Bioaerosols were collected by using a six-stage bioaerosols sampler from September 2007 to August 2008 in the coastal region of Qingdao, China. The terrestrial and marine microbes(including bacteria and fungi) were an...Bioaerosols were collected by using a six-stage bioaerosols sampler from September 2007 to August 2008 in the coastal region of Qingdao, China. The terrestrial and marine microbes(including bacteria and fungi) were analyzed in order to understand the distribution features of bioaerosols. The results show that the average monthly concentrations of terrestrial bacteria, marine bacteria, terrestrial fungi and marine fungi are in the ranges of 80–615 CFU m-3, 91–468 CFU m-3, 76–647 CFU m-3 and 231–1959 CFU m-3, respectively. The concentrations of terrestrial bacteria, marine bacteria, terrestrial fungi, marine fungi and total microbes are the highest in each microbial category during fall, high in spring, and the lowest in the summer and winter. The bacterial particles are coarse in spring, autumn and winter. The sizes of fungal particle present the log-normal distribution in all the seasons.展开更多
Bioaerosol emissions from animal feeding operation (AFO) facilities are of increasing interest due to the magnitude of the emissions and their potential health effect on local communities. There is limited information...Bioaerosol emissions from animal feeding operation (AFO) facilities are of increasing interest due to the magnitude of the emissions and their potential health effect on local communities. There is limited information about fate and transport of AFO bioaerosol emissions. In this study, concentrations of airborne bacteria and fungi were measured at four ambient stations in four wind directions surrounding an egg production farm through winter, spring and summer using Andersen six-stage samplers. Mean concentrations of ambient bacteria and fungi ranged from 8.7 × 102 CFU m-3 to 1.3 × 103 CFU m-3 and from 2.8 × 102 CFU m-3 to 1.4 × 103 CFU m-3, respectively. Ambient bacterial concentrations were not significantly different over the seasons, while ambient fungal concentrations were the highest in summer and the lowest in winter. There were significant differences between downwind and upwind bacterial concentrations (p < 0.0001). Downwind bacterial and fungal concentrations responded differently to the influencing factors. Bacterial concentrations were quadratically correlated with wind vector (combined effects of wind speed and direction) and emission rate, were positively correlated with temperature, and were negatively correlated with solar radiation. Fungal concentrations were positively correlated with temperature, RH, and emission rate, and were negatively correlated with wind vector.展开更多
The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown thi...The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown this intervention to be an effective mitigation strategy against viral, bacterial, and fungal elements in ambient air. There is an array of available products for generating ClO<sub>2</sub> gas however most involve the use of expensive or sophisticated technology that makes their applicability limited to specialized consumers. The purpose of this study was to determine the virucidal efficacy of three pragmatic and affordable, ClO<sub>2</sub> generating products using an aerosolized MS2 surrogate in a sealed chamber room under five different scenarios. The products tested included: Ultrashock—a ClO<sub>2</sub> releasing pod (30 ppmv), Filter Media—a ClO<sub>2</sub> impregnated zeolite media made to fit into an air blower housing (<0.01 ppmv) and Flow Stick—a smaller ClO<sub>2</sub> impregnated media filled air reactor tube (<0.01 ppmv). Testing scenarios included product deployment post MS2 bioaerosol introduction (Ultrashock and Filter Media), during MS2 bioaerosol introduction (Filter Media and Flow Stick) and prior to MS2 bioaerosol introduction (Filter Media). MS2 surface samples were collected using sterile petri-dishes and MS2 and ClO<sub>2</sub> air samples were collected from sampling ports on the outer chamber wall at 0, 90 and 180 minutes. The Ultrashock and Filter Media with air flow in the rapid sweep scenario showed the greatest reduction in air MS2 (T<sub>180</sub> = 99.992% and T<sub>180</sub> = 99.996% respectively) compared to the control (T<sub>180 </sub>= 99.6%). When compared to the control results, the filter media with air flow engaged prior to the introduction of MS2 yielded reductions of 99.87% and 99.93% in air and on surfaces respectively at T<sub>0</sub>, demonstrating the protective effect residual ClO2 has against air and surface contamination. These product formats have potential uses as remedial and preventative interventions against viral constituents in air and should undergo further evaluation to determine efficacy and human health risk.展开更多
This study was conducted to evaluate the impact of hazy and foggy weather on the bacterial communities in bioaerosols, for which samples were collected from the Qingdao coastal region on sunny, foggy, and hazy days in...This study was conducted to evaluate the impact of hazy and foggy weather on the bacterial communities in bioaerosols, for which samples were collected from the Qingdao coastal region on sunny, foggy, and hazy days in January and March 2013. Bacterial community compositions were determined using polymerase chain reaction denaturing gradient gel electrophoresis(PCR-DGGE). The bacterial community diversity was found to be high on foggy and hazy days, and the dominant species differed during hazy weather. The Shannon-Wiener index revealed that the bacterial community diversity of coarse particles was higher than that of fine particles in the bioaerosols. The bacterial community diversity of fine particles significantly correlated with relative humidity(RH; r^2 = 0.986). The cluster analysis results indicated that the bacterial communities on sunny days differed from those on hazy and foggy days. Compared with sunny days, the bacterial communities in the fine particles during hazy weather exhibited greater changes than those in the coarse particles. Most of the sequenced bacteria were found to be closely affiliated with uncultured bacteria. During hazy weather, members of the classes Bacilli and Gammaproteobacteria(Pseudomonas and Acinetobacter) were dominant. The DGGE analysis revealed that Proteobacteria and Firmicutes were the predominant phyla, and their relative percentages to all the measured species changed significantly on hazy days, particularly in the fine particles. Haze and fog had a significant impact on the bacterial communities in bioaerosols, and the bacterial community diversity varied on different hazy days.展开更多
