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Greenhalgh T, MacIntyre CR, Baker MG, Bhattacharjee S, Chughtai AA, Fisman D, Kunasekaran M, Kvalsvig A, Lupton D, Oliver M, Tawfiq E, Ungrin M, Vipond J. Masks and respirators for prevention of respiratory infections: a state of the science review. Clin Microbiol Rev 2024; 37:e0012423. [PMID: 38775460 DOI: 10.1128/cmr.00124-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024] Open
Abstract
SUMMARYThis narrative review and meta-analysis summarizes a broad evidence base on the benefits-and also the practicalities, disbenefits, harms and personal, sociocultural and environmental impacts-of masks and masking. Our synthesis of evidence from over 100 published reviews and selected primary studies, including re-analyzing contested meta-analyses of key clinical trials, produced seven key findings. First, there is strong and consistent evidence for airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Second, masks are, if correctly and consistently worn, effective in reducing transmission of respiratory diseases and show a dose-response effect. Third, respirators are significantly more effective than medical or cloth masks. Fourth, mask mandates are, overall, effective in reducing community transmission of respiratory pathogens. Fifth, masks are important sociocultural symbols; non-adherence to masking is sometimes linked to political and ideological beliefs and to widely circulated mis- or disinformation. Sixth, while there is much evidence that masks are not generally harmful to the general population, masking may be relatively contraindicated in individuals with certain medical conditions, who may require exemption. Furthermore, certain groups (notably D/deaf people) are disadvantaged when others are masked. Finally, there are risks to the environment from single-use masks and respirators. We propose an agenda for future research, including improved characterization of the situations in which masking should be recommended or mandated; attention to comfort and acceptability; generalized and disability-focused communication support in settings where masks are worn; and development and testing of novel materials and designs for improved filtration, breathability, and environmental impact.
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Affiliation(s)
- Trisha Greenhalgh
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - C Raina MacIntyre
- Biosecurity Program, The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Michael G Baker
- Department of Public Health, University of Otago, Wellington, New Zealand
| | - Shovon Bhattacharjee
- Biosecurity Program, The Kirby Institute, University of New South Wales, Sydney, Australia
- School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia
| | - Abrar A Chughtai
- School of Population Health, University of New South Wales, Sydney, Australia
| | - David Fisman
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Mohana Kunasekaran
- Biosecurity Program, The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Amanda Kvalsvig
- Department of Public Health, University of Otago, Wellington, New Zealand
| | - Deborah Lupton
- Centre for Social Research in Health and Social Policy Research Centre, Faculty of Arts, Design and Architecture, University of New South Wales, Sydney, Australia
| | - Matt Oliver
- Professional Standards Advocate, Edmonton, Canada
| | - Essa Tawfiq
- Biosecurity Program, The Kirby Institute, University of New South Wales, Sydney, Australia
| | - Mark Ungrin
- Faculty of Veterinary Medicine; Department of Biomedical Engineering, Schulich School of Engineering; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Joe Vipond
- Department of Emergency Medicine, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Gibbons AM, Ohno PE. Relative Humidity-Dependent Phase Transitions in Submicron Respiratory Aerosols. J Phys Chem A 2024; 128:3015-3023. [PMID: 38593044 DOI: 10.1021/acs.jpca.4c00691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Respiratory viruses, such as influenza and severe acute respiratory syndrome coronavirus 2, represent a substantial public health burden and are largely transmitted through respiratory droplets and aerosols. Environmental factors such as relative humidity (RH) and temperature impact virus transmission rates, and a precise mechanistic understanding of the connection between these environmental factors and virus transmission would improve efforts to mitigate respiratory disease transmission. Previous studies on supermicrometer particles observed RH-dependent phase transitions and linked particle phase state to virus viability. Phase transitions in atmospheric aerosols are dependent on size in the submicrometer range, and actual respiratory particles are expelled over a large size range, including submicrometer aerosols that can transmit diseases over long distances. Here, we directly investigated the phase transitions of submicrometer model respiratory aerosols. A probe molecule, Nile red, was added to particle systems including multiple mucin/salt mixtures, a growth medium, and simulated lung fluid. For each system, the polarity-dependent fluorescence emission was measured following RH conditioning. Notably, the fluorescence measurements of mucin/NaCl and Dulbecco's modified Eagle's medium particles indicated that liquid-liquid phase separation (LLPS) also occurs in submicron particles, suggesting that LLPS can also impact the viability of viruses in submicron particles and thus affect aerosol virus transmission. Furthermore, the utility of fluorescence-based measurements to study submicrometer respiratory particle physicochemical properties in situ is demonstrated.
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Affiliation(s)
- Angel M Gibbons
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Paul E Ohno
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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3
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Wolkoff P. Indoor air humidity revisited: Impact on acute symptoms, work productivity, and risk of influenza and COVID-19 infection. Int J Hyg Environ Health 2024; 256:114313. [PMID: 38154254 DOI: 10.1016/j.ijheh.2023.114313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/30/2023] [Accepted: 12/18/2023] [Indexed: 12/30/2023]
Abstract
Recent epidemiological and experimental findings reconfirm that low indoor air humidity (dry air) increases the prevalence of acute eye and airway symptoms in offices, result in lower mucociliary clearance in the airways, less efficient immune defense, and deteriorate the work productivity. New epidemiological and experimental research also support that the environmental conditions for the risk of infection of influenza and COVID-19 virus is lowest in the Goldilocks zone of 40-60% relative humidity (RH) by decrease of the airways' susceptibility, which can be elevated by particle exposure. Furthermore, low RH increases the generation of infectious virus laden aerosols exhaled from infected people. In general, elevation of the indoor air humidity from dry air increases the health of the airways concomitantly with lower viability of infectious virus. Thus, the negative effects of ventilation with dry outdoor air (low absolute air humidity) should be assessed according to 1) weakened health and functionality of the airways, 2) increased viability and possible increased transmissibility of infectious virus, and 3) evaporation of virus containing droplets to dry out to droplet nuclei (also possible at high room temperature), which increases their floating time in the indoor air. The removal of acid-containing ambient aerosols from the indoor air by filtration increases pH, viability of infectious viruses, and the risk of infection, which synergistically may further increase by particle exposure. Thus, the dilution of indoor air pollutants and virus aerosols by dry outdoor air ventilation should be assessed and compared with the beneficial health effects by control of the center zone of 40-60% RH, an essential factor for optimal functionality of the airways, and with the additional positive impact on acute symptoms, work productivity, and reduced risk of infection.
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Affiliation(s)
- Peder Wolkoff
- National Research Centre for the Working Environment, Denmark.
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Obeid S, White P, Rosati Rowe J, Ilacqua V, Rawat MS, Ferro AR, Ahmadi G. Airborne respiratory aerosol transport and deposition in a two-person office using a novel diffusion-based numerical model. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2024; 34:356-375. [PMID: 37337048 DOI: 10.1038/s41370-023-00546-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 03/24/2023] [Accepted: 03/30/2023] [Indexed: 06/21/2023]
Abstract
BACKGROUND The COVID-19 pandemic was caused by the SARS-CoV-2 coronaviruses transmitted mainly through exposure to airborne respiratory droplets and aerosols carrying the virus. OBJECTIVE To assess the transport and dispersion of respiratory aerosols containing the SARS-CoV-2 virus and other viruses in a small office space using a diffusion-based computational modeling approach. METHODS A 3-D computational model was used to simulate the airflow inside the 70.2 m3 ventilated office. A novel diffusion model accounting for turbulence dispersion and gravitational sedimentation was utilized to predict droplet concentration transport and deposition. The numerical model was validated and used to investigate the influences of partition height and different ventilation rates on the concentration of respiratory aerosols of various sizes (1, 10, 20, and 50 µm) emitted by continuous speaking. RESULTS An increase in the hourly air change rate (ACH) from 2.0 to 5.6 decreased the 1 μm droplet concentration inside the office by a factor of 2.8 and in the breathing zone of the receptor occupant by a factor of 3.2. The concentration at the receptor breathing zone is estimated by the area-weighted average of a 1 m diameter circular disk, with its centroid at the center of the receptor mannequin mouth. While all aerosols were dispersed by airflow turbulence, the gravitational sedimentation significantly influenced the transport of larger aerosols in the room. The 1 and 10 μm aerosols remained suspended in the air and dispersed throughout the room. In contrast, the larger 20 and 50 μm aerosols deposited on the floor quickly due to the gravitational sedimentation. Increasing the partition between cubicles by 0.254 m (10") has little effect on the smaller aerosols and overall exposure. IMPACT This paper provides an efficient computational model for analyzing the concentration of different respiratory droplets and aerosols in an indoor environment. Thus, the approach could be used for assessing the influence of the spatial concentration variations on exposure for which the fully mixed model cannot be used.
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Affiliation(s)
- Sohaib Obeid
- Department of Mechanical and Aerospace Engineering, Clarkson University, Potsdam, NY, 13699, USA
| | - Paul White
- U.S. Environmental Protection Agency (EPA), Office of Research and Development, Research Triangle Park, Washington, DC, NC, USA
| | - Jacky Rosati Rowe
- U.S. Environmental Protection Agency (EPA), Office of Research and Development, Research Triangle Park, Washington, DC, NC, USA
| | - Vito Ilacqua
- U.S. Environmental Protection Agency (EPA), Office of Research and Development, Research Triangle Park, Washington, DC, NC, USA
| | - Mahender Singh Rawat
- Department of Civil and Environmental Engineering, Clarkson University, Potsdam, NY, 13699, USA
| | - Andrea R Ferro
- Department of Mechanical and Aerospace Engineering, Clarkson University, Potsdam, NY, 13699, USA
| | - Goodarz Ahmadi
- Department of Mechanical and Aerospace Engineering, Clarkson University, Potsdam, NY, 13699, USA.
