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Ruuskanen O, Dollner H, Luoto R, Valtonen M, Heinonen OJ, Waris M. Contraction of Respiratory Viral Infection During air Travel: An Under-Recognized Health Risk for Athletes. SPORTS MEDICINE - OPEN 2024; 10:60. [PMID: 38776030 PMCID: PMC11111432 DOI: 10.1186/s40798-024-00725-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 05/09/2024] [Indexed: 05/25/2024]
Abstract
Air travel has an important role in the spread of viral acute respiratory infections (ARIs). Aircraft offer an ideal setting for the transmission of ARI because of a closed environment, crowded conditions, and close-contact setting. Numerous studies have shown that influenza and COVID-19 spread readily in an aircraft with one virus-positive symptomatic or asymptomatic index case. The numbers of secondary cases differ markedly in different studies most probably because of the wide variation of the infectiousness of the infector as well as the susceptibility of the infectees. The primary risk factor is sitting within two rows of an infectious passenger. Elite athletes travel frequently and are thus prone to contracting an ARI during travel. It is anecdotally known in the sport and exercise medicine community that athletes often contract ARI during air travel. The degree to which athletes are infected in an aircraft by respiratory viruses is unclear. Two recent studies suggest that 8% of Team Finland members traveling to major winter sports events contracted the common cold most probably during air travel. Further prospective clinical studies with viral diagnostics are needed to understand the transmission dynamics and to develop effective and socially acceptable preventive measures during air travel.
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Affiliation(s)
- Olli Ruuskanen
- Department of Paediatrics and Adolescent Medicine, Turku University Hospital and University of Turku, PL 52, 20521, Turku, Finland
| | - Henrik Dollner
- Department of Clinical and Molecular Medicine, Children's Clinic, St. Olavs University Hospital, Norwegian University of Science and Technology, Trondheim, Norway
| | - Raakel Luoto
- Department of Paediatrics and Adolescent Medicine, Turku University Hospital and University of Turku, PL 52, 20521, Turku, Finland
| | | | - Olli J Heinonen
- Paavo Nurmi Centre and Unit for Health and Physical Activity, University of Turku, Turku, Finland
| | - Matti Waris
- Institute of Biomedicine, University of Turku and Department of Clinical Virology, Turku University Hospital, Kiinamyllynkatu 10, 20520, Turku, Finland.
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Pan Y, Huang W, Dai HK, Bian Y, Ho KF, Chen C. Evaluation of intervention measures in reducing the driver's exposure to respiratory particles in a taxi with infected passengers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 902:166099. [PMID: 37558075 DOI: 10.1016/j.scitotenv.2023.166099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 08/02/2023] [Accepted: 08/05/2023] [Indexed: 08/11/2023]
Abstract
In the fifth wave of the COVID-19 epidemic in Hong Kong in early 2022, the large number of infected persons caused a shortage of ambulances and transportation vehicles operated by the government. To solve the problem, taxi drivers were recruited to transport infected persons to hospitals in their taxis. However, many of the drivers were infected after they began to participate in the plan. To tackle this issue, the present study numerically evaluated the effectiveness of several intervention measures in reducing the infection risk for taxi drivers. First, experiments were conducted inside a car to validate the large-eddy simulation (LES)-Lagrangian model for simulation of particle transport in a car. The validated model was then applied to calculate the particle dispersion and deposition in a Hong Kong taxi with intervention measures that included opening windows, installing partitions, and using a far-UVC lamp. The results show that opening the windows can significantly reduce the driver's total exposure by 97.4 %. Installing partitions and using a far-UVC lamp can further reduce the infection risk of driver by 55.9 % and 32.1 %, respectively. The results of this study can be used to support the implementation of effective intervention measures to protect taxi drivers from infection.
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Affiliation(s)
- Yue Pan
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China
| | - Wenjie Huang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China
| | - Ho Kam Dai
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China
| | - Ye Bian
- School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Kin-Fai Ho
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China.
| | - Chun Chen
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China; Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong SAR, China.
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Liang J, Zou G, Gu C, Tao S, Guo L, Tang C, Zhang J, Deng Z, Chen Y. Study on skin infection model of Staphylococcus aureus based on analytic hierarchy process and Delphi method. Heliyon 2023; 9:e16327. [PMID: 37287617 PMCID: PMC10241873 DOI: 10.1016/j.heliyon.2023.e16327] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 06/09/2023] Open
Abstract
Purpose Infectious skin diseases are a type of inflammatory skin lesions caused by pathogenic microorganisms. Because of the uncertainty of methodology, the skin infection model usually have low replication rate and lack of good evaluation system. We aimed to establish multi-index and comprehensive evaluation method for Staphylococcus aureus (S.aureus) skin-infection models through Analytic hierarchy process (AHP) and Delphi method, and screen high quality animal models through it. Materials and methods Firstly, the evaluation indicators of skin infection were collected basing on literature research. The weight of the evaluation indicators were decided according to AHP and Delphi method. Then different ulcer models (mouse or rat) infected by S. aureus were selected as the research objects. Results The evaluation indicators were classified into four groups of criteria (including ten sub-indicators) and given different weights, physical sign changes (0.0518), skin lesion appearance (0.2934), morphological observation (0.3184), etiological examination (0.3364). Through the evaluation system, we screened and found that the mouse ulcer model which caused by a round wound and 1.0 × 1010 CFU/mL (0.1 mL) bacterial concentration got the highest comprehensive score, and also found that the model which caused by a 1.5 cm-round wound and 1.0 × 1010 CFU/mL (0.2 mL) maybe the best rat ulcer model. Conclusions This study has established an evaluation system based on AHP and Delphi method, also provided the best skin ulcer models selected by this system, the models are suitable for disease research and drug development research of skin ulcer.
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Affiliation(s)
- Jiaxin Liang
- Guangdong Pharmaceutical University, Guangzhou, PR China
| | - Guofa Zou
- Guangdong Pharmaceutical University, Guangzhou, PR China
| | - Chiming Gu
- The Second Clinical Medical College of Guangzhou University of Chinese Medicine; Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China
| | - Shuhong Tao
- Guangdong Pharmaceutical University, Guangzhou, PR China
| | - Libing Guo
- Guangdong Pharmaceutical University, Guangzhou, PR China
| | - Chunping Tang
- Guangdong Pharmaceutical University, Guangzhou, PR China
| | - Jinhong Zhang
- Guangdong Pharmaceutical University, Guangzhou, PR China
| | - Zujun Deng
- Guangdong Pharmaceutical University, Guangzhou, PR China
| | - Yanfen Chen
- Guangdong Pharmaceutical University, Guangzhou, PR China
- Guangzhou Key Laboratory of Construction and Application of New Drug Screening Model Systems, Guangzhou, PR China
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Wang F, Zhang TT, You R, Chen Q. Evaluation of infection probability of Covid-19 in different types of airliner cabins. BUILDING AND ENVIRONMENT 2023; 234:110159. [PMID: 36895516 PMCID: PMC9977471 DOI: 10.1016/j.buildenv.2023.110159] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/24/2023] [Accepted: 02/27/2023] [Indexed: 06/09/2023]
Abstract
According to the World Health Organization (https://covid19.who.int/), more than 651 million people have been infected by COVID-19, and more than 6.6 million of them have died. COVID-19 has spread to almost every country in the world because of air travel. Cases of COVID-19 transmission from an index patient to fellow passengers in commercial airplanes have been widely reported. This investigation used computational fluid dynamics (CFD) to simulate airflow and COVID-19 virus (SARS-CoV-2) transport in a variety of airliner cabins. The cabins studied were economy-class with 2-2, 3-3, 2-3-2, and 3-3-3 seat configurations, respectively. The CFD results were validated by using experimental data from a seven-row cabin mockup with a 3-3 seat configuration. This study used the Wells-Riley model to estimate the probability of infection with SARS-CoV-2. The results show that CFD can predict airflow and virus transmission with acceptable accuracy. With an assumed flight time of 4 h, the infection probability was almost the same among the different cabins, except that the 3-3-3 configuration had a lower risk because of its airflow pattern. Flying time was the most important parameter for causing the infection, while cabin type also played a role. Without mask wearing by the passengers and the index patient, the infection probability could be 8% for a 10-h, long-haul flight, such as a twin-aisle air cabin with 3-3-3 seat configuration.