Bioaerosols are a subset of important airborne particulates that present a substantial human health hazard due to their allergenicity and infectivity.Chemical reactions in atmospheric processes can significantly influ...Bioaerosols are a subset of important airborne particulates that present a substantial human health hazard due to their allergenicity and infectivity.Chemical reactions in atmospheric processes can significantly influence the health hazard presented by bioaerosols;however,few studies have summarized such alterations to bioaerosols and the mechanisms involved.In this paper,we systematically review the chemical modifications of bioaerosols and the impact on their health effects,mainly focusing on the exacerbation of allergic diseases such as asthma,rhinitis,and bronchitis.Oxidation,nitration,and oligomerization induced by hydroxyl radicals,ozone,and nitrogen dioxide are the major chemical modifications affecting bioaerosols,all of which can aggravate allergenicity mainly through immunoglobulin E pathways.Such processes can even interact with climate change including the greenhouse effect,suggesting the importance of bioaerosols in the future implementation of carbon neutralization strategies.In summary,the chemical modification of bioaerosols and the subsequent impact on health hazards indicate that the combined management of both chemical and biological components is required to mitigate the health hazards of particulate air pollution.展开更多
The aerosol transmission of coronavirus disease in 2019,along with the spread of other respiratory diseases,caused significant loss of life and property;it impressed upon us the importance of real-time bioaerosol dete...The aerosol transmission of coronavirus disease in 2019,along with the spread of other respiratory diseases,caused significant loss of life and property;it impressed upon us the importance of real-time bioaerosol detection.The complexity,diversity,and large spatiotemporal variability of bioaerosols and their external/internal mixing with abiotic components pose challenges for effective online bioaerosol monitoring.Traditional methods focus on directly capturing bioaerosols before subsequent time-consuming laboratory analysis such as culture-based methods,preventing the high-resolution time-based characteristics necessary for an online approach.Through a comprehensive literature assessment,this review highlights and discusses the most commonly used real-time bioaerosol monitoring techniques and the associated commercially available monitors.Methods applied in online bioaerosol monitoring,including adenosine triphosphate bioluminescence,laser/light-induced fluorescence spectroscopy,Raman spectroscopy,and bioaerosol mass spectrometry are summarized.The working principles,characteristics,sensitivities,and efficiencies of these real-time detection methods are compared to understand their responses to known particle types and to contrast their differences.Approaches developed to analyze the substantial data sets obtained by these instruments and to overcome the limitations of current real-time bioaerosol monitoring technologies are also introduced.Finally,an outlook is proposed for future instrumentation indicating a need for highly revolutionized bioaerosol detection technologies.展开更多
The outbreak of COVID-19 and the spread of infectious pathogens through bioaerosols have once again aroused widespread concern worldwide.Isolation ward is an important place to prevent the spread of infectious bioaero...The outbreak of COVID-19 and the spread of infectious pathogens through bioaerosols have once again aroused widespread concern worldwide.Isolation ward is an important place to prevent the spread of infectious bioaerosols.However,infection of health care workers(HCWs)in the isolation ward often occurs,so it is ur-gent to carry out relevant research to reduce the cross-infection between HCWs and patients.In this paper,the temporal and spatial distribution characteristics of bioaerosols under three mixed ventilation modes in a single ward were studied,namely,upper supply side return air of Case 1 and side supply and side return ventilation are Case 2 and Case 3 respectively.The results show that the removal efficiency of bioaerosol in the ventilation mode of Case 3,in which directional airflow is formed from the air supply inlet to the release source and then to the exhaust outlet,is 46.6%and 67.7%higher than that of Case 1 and Case 2,respectively.In addition,ventilation methods based on mixed theory do not guarantee good air quality in the breathing zone(1.3 m to 1.7 m)of HCWs,which may increase the inhalation risk for HCWs.It is hoped that our results can provide some useful suggestions for optimizing the airflow layout of the isolation ward,reducing the risk of cross-infection,and virus elimination.展开更多
Pathogenic microbes with antibiotic resistance can thrive on municipal solid waste as nutrients and be aerosolized and transported to vicinities during waste disposal processes.However,the characterization of pathogen...Pathogenic microbes with antibiotic resistance can thrive on municipal solid waste as nutrients and be aerosolized and transported to vicinities during waste disposal processes.However,the characterization of pathogenic bioaerosols and assessment of their exposure risks are lacking.Herein,particle size,concentration,activity,antibiotic resistance,and pathogenicity of airborne microorganisms were assessed in different sectors of a typical landfill.Results showed that active sector in downwind direction has the highest bioaerosol level(1234 CFU/m3),while residential area has the highest activity(14.82 mg/L).Botanical deodorizer from mist cannon can effectively remove bioaerosol.Most bioaerosols can be inhaled into respiratory system till bronchi with sizes ranging from 2.1−3.3 and 3.3−4.7μm.Pathogenic bacteria(Bacilli,Bacillus,and Burkholderia-Paraburkholderia)and allergenic fungi(Aspergillus,Cladosporium,and Curvularia)prevailed in landfill.Although high abundance of microbial volatile organic compounds(mVOCs)producing bioaerosols were detected,these mVOCs contributed little to odor issues in landfill.Notably,surrounding areas have higher levels of antibiotic-resistance genes(ARGs)than inner landfill with tetC,acrB,acrF,mdtF,and bacA as dominant ones.Most ARGs were significantly correlated with bacterial community,while environmental parameters mainly influenced fungal prevalence.These findings can assist in reducing and preventing respiratory allergy or infection risks in occupational environments relating to waste management.展开更多