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5
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Groth R, Niazi S, Oswin HP, Haddrell AE, Spann K, Morawska L, Ristovski Z. Toward Standardized Aerovirology: A Critical Review of Existing Results and Methodologies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:3595-3608. [PMID: 38355395 DOI: 10.1021/acs.est.3c07275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
Understanding the airborne survival of viruses is important for public health and epidemiological modeling and potentially to develop mitigation strategies to minimize the transmission of airborne pathogens. Laboratory experiments typically involve investigating the effects of environmental parameters on the viability or infectivity of a target airborne virus. However, conflicting results among studies are common. Herein, the results of 34 aerovirology studies were compared to identify links between environmental and compositional effects on the viability of airborne viruses. While the specific experimental apparatus was not a factor in variability between reported results, it was determined that the experimental procedure was a major factor that contributed to discrepancies in results. The most significant contributor to variability between studies was poorly defined initial viable virus concentration in the aerosol phase, causing many studies to not measure the rapid inactivation, which occurs quickly after particle generation, leading to conflicting results. Consistently, studies that measured their reference airborne viability minutes after aerosolization reported higher viability at subsequent times, which indicates that there is an initial loss of viability which is not captured in these studies. The composition of the particles which carry the viruses was also found to be important in the viability of airborne viruses; however, the mechanisms for this effect are unknown. Temperature was found to be important for aerosol-phase viability, but there is a lack of experiments that directly compare the effects of temperature in the aerosol phase and the bulk phase. There is a need for repeated measurements between different research groups under identical conditions both to assess the degree of variability between studies and also to attempt to better understand already published data. Lack of experimental standardization has hindered the ability to quantify the differences between studies, for which we provide recommendations for future studies. These recommendations are as follows: measuring the reference airborne viability using the "direct method"; use equipment which maximizes time resolution; quantify all losses appropriately; perform, at least, a 5- and 10-min sample, if possible; report clearly the composition of the virus suspension; measure the composition of the gas throughout the experiment. Implementing these recommendations will address the most significant oversights in the existing literature and produce data which can more easily be quantitatively compared.
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Affiliation(s)
- Robert Groth
- School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Sadegh Niazi
- School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Henry P Oswin
- School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Allen E Haddrell
- School of Chemistry, Cantock's Close, University of Bristol, Bristol BS8 1TS, United Kingdom
| | - Kirsten Spann
- School of Biomedical Sciences, Centre for Immunology and Infection Control, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Lidia Morawska
- School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Zoran Ristovski
- School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, Queensland 4000, Australia
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6
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Haghighat Bayan MA, Rinoldi C, Rybak D, Zargarian SS, Zakrzewska A, Cegielska O, Põhako-Palu K, Zhang S, Stobnicka-Kupiec A, Górny RL, Nakielski P, Kogermann K, De Sio L, Ding B, Pierini F. Engineering surgical face masks with photothermal and photodynamic plasmonic nanostructures for enhancing filtration and on-demand pathogen eradication. Biomater Sci 2024; 12:949-963. [PMID: 38221844 DOI: 10.1039/d3bm01125a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
The shortage of face masks and the lack of antipathogenic functions has been significant since the recent pandemic's inception. Moreover, the disposal of an enormous number of contaminated face masks not only carries a significant environmental impact but also escalates the risk of cross-contamination. This study proposes a strategy to upgrade available surgical masks into antibacterial masks with enhanced particle and bacterial filtration. Plasmonic nanoparticles can provide photodynamic and photothermal functionalities for surgical masks. For this purpose, gold nanorods act as on-demand agents to eliminate pathogens on the surface of the masks upon near-infrared light irradiation. Additionally, the modified masks are furnished with polymer electrospun nanofibrous layers. These electrospun layers can enhance the particle and bacterial filtration efficiency, not at the cost of the pressure drop of the mask. Consequently, fabricating these prototype masks could be a practical approach to upgrading the available masks to alleviate the environmental toll of disposable face masks.
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Affiliation(s)
- Mohammad Ali Haghighat Bayan
- Department of Biosystems and Soft Matter, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland.
| | - Chiara Rinoldi
- Department of Biosystems and Soft Matter, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland.
| | - Daniel Rybak
- Department of Biosystems and Soft Matter, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland.
| | - Seyed Shahrooz Zargarian
- Department of Biosystems and Soft Matter, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland.
| | - Anna Zakrzewska
- Department of Biosystems and Soft Matter, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland.
| | - Olga Cegielska
- Laboratory of Polymers and Biomaterials, Institute of Fundamental Technological Research Polish Academy of Sciences, Warsaw 02-106, Poland
| | - Kaisa Põhako-Palu
- Institute of Pharmacy, Faculty of Medicine University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Shichao Zhang
- Innovation Center for Textile Science and Technology, College of Textiles, Donghua University, Shanghai 201620, China
| | - Agata Stobnicka-Kupiec
- Laboratory of Biohazards, Department of Chemical, Aerosol and Biological Hazards, Central Institute for Labour Protection - National Research Institute, Warsaw 00-701, Poland
| | - Rafał L Górny
- Laboratory of Biohazards, Department of Chemical, Aerosol and Biological Hazards, Central Institute for Labour Protection - National Research Institute, Warsaw 00-701, Poland
| | - Paweł Nakielski
- Department of Biosystems and Soft Matter, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland.
| | - Karin Kogermann
- Institute of Pharmacy, Faculty of Medicine University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Luciano De Sio
- Department of Medico-Surgical Sciences and Biotechnologies, Research Center for Biophotonics, Sapienza University of Rome, Latina 04100, Italy
| | - Bin Ding
- Innovation Center for Textile Science and Technology, College of Textiles, Donghua University, Shanghai 201620, China
| | - Filippo Pierini
- Department of Biosystems and Soft Matter, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland.
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7
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Niazi S, Groth R, Morawska L, Spann K, Ristovski Z. Dynamics and Viability of Airborne Respiratory Syncytial Virus under Various Indoor Air Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:21558-21569. [PMID: 38084588 DOI: 10.1021/acs.est.3c03455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
The factors governing the viability of airborne viruses embedded within respiratory particles are not well understood. This study aimed to investigate the relative humidity (RH)-dependent viability of airborne respiratory syncytial virus (RSV) in simulated respiratory particles suspended in various indoor air conditions. We tested airborne RSV viability in three static indoor air conditions, including sub-hysteresis (RH < 39%), hysteresis (39% < RH < 65%), and super-hysteresis (RH > 65%) air as well as in three dynamic indoor air conditions, including the transitions between the static conditions. The dynamic conditions were hysteresis → super-hysteresis → hysteresis, sub-hysteresis → hysteresis, and super-hysteresis → hysteresis. We found that after 45 min of particle aging in static conditions, the viability of RSV in sub-hysteresis, hysteresis, and super-hysteresis air was 0.72% ± 0.06%, 0.03% ± 0.006%, and 0.27% ± 0.008%, respectively. After 45 min of aging in dynamic conditions, the RSV viability decreased for particles that remained in a liquid (deliquesced) state during aging when compared with particles in a solid (effloresced) state. The decreased viability of airborne RSV for deliquesced particles is consistent with prolonged exposure to elevated aqueous solutes. These results represent the first measurements of the survival of airborne RSV over particle aging time, with equal viability in low, intermediate, and high RHs at 5 and 15 min and a V-shaped curve after 45 min.
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Affiliation(s)
- Sadegh Niazi
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Robert Groth
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Lidia Morawska
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Kirsten Spann
- Centre for Immunology and Infection Control (CIIC), School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD 4006, Australia
| | - Zoran Ristovski
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
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8
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Qiu G, Zhang X, deMello AJ, Yao M, Cao J, Wang J. On-site airborne pathogen detection for infection risk mitigation. Chem Soc Rev 2023; 52:8531-8579. [PMID: 37882143 PMCID: PMC10712221 DOI: 10.1039/d3cs00417a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Indexed: 10/27/2023]
Abstract
Human-infecting pathogens that transmit through the air pose a significant threat to public health. As a prominent instance, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that caused the COVID-19 pandemic has affected the world in an unprecedented manner over the past few years. Despite the dissipating pandemic gloom, the lessons we have learned in dealing with pathogen-laden aerosols should be thoroughly reviewed because the airborne transmission risk may have been grossly underestimated. From a bioanalytical chemistry perspective, on-site airborne pathogen detection can be an effective non-pharmaceutic intervention (NPI) strategy, with on-site airborne pathogen detection and early-stage infection risk evaluation reducing the spread of disease and enabling life-saving decisions to be made. In light of this, we summarize the recent advances in highly efficient pathogen-laden aerosol sampling approaches, bioanalytical sensing technologies, and the prospects for airborne pathogen exposure measurement and evidence-based transmission interventions. We also discuss open challenges facing general bioaerosols detection, such as handling complex aerosol samples, improving sensitivity for airborne pathogen quantification, and establishing a risk assessment system with high spatiotemporal resolution for mitigating airborne transmission risks. This review provides a multidisciplinary outlook for future opportunities to improve the on-site airborne pathogen detection techniques, thereby enhancing the preparedness for more on-site bioaerosols measurement scenarios, such as monitoring high-risk pathogens on airplanes, weaponized pathogen aerosols, influenza variants at the workplace, and pollutant correlated with sick building syndromes.