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Affiliation(s)
- Feng Wang
- Tianjin Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, China
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Tengfei Tim Zhang
- Tianjin Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, China
- School of Civil Engineering, Dalian University of Technology, Dalian, China
| | - Ruoyu You
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Qingyan Chen
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
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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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Yang YF, Lin YJ, You SH, Lu TH, Chen CY, Wang WM, Liao CM. Control measure implications of COVID-19 infection in healthcare facilities reconsidered from human physiological and engineering aspects. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:36228-36243. [PMID: 36547825 PMCID: PMC9772602 DOI: 10.1007/s11356-022-24815-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
The Wells-Riley model invokes human physiological and engineering parameters to successfully treat airborne transmission of infectious diseases. Applications of this model would have high potentiality on evaluating policy actions and interventions intended to improve public safety efforts on preventing the spread of COVID-19 in an enclosed space. Here, we constructed the interaction relationships among basic reproduction number (R0) - exposure time - indoor population number by using the Wells-Riley model to provide a robust means to assist in planning containment efforts. We quantified SARS-CoV-2 changes in a case study of two Wuhan (Fangcang and Renmin) hospitals. We conducted similar approach to develop control measures in various hospital functional units by taking all accountable factors. We showed that inhalation rates of individuals proved crucial for influencing the transmissibility of SARS-CoV-2, followed by air supply rate and exposure time. We suggest a minimum air change per hour (ACH) of 7 h-1 would be at least appropriate with current room volume requirements in healthcare buildings when indoor population number is < 10 and exposure time is < 1 h with one infector and low activity levels being considered. However, higher ACH (> 16 h-1) with optimal arranged-exposure time/people and high-efficiency air filters would be suggested if more infectors or higher activity levels are presented. Our models lay out a practical metric for evaluating the efficacy of control measures on COVID-19 infection in built environments. Our case studies further indicate that the Wells-Riley model provides a predictive and mechanistic basis for empirical COVID-19 impact reduction planning and gives a framework to treat highly transmissible but mechanically heterogeneous airborne SARS-CoV-2.
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Affiliation(s)
- Ying-Fei Yang
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Yi-Jun Lin
- Institute of Food Safety and Health Risk Assessment, National Yang Ming Chia Tung University, Taipei, 11221, Taiwan
| | - Shu-Han You
- Institute of Food Safety and Risk Management, National Taiwan Ocean University, Keelung City, 20224, Taiwan
| | - Tien-Hsuan Lu
- Department of Environmental Engineering, Da-Yeh University, Changhua, 515006, Taiwan
| | - Chi-Yun Chen
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Wei-Min Wang
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Chung-Min Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan.
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Ye Q, Zhou R, Asmi F. Evaluating the Impact of the Pandemic Crisis on the Aviation Industry. TRANSPORTATION RESEARCH RECORD 2023; 2677:1551-1566. [PMID: 37063707 PMCID: PMC10083695 DOI: 10.1177/03611981221125741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
This paper investigates the intellectual structure of the literature addressing "epidemic/pandemic" and "aviation industry" through a bibliometric approach to the literature from 1991 to 2021. The final count of 856 publications was collected from Web of Science and analyzed by CiteSpace (version 5.8.R1) and VOS Viewer. Visualization tools are used to perform the co-citation, co-occurrence, and thematic-based cluster analysis. The results highlight the most prominent nodes (articles, authors, journals, countries, and institutions) within the literature on "epidemic/pandemic" and "aviation industry." Furthermore, this study conceptualizes and compares the growth of literature before theCOVID-19 pandemic and during the COVID-19 ("hotspot") era. The conclusion is that the aviation industry is an engine for global economics on the road to recovery from COVID-19, in which soft (human) resources can play an integral part.
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Affiliation(s)
- Qing Ye
- University of Science and Technology of
China, Hefei, Anhui, China
- FuYang Normal University, FuYang, Anhui,
China
| | - Rongting Zhou
- University of Science and Technology of
China, Hefei, Anhui, China
| | - Fahad Asmi
- University of Science and Technology of
China, Hefei, Anhui, China
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8
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Jones DL, Rhymes JM, Green E, Rimmer C, Kevill JL, Malham SK, Weightman AJ, Farkas K. Poor air passenger knowledge of COVID-19 symptoms and behaviour undermines strategies aimed at preventing the import of SARS-CoV-2 into the UK. Sci Rep 2023; 13:3494. [PMID: 36859503 PMCID: PMC9976683 DOI: 10.1038/s41598-023-30654-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 02/27/2023] [Indexed: 03/03/2023] Open
Abstract
Air travel mediates transboundary movement of SARS-CoV-2. To prepare for future pandemics, we sought to understand air passenger behaviour and perceived risk during the COVID-19 pandemic. This study of UK adults (n = 2103) quantified knowledge of COVID-19 symptoms, perceived health risk of contracting COVID-19, likelihood of returning to the UK with COVID-19 symptoms, likelihood to obey self-quarantining guidelines, how safe air travellers felt when flying during the pandemic (n = 305), and perceptions towards face covering effectiveness.Overall knowledge of COVID-19 symptoms was poor. Men and younger age groups (18-44) were less informed than women and older age groups (44 +). A significant proportion (21%) of the population would likely travel back to the UK whilst displaying COVID-19 symptoms with many expressing that they would not fully comply with self-isolation guidelines. Overall, males and younger age groups had a reduced perceived personal risk from contracting COVID-19, posing a higher risk of transporting SARS-CoV-2 back to the UK. Poor passenger knowledge and behaviour undermines government guidelines and policies aimed at preventing SARS-CoV-2 entry into the UK. This supports the need for stricter, clearer and more targeted guidelines with point-of-departure viral testing and stricter quarantining upon arrival.
