for risk determination. While this model represents a worst-case scenario for possible SARS-CoV-2 dispersal, these data showed that the use of HSCAHs can vastly reduce the risk of viral aerosolization and therefore remove the need for clinic fallow time. Furthermore, our findings indicate that the use of particle analysis alone cannot provide sufficient insight to understand bioaerosol infection risk. [ABSTRACT FROM AUTHOR]

There is an increasingly high suspicion of occupational health diseases amongst workers in sawmill factories. Hence this study aimed to determine the microbial diversity in some sawmill factories in Okada, Edo State, Nigeria to evaluate potential implications of the factory’s processing area on the health of the workers and wood merchants. Bacteria and fungi count in the bioaerosols within the processing area of each factory was performed with the passive air sampling technique. While in the sawdust samples, microbial counts were carried out with the pour plate technique. Identification of the microbes was performed with macroscopic and microscopic examinations as well as standard phenotypic tests. Mean total viable count (TVC) and total fungi count (TFC) of bioaerosols in the air within the processing area of the sawmill factories were found to be greater than 4162.99 CFU/m3 while mean total coliform count (TCC) was reported as 756.28 CFU/m3. Fisher (F) one-way ANOVA test of the TVC and TCC dataset of bioaerosols from the four sawmill factories indicated no significant difference (p = 0.77 and 0.83 for TVC and TFC respectively) in the mean TVC and TFC of the bioaerosols. Bacterial (Micrococcus, Staphylococcus, Bacillus, Klebsiella and Serratia) and fungal (Saccharomyces, Aspergillus, Cladosporium and Penicillium) species were isolated from the bioaerosols and sawdust samples. Results of this study indicated that workers in the sawmill factories and other wood merchants who visit sawmill processing area are most likely exposed to airborne contaminants that may cause occupational diseases such as ophthalmic irritations and dermatitis. Hence it is recommended that sawmill workers and other visitors wear personal protective gadgets in the processing area of the sawmill factories.

Abstract Background Reliable identification and quantification of bioaerosols is fundamental in aerosol microbiome research, highlighting the importance of using sampling equipment with well-defined performance characteristics. Following advances in sequencing technology, shotgun metagenomic sequencing (SMS) of environmental samples is now possible. However, SMS of air samples is challenging due to low biomass, but with the use of high-volume air samplers sufficient DNA yields can be obtained. Here we investigate the sampling performance and comparability of two hand-portable, battery-operated, high-volume electret filter air samplers, SASS 3100 and ACD-200 Bobcat, previously used in SMS-based aerosol microbiome research. Results SASS and Bobcat consistently delivered end-to-end sampling efficiencies > 80% during the aerosol chamber evaluation, demonstrating both as effective high-volume air samplers capable of retaining quantitative associations. Filter recovery efficiencies were investigated with manual and sampler-specific semi-automated extraction procedures. Bobcat semi-automated extraction showed reduced efficiency compared to manual extraction. Bobcat tended towards higher sampling efficiencies compared to SASS when combined with manual extraction. To evaluate real-world sampling performance, side-by-side SASS and Bobcat sampling was done in a semi-suburban outdoor environment and subway stations. SMS-based microbiome profiles revealed that highly abundant bacterial species had similar representation across samplers. While alpha diversity did not vary for the two samplers, beta diversity analyses showed significant within-pair variation in subway samples. Certain species were found to be captured only by one of the two samplers, particularly in subway samples. Conclusions SASS and Bobcat were both found capable of collecting sufficient aerosol biomass amounts for SMS, even at sampling times down to 30 min. Bobcat semi-automated filter extraction was shown to be less effective than manual filter extraction. For the most abundant species the samplers were comparable, but systematic sampler-specific differences were observed at species level. This suggests that studies conducted with these highly similar air samplers can be compared in a meaningful way, but it would not be recommended to combine samples from the two samplers in joint analyses. The outcome of this work contributes to improved selection of sampling equipment for use in SMS-based aerosol microbiome research and highlights the importance of acknowledging bias introduced by sampling equipment and sample recovery procedures.