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Affiliation(s)
- Guangyu Qiu
- Institute of Medical Robotics, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
- Institute of Environmental Engineering, ETH Zürich, Zürich 8093, Switzerland
- Laboratory for Advanced Analytical Technologies, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Xiaole Zhang
- Institute of Environmental Engineering, ETH Zürich, Zürich 8093, Switzerland
- Laboratory for Advanced Analytical Technologies, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Andrew J deMello
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg1, Zürich, Switzerland
| | - Maosheng Yao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, China
| | - Junji Cao
- Institute of Atmospheric Physics, Chinese Academy of Science, China
| | - Jing Wang
- Institute of Environmental Engineering, ETH Zürich, Zürich 8093, Switzerland
- Laboratory for Advanced Analytical Technologies, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
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9
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Liu L, Deng Y, Xia S, Sun Z, Zhu Z, Chen W, Xiao D, Sheng W, Chen K. A "safety cap" for improving hospital sanitation and reducing potential disease transmission. BMC Infect Dis 2023; 23:589. [PMID: 37679704 PMCID: PMC10486032 DOI: 10.1186/s12879-023-08566-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
BACKGROUND During endotracheal intubation, extubation, tracheotomy, and tracheotomy tube replacement, the splashed airway secretions of patients will increase the risk of transmission of SARS-CoV-2 and many other potential viral and bacterial diseases, such as influenza virus, adenovirus, respiratory syncytial virus, rhinovirus, Middle East respiratory coronavirus syndrome (MERS-CoV), Streptococcus pneumoniae, and Mycobacterium tuberculosis. Therefore, it is necessary to establish a barrier between patients and medical workers to reduce the risk of operators' infection with potentially pathogenic microorganisms. METHODS We designed a "safety cap" that can be connected to the opening of an endotracheal tube or tracheotomy tube to reduce the diffusion area of respiratory secretions during the process of endotracheal intubation, extubation and tracheotomy tube replace, so as to reduce the infection risk of medical workers. RESULTS Through a series of hydrodynamic simulation analysis and experiments, we demonstrated that the use of "safety cap" can substantially limit the spatter of airway secretions, so as to improve the hospital sanitation. CONCLUSION The "safety cap" can effectively limit the dissemination of patients' respiratory secretions, thus reducing the risk of potential diseases transmission and may have certain application prospects.
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Affiliation(s)
- Lilong Liu
- Department of Urology, TongJi Hospital of TongJi Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China
| | - Yan Deng
- Research Center for Tissue Engineering and Regenerative Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shouli Xia
- Department of Radiology, the First Affiliated Hospital of Wannan Medical College, Wuhu, China
| | - Zengpeng Sun
- Department of Anesthesiology, Affiliated Drum Tower Hospital of Medical Department of Nanjing University, Nanjing, China
| | - Zhipeng Zhu
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang, China
| | - Weiyi Chen
- Department of Emergency Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dongdong Xiao
- Department of Neurosurgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, No. 1277 Jiefang Avenue, Wuhan, Hubei, 430022, China.
| | - Weiyong Sheng
- Department of Cardiothoracic Surgery, the First Affiliated Hospital of Wannan Medical College, No. 2 Zheshan West Road, Wuhu, Anhui, 241001, China.
| | - Ke Chen
- Department of Urology, TongJi Hospital of TongJi Medical College, Huazhong University of Science and Technology, No. 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China.
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10
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Peng Y, Yao M. Quantitatively Visualizing Airborne Disease Transmission Risks of Different Exhalation Activities through CO 2 Imaging. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6865-6875. [PMID: 37074044 PMCID: PMC10124748 DOI: 10.1021/acs.est.2c08503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/23/2023] [Accepted: 04/03/2023] [Indexed: 05/03/2023]
Abstract
Aerosol transmission has played a leading role in COVID-19 pandemic. However, there is still a poor understanding about how it is transmitted. This work was designed to study the exhaled breath flow dynamics and transmission risks under different exhaling modes. Using an infrared photography device, exhaled flow characteristics of different breathing activities, such as deep breathing, dry coughing, and laughing, together with the roles of mouth and nose were characterized by imaging CO2 flow morphologies. Both mouth and nose played an important role in the disease transmission though in the downward direction for the nose. In contrast to the trajectory commonly modeled, the exhaled airflows appeared with turbulent entrainments and obvious irregular movements, particularly the exhalations involving mouth were directed horizontal and had a higher propagation capacity and transmission risk. While the cumulative risk was high for deep breathing, those transient ones from dry coughing, yawning, and laughing were also shown to be significant. Various protective measures including masks, canteen table shields, and wearable devices were visually demonstrated to be effective for altering the exhaled flow directions. This work is useful to understanding the risk of aerosol infection and guiding the formulation of its prevention and control strategies. Experimental data also provide important information for refining model boundary conditions.
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Affiliation(s)
- Yijiao Peng
- State Key Joint Laboratory of Environmental Simulation and
Pollution Control, College of Environmental Sciences and Engineering, Peking
University, Beijing 100871, China
| | - Maosheng Yao
- State Key Joint Laboratory of Environmental Simulation and
Pollution Control, College of Environmental Sciences and Engineering, Peking
University, Beijing 100871, China
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11
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A review on indoor airborne transmission of COVID-19– modelling and mitigation approaches. JOURNAL OF BUILDING ENGINEERING 2023; 64:105599. [PMCID: PMC9699823 DOI: 10.1016/j.jobe.2022.105599] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/11/2022] [Accepted: 11/21/2022] [Indexed: 06/09/2023]
Abstract
In the past few years, significant efforts have been made to investigate the transmission of COVID-19. This paper provides a review of the COVID-19 airborne transmission modeling and mitigation strategies. The simulation models here are classified into airborne transmission infectious risk models and numerical approaches for spatiotemporal airborne transmissions. Mathematical descriptions and assumptions on which these models have been based are discussed. Input data used in previous simulation studies to assess the dispersion of COVID-19 are extracted and reported. Moreover, measurements performed to study the COVID-19 airborne transmission within indoor environments are introduced to support validations for anticipated future modeling studies. Transmission mitigation strategies recommended in recent studies have been classified to include modifying occupancy and ventilation operations, using filters and air purifiers, installing ultraviolet (UV) air disinfection systems, and personal protection compliance, such as wearing masks and social distancing. The application of mitigation strategies to various building types, such as educational, office, public, residential, and hospital, is reviewed. Recommendations for future works are also discussed based on the current apparent knowledge gaps covering both modeling and mitigation approaches. Our findings show that different transmission mitigation measures were recommended for various indoor environments; however, there is no conclusive work reporting their combined effects on the level of mitigation that may be achieved. Moreover, further studies should be conducted to understand better the balance between approaches to mitigating the viral transmissions in buildings and building energy consumption.
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Groth R, Niazi S, Spann K, Johnson GR, Ristovski Z. Physicochemical characterization of porcine respiratory aerosol and considerations for future aerovirology. PNAS NEXUS 2023; 2:pgad087. [PMID: 37007717 PMCID: PMC10063220 DOI: 10.1093/pnasnexus/pgad087] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/08/2023] [Indexed: 06/19/2023]
Abstract
Understanding the mechanisms which inactivate airborne viruses is a current challenge. The composition of human respiratory aerosol is poorly understood and needs to be adequately investigated for use in aerovirology studies. Here, the physicochemical properties of porcine respiratory fluid (PRF) from the trachea and lungs were investigated both in bulk solutions and in aerosols. The mass ratio of Na:K in PRF compared with cell culture media (Dulbecco's Modified Eagle Medium, DMEM), which is frequently used in aerovirology studies, was significantly lower (∼2:1 vs ∼16:1). PRF contained significantly more potassium and protein than DMEM. PRF aerosols of all samples were similarly hygroscopic to human respiratory aerosol. PRF particles could nucleate with spatially separated crystals, indicating that the protein matrix was sufficiently viscous to prevent the complete coalescence of aqueous salts prior to efflorescence. The effects of these differences in compositions on the viability of viruses are currently not well understood. The virus suspensions in aerovirology studies need to be reconsidered to adequately reflect a real-world expiration scenario.
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Affiliation(s)
- Robert Groth
- School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Sadegh Niazi
- School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Kirsten Spann
- School of Biomedical Sciences, Centre for Immunology and Infection Control, Faculty of Health, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Graham R Johnson
- School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
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Gu Z, Han J, Zhang L, Wang H, Luo X, Meng X, Zhang Y, Niu X, Lan Y, Wu S, Cao J, Lichtfouse E. Unanswered questions on the airborne transmission of COVID-19. ENVIRONMENTAL CHEMISTRY LETTERS 2023; 21:725-739. [PMID: 36628267 PMCID: PMC9816530 DOI: 10.1007/s10311-022-01557-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
UNLABELLED Policies and measures to control pandemics are often failing. While biological factors controlling transmission are usually well explored, little is known about the environmental drivers of transmission and infection. For instance, respiratory droplets and aerosol particles are crucial vectors for the airborne transmission of the severe acute respiratory syndrome coronavirus 2, the causation agent of the coronavirus 2019 pandemic (COVID-19). Once expectorated, respiratory droplets interact with atmospheric particulates that influence the viability and transmission of the novel coronavirus, yet there is little knowledge on this process or its consequences on virus transmission and infection. Here we review the effects of atmospheric particulate properties, vortex zones, and air pollution on virus survivability and transmission. We found that particle size, chemical constituents, electrostatic charges, and the moisture content of airborne particles can have notable effects on virus transmission, with higher survival generally associated with larger particles, yet some viruses are better preserved on small particles. Some chemical constituents and surface-adsorbed chemical species may damage peptide bonds in viral proteins and impair virus stability. Electrostatic charges and water content of atmospheric particulates may affect the adherence of virion particles and possibly their viability. In addition, vortex zones and human thermal plumes are major environmental factors altering the aerodynamics of buoyant particles in air, which can strongly influence the transport of airborne particles and the transmission of associated viruses. Insights into these factors may provide explanations for the widely observed positive correlations between COVID-19 infection and mortality with air pollution, of which particulate matter is a common constituent that may have a central role in the airborne transmission of the novel coronavirus. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s10311-022-01557-z.