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Affiliation(s)
- David. L. Jones
- grid.7362.00000000118820937Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, LL57 2UW Gwynedd UK ,grid.1025.60000 0004 0436 6763SoilsWest, Centre for Sustainable Farming Systems, Food Futures Institute, Murdoch University, Murdoch, WA 6105 Australia
| | - Jennifer M. Rhymes
- grid.7362.00000000118820937Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, LL57 2UW Gwynedd UK ,grid.494924.60000 0001 1089 2266UK Centre for Ecology and Hydrology, Environment Centre Wales, Bangor, LL57 2UW Gwynedd UK
| | - Emma Green
- grid.7362.00000000118820937Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, LL57 2UW Gwynedd UK
| | - Charlotte Rimmer
- grid.7362.00000000118820937Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, LL57 2UW Gwynedd UK
| | - Jessica L. Kevill
- grid.7362.00000000118820937Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, LL57 2UW Gwynedd UK
| | - Shelagh K. Malham
- grid.7362.00000000118820937School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB Anglesey UK
| | - Andrew J. Weightman
- grid.5600.30000 0001 0807 5670Microbiomes, Microbes and Informatics Group, School of Biosciences, Cardiff University, Cardiff, CF10 3AX UK
| | - Kata Farkas
- grid.7362.00000000118820937Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, LL57 2UW Gwynedd UK ,grid.7362.00000000118820937School of Ocean Sciences, Bangor University, Menai Bridge, LL59 5AB Anglesey UK
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Aganovic A, Cao G, Kurnitski J, Melikov A, Wargocki P. Zonal modeling of air distribution impact on the long-range airborne transmission risk of SARS-CoV-2. APPLIED MATHEMATICAL MODELLING 2022; 112:800-821. [PMID: 36060304 PMCID: PMC9420246 DOI: 10.1016/j.apm.2022.08.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 08/15/2022] [Accepted: 08/25/2022] [Indexed: 05/10/2023]
Abstract
A widely used analytical model to quantitatively assess airborne infection risk is the Wells-Riley model which is limited to complete air mixing in a single zone. However, this assumption tends not to be feasible (or reality) for many situations. This study aimed to extend the Wells-Riley model so that the infection risk can be calculated in spaces where complete mixing is not present. Some more advanced ventilation concepts create either two horizontally divided air zones in spaces as displacement ventilation or the space may be divided into two vertical zones by downward plane jet as in protective-zone ventilation systems. This is done by evaluating the time-dependent distribution of infectious quanta in each zone and by solving the coupled system of differential equations based on the zonal quanta concentrations. This model introduces a novel approach by estimating the interzonal mixing factor based on previous experimental data for three types of ventilation systems: incomplete mixing ventilation, displacement ventilation, and protective zone ventilation. The modeling approach is applied to a room with one infected and one susceptible person present. The results show that using the Wells-Riley model based on the assumption of completely air mixing may considerably overestimate or underestimate the long-range airborne infection risk in rooms where air distribution is different than complete mixing, such as displacement ventilation, protected zone ventilation, warm air supplied from the ceiling, etc. Therefore, in spaces with non-uniform air distribution, a zonal modeling approach should be preferred in analytical models compared to the conventional single-zone Wells-Riley models when assessing long-range airborne transmission risk of infectious respiratory diseases.
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Affiliation(s)
- Amar Aganovic
- Department of Automation and Process Engineering, UiT The Arctic University of Norway, Postboks 6050 Langnes, Tromsø 9037, Norway
| | - Guangyu Cao
- Department of Energy and Process Engineering, Norwegian University of Science and Technology - NTNU, Trondheim, Norway
| | - Jarek Kurnitski
- REHVA Technology and Research Committee, Tallinn University of Technology, Tallinn, Estonia
| | - Arsen Melikov
- Department of Civil Engineering, Technical University of Denmark, Copenhagen, Denmark
| | - Pawel Wargocki
- Department of Civil Engineering, Technical University of Denmark, Copenhagen, Denmark
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Zhen Q, Zhang A, Huang Q, Li J, Du Y, Zhang Q. Overview of the Role of Spatial Factors in Indoor SARS-CoV-2 Transmission: A Space-Based Framework for Assessing the Multi-Route Infection Risk. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:11007. [PMID: 36078723 PMCID: PMC9518419 DOI: 10.3390/ijerph191711007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 06/15/2023]
Abstract
The COVID-19 pandemic has lasted from 2019 to 2022, severely disrupting human health and daily life. The combined effects of spatial, environmental, and behavioral factors on indoor COVID-19 spread and their interactions are usually ignored. Especially, there is a lack of discussion on the role of spatial factors in reducing the risk of virus transmission in complex and diverse indoor environments. This paper endeavours to summarize the spatial factors and their effects involved in indoor virus transmission. The process of release, transport, and intake of SARS-CoV-2 was reviewed, and six transmission routes according to spatial distance and exposure way were classified. The triangular relationship between spatial, environmental and occupant behavioral parameters during virus transmission was discussed. The detailed effects of spatial parameters on droplet-based, surface-based and air-based transmission processes and virus viability were summarized. We found that spatial layout, public-facility design and openings have a significant indirect impact on the indoor virus distribution and transmission by affecting occupant behavior, indoor airflow field and virus stability. We proposed a space-based indoor multi-route infection risk assessment framework, in which the 3D building model containing detailed spatial information, occupant behavior model, virus-spread model and infection-risk calculation model are linked together. It is also applicable to other, similar, respiratory infectious diseases such as SARS, influenza, etc. This study contributes to developing building-level, infection-risk assessment models, which could help building practitioners make better decisions to improve the building's epidemic-resistance performance.
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Affiliation(s)
- Qi Zhen
- School of Architecture, Tianjin University, Tianjin 300072, China
| | - Anxiao Zhang
- School of Architecture, Tianjin University, Tianjin 300072, China
| | - Qiong Huang
- School of Architecture, Tianjin University, Tianjin 300072, China
| | - Jing Li
- Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin 300072, China
| | - Yiming Du
- School of Architecture, Tianjin University, Tianjin 300072, China
| | - Qi Zhang
- School of Architecture, Tianjin University, Tianjin 300072, China
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11
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Izadyar N, Miller W. Ventilation strategies and design impacts on indoor airborne transmission: A review. BUILDING AND ENVIRONMENT 2022; 218:109158. [PMID: 35573806 PMCID: PMC9075988 DOI: 10.1016/j.buildenv.2022.109158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/26/2022] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
The COVID-19 outbreak has brought the indoor airborne transmission issue to the forefront. Although ventilation systems provide clean air and dilute indoor contaminated air, there is strong evidence that airborne transmission is the main route for contamination spread. This review paper aims to critically investigate ventilation impacts on particle spread and identify efficient ventilation strategies in controlling aerosol distribution in clinical and non-clinical environments. This article also examines influential ventilation design features (i.e., exhaust location) affecting ventilation performance in preventing aerosols spread. This paper shortlisted published documents for a review based on identification (keywords), pre-processing, screening, and eligibility of these articles. The literature review emphasizes the importance of ventilation systems' design and demonstrates all strategies (i.e., mechanical ventilation) could efficiently remove particles if appropriately designed. The study highlights the need for occupant-based ventilation systems, such as personalized ventilation instead of central systems, to reduce cross-infections. The literature underlines critical impacts of design features like ventilation rates and the number and location of exhausts and suggests designing systems considering airborne transmission. This review underpins that a higher ventilation rate should not be regarded as a sole indicator for designing ventilation systems because it cannot guarantee reducing risks. Using filtration and decontamination devices based on building functionalities and particle sizes can also increase ventilation performance. This paper suggests future research on optimizing ventilation systems, particularly in high infection risk spaces such as multi-storey hotel quarantine facilities. This review contributes to adjusting ventilation facilities to control indoor aerosol transmission.
