There are limited biosecurity measures directed at preventing airborne transmission of viruses in swine.The effectiveness of dust mitigation strategies such as oil sprinkling,to decrease risk of airborne virus transmi...There are limited biosecurity measures directed at preventing airborne transmission of viruses in swine.The effectiveness of dust mitigation strategies such as oil sprinkling,to decrease risk of airborne virus transmission are unknown.Metagenomics and qPCR for common fecal viruses were used to hunt for a ubiquitous virus to serve as a proxy when evaluating the efficiency of mitigation strategies against airborne viral infectious agents.Air particles were collected from swine buildings using high-volume air samplers.Extracted DNA and RNA were used to perform specific RT-qPCR and qPCR and analyzed by highthroughput sequencing.Porcine astroviruses group 2 were common(from 102 to 105 genomic copies per cubic meter of air or gc/m^(3),93%positivity)while no norovirus genogroup II was recovered from air samples.Porcine torque teno sus virus were detected by qPCR in low concentrations(from 101 to 102 gc/m^(3),47%positivity).Among the identified viral families by metagenomics analysis,Herelleviridae,Microviridae,Myoviridae,Podoviridae,and Siphoviridae were dominant.The phage vB_AviM_AVP of Aerococcus was present in all air samples and a newly designed qPCR revealed between 101 and 105 gc/m^(3) among the samples taken for the present study(97%positivity)and banked samples from5-and 15-year old studies(89%positivity).According to the present study,both the porcine astrovirus group 2 and the phage vB_AviM_AVP of Aerococcus could be proxy for airborne viruses of swine buildings.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
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
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
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 significantly affect atmospheric processes while they undergo long-range vertical and horizontal transport and influence atmospheric chemistry and physics and climate change.Accumulating evidence suggests ...Bioaerosols significantly affect atmospheric processes while they undergo long-range vertical and horizontal transport and influence atmospheric chemistry and physics and climate change.Accumulating evidence suggests that exposure to bioaerosols may cause adverse health effects,including severe disease.Studies of bioaerosols have primarily focused on their chemical composition and largely neglected their biological composition and the negative effects of biological composition on ecosystems and human health.Here,current molecular methods for the identification,quantification,and distribution of bioaerosol agents are reviewed.Modern developments in environmental microbiology technology would be favorable in elucidation of microbial temporal and spatial distribution in the atmosphere at high resolution.In addition,these provide additional supports for growing evidence that microbial diversity or composition in the bioaerosol is an indispensable environmental aspect linking with public health.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
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
Microbial diversity and abundance in bioaerosols of a coal mine were analyzed based on 454 pyrosequencing and real-time polymerase chain reaction（PCR）. A total of 37,191 high quality sequences were obtained and coul...Microbial diversity and abundance in bioaerosols of a coal mine were analyzed based on 454 pyrosequencing and real-time polymerase chain reaction（PCR）. A total of 37,191 high quality sequences were obtained and could be classified into 531, 1730 and 448 operational taxonomic units respectively for archaea, bacteria and fungi at 97% sequence similarity. The Shannon diversity index for archaea, bacteria and fungi was respectively 4.71, 6.29 and 3.86, indicating a high diversity in coal mine bioaerosols. Crenarchaeota, Proteobacteria and Ascomycota were the dominant phyla for archaea, bacteria and fungi, respectively. The concentrations of total archaea, bacteria and fungi were 1.44 × 10^8, 1.02 × 10^8 and 9.60 × 10^4cells/m^3, respectively.Methanotrophs observed in bioaerosols suggested possible methane oxidation in the coal mine. The identified potential pathogens to coal miners, such as Acinetobacter schindleri,Aeromonas cavernicola, Alternaria alternata, Aspergillus penicillioides, Cladosporium cladosporioides,and Penicillium brevicompactum were also observed. This was the first investigation of microbial diversity and abundance in coal mine bioaerosols. The investigation of microbial communities would be favorable in promoting the progress of methane control based on microbial technique and concern on coal miners＇ health.展开更多