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Affiliation(s)
- Zhaolin Gu
- School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an, 710049 People’s Republic of China
| | - Jie Han
- School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an, 710049 People’s Republic of China
| | - Liyuan Zhang
- School of Water and Environment, Chang’an University, Xi’an, 710064 People’s Republic of China
| | - Hongliang Wang
- Health Science Center, Xi’an Jiaotong University, Xi’an, 710049 People’s Republic of China
| | - Xilian Luo
- School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an, 710049 People’s Republic of China
| | - Xiangzhao Meng
- School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an, 710049 People’s Republic of China
| | - Yue Zhang
- School of Architecture, Chang’an University, Xi’an, 710064 People’s Republic of China
| | - Xinyi Niu
- School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an, 710049 People’s Republic of China
| | - Yang Lan
- School of Public Health, Xi’an Jiaotong University, Xi’an, 710049 People’s Republic of China
| | - Shaowei Wu
- School of Public Health, Xi’an Jiaotong University, Xi’an, 710049 People’s Republic of China
| | - Junji Cao
- Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029 People’s Republic of China
| | - Eric Lichtfouse
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 Shaanxi People’s Republic of China
- CNRS, IRD, INRAE, CEREGE, Aix-Marseille University, 13100, Aix-en-Provence, France
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Geospatial epidemiology of hospitalized patients with a positive influenza assay: A nationwide study in Iran, 2016-2018. PLoS One 2022; 17:e0278900. [PMID: 36512615 PMCID: PMC9747007 DOI: 10.1371/journal.pone.0278900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 11/24/2022] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION Seasonal influenza is a significant public health challenge worldwide. This study aimed to investigate the epidemiological characteristics and spatial patterns of severe hospitalized influenza cases confirmed by polymerase chain reaction (PCR) in Iran. METHODS Data were obtained from Iran's Ministry of Health and Medical Education and included all hospitalized lab-confirmed influenza cases from January 1, 2016, to December 30, 2018 (n = 9146). The Getis-Ord Gi* and Local Moran's I statistics were used to explore the hotspot areas and spatial cluster/outlier patterns of influenza. We also built a multivariable logistic regression model to identify covariates associated with patients' mortality. RESULTS Cumulative incidence and mortality rate were estimated at 11.44 and 0.49 (per 100,000), respectively, and case fatality rate was estimated at 4.35%. The patients' median age was 40 (interquartile range: 22-63), and 55.5% (n = 5073) were female. The hotspot and cluster analyses revealed high-risk areas in northern parts of Iran, especially in cold, humid, and densely populated areas. Moreover, influenza hotspots were more common during the colder months of the year, especially in high-elevated regions. Mortality was significantly associated with older age (adjusted odds ratio [aOR]: 1.01, 95% confidence interval [CI]: 1.01-1.02), infection with virus type-A (aOR: 1.64, 95% CI: 1.27-2.15), male sex (aOR: 1.77, 95% CI: 1.44-2.18), cardiovascular disease (aOR: 1.71, 95% CI: 1.33-2.20), chronic obstructive pulmonary disease (aOR: 1.82, 95% CI: 1.40-2.34), malignancy (aOR: 4.77, 95% CI: 2.87-7.62), and grade-II obesity (aOR: 2.11, 95% CI: 1.09-3.74). CONCLUSIONS We characterized the spatial and epidemiological heterogeneities of severe hospitalized influenza cases confirmed by PCR in Iran. Detecting influenza hotspot clusters could inform prioritization and geographic specificity of influenza prevention, testing, and mitigation resource management, including vaccination planning in Iran.
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Ren C, Haghighat F, Feng Z, Kumar P, Cao SJ. Impact of ionizers on prevention of airborne infection in classroom. BUILDING SIMULATION 2022; 16:749-764. [PMID: 36474607 PMCID: PMC9716175 DOI: 10.1007/s12273-022-0959-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 10/12/2022] [Accepted: 10/31/2022] [Indexed: 06/17/2023]
Abstract
UNLABELLED Infectious diseases (e.g., coronavirus disease 2019) dramatically impact human life, economy and social development. Exploring the low-cost and energy-saving approaches is essential in removing infectious virus particles from indoors, such as in classrooms. The application of air purification devices, such as negative ion generators (ionizers), gains popularity because of the favorable removal capacity for particles and the low operation cost. However, small and portable ionizers have potential disadvantages in the removal efficiency owing to the limited horizontal diffusion of negative ions. This study aims to investigate the layout strategy (number and location) of ionizers based on the energy-efficient natural ventilation in the classroom to improve removal efficiency (negative ions to particles) and decrease infection risk. Three infected students were considered in the classroom. The simulations of negative ion and particle concentrations were performed and validated by the experiment. Results showed that as the number of ionizers was 4 and 5, the removal performance was largely improved by combining ionizer with natural ventilation. Compared with the scenario without an ionizer, the scenario with 5 ionizers largely increased the average removal efficiency from around 20% to 85% and decreased the average infection risk by 23%. The setup with 5 ionizers placed upstream of the classroom was determined as the optimal layout strategy, particularly when the location and number of the infected students were unknown. This work can provide a guideline for applying ionizers to public buildings when natural ventilation is used. ELECTRONIC SUPPLEMENTARY MATERIAL ESM the Appendix is available in the online version of this article at 10.1007/s12273-022-0959-z.
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Affiliation(s)
- Chen Ren
- School of Architecture, Southeast University, 2 Sipailou, Nanjing, 210096 China
| | - Fariborz Haghighat
- School of Architecture, Southeast University, 2 Sipailou, Nanjing, 210096 China
- Energy and Environment Group, Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, H3G 1M8 Canada
| | - Zhuangbo Feng
- School of Architecture, Southeast University, 2 Sipailou, Nanjing, 210096 China
| | - Prashant Kumar
- School of Architecture, Southeast University, 2 Sipailou, Nanjing, 210096 China
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil & Environmental Engineering, Faculty of Engineering & Physical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH UK
- Institute for Sustainability, University of Surrey, Guildford, Surrey, GU2 7XH UK
| | - Shi-Jie Cao
- School of Architecture, Southeast University, 2 Sipailou, Nanjing, 210096 China
- Global Centre for Clean Air Research (GCARE), School of Sustainability, Civil & Environmental Engineering, Faculty of Engineering & Physical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH UK
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16
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Groth R, Niazi S, Johnson GR, Ristovski Z. Nanomechanics and Morphology of Simulated Respiratory Particles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:10879-10890. [PMID: 35852155 DOI: 10.1021/acs.est.2c01829] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The impact of respiratory particle composition on the equilibrium morphology and phase is not well understood. Furthermore, the effects of these different phases and morphologies on the viability of viruses embedded within these particles are equally unknown. Physiologically relevant respiratory fluid analogues were constructed, and their hygroscopic behavior was measured using an ensemble technique. A relationship between hygroscopicity and protein concentration was determined, providing additional validation to the high protein content of respiratory aerosol measured in prior works (>90%). It was found that the salt component of the respiratory particles could crystallize as a single crystal, multiple crystals, or would not crystallize at all. It was found that dried protein particles at indoor-relevant climatic conditions could exist separately in a glassy (∼77% of particles) or viscoelastic state (∼23% of particles). The phase state and morphology of respiratory particles may influence the viability of embedded pathogens. We recommend that pathogen research aiming to mimic the native composition of respiratory fluid should use a protein concentration of at least 90% by solute volume to improve the representativity of the pathogen's microenvironment.
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Affiliation(s)
- Robert Groth
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Sadegh Niazi
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Graham R Johnson
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Zoran Ristovski
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
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Ahlawat A, Mishra SK, Herrmann H, Rajeev P, Gupta T, Goel V, Sun Y, Wiedensohler A. Impact of Chemical Properties of Human Respiratory Droplets and Aerosol Particles on Airborne Viruses' Viability and Indoor Transmission. Viruses 2022; 14:v14071497. [PMID: 35891477 PMCID: PMC9318922 DOI: 10.3390/v14071497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/01/2022] [Accepted: 07/01/2022] [Indexed: 02/04/2023] Open
Abstract
The airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been identified as a potential pandemic challenge, especially in poorly ventilated indoor environments, such as certain hospitals, schools, public buildings, and transports. The impacts of meteorological parameters (temperature and humidity) and physical property (droplet size) on the airborne transmission of coronavirus in indoor settings have been previously investigated. However, the impacts of chemical properties of viral droplets and aerosol particles (i.e., chemical composition and acidity (pH)) on viability and indoor transmission of coronavirus remain largely unknown. Recent studies suggest high organic content (proteins) in viral droplets and aerosol particles supports prolonged survival of the virus by forming a glassy gel-type structure that restricts the virus inactivation process under low relative humidity (RH). In addition, the virus survival was found at neutral pH, and inactivation was observed to be best at low (<5) and high pH (>10) values (enveloped bacteriophage Phi6). Due to limited available information, this article illustrates an urgent need to research the impact of chemical properties of exhaled viral particles on virus viability. This will improve our fundamental understanding of indoor viral airborne transmission mechanisms.
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Affiliation(s)
- Ajit Ahlawat
- Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany; (H.H.); (A.W.)
- Correspondence:
| | | | - Hartmut Herrmann
- Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany; (H.H.); (A.W.)
| | - Pradhi Rajeev
- Department of Civil Engineering, Indian Institute of Technology (IIT), Kanpur 208016, India; (P.R.); (T.G.)
| | - Tarun Gupta
- Department of Civil Engineering, Indian Institute of Technology (IIT), Kanpur 208016, India; (P.R.); (T.G.)
| | - Vikas Goel
- School of Interdisciplinary Research, Indian Institute of Technology (IIT), Delhi 110016, India;
| | - Yele Sun
- LAPC, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100017, China;
| | - Alfred Wiedensohler
- Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany; (H.H.); (A.W.)