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Affiliation(s)
- Nima Izadyar
- School of Built Environment, College of Engineering and Science, Victoria University, Melbourne, VIC, Australia
| | - Wendy Miller
- School of Architecture & Built Environment, Science and Engineering Faculty, Queensland University of Technology (QUT), Brisbane, QLD, 4001, Australia
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12
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Numerical Investigation on the Droplet Dispersion inside a Bus and the Infection Risk Prediction. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12125909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
COVID-19 can be easily transmitted to passengers by inhaling exhaled droplets from the infected person in a bus. Therefore, studying droplet dispersion would provide further insight into the mechanism of virus transmission and predict the risk of infection among passengers on a bus. In this research, a bus equipped with air-conditioning was employed as the research object. To determine the dispersion path, concentration distribution, and escape time of the droplets, computational fluid dynamic (CFD) was applied to simulate the flow field and the droplets’ dispersion. The effect of the air supply rate, the location of vents, and the location of infected persons on the dispersion were discussed. Based on the distribution of droplets in the cabin calculated by CFD, a superposition method was used to determine the number of virus particles inhaled by every individual passenger over a four-hour journey. Then, infection risk was assessed by the Wells-Riley equation for all the passengers in the cabin after the whole journey. The results show that the distribution of droplets in the cabin is greatly influenced by the location of the infected person, and the airflow pattern is highly associated with the air supply rate and the location of vents. The infection risk of passengers located at the droplet dispersion path and the distance from the infected persons less than 2.2 m is over 10%. The increase in the air supply rate could speed up the spread of the droplets but at the same time, it could reduce the infection risk.
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Model and Validation Study for Optimizing Students’ Positions in Classrooms to Limit the Spread of Infectious Diseases Such as COVID. EDUCATION SCIENCES 2022. [DOI: 10.3390/educsci12060390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Classrooms at any educational institution have become high-risk sites for contagion during past and present pandemic periods caused by the SARS-CoV-2 (COVID-19) viral siege, given the prolonged time educators and students spend in joint activity. Among the several strategies employed by educational institutions to minimize the outbreak of contagion are regulating classroom capacity and studying the optimal spatial arrangement of students. The architectural features of each classroom, which include corridors, ventilation components, total volume, and maximum capacity, among other factors, have a direct impact on the risk of human contagion. This work is a proposal to optimize the spatial arrangement of students to minimize the risk of contagion, considering not only the distance between them, but also the different architectural features in the classrooms. The analyses conducted in the different scenarios conclude with a comparison of risk in terms of the arrangement of students that various educators would have used at different education levels in their classrooms based solely on intuitive criteria. The results indicate that in some situations, the locations chosen by educators can double the risk of infection compared to optimal arrangements.
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14
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Identifying mitigation strategies for COVID-19 superspreading on flights using models that account for passenger movement. Travel Med Infect Dis 2022; 47:102313. [PMID: 35306163 PMCID: PMC8925197 DOI: 10.1016/j.tmaid.2022.102313] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 03/10/2022] [Accepted: 03/14/2022] [Indexed: 11/24/2022]
Abstract
Background Despite commercial airlines mandating masks, there have been multiple documented events of COVID-19 superspreading on flights. Conventional models do not adequately explain superspreading patterns on flights, with infection spread wider than expected from proximity based on passenger seating. An important reason for this is that models typically do not consider the movement of passengers during the flight, boarding, or deplaning. Understanding the risks for each of these aspects could provide insight into effective mitigation measures. Methods We modeled infection risk from seating and fine-grained movement patterns – boarding, deplaning, and inflight movement. We estimated infection model parameters from a prior superspreading event. We validated the model and the impact of interventions using available data from three flights, including cabin layout and seat locations of infected and uninfected passengers, to suggest interventions to mitigate COVID-19 superspreading events during air travel. Specifically, we studied: 1) London to Hanoi with 201 passengers, including 13 secondary infections among passengers; 2) Singapore to Hangzhou with 321 passengers, including 12 to 14 secondary infections; 3) a non-superspreading event on a private jet in Japan with 9 passengers and no secondary infections. Results Our results show that the inclusion of passenger movement better explains the infection spread patterns than conventional models do. We also found that FFP2/N95 mask usage would have reduced infection by 95–100%, while cloth masks would have reduced it by only 40–80%. Results indicate that leaving the middle seat vacant is effective in reducing infection, and the effectiveness increases when combined with good quality masks. However, with a good mask, the risk is quite low even without the middle seats being empty. Conclusions Our results suggest the need for more stringent guidelines to reduce aviation-related superspreading events of COVID-19.
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15
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Wang F, You R, Zhang T, Chen Q. Recent progress on studies of airborne infectious disease transmission, air quality, and thermal comfort in the airliner cabin air environment. INDOOR AIR 2022; 32:e13032. [PMID: 35481932 PMCID: PMC9111434 DOI: 10.1111/ina.13032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 03/03/2022] [Accepted: 03/17/2022] [Indexed: 05/08/2023]
Abstract
Airborne transmission of infectious diseases through air travel has become a major concern, especially during the COVID-19 pandemic. The flying public and crew members have long demanded better air quality and thermal comfort in commercial airliner cabins. This paper reviewed studies related to the airliner cabin air environment that have been published in scientific journals since 2000, to understand the state-of-the-art in cabin air environment design and the efforts made to improve this environment. In this critical review, this paper discusses the challenges and opportunities in studying the cabin air environment. The literature review concluded that current environmental control systems for airliner cabins have done little to stop the airborne transmission of infectious diseases. There were no reports of significant air quality problems in cabins, although passengers and crew members have complained of some health-related issues. The air temperature in cabins needs to be better controlled, and therefore, better thermal comfort models for airliners should be developed. Low humidity is a major complaint from passengers and crew members. Gaspers are used by passengers to adjust thermal comfort, but they do not improve air quality. Various personalized and displacement ventilation systems have been developed to improve air quality and thermal comfort. Air cleaning technologies need to be further developed. Good tools are available for designing a better cabin air environment.
