Recent progress in online detection methods of bioaerosols

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.

The exposure risks associated with pathogens and antibiotic resistance genes in bioaerosol from municipal landfill and surrounding area

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.