This study aimed to evaluate the suitability of two bioaerosol generation systems（dry and wet generation） for the aerosolization of microorganisms isolated from the International Space Station, and to calibrate the ...This study aimed to evaluate the suitability of two bioaerosol generation systems（dry and wet generation） for the aerosolization of microorganisms isolated from the International Space Station, and to calibrate the produced bioaerosols to fulfill the requirements of computational fluid dynamics model（CFD） validation. Concentration, stability, size distribution, agglomeration of generated bioaerosol and deposition of bioaerosols were analyzed. In addition, the dispersion of non-viable particles in the air was studied.Experiments proved that wet generation from microbial suspensions could be used for the production of well-calibrated and stabile bioaerosols for model validation. For the simulation of the natural release of fungal spores, a dry generation method should be used. This study showed that the used CFD model simulated the spread of non-viable particles fairly well. The mathematical deposition model by Lai and Nazaroff could be used to estimate the deposition velocities of bioaerosols on surfaces, although it somewhat underestimated the measured deposition velocities.展开更多
Objective To develop a new sampling medium for detecting of bioaerosols. Methods The sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditio...Objective To develop a new sampling medium for detecting of bioaerosols. Methods The sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditions, preliminary applications were performed using AGI-10 and high volume sampler. Results The average recovery rates were raised to 24.7%, 58.2%, 40.5%, 44.1%, 20.5%, and 15.4%, respectively in six consecutive experiments under static condition for 60 min at room temperature. Four kinds of sampling media were singled out after static experiments, which were referred to as “samplutions” PD1, PX2, TD1, and TX2, respectively. Under the active condition, the protective efficacy of PD1, PX2, TD1, and TX2 was 226% (153/47), 553% (111/17), 150% (120/48), and 268% (419/114), respectively. Conclusion The samplutions have some effects on the subsequent nucleic acid detection, which could be avoided by employing standard nucleic acid extraction procedure. The newly developed samplution can be applied to the detection of bioaerosols.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
Bioaerosols,particles of biological origins suspended in the air,are the major means for pathogens to spread and infect humans through the air(Morawska et al.,2021;Xu et al.,2011).This has posed a serious threat to pu...Bioaerosols,particles of biological origins suspended in the air,are the major means for pathogens to spread and infect humans through the air(Morawska et al.,2021;Xu et al.,2011).This has posed a serious threat to public health,e.g.,the COVID-19 pandemic(Ma et al.,2021;Prather et al.,2020).Early,rapid,and accurate detection of bioaerosols is crucial for controlling the spread of pathogens,thus preventing outbreaks of epidemics,and ensuring biological safety.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
Recent pandemic outbreak of the corona-virus disease 2019(COVID-19)has raised widespread concerns about the importance of the bioaerosols.They are atmospheric aerosol particles of biological origins,mainly including b...Recent pandemic outbreak of the corona-virus disease 2019(COVID-19)has raised widespread concerns about the importance of the bioaerosols.They are atmospheric aerosol particles of biological origins,mainly including bacteria,fungi,viruses,pollen,and cell debris.Bioaerosols can exert a substantial impact on ecosystems,climate change,air quality,and public health.Here,we review several relevant topics on bioaerosols,including sampling and detection techniques,characterization,effects on health and air quality,and control methods.However,very few studies have focused on the source apportionment and transport of bioaerosols.The knowledge of the sources and transport pathways of bioaerosols is essential for a comprehensive understanding of the role microorganisms play in the atmosphere and control the spread of epidemic diseases associated with them.Therefore,this review comprehensively summarizes the up to date progress on the source characteristics,source identification,and diffusion and transport process of bioaerosols.We intercompare three types of diffusion and transport models,with a special emphasis on a widely used mathematical model.This review also highlights the main factors affecting the source emission and transport process,such as biogeographic regions,land-use types,and environmental factors.Finally,this review outlines future perspectives on bioaerosols.展开更多
Bioaerosols are defined as airbome particles(0.05-100 um in size)of biological origin.They are considered potentially harmful to human health as they can contain pathogens such as bacteria,fungi,and viruses.This revie...Bioaerosols are defined as airbome particles(0.05-100 um in size)of biological origin.They are considered potentially harmful to human health as they can contain pathogens such as bacteria,fungi,and viruses.This review summarizes the most recent research on the health risks of bioaerosols emitted from wastewater treatment plants(WWTPs)in order to improve the control of such bioaerosols.The concentration and size distribution of WWTP bioaerosols;their major emission sources,composition,and health risks;and considerations for future research are discussed.The major themes and findings in the literature are as follows:the major emission sources of WWTP bioaerosols include screen rooms,sludge-dewatering rooms,and acration tanks;the bioaerosol concentrations in screen and sludge-dewatering rooms are higher than those outdoors.WWTP bioacrosols contain a variety of potentially pathogenic bacteria,fungi,antibiotic resistance genes,viruses,endotoxins,and toxic metal(loid)s.These potentially,pathogenic substances spread with the bioaerosols,thereby posing health risks to workers and residents in and around the WWTP.Inhalation has been identified as the main exposure route,and children are at a higher risk of this than adults.Future studies should identify emerging contaminants,establish health risk assessments,and develop prevention and control systems.展开更多