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Affiliation(s)
- Feng Wang
- Tianjin Key Laboratory of Indoor Air Environmental Quality ControlSchool of Environmental Science and EngineeringTianjin UniversityTianjinChina
- Department of Building Environment and Energy EngineeringThe Hong Kong Polytechnic UniversityKowloon, Hong Kong SARChina
| | - Ruoyu You
- Department of Building Environment and Energy EngineeringThe Hong Kong Polytechnic UniversityKowloon, Hong Kong SARChina
| | - Tengfei Zhang
- Tianjin Key Laboratory of Indoor Air Environmental Quality ControlSchool of Environmental Science and EngineeringTianjin UniversityTianjinChina
| | - Qingyan Chen
- Department of Building Environment and Energy EngineeringThe Hong Kong Polytechnic UniversityKowloon, Hong Kong SARChina
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16
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Exposure Risk to Medical Staff in a Nasopharyngeal Swab Sampling Cabin under Four Different Ventilation Strategies. BUILDINGS 2022. [DOI: 10.3390/buildings12030353] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Medical staff working in a nasopharyngeal swab sampling cabin are exposed to a higher exposure risk of COVID-19. In this study, computational fluid dynamics (CFD) are used to evaluate the exposure risk to medical staff in a nasopharyngeal swab sampling cabin of Chinese customs under four different ventilation strategies, i.e., multiple supply fans ventilation (MSFV), multiple exhaust fans ventilation (MEFV), single exhaust fan and outer windows closed ventilation (SEFV), and single exhaust fan and outer windows opened ventilation (SEFV-W). The impact of physical partitions on exposure risk is also discussed. The results show that MSFV performed best in reducing exposure risk. No significant difference was found between MEFV and SEFV. SEFV-W performed better than SEFV with a ventilation rate of 10–50 L/(s∙Person), while it performed worse with a ventilation rate of 50–90 L/(s∙Person). The exposure risk to medical staff did not decrease linearly with the increase in the ventilation flow rate under the four ventilation strategies. For MSFV, the installation of partitions is conducive to the reduction in the exposure risk. This study is expected to provide some guidance for ventilation designs in sampling cabins.
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17
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Salthammer T, Fauck C, Omelan A, Wientzek S, Uhde E. Time and spatially resolved tracking of the air quality in local public transport. Sci Rep 2022; 12:3262. [PMID: 35228615 PMCID: PMC8885640 DOI: 10.1038/s41598-022-07290-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/16/2022] [Indexed: 12/28/2022] Open
Abstract
As an indoor environment, public transport is subject to special conditions with many passengers in a comparatively small space. Therefore, both an efficient control of the climatic parameters and a good air exchange are necessary to avoid transmission and spread of respiratory diseases. However, in such a dynamic system it is practically impossible to determine pathogenic substances with the necessary temporal and spatial resolution, but easy-to-measure parameters allow the air quality to be assessed in a passenger compartment. Carbon dioxide has already proven to be a useful indicator, especially in environments with a high occupancy of people. Airborne particulate matter can also be an important aspect for assessing the air quality in an indoor space. Consequently, the time courses of temperature, relative humidity, carbon dioxide and particulate matter (PM10) were tracked and evaluated in local public transport buses, trams and trains in the Brunswick/Hanover region. In all measurements, the climatic conditions were comfortable for the passengers. Carbon dioxide was strongly correlated with occupancy and has proven to be the most informative parameter. The PM10 concentration, however, often correlated with the dynamics of people when getting on and off, but not with the occupancy. Sensors, equipped with integrated GPS, were installed in the passenger cabins and were found to be useful for recording location-related effects such as stops. The results of this study show that the online recording of simple parameters is a valuable tool for assessing air quality as a function of time, location and number of people. When the occupancy is high, a low carbon dioxide level indicates good ventilation, which automatically reduces the risk of infection. It is therefore recommended to take more advantage of low-cost sensors as a control for air conditioning systems in passenger cabins and for evaluations of the dynamics in public transport.
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Affiliation(s)
- Tunga Salthammer
- Department of Material Analysis and Indoor Chemistry, Fraunhofer WKI, Bienroder Weg 54 E, 38108, Brunswick, Germany.
| | - Christian Fauck
- Department of Material Analysis and Indoor Chemistry, Fraunhofer WKI, Bienroder Weg 54 E, 38108, Brunswick, Germany
| | - Alexander Omelan
- Department of Material Analysis and Indoor Chemistry, Fraunhofer WKI, Bienroder Weg 54 E, 38108, Brunswick, Germany
| | - Sebastian Wientzek
- Department of Material Analysis and Indoor Chemistry, Fraunhofer WKI, Bienroder Weg 54 E, 38108, Brunswick, Germany
| | - Erik Uhde
- Department of Material Analysis and Indoor Chemistry, Fraunhofer WKI, Bienroder Weg 54 E, 38108, Brunswick, Germany
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18
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Mohamadi F, Fazeli A. A Review on Applications of CFD Modeling in COVID-19 Pandemic. ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING : STATE OF THE ART REVIEWS 2022; 29:3567-3586. [PMID: 35079217 PMCID: PMC8773396 DOI: 10.1007/s11831-021-09706-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 12/28/2021] [Indexed: 05/25/2023]
Abstract
COVID-19 pandemic has started a big challenge to the world health and economy during recent years. Many efforts were made to use the computation fluid dynamic (CFD) approach in this pandemic. CFD was used to understanding the airborne dispersion and transmission of this virus in different situations and buildings. The effect of the different conditions of the ventilation was studied by the CFD modeling to discuss preventing the COVID-19 transmission. Social distancing and using the facial masks were also modeled by the CFD approach to study the effect on reducing dispersion of the microdroplets containing the virus. Most of these recent applications of the CFD were reviewed for COVID-19 in this article. Special applications of the CFD modeling such as COVID-19 microfluidic biosensors, and COVID-19 inactivation using UV radiation were also reviewed in this research. The main findings of each research were also summarized in a table to answer critical questions about the effectiveness levels of applying the COVID-19 health protocols. CFD applications for modeling of COVID-19 dispersion in an airplane cabin, an elevator, a small classroom, a supermarket, an operating room of a hospital, a restaurant, a hospital waiting room, and a children's recovery room in a hospital were discussed briefly in different scenarios. CFD modeling for studying the effect of social distancing with different spaces, using and not using facial masks, difference of sneezing and coughing, different inlet/outlet ventilation layouts, combining air-conditioning and sanitizing machine, and using general or local air-conditioning systems were reviewed.
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Affiliation(s)
- Fateme Mohamadi
- Department of Chemical Engineering, Caspian Faculty of Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Ali Fazeli
- Department of Chemical Engineering, Caspian Faculty of Engineering, College of Engineering, University of Tehran, Tehran, Iran
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19
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Liu M, Liu J, Cao Q, Li X, Liu S, Ji S, Lin CH, Wei D, Shen X, Long Z, Chen Q. Evaluation of different air distribution systems in a commercial airliner cabin in terms of comfort and COVID-19 infection risk. BUILDING AND ENVIRONMENT 2022; 208:108590. [PMID: 34812218 PMCID: PMC8599143 DOI: 10.1016/j.buildenv.2021.108590] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/09/2021] [Accepted: 11/15/2021] [Indexed: 05/24/2023]
Abstract
The air distribution system in an airliner plays a key role in maintaining a comfortable and healthy environment in the aircraft cabin. To evaluate the performance of a novel displacement ventilation (DV) system and a traditional mixing ventilation (MV) system in an airliner cabin, this study conducted experiments and simulations in a seven-row cabin mockup. This investigation used ultrasonic anemometers and T-thermocouples to measure the air velocity, temperature and distribution of 1 μm and 5 μm particles. Simulation verifications were performed for these operating conditions, and additional scenarios with different occurrence source locations were also simulated. This study combined the Wells-Riley equation with a real case based on a COVID-19 outbreak among passengers on a long-distance bus to obtain the COVID-19 quanta value. Through an evaluation of the airflow organization, thermal comfort, and risk of COVID-19 infection, the two ventilation systems were compared. This investigation found that polydisperse particles should be used to calculate the risk of infection in airliner cabins. In addition, at the beginning of the pandemic, the infection risk with DV was lower than that with MV. In the middle and late stages of the epidemic, the infection risk with MV can be reduced when passengers wear masks, leading to an infection risk approximately equal to that of DV.