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Wei Y, Dong Z, Fan W, Xu K, Tang S, Wang Y, Wu F. A narrative review on the role of temperature and humidity in COVID-19: Transmission, persistence, and epidemiological evidence. ECO-ENVIRONMENT & HEALTH (ONLINE) 2022; 1:73-85. [PMID: 38013745 PMCID: PMC9181277 DOI: 10.1016/j.eehl.2022.04.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/30/2022] [Accepted: 04/28/2022] [Indexed: 12/11/2022]
Abstract
Since December 2019, the 2019 coronavirus disease (COVID-19) outbreak has become a global pandemic. Understanding the role of environmental conditions is important in impeding the spread of COVID-19. Given that airborne spread and contact transmission are considered the main pathways for the spread of COVID-19, this narrative review first summarized the role of temperature and humidity in the airborne trajectory of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Meanwhile, we reviewed the persistence of the virus in aerosols and on inert surfaces and summarized how the persistence of SARS-CoV-2 is affected by temperature and humidity. We also examined the existing epidemiological evidence and addressed the limitations of these epidemiological studies. Although uncertainty remains, more evidence may support the idea that high temperature is slightly and negatively associated with COVID-19 growth, while the conclusion for humidity is still conflicting. Nonetheless, the spread of COVID-19 appears to have been controlled primarily by government interventions rather than environmental factors.
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Affiliation(s)
- Yuan Wei
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zhaomin Dong
- School of Space and Environment, Beihang University, Beijing 102206, China
| | - Wenhong Fan
- School of Space and Environment, Beihang University, Beijing 102206, China
- Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University, Beijing 100083, China
| | - Kaiqiang Xu
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China
| | - Song Tang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China
- Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China
| | - Ying Wang
- School of Space and Environment, Beihang University, Beijing 102206, China
| | - Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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Giampieri A, Ma Z, Ling-Chin J, Roskilly AP, Smallbone AJ. An overview of solutions for airborne viral transmission reduction related to HVAC systems including liquid desiccant air-scrubbing. ENERGY (OXFORD, ENGLAND) 2022; 244:122709. [PMID: 34840405 PMCID: PMC8605622 DOI: 10.1016/j.energy.2021.122709] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 11/18/2021] [Accepted: 11/20/2021] [Indexed: 05/31/2023]
Abstract
The spread of the coronavirus SARS-CoV-2 affects the health of people and the economy worldwide. As air transmits the virus, heating, ventilation and air-conditioning (HVAC) systems in buildings, enclosed spaces and public transport play a significant role in limiting the transmission of airborne pathogens at the expenses of increased energy consumption and possibly reduced thermal comfort. On the other hand, liquid desiccant technology could be adopted as an air scrubber to increase indoor air quality and inactivate pathogens through temperature and humidity control, making them less favourable to the growth, proliferation and infectivity of microorganisms. The objectives of this study are to review the role of HVAC in airborne viral transmission, estimate its energy penalty associated with the adoption of HVAC for transmission reduction and understand the potential of liquid desiccant technology. Factors affecting the inactivation of pathogens by liquid desiccant solutions and possible modifications to increase their heat and mass transfer and sanitising characteristics are also described, followed by an economic evaluation. It is concluded that the liquid desiccant technology could be beneficial in buildings (requiring humidity control or moisture removal in particular when viruses are likely to present) or in high-footfall enclosed spaces (during virus outbreaks).
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Key Words
- ASHRAE, American Society of Heating, Refrigerating and Air-Conditioning Engineers
- Airborne viral transmission
- CIBSE, Chartered Institution of Building Services Engineers
- COP, Coefficient of performance
- COVID-19
- COVID-19, Coronavirus disease 19
- CaCl2, Calcium chloride
- Economic analysis
- HCO2K, Potassium formate
- HEPA, High-efficiency particulate air filter
- HVAC energy consumption
- HVAC, Heating, ventilation and air-conditioning
- Humidity control
- IAQ, Indoor air quality
- IBV, Infectious bronchitis virus
- IL, Ionic liquid
- LiBr, Lithium bromide
- LiCl, Lithium chloride
- Liquid desiccant
- MERS-CoV, Middle East respiratory syndrome coronavirus
- MERV, Minimum efficiency reporting value
- PRRSV, Porcine reproductive and respiratory syndrome virus
- REHVA, Federation of European Heating, Ventilation and Air Conditioning Associations
- SARS-CoV-1, Severe acute respiratory syndrome coronavirus 1
- SARS-CoV-2, Severe acute respiratory syndrome coronavirus 2
- TEG, Triethylene glycol
- TGEV, Transmissible gastroenteritis virus
- UVA, Long-wave ultraviolet light
- UVB, Middle-wave ultraviolet light
- UVC, Short-wave ultraviolet light
- UVGI, Ultraviolet germicidal irradiation
- WHO, World Health Organization
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Affiliation(s)
- A Giampieri
- Department of Engineering, Durham University, Durham, DH1 3LE, United Kingdom
| | - Z Ma
- Department of Engineering, Durham University, Durham, DH1 3LE, United Kingdom
| | - J Ling-Chin
- Department of Engineering, Durham University, Durham, DH1 3LE, United Kingdom
| | - A P Roskilly
- Department of Engineering, Durham University, Durham, DH1 3LE, United Kingdom
| | - A J Smallbone
- Department of Engineering, Durham University, Durham, DH1 3LE, United Kingdom
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Dinoi A, Feltracco M, Chirizzi D, Trabucco S, Conte M, Gregoris E, Barbaro E, La Bella G, Ciccarese G, Belosi F, La Salandra G, Gambaro A, Contini D. A review on measurements of SARS-CoV-2 genetic material in air in outdoor and indoor environments: Implication for airborne transmission. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 809:151137. [PMID: 34699823 PMCID: PMC8539199 DOI: 10.1016/j.scitotenv.2021.151137] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/15/2021] [Accepted: 10/17/2021] [Indexed: 05/03/2023]
Abstract
Airborne transmission of SARS-CoV-2 has been object of debate in the scientific community since the beginning of COVID-19 pandemic. This mechanism of transmission could arise from virus-laden aerosol released by infected individuals and it is influenced by several factors. Among these, the concentration and size distribution of virus-laden particles play an important role. The knowledge regarding aerosol transmission increases as new evidence is collected in different studies, even if it is not yet available a standard protocol regarding air sampling and analysis, which can create difficulties in the interpretation and application of results. This work reports a systematic review of current knowledge gained by 73 published papers on experimental determination of SARS-CoV-2 RNA in air comparing different environments: outdoors, indoor hospitals and healthcare settings, and public community indoors. Selected papers furnished 77 datasets: outdoor studies (9/77, 11.7%) and indoor studies (68/77. 88.3%). The indoor datasets in hospitals were the vast majority (58/68, 85.3%), and the remaining (10/68, 14.7%) were classified as community indoors. The fraction of studies having positive samples, as well as positivity rates (i.e. ratios between positive and total samples) are significantly larger in hospitals compared to the other typologies of sites. Contamination of surfaces was more frequent (in indoor datasets) compared to contamination of air samples; however, the average positivity rate was lower compared to that of air. Concentrations of SARS-CoV-2 RNA in air were highly variables and, on average, lower in outdoors compared to indoors. Among indoors, concentrations in community indoors appear to be lower than those in hospitals and healthcare settings.
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Affiliation(s)
- Adelaide Dinoi
- Istituto di Scienze dell'Atmosfera e del Clima (ISAC-CNR), Str. Prv. Lecce-Monteroni km 1.2, Lecce, Italy
| | - Matteo Feltracco
- Istituto di Scienze Polari (ISP-CNR), Via Torino 155, Venice, Mestre, Italy; Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari di Venezia, Via Torino 155, Venezia, Mestre, Italy
| | - Daniela Chirizzi
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (IZSPB), Via Manfredonia 20, Foggia, Italy
| | - Sara Trabucco
- Istituto di Scienze dell'Atmosfera e del Clima (ISAC-CNR), Via Gobetti 101, Bologna, Italy
| | - Marianna Conte
- Istituto di Scienze dell'Atmosfera e del Clima (ISAC-CNR), Str. Prv. Lecce-Monteroni km 1.2, Lecce, Italy; Laboratory for Observations and Analyses of Earth and Climate, Agenzia Nazionale per le Nuove Tecnologie, l'Energia e lo Sviluppo Economico Sostenibile (ENEA), 00123 Rome, Italy
| | - Elena Gregoris
- Istituto di Scienze Polari (ISP-CNR), Via Torino 155, Venice, Mestre, Italy; Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari di Venezia, Via Torino 155, Venezia, Mestre, Italy
| | - Elena Barbaro
- Istituto di Scienze Polari (ISP-CNR), Via Torino 155, Venice, Mestre, Italy; Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari di Venezia, Via Torino 155, Venezia, Mestre, Italy
| | - Gianfranco La Bella
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (IZSPB), Via Manfredonia 20, Foggia, Italy
| | - Giuseppina Ciccarese
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (IZSPB), Via Manfredonia 20, Foggia, Italy
| | - Franco Belosi
- Istituto di Scienze dell'Atmosfera e del Clima (ISAC-CNR), Via Gobetti 101, Bologna, Italy
| | - Giovanna La Salandra
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata (IZSPB), Via Manfredonia 20, Foggia, Italy
| | - Andrea Gambaro
- Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari di Venezia, Via Torino 155, Venezia, Mestre, Italy
| | - Daniele Contini
- Istituto di Scienze dell'Atmosfera e del Clima (ISAC-CNR), Str. Prv. Lecce-Monteroni km 1.2, Lecce, Italy.