Bioaerosols exhibit significant broadband extinction performance and have vital impacts on climate change,optical detection,communication,disease transmission,and the development of optical attenuation materials.Micro...Bioaerosols exhibit significant broadband extinction performance and have vital impacts on climate change,optical detection,communication,disease transmission,and the development of optical attenuation materials.Microbial spores and microbial hyphae represent two primary forms of bioaerosol particles.However,a comprehensive investigation and comparison of their optical properties have not been conducted yet.In this paper,the spectra of spores and hyphae were tested,and the absorption peaks,component contents,and protein structural differences were compared.Accurate structural models were established,and the optical attenuation parameters were calculated.Aerosol chamber experiments were conducted to verify the optical attenuation performance of microbial spores and hyphae in the mid-infrared and far-infrared spectral bands.Results demonstrate that selecting spores and hyphae can significantly reduce the average transmittance from 21.2%to 6.4%in the mid-infrared band and from 31.3%to 19.6%in the far-infrared band within three minutes.The conclusions have significant implications for the selection of high-performance microbial optical attenuation materials as well as for the rapid detection of bioaerosol types in research on climate change and the spread of pathogenic aerosols.展开更多
Aerosols of biological origins,known as bioaerosols,in addition to having the aerosol properties,have those of a living system that offers them some enabling functionalities.From science to technology,visible progress...Aerosols of biological origins,known as bioaerosols,in addition to having the aerosol properties,have those of a living system that offers them some enabling functionalities.From science to technology,visible progress around the world has been made in bioaerosol field before and especially during the COVID-19 pandemic.Here the roles of bioaerosol across various disciplines,including air quality,climate and human health are highlighted and appreciated in light of Anthropocene and one health concept.In particular,we recognized the importance of aerobiology under haze air pollution,allergenic pollen and bioaerosol involvement in infectious and inflammation-related non-communicable diseases.Future interdisciplinary studies focusing on the chemical and biological process of microorganisms in air,airborne transmission of emerging pathogens and allergens and the association between bioaerosol exposure and the development and variations of human microbiome and immune response are needed to elucidate the interactions of bioaerosols with the earth system.展开更多
Biostabilization is a cost-effective method for the beneficial utilization of sewage sludge.However,during the operation of sludge biostabilization,some microbial species could be released into the atmospheric environ...Biostabilization is a cost-effective method for the beneficial utilization of sewage sludge.However,during the operation of sludge biostabilization,some microbial species could be released into the atmospheric environment from the solid-phase of sludge easily and present a high risk to human health.This study aimed to evaluate the risk of bioaerosol during sludge biostabilization.We found a total of nine bacterial phyla,one archaeal phylum,and two fungal phyla in the bioaerosol samples.Among them,Proteobacteria,Actinobacteria,Bacteroidetes,and Ascomycota were the dominant phyla.In addition,the bioaerosolization indexes(BI)of prokaryotic phyla and flingal phyla ranged 0-45 and 0-487,respectively.Mass ilia y Pseudarthrobacter,Pseudomonas,Tremellales spp.,and Fusarium were the preferentially aerosolized microbial genera with maximum bioaerosolization indexes of 19962,10360,1802,3055,and 7398.The bioaerosol concentration during the biostabilization ranged from 160 to 1440 cell/m^(3),and we identified species such as Stenotrophomonas rhizophila and Fusarium graminerum with high bioaerosolization indexes that could be threats to human health.Euryachaeota,which belongs to archaeal phyla,had the highest biostabilization index in our study.We also found that Pseudarthrobacter was the easiest to aerosolize during the sludge biostabilization process.展开更多
The airborne microbiome is one of the relevant topics in ecology,biogeochemistiy,environment,and human health.Bioaerosols are ubiquitous air pollutants that play a vital role in the linking of the ecosystem with the b...The airborne microbiome is one of the relevant topics in ecology,biogeochemistiy,environment,and human health.Bioaerosols are ubiquitous air pollutants that play a vital role in the linking of the ecosystem with the biosphere,atmosphere,climate,and public health.However,the sources,abundance,composition,properties,and atmospheric transport mechanisms of bioaerosols are not clearly understood.To screen the effects of climate change on aerosol microbial composition and its consequences for human health,it is first essential to develop standards that recognize the existing microbial components and how they vary naturally.Bioaerosol particles can be considered an information-rich unit comprising diverse cellular and protein materials emitted by humans,animals,and plants.Hence,no single standard technique can satisfactorily extract the required information about bioaerosols.To account for these issues,metagenomics,mass spectrometry,and biological and chemical analyses can be combined with climatic studies to understand the physical and biological relationships among bioaerosols.This can be achieved by strengthening interdisciplinary teamwork in biology,chemistry,earth science,and life sciences and by sharing knowledge and expertise globally.Thus,the coupled use of various advanced analytical approaches is the ultimate key to opening up the biological treasure that lies in the environment.展开更多