A novel three-stage integrated biofilter(TSIBF)composed of acidophilic bacteria reaction segment(ABRS),fungal reaction segment(FRS)and heterotrophic bacteria reaction segment(HBRS)was constructed for the treatment of ...A novel three-stage integrated biofilter(TSIBF)composed of acidophilic bacteria reaction segment(ABRS),fungal reaction segment(FRS)and heterotrophic bacteria reaction segment(HBRS)was constructed for the treatment of odors and volatile organic compounds(VOCs)from municipal solid waste(MSW)comprehensive treatment plants.The performance,counts of predominant microorganisms,and bioaerosol emissions of a flill-scale TSIBF system were studied.High and stable removal efficiencies of hydrogen sulfide,ammonia and VOCs could be achieved with the TSIBF system,and the emissions of culturable heterotrophic bacteria,fungi and acidophilic sulfur bacteria were relatively low.The removal efficiencies of different odors and VOCs,emissions of culturable microorganisms,and types of predominant microorganisms were different in the ABRS,FRS and HBRS due to the differences in reaction conditions and mass transfer in each segment.The emissions of bioaerosols from the TSIBF depended on the capture of microorganisms and their volatilization from the packing.The rational segmentation,filling of high-density packings and the accumulation of the predominant functional microorganisms in each segment enhanced the capture effect of the bioaerosols,thus reducing the emissions of microorganisms from the bioreactor.展开更多
文摘There are limited biosecurity measures directed at preventing airborne transmission of viruses in swine.The effectiveness of dust mitigation strategies such as oil sprinkling,to decrease risk of airborne virus transmission are unknown.Metagenomics and qPCR for common fecal viruses were used to hunt for a ubiquitous virus to serve as a proxy when evaluating the efficiency of mitigation strategies against airborne viral infectious agents.Air particles were collected from swine buildings using high-volume air samplers.Extracted DNA and RNA were used to perform specific RT-qPCR and qPCR and analyzed by highthroughput sequencing.Porcine astroviruses group 2 were common(from 102 to 105 genomic copies per cubic meter of air or gc/m^(3),93%positivity)while no norovirus genogroup II was recovered from air samples.Porcine torque teno sus virus were detected by qPCR in low concentrations(from 101 to 102 gc/m^(3),47%positivity).Among the identified viral families by metagenomics analysis,Herelleviridae,Microviridae,Myoviridae,Podoviridae,and Siphoviridae were dominant.The phage vB_AviM_AVP of Aerococcus was present in all air samples and a newly designed qPCR revealed between 101 and 105 gc/m^(3) among the samples taken for the present study(97%positivity)and banked samples from5-and 15-year old studies(89%positivity).According to the present study,both the porcine astrovirus group 2 and the phage vB_AviM_AVP of Aerococcus could be proxy for airborne viruses of swine buildings.
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.
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 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.
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.
基金supported by the National Research Foundation(NRF)of Korea via a grant(No.2011-0030040)funded by the Korea government(MSIP)GAIA project from Korea Ministry of Environment for the performance of this study
文摘Bioaerosols significantly affect atmospheric processes while they undergo long-range vertical and horizontal transport and influence atmospheric chemistry and physics and climate change.Accumulating evidence suggests that exposure to bioaerosols may cause adverse health effects,including severe disease.Studies of bioaerosols have primarily focused on their chemical composition and largely neglected their biological composition and the negative effects of biological composition on ecosystems and human health.Here,current molecular methods for the identification,quantification,and distribution of bioaerosol agents are reviewed.Modern developments in environmental microbiology technology would be favorable in elucidation of microbial temporal and spatial distribution in the atmosphere at high resolution.In addition,these provide additional supports for growing evidence that microbial diversity or composition in the bioaerosol is an indispensable environmental aspect linking with public health.