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Affiliation(s)
- Mingxin Liu
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Junjie Liu
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Qing Cao
- School of Civil Engineering, Dalian University of Technology (DUT), 2 Linggong Road, Dalian, 116024, China
- Dalian University of Technology, Dalian, China
| | - Xingyang Li
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Sumei Liu
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Shengcheng Ji
- Beijing Aeronautical Science & Technology Research Institute of COMAC, Beijing, China
| | - Chao-Hsin Lin
- Environmental Control Systems, Boeing Commercial Airplanes, Everett, WA, 98203, USA
| | - Daniel Wei
- Boeing Research & Technology, Beijing, 100027, China
| | - Xiong Shen
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Zhengwei Long
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Qingyan Chen
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Hong Kong
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20
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Auvinen M, Kuula J, Grönholm T, Sühring M, Hellsten A. High-resolution large-eddy simulation of indoor turbulence and its effect on airborne transmission of respiratory pathogens-Model validation and infection probability analysis. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2022; 34:015124. [PMID: 35340682 PMCID: PMC8939551 DOI: 10.1063/5.0076495] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/10/2021] [Indexed: 05/18/2023]
Abstract
High-resolution large-eddy simulation (LES) is exploited to study indoor air turbulence and its effect on the dispersion of respiratory virus-laden aerosols and subsequent transmission risks. The LES modeling is carried out with unprecedented accuracy and subsequent analysis with novel mathematical robustness. To substantiate the physical relevance of the LES model under realistic ventilation conditions, a set of experimental aerosol concentration measurements are carried out, and their results are used to successfully validate the LES model results. The obtained LES dispersion results are subjected to pathogen exposure and infection probability analysis in accordance with the Wells-Riley model, which is here mathematically extended to rely on LES-based space- and time-dependent concentration fields. The methodology is applied to assess two dissimilar approaches to reduce transmission risks: a strategy to augment the indoor ventilation capacity with portable air purifiers and a strategy to utilize partitioning by exploiting portable space dividers. The LES results show that use of air purifiers leads to greater reduction in absolute risks compared to the analytical Wells-Riley model, which fails to predict the original risk level. However, the two models do agree on the relative risk reduction. The spatial partitioning strategy is demonstrated to have an undesirable effect when employed without other measures, but may yield desirable outcomes with targeted air purifier units. The study highlights the importance of employing accurate indoor turbulence modeling when evaluating different risk-reduction strategies.
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Affiliation(s)
- Mikko Auvinen
- Finnish Meteorological Institute, Erik Palmenin aukio 1, 00560 Helsinki, Finland
- Author to whom correspondence should be addressed:
| | - Joel Kuula
- Finnish Meteorological Institute, Erik Palmenin aukio 1, 00560 Helsinki, Finland
| | - Tiia Grönholm
- Finnish Meteorological Institute, Erik Palmenin aukio 1, 00560 Helsinki, Finland
| | - Matthias Sühring
- Institute of Meteorology and Climatology, Leibniz University Hannover, Herrenhäuser Strasse 2, 30419 Hannover, Germany
| | - Antti Hellsten
- Finnish Meteorological Institute, Erik Palmenin aukio 1, 00560 Helsinki, Finland
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21
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Yang Y, Wang Y, Tian L, Su C, Chen Z, Huang Y. Effects of purifiers on the airborne transmission of droplets inside a bus. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2022; 34:017108. [PMID: 35340683 PMCID: PMC8939553 DOI: 10.1063/5.0081230] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 12/28/2021] [Indexed: 05/25/2023]
Abstract
During an airborne infectious disease outbreak, bus passengers can be easily infected by the dispersion of exhaled droplets from an infected passenger. Therefore, measures to control the transport of droplets are necessary, such as a mask or purifier. The current research examined aerosol transport in a bus with air-conditioning. To determine the dispersion path, deposition distribution, and droplet escape time, the computational fluid dynamics were used to predict the flow field and the dispersion of droplets considering the effects of droplet size, location of the infected person, and purifier type. In addition, based on the viability and the number of virus particles in a droplet, the total number of virus particles inhaled by passengers over a 4-h journey was obtained by the superposition method. The Wells-Riley equation was then used to assess the infection risk of the passengers in the bus cabin. The results showed that droplets with a size of 1-20 μm have essentially the same deposition characteristics, and the location of the infected passenger affects the distribution of droplets' transport and the effectiveness of a purifier in removing droplets. A purifier can effectively remove droplets from passengers' coughs and reduce the infection risk of passengers. The performance of the smaller purifiers is not as stable as that of the larger purifiers, and the performance is influenced by the airflow structure where the infected passenger is located.
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Affiliation(s)
| | | | - Linli Tian
- Author to whom correspondence should be addressed:. Tel.: 0086-13317136217
| | | | - Zhixin Chen
- Hubei Key Laboratory of Advanced Technology for Automotive Components, Wuhan University of Technology, Wuhan, Hubei 430070, China
| | - Yuanyi Huang
- SAIC GM Wuling Automobile Co., Ltd, Liuzhou, Guangxi 545000, China
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22
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Wang W, Wang F, Lai D, Chen Q. Evaluation of SARS-COV-2 transmission and infection in airliner cabins. INDOOR AIR 2022; 32:e12979. [PMID: 35048429 DOI: 10.1111/ina.12979] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/30/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Commercial airliners have played an important role in spreading the SARS-CoV-2 virus worldwide. This study used computational fluid dynamics (CFD) to simulate the transmission of SARS-CoV-2 on a flight from London to Hanoi and another from Singapore to Hangzhou. The dispersion of droplets of different sizes generated by coughing, talking, and breathing activities in a cabin by an infected person was simulated by means of the Lagrangian method. The SARS-CoV-2 virus contained in expiratory droplets traveled with the cabin air distribution and was inhaled by other passengers. Infection was determined by counting the number of viral copies inhaled by each passenger. According to the results, our method correctly predicted 84% of the infected/uninfected cases on the first flight. The results also show that wearing masks and reducing conversation frequency between passengers could help to reduce the risk of exposure on the second flight.