Characterizations and relationships between indoor and outdoor bioaerosols were examined in an occupied office building, equipped with an air conditioning (HVAC) system, in Tempe, Arizona, USA. A two-stage microbial a...Characterizations and relationships between indoor and outdoor bioaerosols were examined in an occupied office building, equipped with an air conditioning (HVAC) system, in Tempe, Arizona, USA. A two-stage microbial air sampler was used to collect bioaerosols both inside and outside the office at fixed locations in space and at regular time intervals from August to December, 2000. Simultaneous measurements of bioaerosol, temperature, relative humidity, light intensity and wind speed were performed to explore the effects of environmental factors on bioaerosol levels. Twenty species of airborne bacteria and four genera of airborne fungi were found in our samples. The particle sizes of most outdoor and indoor bioaerosols were larger than 8.0 mm. According to the measurements of sampling days, the concentrations of outdoor bioaerosols were highest in the morning, but declined in the afternoon and reached the lowest point in the evening. The concentration peak of indoor bioaerosol (especially at the lower level) occurred in the evening, suggesting that the concentration of indoor bioaerosols follows that of outdoors, but with a time delay due to the lag associated with indoor-outdoor air exchange. With regard to the effects of four environmental factors temperature, relative humidity, light intensity, and wind speed, the relative humidity had the most pronounced influence on the outdoor bioaerosol concentrations with the number of bacteria and fungi increasing sharply on a day of high relative humidity in the desert area.展开更多
Sulfur dioxide(SO_2) and benzene homologs are frequently present in the off-gas during the process of sewage sludge drying. A laboratory scale biofilter was set up to co-treat SO_2 and o-xylene in the present study....Sulfur dioxide(SO_2) and benzene homologs are frequently present in the off-gas during the process of sewage sludge drying. A laboratory scale biofilter was set up to co-treat SO_2 and o-xylene in the present study. SO_2 and o-xylene could be removed simultaneously in a single biofilter. Their concentration ratio in the inlet stream influenced the removal efficiencies. It is worth noting that the removal of SO_2 could be enhanced when low concentrations of o-xylene were introduced into the biofilter. Pseudomonas sp., Paenibacillus sp., and Bacillus sp. were the main functional bacteria groups in the biofilter. Sulfur-oxidizing bacteria(SOB) and o-xylene-degrading bacteria(XB) thrived in the biofilter and their counts as well as their growth rate increased with the increase in amount of SO2 and o-xylene supplied. The microbial populations differed in counts and species due to the properties and components of the compounds being treated in the biofilter. The presence of mixed substrates enhanced the diversity of the microbial population. During the treatment process, bioaerosols including potentially pathogenic bacteria, e.g., Acinetobacter lwoffii and Aeromonas sp., were emitted from the biofilter. Further investigation is needed to focus on the potential hazards caused by the bioaerosols emitted from waste gas treatment bioreactors.展开更多
Bioaerosols from wastewater treatment processes are a significant subgroup of atmospheric aerosols. In the present study,airborne microorganisms generated from a wastewater treatment station(WWTS) that uses an oxida...Bioaerosols from wastewater treatment processes are a significant subgroup of atmospheric aerosols. In the present study,airborne microorganisms generated from a wastewater treatment station(WWTS) that uses an oxidation ditch process were diminished by ventilation.Conventional sampling and detection methods combined with cloning/sequencing techniques were applied to determine the groups,concentrations,size distributions,and species diversity of airborne microorganisms before and after ventilation. There were 3021 ± 537 CFU/m3 of airborne bacteria and 926 ± 132 CFU/m3 of airborne fungi present in the WWTS bioaerosol.Results showed that the ventilation reduced airborne microorganisms significantly compared to the air in the WWTS. Over 60% of airborne bacteria and airborne fungi could be reduced after4 hr of air exchange. The highest removal(92.1% for airborne bacteria and 89.1% for fungi) was achieved for 0.65–1.1 μm sized particles. The bioaerosol particles over 4.7 μm were also reduced effectively. Large particles tended to be lost by gravitational settling and small particles were generally carried away,which led to the relatively easy reduction of bioaerosol particles0.65–1.1 μm and over 4.7 μm in size. An obvious variation occurred in the structure of the bacterial communities when ventilation was applied to control the airborne microorganisms in enclosed spaces.展开更多
Pharmaceutical wastewater treatment plants(WWTPs) are thought to be a "seedbed" and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. W...Pharmaceutical wastewater treatment plants(WWTPs) are thought to be a "seedbed" and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria(GNOPB) were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance(MAR) index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.展开更多
基金supported by NSFC under Grant No.40705047Natural Science Foundation of Shandong Province(No.ZR2012DM003)
文摘Bioaerosols were collected by using a six-stage bioaerosols sampler from September 2007 to August 2008 in the coastal region of Qingdao, China. The terrestrial and marine microbes(including bacteria and fungi) were analyzed in order to understand the distribution features of bioaerosols. The results show that the average monthly concentrations of terrestrial bacteria, marine bacteria, terrestrial fungi and marine fungi are in the ranges of 80–615 CFU m-3, 91–468 CFU m-3, 76–647 CFU m-3 and 231–1959 CFU m-3, respectively. The concentrations of terrestrial bacteria, marine bacteria, terrestrial fungi, marine fungi and total microbes are the highest in each microbial category during fall, high in spring, and the lowest in the summer and winter. The bacterial particles are coarse in spring, autumn and winter. The sizes of fungal particle present the log-normal distribution in all the seasons.