Abstract Background Staphylococci species are the major constituents of infectious bioaerosols, particularly methicillin-resistant Staphylococci (MRS) have serious health impacts. Here, the bacterial burden was quantified, especially prevalence of MRS in bioaerosols collected from indoors of Dr. B.R. Ambedkar Central Library (DBRACL) and Central Laboratory Animal Resources (CLAR) of Jawaharlal Nehru University, New Delhi, India. Air samplings from DBRACL and CLAR were done using the settle plate method and SKC biosampler, respectively. Results This study showed a maximum 6757 CFU/m2/hr of bacterial load in the DBRACL reading room, while unacceptable bacterial loads (> 1000 CFU/m3 of air) at different sites of CLAR. Further, at both the sampling sites the predominance of coagulase negative Staphylococci (CNS) was observed. A total 22 and 35 Staphylococci isolates were isolated from DBRACL and CLAR bioaerosols, respectively. Majority (16/22) of the Staphylococcal isolates from DBRACL belonged to human-associated Staphylococci where S. haemolyticus (5/22) was the most dominating species. However, in CLAR facility centre, animal-associated Staphylococci (19/35) were dominating, where S. xylosus (12/35) was the most dominating species. Further, antibiotic sensitivity tests revealed 41% MRS and 73% multidrug resistant (MDR) among airborne Staphylococci from DBRACL indoor bioaerosols. Similarly, in CLAR facility, approximately, 66% Staphylococci isolates were methicillin resistant, out of which 2 isolates showed high MIC value ≥ 16 μg/mL. Further, we confirmed the presence of 49% multidrug resistant Staphylococci in the indoor air of CLAR facility. Conclusions This study suggested that the exposure of workers and students in CLAR to such a high concentration of drug-resistant Staphylococci should not be undermined, as these bacterial concentrations are the direct representative of inhalable particulate matter (PM2.5) as per collection procedure. Simultaneously, passive sampling from DBRACL assessed the risks due to microbial contamination in particle agglomerates, which may deposit on the crucial surfaces such as wounds/ cuts or on the frequently used items.

Background The aim of the study was to assess the occupational exposure to Staphylococcus aureus bacteria, including methicillin- resistant S. aureus (MRSA) and other antibiotic-resistant strains in the municipal wastewater treatment plants (WWTPs) environment. Material and Methods In 16 WWTPs in Poland, 33 wastewater and 253 air samples were collected in the spring–summer season. The microbiological analysis was carried out using a chromogenic medium. Species identification was carried out using the matrix assisted laser desorption ionization time-of-flight method, while the antibiotic-resistance analysis was performed with an automatic method. Results Among 2805 bacterial isolates from the air and wastewater, 574 were identified as S. aureus species (20.5%). The presence of S. aureus species was found in 11 WWTPs (69%), among them in 11 WWTPs in raw wastewater and in 1 WWTP additionally in treated wastewater. The concentrations of S. aureus in wastewater ranged 2–1215 colony-forming units per milliliter (CFU/ml). In the air, 2 S. aureus isolates were identified in concentrations of 5 and 10 CFU/m 3 ; both samples were collected at the stage of mechanical wastewater treatment. The results revealed the following trend: the higher the outdoor temperature, the bigger the number of WWTPs with confirmed S. aureus presence. Among 149 S. aureus isolates (2 from the air and 147 from wastewater, including 2 MRSA), 100 isolates were resistant only to penicillin, while 34 isolates showed multi-antibiotic resistance (to penicillin and other drugs). It was found that isolated bacteria were resistant almost strictly to critical and highly important antibiotics in veterinary medicine. Conclusions In general, WWTPs workers are occupationally exposed to S. aureus , including MRSA, and other antibiotic- and multi-antibiotic-resistant strains. The highest risk of infection concerns the activities carried out in direct contact with wastewater or devices through which wastewater flows, particularly at the stage of mechanical treatment. A significant source of S. aureus seems to be intensive livestock farming located in the area of the WWTPs under analysis. The study confirms the necessity to disinfect the wastewater discharging into WWTPs. Med Pr. 2020;71(3):265–78

Introduction Workers of pellet production facilities (WPPF) are exposed to high concentrations of wood dust and microbial pollutants. Such stimulation may lead to numerous allergic and toxic reactions, infections, and other non-specific syndromes. Objective To check the influence of individual traits of workers and characteristic features / factors of their living and working environments on the probability of adverse outcomes’ appearance. Material and Methods The questionnaire study assessing adverse health effects resulting from individual exposure was conducted among 28 workers of 10 Polish WPPF. The logistic regression (for dichotomous variables) was used to determine the appearance probability (given as odds ratio) of adverse symptoms or diseases. Results and Conclusions WPPF workers may have an increased risk of developing work-related adverse health outcomes. Both the individual traits and environmental exposure factors significantly influence the probability of their occurrence.

Abstract In 2018, our team collected aerosols samples from five poultry farms in Malaysia. Influenza D virus was detected in 14% of samples. One sample had an 86.3% identity score similar to NCBI accession number MH785020.1. This is the first molecular sequence of influenza D virus detected in Southeast Asia from a bioaerosol sample. Our findings indicate that further study of role of IDV in poultry is necessary.