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Affiliation(s)
- Wensi Wang
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, China
| | - Feng Wang
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin, China
| | - Dayi Lai
- Department of Architecture, Shanghai Jiao Tong University, Shanghai, China
| | - Qingyan Chen
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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23
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Lloret J, Carreño A, Carić H, San J, Fleming LE. Environmental and human health impacts of cruise tourism: A review. MARINE POLLUTION BULLETIN 2021; 173:112979. [PMID: 34598093 DOI: 10.1016/j.marpolbul.2021.112979] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 06/13/2023]
Abstract
The intensive growth of cruise tourism worldwide during recent decades is leading to growing concerns over the sector's global environmental and health impacts. This review combines for the first time various sources of information to estimate the magnitude of the cruise industry's environmental and public health footprints. This research shows that cruising, despite technical advances and some surveillance programmes, remains a major source of air, water (fresh and marine) and land pollution affecting fragile habitats, areas and species, and a potential source of physical and mental human health risks. Health risks impact both the people on board (crew and passengers) and on land (workers of shipyards where cruise ships are dismantled and citizens inhabiting cities with cruise ports and shipyards). In this context, we argue that the cruise industry should be held accountable with more monitoring and regulation to prevent or minimize the growing negative environmental and human health impacts.
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Affiliation(s)
- Josep Lloret
- Oceans & Human Health Chair, Institute of Aquatic Ecology, Faculty of Science, University of Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Spain.
| | - Arnau Carreño
- Oceans & Human Health Chair, Institute of Aquatic Ecology, Faculty of Science, University of Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Spain
| | - Hrvoje Carić
- Institute for Tourism, Vrhovec 5, 10000 Zagreb, Croatia
| | - Joan San
- Faculty of Medicine, University of Girona, c/ Emili Grahit, 77, 17003 Girona, Catalonia, Spain
| | - Lora E Fleming
- European Centre for Environment and Human Health, University of Exeter Medical School, Cornwall TR1 3HD, UK.
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Li R, Zhang M, Wu Y, Tang P, Sun G, Wang L, Mandal S, Wang L, Lang J, Passalacqua A, Subramaniam S, Song G. What We Are Learning from COVID-19 for Respiratory Protection: Contemporary and Emerging Issues. Polymers (Basel) 2021; 13:4165. [PMID: 34883668 PMCID: PMC8659889 DOI: 10.3390/polym13234165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 02/07/2023] Open
Abstract
Infectious respiratory diseases such as the current COVID-19 have caused public health crises and interfered with social activity. Given the complexity of these novel infectious diseases, their dynamic nature, along with rapid changes in social and occupational environments, technology, and means of interpersonal interaction, respiratory protective devices (RPDs) play a crucial role in controlling infection, particularly for viruses like SARS-CoV-2 that have a high transmission rate, strong viability, multiple infection routes and mechanisms, and emerging new variants that could reduce the efficacy of existing vaccines. Evidence of asymptomatic and pre-symptomatic transmissions further highlights the importance of a universal adoption of RPDs. RPDs have substantially improved over the past 100 years due to advances in technology, materials, and medical knowledge. However, several issues still need to be addressed such as engineering performance, comfort, testing standards, compliance monitoring, and regulations, especially considering the recent emergence of pathogens with novel transmission characteristics. In this review, we summarize existing knowledge and understanding on respiratory infectious diseases and their protection, discuss the emerging issues that influence the resulting protective and comfort performance of the RPDs, and provide insights in the identified knowledge gaps and future directions with diverse perspectives.
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Affiliation(s)
- Rui Li
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Mengying Zhang
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Yulin Wu
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Peixin Tang
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA; (P.T.); (G.S.)
| | - Gang Sun
- Department of Biological and Agricultural Engineering, University of California, Davis, CA 95616, USA; (P.T.); (G.S.)
| | - Liwen Wang
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
| | - Sumit Mandal
- Department of Design, Housing and Merchandising, Oklahoma State University, Stillwater, OK 74078, USA;
| | - Lizhi Wang
- Department of Industrial and Manufacturing Systems Engineering, Iowa State University, Ames, IA 50010, USA;
| | - James Lang
- Department of Kinesiology, Iowa State University, Ames, IA 50010, USA;
| | - Alberto Passalacqua
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50010, USA; (A.P.); (S.S.)
| | - Shankar Subramaniam
- Department of Mechanical Engineering, Iowa State University, Ames, IA 50010, USA; (A.P.); (S.S.)
| | - Guowen Song
- Department of Apparel, Events, and Hospitality Management, Iowa State University, Ames, IA 50010, USA; (R.L.); (M.Z.); (Y.W.); (L.W.)
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25
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COVID-19 Impact on Operation and Energy Consumption of Heating, Ventilation and Air-Conditioning (HVAC) Systems. ADVANCES IN APPLIED ENERGY 2021; 3. [PMCID: PMC8166037 DOI: 10.1016/j.adapen.2021.100040] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Heating, ventilation and air-conditioning (HVAC) system is favourable for regulating indoor temperature, relative humidity, airflow pattern and air quality. However, HVAC systems may turn out to be the culprit of microbial contamination in enclosed spaces and deteriorate the environment due to inappropriate design and operation. In the context of COVID-19, significant transformations and new requirements are occurring in HVAC systems. Recently, several updated operational guidelines for HVAC systems have been issued by various institutions to control the airborne transmission and mitigate infection risks in enclosed environments. Challenges and innovations emerge in response to operational variations of HVAC systems. To efficiently prevent the spread of the pandemic and reduce infection risks, it is essential to have an overall understanding of impacts caused by COVID-19 on HVAC systems. Therefore, the objectives of this article are to: (a) provide a comprehensive review of the airborne transmission characteristics of SARS-CoV-2 in enclosed spaces and a theoretical basis for HVAC operation guideline revision; (b) investigate HVAC-related guidelines to clarify the operational variations of HVAC systems during the pandemic; (c) analyse how operational variations of HVAC systems affect energy consumption; and (d) identify the innovations and research trends concerning future HVAC systems. Furthermore, this paper compares the energy consumption of HVAC system operation during the normal times versus pandemic period, based on a case study in China, providing a reference for other countries around the world. Results of this paper offer comprehensive insights into how to keep indoor environments safe while maintaining energy-efficient operation of HVAC systems.