文摘Bioaerosol emissions from animal feeding operation (AFO) facilities are of increasing interest due to the magnitude of the emissions and their potential health effect on local communities. There is limited information about fate and transport of AFO bioaerosol emissions. In this study, concentrations of airborne bacteria and fungi were measured at four ambient stations in four wind directions surrounding an egg production farm through winter, spring and summer using Andersen six-stage samplers. Mean concentrations of ambient bacteria and fungi ranged from 8.7 × 102 CFU m-3 to 1.3 × 103 CFU m-3 and from 2.8 × 102 CFU m-3 to 1.4 × 103 CFU m-3, respectively. Ambient bacterial concentrations were not significantly different over the seasons, while ambient fungal concentrations were the highest in summer and the lowest in winter. There were significant differences between downwind and upwind bacterial concentrations (p < 0.0001). Downwind bacterial and fungal concentrations responded differently to the influencing factors. Bacterial concentrations were quadratically correlated with wind vector (combined effects of wind speed and direction) and emission rate, were positively correlated with temperature, and were negatively correlated with solar radiation. Fungal concentrations were positively correlated with temperature, RH, and emission rate, and were negatively correlated with wind vector.
文摘The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown this intervention to be an effective mitigation strategy against viral, bacterial, and fungal elements in ambient air. There is an array of available products for generating ClO<sub>2</sub> gas however most involve the use of expensive or sophisticated technology that makes their applicability limited to specialized consumers. The purpose of this study was to determine the virucidal efficacy of three pragmatic and affordable, ClO<sub>2</sub> generating products using an aerosolized MS2 surrogate in a sealed chamber room under five different scenarios. The products tested included: Ultrashock—a ClO<sub>2</sub> releasing pod (30 ppmv), Filter Media—a ClO<sub>2</sub> impregnated zeolite media made to fit into an air blower housing (<0.01 ppmv) and Flow Stick—a smaller ClO<sub>2</sub> impregnated media filled air reactor tube (<0.01 ppmv). Testing scenarios included product deployment post MS2 bioaerosol introduction (Ultrashock and Filter Media), during MS2 bioaerosol introduction (Filter Media and Flow Stick) and prior to MS2 bioaerosol introduction (Filter Media). MS2 surface samples were collected using sterile petri-dishes and MS2 and ClO<sub>2</sub> air samples were collected from sampling ports on the outer chamber wall at 0, 90 and 180 minutes. The Ultrashock and Filter Media with air flow in the rapid sweep scenario showed the greatest reduction in air MS2 (T<sub>180</sub> = 99.992% and T<sub>180</sub> = 99.996% respectively) compared to the control (T<sub>180 </sub>= 99.6%). When compared to the control results, the filter media with air flow engaged prior to the introduction of MS2 yielded reductions of 99.87% and 99.93% in air and on surfaces respectively at T<sub>0</sub>, demonstrating the protective effect residual ClO2 has against air and surface contamination. These product formats have potential uses as remedial and preventative interventions against viral constituents in air and should undergo further evaluation to determine efficacy and human health risk.
基金supported by the National Natural Science Foundation of China (No. 41775148)the Program for New Century Excellent Talents in University (No. NCET-13-0531)the Fundamental Research Funds for the Central Universities (No. 201762006)
文摘This study was conducted to evaluate the impact of hazy and foggy weather on the bacterial communities in bioaerosols, for which samples were collected from the Qingdao coastal region on sunny, foggy, and hazy days in January and March 2013. Bacterial community compositions were determined using polymerase chain reaction denaturing gradient gel electrophoresis(PCR-DGGE). The bacterial community diversity was found to be high on foggy and hazy days, and the dominant species differed during hazy weather. The Shannon-Wiener index revealed that the bacterial community diversity of coarse particles was higher than that of fine particles in the bioaerosols. The bacterial community diversity of fine particles significantly correlated with relative humidity(RH; r^2 = 0.986). The cluster analysis results indicated that the bacterial communities on sunny days differed from those on hazy and foggy days. Compared with sunny days, the bacterial communities in the fine particles during hazy weather exhibited greater changes than those in the coarse particles. Most of the sequenced bacteria were found to be closely affiliated with uncultured bacteria. During hazy weather, members of the classes Bacilli and Gammaproteobacteria(Pseudomonas and Acinetobacter) were dominant. The DGGE analysis revealed that Proteobacteria and Firmicutes were the predominant phyla, and their relative percentages to all the measured species changed significantly on hazy days, particularly in the fine particles. Haze and fog had a significant impact on the bacterial communities in bioaerosols, and the bacterial community diversity varied on different hazy days.