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Evidence for a semisolid phase state of aerosols and droplets relevant to the airborne and surface survival of pathogens. Proc Natl Acad Sci U S A 2022; 119:2109750119. [PMID: 35064080 PMCID: PMC8794803 DOI: 10.1073/pnas.2109750119] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2021] [Indexed: 01/25/2023] Open
Abstract
Ambient humidity can influence the survival of pathogens in respiratory aerosols and droplets, although the mechanism and optimum humidity level for public health remain unclear. Here, we present evidence for a humidity-dependent, semisolid state of aerosols and droplets relevant to pathogen survival. These observations indicate that a semisolid state may protect pathogens from inactivation by hindering disinfection reactions at intermediate-to-low humidity levels. The formation of the semisolid state was dependent on the composition of the aerosols, which suggests that the humidity for optimum pathogen destruction will depend on the composition of respiratory particles released from an infected host. These observations can be used to help interpret laboratory studies and inform public health recommendations. The phase state of respiratory aerosols and droplets has been linked to the humidity-dependent survival of pathogens such as SARS-CoV-2. To inform strategies to mitigate the spread of infectious disease, it is thus necessary to understand the humidity-dependent phase changes associated with the particles in which pathogens are suspended. Here, we study phase changes of levitated aerosols and droplets composed of model respiratory compounds (salt and protein) and growth media (organic–inorganic mixtures commonly used in studies of pathogen survival) with decreasing relative humidity (RH). Efflorescence was suppressed in many particle compositions and thus unlikely to fully account for the humidity-dependent survival of viruses. Rather, we identify organic-based, semisolid phase states that form under equilibrium conditions at intermediate RH (45 to 80%). A higher-protein content causes particles to exist in a semisolid state under a wider range of RH conditions. Diffusion and, thus, disinfection kinetics are expected to be inhibited in these semisolid states. These observations suggest that organic-based, semisolid states are an important consideration to account for the recovery of virus viability at low RH observed in previous studies. We propose a mechanism in which the semisolid phase shields pathogens from inactivation by hindering the diffusion of solutes. This suggests that the exogenous lifetime of pathogens will depend, in part, on the organic composition of the carrier respiratory particle and thus its origin in the respiratory tract. Furthermore, this work highlights the importance of accounting for spatial heterogeneities and time-dependent changes in the properties of aerosols and droplets undergoing evaporation in studies of pathogen viability.
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22
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Terrosi C, Anichini G, Docquier JD, Gori Savellini G, Gandolfo C, Pavone FS, Cusi MG. Efficient Inactivation of SARS-CoV-2 and Other RNA or DNA Viruses with Blue LED Light. Pathogens 2021; 10:pathogens10121590. [PMID: 34959545 PMCID: PMC8708627 DOI: 10.3390/pathogens10121590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/16/2021] [Accepted: 12/06/2021] [Indexed: 11/16/2022] Open
Abstract
Blue LED light has proven to have a powerful bacteria-killing ability; however, little is known about its mechanism of virucidal activity. Therefore, we analyzed the effect of blue light on different respiratory viruses, such as adenovirus, respiratory syncytial virus and SARS-CoV-2. The exposure of samples to a blue LED light with a wavelength of 420 nm (i.e., in the visible range) at 20 mW/cm2 of irradiance for 15 min appeared optimal and resulted in the complete inactivation of the viral load. These results were similar for all the three viruses, demonstrating that both enveloped and naked viruses could be efficiently inactivated with blue LED light, regardless of the presence of envelope and of the viral genome nature (DNA or RNA). Moreover, we provided some explanations to the mechanisms by which the blue LED light could exert its antiviral activity. The development of such safe and low-cost light-based devices appears to be of fundamental utility for limiting viral spread and for sanitizing small environments, objects and surfaces, especially in the pandemic era.
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Affiliation(s)
- Chiara Terrosi
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (C.T.); (G.A.); (J.D.D.); (G.G.S.); (C.G.)
| | - Gabriele Anichini
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (C.T.); (G.A.); (J.D.D.); (G.G.S.); (C.G.)
| | - Jean Denis Docquier
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (C.T.); (G.A.); (J.D.D.); (G.G.S.); (C.G.)
| | - Gianni Gori Savellini
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (C.T.); (G.A.); (J.D.D.); (G.G.S.); (C.G.)
| | - Claudia Gandolfo
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (C.T.); (G.A.); (J.D.D.); (G.G.S.); (C.G.)
| | - Francesco Saverio Pavone
- Department of Physics and Astronomy, European Laboratory for Non Linear Spectroscopy (LENS), University of Florence, 50121 Florence, Italy;
| | - Maria Grazia Cusi
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (C.T.); (G.A.); (J.D.D.); (G.G.S.); (C.G.)
- Correspondence: ; Tel.: +39-0577-233871; Fax: +39-0577-233870
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23
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Jarvis MC. Drying of virus-containing particles: modelling effects of droplet origin and composition. JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE & ENGINEERING 2021; 19:1987-1996. [PMID: 34754455 PMCID: PMC8569499 DOI: 10.1007/s40201-021-00750-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 10/17/2021] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND PURPOSE Virus-containing aerosol droplets emitted by breathing, speech or coughing dry rapidly to equilibrium with ambient relative humidity (RH), increasing in solute concentration with effects on virus survival and decreasing in diameter with effects on sedimentation and respiratory uptake. The aim of this paper is to model the effect of ionic and macromolecular solutes on droplet drying and solute concentration. METHODS Deliquescence-efflorescence concepts and Kohler theory were used to simulate the evolution of solute concentrations and water activity in respiratory droplets, starting from efflorescence data on mixed NaCl/KCl aerosols and osmotic pressure data on respiratory macromolecules. RESULTS In NaCl/KCl solutions total salt concentrations were shown to reach 10-13 M at the efflorescence RH of 40-55%, depending on the K:Na ratio. Dependence on K:Na ratio implies that the evaporation curves differ between aerosols derived from saliva and from airway surfaces. The direct effect of liquid droplet size through the Kelvin term was shown to be smaller and restricted to the evolution of breath emissions. Modelling the effect of proteins and glycoproteins showed that salts determine drying equilibria down to the efflorescence RH, and macromolecules at lower RH. CONCLUSION Differences in solute composition between airway surfaces and saliva are predicted to lead to different drying behaviour of droplets emitted by breathing, speech and coughing. These differences may influence the inactivation of viruses.
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Affiliation(s)
- Michael C. Jarvis
- School of Chemistry, Glasgow University, Glasgow, Scotland G12 8QQ UK
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24
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Birmili W, Selinka HC, Moriske HJ, Daniels A, Straff W. [Ventilation concepts in schools for the prevention of transmission of highly infectious viruses (SARS-CoV-2) by aerosols in indoor air]. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2021; 64:1570-1580. [PMID: 34739549 PMCID: PMC8569287 DOI: 10.1007/s00103-021-03452-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/19/2021] [Indexed: 01/12/2023]
Abstract
Exhaled aerosol particles play an important role in the transmission of SARS-CoV‑2, particularly when many people gather indoors. This article summarises the knowledge on virus transmission in schools and practical measures to reduce aerosol-driven infections. A central preventive measure is to enhance room and building ventilation, i.e. the exchange of possibly contaminated indoor air with ambient air. Besides the concentrations of possibly infectious particles, ventilation reduces carbon dioxide concentrations, humidity and other chemical substances in indoor air as well. Irrespective of ventilation, face masks (surgical or FFP2) represent a vital part of hygiene measures. Fixed or mobile air purifiers can support these measures particularly when rooms providing only poor ventilation must be utilized. The article reflects the state of knowledge in October 2021 of the various techniques that have been shown as useful for the prevention of indirect infections. New variants of SARS-CoV‑2, the progress of the vaccination campaign in children and adolescents, and the increase in general immunity might require a re-evaluation of the prevention strategies described. The COVID-19 pandemic has revealed common deficits in room and building ventilation, not least in schools. Apart from short-term measures for the prevention of airborne infectious diseases, a long-term strategy seems advisable to alleviate the deficits encountered in schools with respect to room and building ventilation. In view of a permanent improvement of indoor air and prevention against airborne infections the fitting of schools with fixed ventilation systems - preferably including heat and moisture recovery - appears to be a sustainable social investment.
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Affiliation(s)
- Wolfram Birmili
- Umweltbundesamt, Abteilung II 1 "Umwelthygiene", Corrensplatz 1, 14195, Berlin, Deutschland.
| | - Hans-Christoph Selinka
- Umweltbundesamt, Abteilung II 1 "Umwelthygiene", Corrensplatz 1, 14195, Berlin, Deutschland
| | - Heinz-Jörn Moriske
- Umweltbundesamt, Beratungsstelle Umwelthygiene II BU, Wörlitzer Platz 1, 06844, Dessau, Deutschland
| | - Anja Daniels
- Umweltbundesamt, Abteilung II 1 "Umwelthygiene", Corrensplatz 1, 14195, Berlin, Deutschland
| | - Wolfgang Straff
- Umweltbundesamt, Abteilung II 1 "Umwelthygiene", Corrensplatz 1, 14195, Berlin, Deutschland
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25
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Locke L, Dada O, Shedd JS. Aerosol Transmission of Infectious Disease and the Efficacy of Personal Protective Equipment (PPE): A Systematic Review. J Occup Environ Med 2021; 63:e783-e791. [PMID: 34419986 PMCID: PMC8562920 DOI: 10.1097/jom.0000000000002366] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Health care professionals and governmental agencies are in consensus regarding contact and droplet transmission of infectious diseases. However, personal protective equipment (PPE) efficacy is not considered for aerosol or airborne transmission of infectious diseases. This review discusses the inhalation of virus-laden aerosols as a viable mechanism of transmission of various respiratory infectious diseases and PPE efficacy. METHODS The Preferred Reporting Items for Systematic reviews, and Meta-Analysis (PRISMA) guidelines was used. RESULTS The transmission of infectious disease is of concern for all respirable diseases discussed (SARS-CoV-1, SARS-CoV-2, MERS, influenza, and tuberculosis), and the effectiveness of facemasks is dependent on the efficiency of the filter, fit, and proper use. CONCLUSION PPE should be the last resort in preventing the spread of infectious disease and should only be used for protection and not to control the transmission.