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.
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.
基金supported by the National Natural Science Foundation of China (No. 21177153)the National Science and Technology Major Project, China (No. 2012ZX05060-005)the Key Research Program of the Chinese Academy of Sciences (No. KZZD-EW-09-1)
文摘Microbial diversity and abundance in bioaerosols of a coal mine were analyzed based on 454 pyrosequencing and real-time polymerase chain reaction（PCR）. A total of 37,191 high quality sequences were obtained and could be classified into 531, 1730 and 448 operational taxonomic units respectively for archaea, bacteria and fungi at 97% sequence similarity. The Shannon diversity index for archaea, bacteria and fungi was respectively 4.71, 6.29 and 3.86, indicating a high diversity in coal mine bioaerosols. Crenarchaeota, Proteobacteria and Ascomycota were the dominant phyla for archaea, bacteria and fungi, respectively. The concentrations of total archaea, bacteria and fungi were 1.44 × 10^8, 1.02 × 10^8 and 9.60 × 10^4cells/m^3, respectively.Methanotrophs observed in bioaerosols suggested possible methane oxidation in the coal mine. The identified potential pathogens to coal miners, such as Acinetobacter schindleri,Aeromonas cavernicola, Alternaria alternata, Aspergillus penicillioides, Cladosporium cladosporioides,and Penicillium brevicompactum were also observed. This was the first investigation of microbial diversity and abundance in coal mine bioaerosols. The investigation of microbial communities would be favorable in promoting the progress of methane control based on microbial technique and concern on coal miners＇ health.
基金funding from the European Union Seventh Framework Programme(FP/2007-2013)grant agreement number 263076 within the BIOSMHARS Project(BIO contamination Specific Modeling in Habitats Related to Space)
文摘This study aimed to evaluate the suitability of two bioaerosol generation systems（dry and wet generation） for the aerosolization of microorganisms isolated from the International Space Station, and to calibrate the produced bioaerosols to fulfill the requirements of computational fluid dynamics model（CFD） validation. Concentration, stability, size distribution, agglomeration of generated bioaerosol and deposition of bioaerosols were analyzed. In addition, the dispersion of non-viable particles in the air was studied.Experiments proved that wet generation from microbial suspensions could be used for the production of well-calibrated and stabile bioaerosols for model validation. For the simulation of the natural release of fungal spores, a dry generation method should be used. This study showed that the used CFD model simulated the spread of non-viable particles fairly well. The mathematical deposition model by Lai and Nazaroff could be used to estimate the deposition velocities of bioaerosols on surfaces, although it somewhat underestimated the measured deposition velocities.
文摘Objective To develop a new sampling medium for detecting of bioaerosols. Methods The sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditions, preliminary applications were performed using AGI-10 and high volume sampler. Results The average recovery rates were raised to 24.7%, 58.2%, 40.5%, 44.1%, 20.5%, and 15.4%, respectively in six consecutive experiments under static condition for 60 min at room temperature. Four kinds of sampling media were singled out after static experiments, which were referred to as “samplutions” PD1, PX2, TD1, and TX2, respectively. Under the active condition, the protective efficacy of PD1, PX2, TD1, and TX2 was 226% (153/47), 553% (111/17), 150% (120/48), and 268% (419/114), respectively. Conclusion The samplutions have some effects on the subsequent nucleic acid detection, which could be avoided by employing standard nucleic acid extraction procedure. The newly developed samplution can be applied to the detection of bioaerosols.
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 Guangzhou National Laboratory grant(GZNL2024A01028)the National Natural Science Foundation of China(NSFC)Creative Group Funds(22221004)。
文摘Bioaerosols,particles of biological origins suspended in the air,are the major means for pathogens to spread and infect humans through the air(Morawska et al.,2021;Xu et al.,2011).This has posed a serious threat to public health,e.g.,the COVID-19 pandemic(Ma et al.,2021;Prather et al.,2020).Early,rapid,and accurate detection of bioaerosols is crucial for controlling the spread of pathogens,thus preventing outbreaks of epidemics,and ensuring biological safety.