基金supported by the National Natural Science Foundation of China(42293324,41961134034,and 21876002).
文摘Bioaerosols are a subset of important airborne particulates that present a substantial human health hazard due to their allergenicity and infectivity.Chemical reactions in atmospheric processes can significantly influence the health hazard presented by bioaerosols;however,few studies have summarized such alterations to bioaerosols and the mechanisms involved.In this paper,we systematically review the chemical modifications of bioaerosols and the impact on their health effects,mainly focusing on the exacerbation of allergic diseases such as asthma,rhinitis,and bronchitis.Oxidation,nitration,and oligomerization induced by hydroxyl radicals,ozone,and nitrogen dioxide are the major chemical modifications affecting bioaerosols,all of which can aggravate allergenicity mainly through immunoglobulin E pathways.Such processes can even interact with climate change including the greenhouse effect,suggesting the importance of bioaerosols in the future implementation of carbon neutralization strategies.In summary,the chemical modification of bioaerosols and the subsequent impact on health hazards indicate that the combined management of both chemical and biological components is required to mitigate the health hazards of particulate air pollution.
基金financially supported by National Natural Science Foundation of China(U1901210,42177410 and 42130611)Science and Technology Project of Guangdong Province,China(2021A0505030070)+2 种基金Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Z032)Science and Technology Program of Guangzhou(202201010684)and Young S&T Talent Training Program of Guangdong Provincial Association for S&T(GDSTA),China(2022QNRC23).
文摘The aerosol transmission of coronavirus disease in 2019,along with the spread of other respiratory diseases,caused significant loss of life and property;it impressed upon us the importance of real-time bioaerosol detection.The complexity,diversity,and large spatiotemporal variability of bioaerosols and their external/internal mixing with abiotic components pose challenges for effective online bioaerosol monitoring.Traditional methods focus on directly capturing bioaerosols before subsequent time-consuming laboratory analysis such as culture-based methods,preventing the high-resolution time-based characteristics necessary for an online approach.Through a comprehensive literature assessment,this review highlights and discusses the most commonly used real-time bioaerosol monitoring techniques and the associated commercially available monitors.Methods applied in online bioaerosol monitoring,including adenosine triphosphate bioluminescence,laser/light-induced fluorescence spectroscopy,Raman spectroscopy,and bioaerosol mass spectrometry are summarized.The working principles,characteristics,sensitivities,and efficiencies of these real-time detection methods are compared to understand their responses to known particle types and to contrast their differences.Approaches developed to analyze the substantial data sets obtained by these instruments and to overcome the limitations of current real-time bioaerosol monitoring technologies are also introduced.Finally,an outlook is proposed for future instrumentation indicating a need for highly revolutionized bioaerosol detection technologies.
基金This work was supported by the National Natural Science Foundation of China(Nos.42122058 and 41977368)the National Key R&D Program of China(2021YFF0604000)Natural Science Foundation of Hebei Province(No.E2021502046,and Fundamental Research Funds for the Central Universities(Nos.2021MS075 and 2020YJ007).
文摘The outbreak of COVID-19 and the spread of infectious pathogens through bioaerosols have once again aroused widespread concern worldwide.Isolation ward is an important place to prevent the spread of infectious bioaerosols.However,infection of health care workers(HCWs)in the isolation ward often occurs,so it is ur-gent to carry out relevant research to reduce the cross-infection between HCWs and patients.In this paper,the temporal and spatial distribution characteristics of bioaerosols under three mixed ventilation modes in a single ward were studied,namely,upper supply side return air of Case 1 and side supply and side return ventilation are Case 2 and Case 3 respectively.The results show that the removal efficiency of bioaerosol in the ventilation mode of Case 3,in which directional airflow is formed from the air supply inlet to the release source and then to the exhaust outlet,is 46.6%and 67.7%higher than that of Case 1 and Case 2,respectively.In addition,ventilation methods based on mixed theory do not guarantee good air quality in the breathing zone(1.3 m to 1.7 m)of HCWs,which may increase the inhalation risk for HCWs.It is hoped that our results can provide some useful suggestions for optimizing the airflow layout of the isolation ward,reducing the risk of cross-infection,and virus elimination.
基金This work was supported by the National Natural Science Foundation of China(Nos.U1901210,41877363,42130611,and 42177410)the Science and Technology Project of Guangdong Province,China(No.2021A0505030070)+2 种基金the Natural Science Foundation of Guangdong Province(No.2019A1515010599)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)the Young S&T Talent Training Program of Guangdong Provincial Association,China(No.2022QNRC23).