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Affiliation(s)
- Laramie Locke
- Department of Occupational Safety and Health, Murray State University, Kentucky (Mr Locke, Dr Dada); Eastman Chemical Company, Tennessee (Mr Locke); and Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, Alabama (Mr Shedd)
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26
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Wang CC, Prather KA, Sznitman J, Jimenez JL, Lakdawala SS, Tufekci Z, Marr LC. Airborne transmission of respiratory viruses. Science 2021; 373:eabd9149. [PMID: 34446582 PMCID: PMC8721651 DOI: 10.1126/science.abd9149] [Citation(s) in RCA: 457] [Impact Index Per Article: 152.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The COVID-19 pandemic has revealed critical knowledge gaps in our understanding of and a need to update the traditional view of transmission pathways for respiratory viruses. The long-standing definitions of droplet and airborne transmission do not account for the mechanisms by which virus-laden respiratory droplets and aerosols travel through the air and lead to infection. In this Review, we discuss current evidence regarding the transmission of respiratory viruses by aerosols-how they are generated, transported, and deposited, as well as the factors affecting the relative contributions of droplet-spray deposition versus aerosol inhalation as modes of transmission. Improved understanding of aerosol transmission brought about by studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection requires a reevaluation of the major transmission pathways for other respiratory viruses, which will allow better-informed controls to reduce airborne transmission.
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Affiliation(s)
- Chia C Wang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
| | - Kimberly A Prather
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA.
| | - Josué Sznitman
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
| | - Jose L Jimenez
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
- Department of Chemistry and CIRES, University of Colorado, Boulder, CO 80309, USA
| | - Seema S Lakdawala
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zeynep Tufekci
- School of Information and Department of Sociology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Linsey C Marr
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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27
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Wang CC, Prather KA, Sznitman J, Jimenez JL, Lakdawala SS, Tufekci Z, Marr LC. Airborne transmission of respiratory viruses. Science 2021. [PMID: 34446582 DOI: 10.1126/science:abd9149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
The COVID-19 pandemic has revealed critical knowledge gaps in our understanding of and a need to update the traditional view of transmission pathways for respiratory viruses. The long-standing definitions of droplet and airborne transmission do not account for the mechanisms by which virus-laden respiratory droplets and aerosols travel through the air and lead to infection. In this Review, we discuss current evidence regarding the transmission of respiratory viruses by aerosols-how they are generated, transported, and deposited, as well as the factors affecting the relative contributions of droplet-spray deposition versus aerosol inhalation as modes of transmission. Improved understanding of aerosol transmission brought about by studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection requires a reevaluation of the major transmission pathways for other respiratory viruses, which will allow better-informed controls to reduce airborne transmission.
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Affiliation(s)
- Chia C Wang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
| | - Kimberly A Prather
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA.
| | - Josué Sznitman
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
| | - Jose L Jimenez
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
- Department of Chemistry and CIRES, University of Colorado, Boulder, CO 80309, USA
| | - Seema S Lakdawala
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zeynep Tufekci
- School of Information and Department of Sociology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Linsey C Marr
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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28
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Abstract
AbstractMist is generated by ultrasonic cavitation of water (Fisher Biograde, pH 5.5–6.5) at room temperature (20–25 °C) in open air with nearly constant temperature (22–25 °C) but varying relative humidity (RH; 24–52%) over the course of many months. Water droplets in the mist are initially about 7 μm in diameter at about 50% RH. They are collected, and the concentration of hydrogen peroxide (H2O2) is measured using commercial peroxide test strips and by bromothymol blue oxidation. The quantification method is based on the Fenton chemistry of dye degradation to determine the oxidation capacity of water samples that have been treated by ultrasonication. It is found that the hydrogen peroxide concentration varies nearly linearly with RH over the range studied, reaching a low of 2 parts per million (ppm) at 24% RH and a high of 6 ppm at 52% RH. Some possible public health implications concerning the transmission of respiratory viral infections are suggested for this threefold change in H2O2 concentration with RH.
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Utility of Three Nebulizers in Investigating the Infectivity of Airborne Viruses. Appl Environ Microbiol 2021; 87:e0049721. [PMID: 34085856 DOI: 10.1128/aem.00497-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Laboratory-generated bioaerosols are widely used in aerobiology studies of viruses; however, few comparisons of alternative nebulizers exist. We compared aerosol production and virus survival for a Collison nebulizer, vibrating mesh nebulizer (VMN), and hydraulic spray atomizer (HSA). We also measured the dry size distribution of the aerosols produced and calculated the droplet sizes before evaporation and the dry size distribution from normal saline solution. Dry count median diameters of 0.11, 0.22, and 0.30 μm were found for normal saline from the Collison nebulizer, VMN, and HSA, respectively. The volume median diameters were 0.323, 1.70, and 1.30 μm, respectively. The effect of nebulization on the viability of two influenza A viruses (IAVs) (H1N1 and H3N2) and human rhinovirus 16 (HRV-16) was assessed by nebulization into an SKC BioSampler. The HSA had the least impact on surviving fractions (SFs) of H1N1 and H3N2 (89% ± 3% and 94% ± 2%, respectively), followed by the Collison nebulizer (83% ± 1% and 82% ± 2%, respectively). The VMN yielded SFs of 78% ± 2% and 76% ± 2%, respectively. Conversely, for HRV-16, the VMN produced higher SFs (87% ± 8%). Our findings indicate that there were no statistical differences between SFs of the viruses nebulized by these nebulizers. However, VMN produced higher aerosol concentrations within the airborne size range, making it more suitable where high aerosol mass production is required. IMPORTANCE Viral respiratory tract infections cause millions of lost days of work and physician visits globally, accounting for significant morbidity and mortality. Respiratory droplets and droplet nuclei from infected hosts are the potential carriers of such viruses within indoor environments. Laboratory-generated bioaerosols are applied in understanding the transmission and infection of viruses, modeling the physiological aspects of bioaerosol generation in a controlled environment. However, little comparative characterization exists for nebulizers used in infectious disease aerobiology, including Collison nebulizer, vibrating mesh nebulizer, and hydraulic spray atomizer. This study characterized the physical features of aerosols generated by laboratory nebulizers and their performance in producing aerosols at a size relevant to airborne transmission used in infectious disease aerobiology. We also determined the impact of nebulization mechanisms of these nebulizers on the viability of human respiratory viruses, including IAV H1N1, IAV H3N2, and HRV-16.
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30
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DISPERSION OF AEROSOLIZED BACTERIA FROM ASIAN ELEPHANTS ( ELEPHAS MAXIMUS). J Zoo Wildl Med 2021; 52:749-754. [PMID: 34130422 DOI: 10.1638/2020-0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2021] [Indexed: 11/21/2022] Open
Abstract
Transmission of tuberculosis typically requires close and prolonged contact with an infected individual. However, several cases of transmission between elephants and from elephants to humans or other animals without direct contact or over long distances have been reported. Elephants have been shown to be capable of producing aerosolized bacterial droplets, suggesting a possible route of transmission that is magnified by the size and force of the elephant respiratory tract. To investigate the dispersion and viability of aerosolized bacteria generated from the elephant respiratory tract, a pre-existing model with a proxy organism was used. A six-stage Andersen sampler was used to detect the proxy organism, a commensal elephant respiratory bacterium, at different locations around an elephant barn at a zoo. The amount of proxy organism detected at various time points and distances from the elephants indicates they are capable of dispersing viable bacterial aerosols further than humans can. The concentration of these aerosols is dependent on proximity to the elephants and does not remain at a high level for prolonged periods of time. These findings support the model of aerosol-mediated transmission of bacteria from elephants and can be used to improve disease management practices and prevent the spread of pathogens from elephants in zoos and other facilities.
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31
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Faridi S, Yousefian F, Janjani H, Niazi S, Azimi F, Naddafi K, Hassanvand MS. The effect of COVID-19 pandemic on human mobility and ambient air quality around the world: A systematic review. URBAN CLIMATE 2021; 38:100888. [PMID: 36536793 PMCID: PMC9750834 DOI: 10.1016/j.uclim.2021.100888] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/18/2021] [Accepted: 06/13/2021] [Indexed: 05/19/2023]
Abstract
We conducted this systematic review to identify and appraise studies investigating the coronavirus disease 2019 (COVID-19) effect on ambient air pollution status worldwide. The review of studies was conducted using determined search terms via three major electronic databases (PubMed, Web of Science, and Scopus) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. A total of 26 full-text studies were included in our analysis. The lockdown measures related to COVID-19 pandemic caused significant decreases in the concentrations of PM2.5, NO2, PM10, SO2 and CO globally in the range of 2.9%-76.5%, 18.0%-96.0%, 6.0%-75.0%, 6.8%-49.0% and 6.2%-64.8%, respectively. However, O3 concentration increased in the range of 2.4%-252.3%. The highest decrease of PM2.5 was found in 16 states of Malaysia (76.5%), followed by Zaragoza (Spain) with 58.0% and Delhi (India) with 53.1%. The highest reduction of NO2 was found in Salé city (Morocco) with 96.0%, followed by Mumbai (India) with 75.0%, India with 70.0%, Valencia (Spain) with 69.0%, and São Paulo (Brazil) with 68.0%, respectively. The highest increase of O3 was recorded for Milan (Italy) with 252.3% and 169.9% during the first and third phases of lockdown measures, and for Kolkata (India) with 87% at the second phase of lockdown measures. Owing to the lockdown restrictions in the studied countries and cities, driving and public transit as a proxy of human mobilities and the factors affecting emission sources of ambient air pollution decreased in the ranges of 30-88% and 45-94%, respectively. There was a considerable variation in the reduction of ambient air pollutants in the countries and cities as the degree of lockdown measures had varied there. Our results illustrated that the COVID-19 pandemic had provided lessons and extra motivations for comprehensive implementing policies to reduce air pollution and its health effects in the future.