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the National Natural Science Foundation of China(Grant No.51478045)the Fund Project of Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control(GKECHRC-07)+1 种基金the Fund Project of Shaanxi Key Laboratory of Land Consolidation(2018-ZD04)the Opening Fund of State Key Laboratory of Green Building in Western China(LSKF202008).
文摘Recent pandemic outbreak of the corona-virus disease 2019(COVID-19)has raised widespread concerns about the importance of the bioaerosols.They are atmospheric aerosol particles of biological origins,mainly including bacteria,fungi,viruses,pollen,and cell debris.Bioaerosols can exert a substantial impact on ecosystems,climate change,air quality,and public health.Here,we review several relevant topics on bioaerosols,including sampling and detection techniques,characterization,effects on health and air quality,and control methods.However,very few studies have focused on the source apportionment and transport of bioaerosols.The knowledge of the sources and transport pathways of bioaerosols is essential for a comprehensive understanding of the role microorganisms play in the atmosphere and control the spread of epidemic diseases associated with them.Therefore,this review comprehensively summarizes the up to date progress on the source characteristics,source identification,and diffusion and transport process of bioaerosols.We intercompare three types of diffusion and transport models,with a special emphasis on a widely used mathematical model.This review also highlights the main factors affecting the source emission and transport process,such as biogeographic regions,land-use types,and environmental factors.Finally,this review outlines future perspectives on bioaerosols.
基金the Special Fund from the State Key Joint Laboratory of Environment Simulation and Pollution Control(Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences)(No.19Z03ESPCR)the National Natural Science Foundation of China(Grant Nos.51478456 and 41961134033).
文摘Bioaerosols are defined as airbome particles(0.05-100 um in size)of biological origin.They are considered potentially harmful to human health as they can contain pathogens such as bacteria,fungi,and viruses.This review summarizes the most recent research on the health risks of bioaerosols emitted from wastewater treatment plants(WWTPs)in order to improve the control of such bioaerosols.The concentration and size distribution of WWTP bioaerosols;their major emission sources,composition,and health risks;and considerations for future research are discussed.The major themes and findings in the literature are as follows:the major emission sources of WWTP bioaerosols include screen rooms,sludge-dewatering rooms,and acration tanks;the bioaerosol concentrations in screen and sludge-dewatering rooms are higher than those outdoors.WWTP bioacrosols contain a variety of potentially pathogenic bacteria,fungi,antibiotic resistance genes,viruses,endotoxins,and toxic metal(loid)s.These potentially,pathogenic substances spread with the bioaerosols,thereby posing health risks to workers and residents in and around the WWTP.Inhalation has been identified as the main exposure route,and children are at a higher risk of this than adults.Future studies should identify emerging contaminants,establish health risk assessments,and develop prevention and control systems.
基金by the key Projects in the National Science&Technology Pillar Program of China during the Twelfth Five-Year Plan Period(No.2013BAC25B00-004).
文摘A novel three-stage integrated biofilter(TSIBF)composed of acidophilic bacteria reaction segment(ABRS),fungal reaction segment(FRS)and heterotrophic bacteria reaction segment(HBRS)was constructed for the treatment of odors and volatile organic compounds(VOCs)from municipal solid waste(MSW)comprehensive treatment plants.The performance,counts of predominant microorganisms,and bioaerosol emissions of a flill-scale TSIBF system were studied.High and stable removal efficiencies of hydrogen sulfide,ammonia and VOCs could be achieved with the TSIBF system,and the emissions of culturable heterotrophic bacteria,fungi and acidophilic sulfur bacteria were relatively low.The removal efficiencies of different odors and VOCs,emissions of culturable microorganisms,and types of predominant microorganisms were different in the ABRS,FRS and HBRS due to the differences in reaction conditions and mass transfer in each segment.The emissions of bioaerosols from the TSIBF depended on the capture of microorganisms and their volatilization from the packing.The rational segmentation,filling of high-density packings and the accumulation of the predominant functional microorganisms in each segment enhanced the capture effect of the bioaerosols,thus reducing the emissions of microorganisms from the bioreactor.