文摘Pathogenic microbes with antibiotic resistance can thrive on municipal solid waste as nutrients and be aerosolized and transported to vicinities during waste disposal processes.However,the characterization of pathogenic bioaerosols and assessment of their exposure risks are lacking.Herein,particle size,concentration,activity,antibiotic resistance,and pathogenicity of airborne microorganisms were assessed in different sectors of a typical landfill.Results showed that active sector in downwind direction has the highest bioaerosol level(1234 CFU/m3),while residential area has the highest activity(14.82 mg/L).Botanical deodorizer from mist cannon can effectively remove bioaerosol.Most bioaerosols can be inhaled into respiratory system till bronchi with sizes ranging from 2.1−3.3 and 3.3−4.7μm.Pathogenic bacteria(Bacilli,Bacillus,and Burkholderia-Paraburkholderia)and allergenic fungi(Aspergillus,Cladosporium,and Curvularia)prevailed in landfill.Although high abundance of microbial volatile organic compounds(mVOCs)producing bioaerosols were detected,these mVOCs contributed little to odor issues in landfill.Notably,surrounding areas have higher levels of antibiotic-resistance genes(ARGs)than inner landfill with tetC,acrB,acrF,mdtF,and bacA as dominant ones.Most ARGs were significantly correlated with bacterial community,while environmental parameters mainly influenced fungal prevalence.These findings can assist in reducing and preventing respiratory allergy or infection risks in occupational environments relating to waste management.
文摘Bioaerosols exhibit significant broadband extinction performance and have vital impacts on climate change,optical detection,communication,disease transmission,and the development of optical attenuation materials.Microbial spores and microbial hyphae represent two primary forms of bioaerosol particles.However,a comprehensive investigation and comparison of their optical properties have not been conducted yet.In this paper,the spectra of spores and hyphae were tested,and the absorption peaks,component contents,and protein structural differences were compared.Accurate structural models were established,and the optical attenuation parameters were calculated.Aerosol chamber experiments were conducted to verify the optical attenuation performance of microbial spores and hyphae in the mid-infrared and far-infrared spectral bands.Results demonstrate that selecting spores and hyphae can significantly reduce the average transmittance from 21.2%to 6.4%in the mid-infrared band and from 31.3%to 19.6%in the far-infrared band within three minutes.The conclusions have significant implications for the selection of high-performance microbial optical attenuation materials as well as for the rapid detection of bioaerosol types in research on climate change and the spread of pathogenic aerosols.
基金F.Shen is supported by the National Natural Science Foundation of China(NSFC)(42075117,41807306)Young Talent Program of Beihang University(KG16137601)+3 种基金Ministry of Education program(30800002022133001)M.Yao is supported by the National Natural Science Foundation of China(NSFC)(22221004,92043302)the NSFC Distinguished Young Scholars Fund(21725701)a grant from Guangzhou National Laboratory(EKPG21-02).
文摘Aerosols of biological origins,known as bioaerosols,in addition to having the aerosol properties,have those of a living system that offers them some enabling functionalities.From science to technology,visible progress around the world has been made in bioaerosol field before and especially during the COVID-19 pandemic.Here the roles of bioaerosol across various disciplines,including air quality,climate and human health are highlighted and appreciated in light of Anthropocene and one health concept.In particular,we recognized the importance of aerobiology under haze air pollution,allergenic pollen and bioaerosol involvement in infectious and inflammation-related non-communicable diseases.Future interdisciplinary studies focusing on the chemical and biological process of microorganisms in air,airborne transmission of emerging pathogens and allergens and the association between bioaerosol exposure and the development and variations of human microbiome and immune response are needed to elucidate the interactions of bioaerosols with the earth system.
基金the National Key R&D Program of China(No.2018YFD-1100600).
文摘Biostabilization is a cost-effective method for the beneficial utilization of sewage sludge.However,during the operation of sludge biostabilization,some microbial species could be released into the atmospheric environment from the solid-phase of sludge easily and present a high risk to human health.This study aimed to evaluate the risk of bioaerosol during sludge biostabilization.We found a total of nine bacterial phyla,one archaeal phylum,and two fungal phyla in the bioaerosol samples.Among them,Proteobacteria,Actinobacteria,Bacteroidetes,and Ascomycota were the dominant phyla.In addition,the bioaerosolization indexes(BI)of prokaryotic phyla and flingal phyla ranged 0-45 and 0-487,respectively.Mass ilia y Pseudarthrobacter,Pseudomonas,Tremellales spp.,and Fusarium were the preferentially aerosolized microbial genera with maximum bioaerosolization indexes of 19962,10360,1802,3055,and 7398.The bioaerosol concentration during the biostabilization ranged from 160 to 1440 cell/m^(3),and we identified species such as Stenotrophomonas rhizophila and Fusarium graminerum with high bioaerosolization indexes that could be threats to human health.Euryachaeota,which belongs to archaeal phyla,had the highest biostabilization index in our study.We also found that Pseudarthrobacter was the easiest to aerosolize during the sludge biostabilization process.
基金This work was supported by China Postdoctoral Science Funding(Grant No.2019M663859)The second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0605).