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Affiliation(s)
- Sasan Faridi
- Centre for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Yousefian
- Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran
| | - Hosna Janjani
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Sadegh Niazi
- Queensland University of Technology (QUT), Faculty of Science, School of Earth and Atmospheric Siences, Brisbane 4001, Australia
| | - Faramarz Azimi
- Department of Environment Health Engineering, Environmental Health Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Kazem Naddafi
- Centre for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sadegh Hassanvand
- Centre for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran
- Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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32
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Smolinska A, Jessop DS, Pappan KL, De Saedeleer A, Kang A, Martin AL, Allsworth M, Tyson C, Bos MP, Clancy M, Morel M, Cooke T, Dymond T, Harris C, Galloway J, Bresser P, Dijkstra N, Jagesar V, Savelkoul PHM, Beuken EVH, Nix WHV, Louis R, Delvaux M, Calmes D, Ernst B, Pollini S, Peired A, Guiot J, Tomassetti S, Budding AE, McCaughan F, Marciniak SJ, van der Schee MP. The SARS-CoV-2 viral load in COVID-19 patients is lower on face mask filters than on nasopharyngeal swabs. Sci Rep 2021; 11:13476. [PMID: 34188082 PMCID: PMC8242000 DOI: 10.1038/s41598-021-92665-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/08/2021] [Indexed: 11/22/2022] Open
Abstract
Face masks and personal respirators are used to curb the transmission of SARS-CoV-2 in respiratory droplets; filters embedded in some personal protective equipment could be used as a non-invasive sample source for applications, including at-home testing, but information is needed about whether filters are suited to capture viral particles for SARS-CoV-2 detection. In this study, we generated inactivated virus-laden aerosols of 0.3–2 microns in diameter (0.9 µm mean diameter by mass) and dispersed the aerosolized viral particles onto electrostatic face mask filters. The limit of detection for inactivated coronaviruses SARS-CoV-2 and HCoV-NL63 extracted from filters was between 10 to 100 copies/filter for both viruses. Testing for SARS-CoV-2, using face mask filters and nasopharyngeal swabs collected from hospitalized COVID-19-patients, showed that filter samples offered reduced sensitivity (8.5% compared to nasopharyngeal swabs). The low concordance of SARS-CoV-2 detection between filters and nasopharyngeal swabs indicated that number of viral particles collected on the face mask filter was below the limit of detection for all patients but those with the highest viral loads. This indicated face masks are unsuitable to replace diagnostic nasopharyngeal swabs in COVID-19 diagnosis. The ability to detect nucleic acids on face mask filters may, however, find other uses worth future investigation.
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Affiliation(s)
- Agnieszka Smolinska
- Owlstone Medical Ltd., Cambridge, Cambridgeshire, UK.,Department of Pharmacology and Toxicology, Maastricht University, Maastricht, The Netherlands
| | | | - Kirk L Pappan
- Owlstone Medical Ltd., Cambridge, Cambridgeshire, UK
| | | | - Amerjit Kang
- Owlstone Medical Ltd., Cambridge, Cambridgeshire, UK
| | | | - Max Allsworth
- Owlstone Medical Ltd., Cambridge, Cambridgeshire, UK
| | | | | | | | - Mike Morel
- Cambridge Clinical Laboratories Ltd., Cambridge, Cambridgeshire, UK
| | - Tony Cooke
- Cambridge Clinical Laboratories Ltd., Cambridge, Cambridgeshire, UK
| | - Tom Dymond
- Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK
| | - Claire Harris
- Department of Medicine, Addenbrooke's Hospital, Cambridge, UK.,University of Cambridge, Cambridge, UK
| | - Jacqui Galloway
- Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK
| | | | | | | | - Paul H M Savelkoul
- Department of Medical Microbiology, Maastricht University Medical Center, Care and Public Health Research Institute (Caphri), Maastricht, The Netherlands
| | - Erik V H Beuken
- Department of Medical Microbiology, Maastricht University Medical Center, Care and Public Health Research Institute (Caphri), Maastricht, The Netherlands
| | - Wesley H V Nix
- Department of Medical Microbiology, Maastricht University Medical Center, Care and Public Health Research Institute (Caphri), Maastricht, The Netherlands
| | - Renaud Louis
- Repiratory Department, CHU Liège, Liège, Belgium
| | | | | | - Benoit Ernst
- Repiratory Department, CHU Liège, Liège, Belgium
| | - Simona Pollini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.,Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy
| | - Anna Peired
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
| | - Julien Guiot
- Repiratory Department, CHU Liège, Liège, Belgium
| | - Sara Tomassetti
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.,Interventional Pulmonology Unit, Careggi University Hospital, Florence, Italy
| | | | - Frank McCaughan
- Department of Medicine, Addenbrooke's Hospital, Cambridge, UK.,University of Cambridge, Cambridge, UK
| | - Stefan J Marciniak
- Department of Medicine, Addenbrooke's Hospital, Cambridge, UK.,University of Cambridge, Cambridge, UK
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33
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Groth R, Cravigan LT, Niazi S, Ristovski Z, Johnson GR. In situ measurements of human cough aerosol hygroscopicity. J R Soc Interface 2021; 18:20210209. [PMID: 33947221 PMCID: PMC8097516 DOI: 10.1098/rsif.2021.0209] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 04/12/2021] [Indexed: 12/13/2022] Open
Abstract
The airborne dynamics of respiratory droplets, and the transmission routes of pathogens embedded within them, are governed primarily by the diameter of the particles. These particles are composed of the fluid which lines the respiratory tract, and is primarily mucins and salts, which will interact with the atmosphere and evaporate to reach an equilibrium diameter. Measuring organic volume fraction (OVF) of cough aerosol has proved challenging due to large variability and low material volume produced after coughing. Here, the diametric hygroscopic growth factors (GF) of the cough aerosol produced by healthy participants were measured in situ using a rotating aerosol suspension chamber and a humidification tandem differential mobility analyser. Using hygroscopicity models, it was estimated that the average OVF in the evaporated cough aerosol was 0.88 ± 0.07 and the average GF at 90% relative humidity (RH) was 1.31 ± 0.03. To reach equilibrium in dry air the droplets will reduce in diameter by a factor of approximately 2.8 with an evaporation factor of 0.36 ± 0.05. Hysteresis was observed in cough aerosol at RH = ∼35% and RH = ∼65% for efflorescence and deliquescence, respectively, and may depend on the OVF. The same behaviour and GF were observed in nebulized bovine bronchoalveolar lavage fluid.
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Affiliation(s)
- Robert Groth
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia
| | - Luke T. Cravigan
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia
| | - Sadegh Niazi
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia
| | - Zoran Ristovski
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia
| | - Graham R. Johnson
- International Laboratory for Air Quality and Health (ILAQH), School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, Australia
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Liu J, Liu J, He Z, Yang Z, Yuan J, Wu H, Zhu P, Fu X, Lin Y, Zhang Y, Zhao Z, He S, Ma X. Duration of SARS-CoV-2 positive in quarantine room environments: A perspective analysis. Int J Infect Dis 2021; 105:68-74. [PMID: 33578005 PMCID: PMC7872842 DOI: 10.1016/j.ijid.2021.02.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/02/2021] [Accepted: 02/05/2021] [Indexed: 12/12/2022] Open
Abstract
Objective To determine the duration of SARS-CoV-2 persistence in quarantine hotel environments. Methods 39 Patients confirmed by RT-PCR were included. We collected clinical features, laboratory test results, smear sample information, and quarantine room information. Genome sequencing and phylogenetic analysis were conducted. We analyzed the factors associated with environmental contamination. Result Among 39 COVID-19 cases, 10 were asymptomatic and 37 were imported from aboard. We collected 271 swab samples from environmental surfaces related to observational patients. Eighteen swab samples from seven patients were positive. The highest contamination rates occurred on cups (100%), followed by hand sink (12.82%), toilet seat and flush (7.89%), telephone (5.56%), bedside table (5.56%), and floor drain (5.41%). The results showed that environmental surface contamination was associated with the clinical cycle threshold values for patients (P = 0.01) and the sampling interval time after the cases left their rooms (P = 0.03). The duration of environmental surface contamination was associated with the wet status of the sampling site (P = 0.01). Conclusion Our findings showed that environmental contamination might be attributed to the viral load in the respiratory tracts of patients and the sampling interval time after the cases left their rooms. Moist surfaces were more vulnerable to remaining SARS-CoV-2 RNA-positive. Our study highlights the importance of implementing strict chemical disinfection strategies in quarantine rooms.
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Affiliation(s)
- Jie Liu
- Department of Disinfection, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Jingwen Liu
- Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Zheng He
- Department of Disinfection, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Zhicong Yang
- Director Office, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Jun Yuan
- Director Office, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Haoying Wu
- Department of Disinfection, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Pingting Zhu
- Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Xuesong Fu
- Department of School Health, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Yunwan Lin
- Department of Disinfection, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Ying Zhang
- Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Zhengyang Zhao
- Department of Disinfection, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Shiyu He
- Department of Disinfection, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China
| | - Xiaowei Ma
- Department of Public Health Emergency Response, Guangzhou Center for Disease Control and Prevention, Baiyun District Qi De Road in Guangzhou, Guangdong Province, 510440, China.
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