Bioaerosol sampling is a critical step toward characterizing airborne pathogen exposure risks for many respiratory infectious diseases in human-to-human or human-to-animal outbreaks. The integrated performance-parameter design and sampling efficiency of aerosol-to-hydrosol samplers (cyclones) has been rarely published or studied. This review focuses on the determination of cyclone performance-parameter design and impact factors of the sampling efficiency, discusses their mechanisms of collection and describes their advantages and drawbacks. The crucial design parameters of cyclones in different applications are then discussed in detail. We also discuss how the aerosol-to-hydrosol sampling efficiency is intrinsically related to the performance parameters for bioaerosol cyclone design. In the final section of this review, scientific questions and challenges for future work are presented to encourage high collection efficiency design and high-quality cyclones.

Abstract Background Coagulase-negative staphylococci (CoNS) are a group of opportunistic pathogens, which are widely spread in the environment. Animal breeding is an important source of pathogen spreading. However, the concentration and characteristics of CoNS in the bioaerosols of henhouses are unclear. Results In this study, we showed that CoNS were significantly increased in bioaerosols of henhouses during the first 60 days, and reached 2.0 × 106 CFU/m3, which account for 75.4% of total bacteria. One hundred and two CoNS isolates from bioaerosols and nasal swabs of farmers were further identified, covering seven species. Among these, 41.2% isolates were Staphylococcus sciuri, which was the predominant species, followed by S. equorum, S. saprophyticus, S. haemolyticus, S. xylosus, S. arlettae and S. gallinarum. There were high rates of resistance to oxacillin in CoNS (49.0%), which were defined as Methicillin-Resistant CoNS (MRCoNS), and 36.3% isolates contained resistance gene mecA. Bioaerosol infection models showed that, chickens exposed to aerosolized S. sciuri had significant induction of inflammatory cytokines interleukin (IL)-1β, IL-6, IL-8 and IL-10 at 5 days post-infection (dpi) in lungs and at 7 dpi in spleens. Conclusions We reported a high concentration of CoNS in henhouses, and S. sciuri was the preponderant CoNS species. Antibiotic resistance analysis and bioaerosols infection of CoNS further highlighted its hazards on resistance and immunological challenge. These results suggested that, CoNS in bioaerosols could be one serious factor in the henhouses for not only poultry industry but also public health.

Introdution: During many dental interventions, performed using handpiece instruments and pusters, an aerosol is created,which is converted into a bioaerosol (BIOA) by mixing with the particles of various organic components from the patient's oral cavity.When the high-speed mashine is started, the air becomes instantly contaminated and practically covers the entire room. Pollution is registered all the times, as well as after prosthetic treatment. BIOA created during prosthetic workcontains various bacteria, fungi and viruses from the patient's oral cavity. These microorganisms pose a real hazard to health workers and are a potential risk for infection. The most common pathogens include influenza viruses, herpes viruses, as well as pathogenic streptococci and staphylococci. Infectious diseases, biosynosis, acute toxic reactions, allergies, atopic diseases, conjunctivitis, contact dermatitis, infections of the respiratory system, and even some types of cancer, are possible manifestations of side effects of BIOA. Conclusion:BIOA poses a potential danger to contamination of air, work surfaces and objects in dental offices. Direct and indirect exposure of dental staff and patients to BIOA is especially pronounced in the conditions of COVID 19. Although it is impossible to completely eliminate the risk of adverse effects of BIOA, it is important to pay attention to all prevention measures that can reduce the likelihood of contamination.

Background and Aim: The assessment of indoor air quality and detection of its microbial pollutants in classrooms is very important because of the presence of children sensitive to these pollutants. The aim of this study was to determine the concentration and characterization of dominant species of biological aerosols and their relationship with environmental factors in two selected primary schools in Arak, Iran. Methods & Materials: This cross-sectional study was conducted at two primary schools in Arak, Iran in Fall 2018. Indoor air sampling was performed using single-stage Andersen microbial sampler (at flow rate of 28.3 liters/min) containing bacterial and fungal culture media. The effects of suspended Particulate Matter (PM) and environmental parameters (temperature and humidity) on the density of bioaerosols were evaluated. Ethical Considerations: This study with an ethics code of IR.ARAKMU.REC.1397.76 was approved by the Research Ethics Committee at Arak University of Medical Sciences. Results: The overall mean density of indoor bacteria and fungi was 448 cfu/m3 and 394 cfu/m3, while the mean density of outdoor bacteria and fungi was 210 cfu/m3 and 127 cfu/m3, respectively. There was a positive correlation between indoor density of airborne bacteria and suspected PM concentrations (PM 10 and PM 2.5), and between PM2.5 concentration and indoor fungal density (P