文摘The airborne microbiome is one of the relevant topics in ecology,biogeochemistiy,environment,and human health.Bioaerosols are ubiquitous air pollutants that play a vital role in the linking of the ecosystem with the biosphere,atmosphere,climate,and public health.However,the sources,abundance,composition,properties,and atmospheric transport mechanisms of bioaerosols are not clearly understood.To screen the effects of climate change on aerosol microbial composition and its consequences for human health,it is first essential to develop standards that recognize the existing microbial components and how they vary naturally.Bioaerosol particles can be considered an information-rich unit comprising diverse cellular and protein materials emitted by humans,animals,and plants.Hence,no single standard technique can satisfactorily extract the required information about bioaerosols.To account for these issues,metagenomics,mass spectrometry,and biological and chemical analyses can be combined with climatic studies to understand the physical and biological relationships among bioaerosols.This can be achieved by strengthening interdisciplinary teamwork in biology,chemistry,earth science,and life sciences and by sharing knowledge and expertise globally.Thus,the coupled use of various advanced analytical approaches is the ultimate key to opening up the biological treasure that lies in the environment.
文摘Characterizations and relationships between indoor and outdoor bioaerosols were examined in an occupied office building, equipped with an air conditioning (HVAC) system, in Tempe, Arizona, USA. A two-stage microbial air sampler was used to collect bioaerosols both inside and outside the office at fixed locations in space and at regular time intervals from August to December, 2000. Simultaneous measurements of bioaerosol, temperature, relative humidity, light intensity and wind speed were performed to explore the effects of environmental factors on bioaerosol levels. Twenty species of airborne bacteria and four genera of airborne fungi were found in our samples. The particle sizes of most outdoor and indoor bioaerosols were larger than 8.0 mm. According to the measurements of sampling days, the concentrations of outdoor bioaerosols were highest in the morning, but declined in the afternoon and reached the lowest point in the evening. The concentration peak of indoor bioaerosol (especially at the lower level) occurred in the evening, suggesting that the concentration of indoor bioaerosols follows that of outdoors, but with a time delay due to the lag associated with indoor-outdoor air exchange. With regard to the effects of four environmental factors temperature, relative humidity, light intensity, and wind speed, the relative humidity had the most pronounced influence on the outdoor bioaerosol concentrations with the number of bacteria and fungi increasing sharply on a day of high relative humidity in the desert area.
基金financially supported by the National Natural Science Foundation of China(Nos.51478456 and 51308527)
文摘Sulfur dioxide(SO_2) and benzene homologs are frequently present in the off-gas during the process of sewage sludge drying. A laboratory scale biofilter was set up to co-treat SO_2 and o-xylene in the present study. SO_2 and o-xylene could be removed simultaneously in a single biofilter. Their concentration ratio in the inlet stream influenced the removal efficiencies. It is worth noting that the removal of SO_2 could be enhanced when low concentrations of o-xylene were introduced into the biofilter. Pseudomonas sp., Paenibacillus sp., and Bacillus sp. were the main functional bacteria groups in the biofilter. Sulfur-oxidizing bacteria(SOB) and o-xylene-degrading bacteria(XB) thrived in the biofilter and their counts as well as their growth rate increased with the increase in amount of SO2 and o-xylene supplied. The microbial populations differed in counts and species due to the properties and components of the compounds being treated in the biofilter. The presence of mixed substrates enhanced the diversity of the microbial population. During the treatment process, bioaerosols including potentially pathogenic bacteria, e.g., Acinetobacter lwoffii and Aeromonas sp., were emitted from the biofilter. Further investigation is needed to focus on the potential hazards caused by the bioaerosols emitted from waste gas treatment bioreactors.
基金financially supported by the National Key Technology R & D Program of China (No.2012BAC13B04-08)the National Natural Science Foundation of China (Nos.51178451 and 51221892)
文摘Bioaerosols from wastewater treatment processes are a significant subgroup of atmospheric aerosols. In the present study,airborne microorganisms generated from a wastewater treatment station(WWTS) that uses an oxidation ditch process were diminished by ventilation.Conventional sampling and detection methods combined with cloning/sequencing techniques were applied to determine the groups,concentrations,size distributions,and species diversity of airborne microorganisms before and after ventilation. There were 3021 ± 537 CFU/m3 of airborne bacteria and 926 ± 132 CFU/m3 of airborne fungi present in the WWTS bioaerosol.Results showed that the ventilation reduced airborne microorganisms significantly compared to the air in the WWTS. Over 60% of airborne bacteria and airborne fungi could be reduced after4 hr of air exchange. The highest removal(92.1% for airborne bacteria and 89.1% for fungi) was achieved for 0.65–1.1 μm sized particles. The bioaerosol particles over 4.7 μm were also reduced effectively. Large particles tended to be lost by gravitational settling and small particles were generally carried away,which led to the relatively easy reduction of bioaerosol particles0.65–1.1 μm and over 4.7 μm in size. An obvious variation occurred in the structure of the bacterial communities when ventilation was applied to control the airborne microorganisms in enclosed spaces.
基金supported by the National Natural Science Foundation of China(No.51478237)
文摘Pharmaceutical wastewater treatment plants(WWTPs) are thought to be a "seedbed" and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria(GNOPB) were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance(MAR) index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.