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Key Words
- energy impacts of hvac systems
- covid-19 pandemic
- airborne transmission
- hvac operation guidelines
- challenges and innovations
- ahu, air handing unit
- asc, architectural society of china
- ashrae, american society of heating refrigerating and air-conditioning engineers
- car, chinese association of refrigeration
- cciaq, canadian committee on indoor air quality
- cop, coefficient of performance
- dcv, demand-controlled ventilation
- ecdc, european centre for disease prevention and control
- eeaf, electrostatic enhanced air filter
- eepf, electrostatic enhanced pleated air filters
- hepa, high efficiency particulate air
- hphe, heat pipe heat exchanger
- epa, environmental protection agency
- hvac, heating, ventilation and air-conditioning
- ishrae, indian society of heating refrigerating and air conditioning engineers
- merv, minimum efficiency reporting value
- mohurd, ministry of housing and urban-rural development of the people's republic of china
- nhc, national health commission of china
- pho, public health ontario
- rehva, federation of european heating ventilation and air conditioning associations
- sac, standardization administration of the people's republic of china
- sbs, sick building syndrome
- shase, society of heating air-conditioning and sanitary engineers in japan
- uv, ultraviolet
- uvgi, ultraviolet germicidal irradiation
- who, world health organization
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Sodiq A, Khan MA, Naas M, Amhamed A. Addressing COVID-19 contagion through the HVAC systems by reviewing indoor airborne nature of infectious microbes: Will an innovative air recirculation concept provide a practical solution? ENVIRONMENTAL RESEARCH 2021; 199:111329. [PMID: 34004171 PMCID: PMC8123526 DOI: 10.1016/j.envres.2021.111329] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 03/22/2021] [Accepted: 05/11/2021] [Indexed: 05/03/2023]
Abstract
As the world continues to grapple with the reality of coronavirus disease, global research communities are racing to develop practical solutions to adjust to the new challenges. One such challenge is the control of indoor air quality in the COVID-19 era and beyond. Since COVID-19 became a global pandemic, the "super spread" of the virus has continued to amaze policymakers despite measures put in place by public health officials to sensitize the general public on the need for social distancing, personal hygiene, etc. In this work, we have reviewed the literature to demonstrate, by investigating the historical and present circumstances, that indoor spread of infectious diseases may be assisted by the conditions of the HVAC systems. While little consideration has been given to the possibility of indoor airborne transmission of the virus, the available reports have demonstrated that the virus, with average aerodynamic diameter up to 80-120 nm, is viable as aerosol in indoor atmosphere for more than 3 h, and its spread may be assisted by the HVAC systems. Having reviewed the vulnerability of the conventional ventilation systems, we recommend innovative air circulation concept supported by the use of UVGI in combination with nanoporous air filter to combat the spread of SARS-CoV-2 and other harmful microbes in enclosed spaces.
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Affiliation(s)
- Ahmed Sodiq
- Qatar Environment and Energy Institute (QEERI), Qatar.
| | | | - Mahmoud Naas
- Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
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Löhner R, Antil H, Srinivasan A, Idelsohn S, Oñate E. High-Fidelity Simulation of Pathogen Propagation, Transmission and Mitigation in the Built Environment. ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING : STATE OF THE ART REVIEWS 2021; 28:4237-4262. [PMID: 34248352 PMCID: PMC8256653 DOI: 10.1007/s11831-021-09606-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/08/2021] [Indexed: 05/31/2023]
Abstract
An overview of high-fidelity modeling of pathogen propagation, transmission and mitigation in the built environment is given. In order to derive the required physical and numerical models, the current understanding of pathogen, and in particular virus transmission and mitigation is summarized. The ordinary and partial differential equations that describe the flow, the particles and possibly the UV radiation loads in rooms or HVAC ducts are presented, as well as proper numerical methods to solve them in an expedient way. Thereafter, the motion of pedestrians, as well as proper ways to couple computational fluid dynamics and computational crowd dynamics to enable high-fidelity pathogen transmission and infection simulations is treated. The present review shows that high-fidelity simulations of pathogen propagation, transmission and mitigation in the built environment have reached a high degree of sophistication, offering a quantum leap in accuracy from simpler probabilistic models. This is particularly the case when considering the propagation of pathogens via aerosols in the presence of moving pedestrians.
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Affiliation(s)
- Rainald Löhner
- Center for Computational Fluid Dynamics, College of Science, George Mason University, Fairfax, VA 22030-4444 USA
| | - Harbir Antil
- Center for Mathematics and Artificial Intelligence, College of Science, George Mason University, Fairfax, VA 22030-4444 USA
| | - Ashok Srinivasan
- Department of Computer Science, University of West Florida, Pensacola, FL 32514 USA
| | - Sergio Idelsohn
- Catalan Institution for Research and Advanced Studies, ICREA, Barcelona, Spain
- International Center for Numerical Methods in Engineering, CIMNE, Barcelona, Spain
| | - Eugenio Oñate
- International Center for Numerical Methods in Engineering, CIMNE, Barcelona, Spain
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Infection Prevention Performance among In-Flight Cabin Crew in South Korea. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18126468. [PMID: 34203806 PMCID: PMC8296313 DOI: 10.3390/ijerph18126468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/10/2021] [Accepted: 06/12/2021] [Indexed: 12/23/2022]
Abstract
COVID-19 was declared a worldwide pandemic in 2020; thus, preventing in-flight infection transmission is important for stopping global spread via air travel. Infection prevention (IP) performance among aircraft cabin crew is crucial for preventing in-flight transmission. We aimed to identify the level of IP performance and factors affecting IP performance among aircraft cabin crew during the COVID-19 pandemic in South Korea. An online survey was conducted with 177 cabin crew members between August and September 2020. The survey assessed IP performance, and IP awareness, using a five-point Likert scale, and also evaluated simulation-based personal protective equipment (PPE) training experience, and organizational culture. The average IP performance score was 4.56 ± 0.44. Although the performance level for mask-wearing was high (4.73 ± 0.35), hand hygiene (HH) performance (4.47 ± 0.56) was low. Multivariate analysis showed that IP performance was significantly associated with IP awareness (p < 0.05) and simulation-based PPE training experience (p < 0.05). Since HH performance was relatively low, cabin crew and airlines should make efforts to improve HH performance. Furthermore, a high level of IP awareness and PPE training experience can improve IP performance among cabin crew members. Therefore, simulation-based PPE training and strategies to improve IP awareness are essential for preventing in-flight infection transmission.
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Yang X, Yang H, Ou C, Luo Z, Hang J. Airborne transmission of pathogen-laden expiratory droplets in open outdoor space. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 773:145537. [PMID: 33582331 DOI: 10.1016/j.scitotenv.2021.145537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 01/27/2021] [Accepted: 01/27/2021] [Indexed: 06/12/2023]
Abstract
Virus-laden droplets dispersion may induce transmissions of respiratory infectious diseases. Existing research mainly focuses on indoor droplet dispersion, but the mechanism of its dispersion and exposure in outdoor environment is unclear. By conducting CFD simulations, this paper investigates the evaporation and transport of solid-liquid droplets in an open outdoor environment. Droplet initial sizes (dp = 10 μm, 50 μm, 100 μm), background relative humidity (RH = 35%, 95%), background wind speed (Uref = 3 m/s, 0.2 m/s) and social distances between two people (D = 0.5 m, 1 m, 1.5 m, 3 m, 5 m) are investigated. Results show that thermal body plume is destroyed when the background wind speed is 3 m/s (Froude number Fr ~ 10). The inhalation fraction (IF) of susceptible person decreases exponentially when the social distance (D) increases from 0.5 m to 5 m. The exponential decay rate of inhalation fraction (b) ranges between 0.93 and 1.06 (IF=IF0e-b(D-0.5)) determined by the droplet initial diameter and relative humidity. Under weak background wind (Uref = 0.2 m/s, Fr ~ 0.01), the upward thermal body plume significantly influences droplet dispersion, which is similar with that in indoor space. Droplets in the initial sizes of 10 μm and 50 μm disperse upwards while most of 100 μm droplets fall down to the ground due to larger gravity force. Interestingly, the deposition fraction on susceptible person is ten times higher at Uref = 3 m/s than that at Uref = 0.2 m/s. Thus, a high outdoor wind speed does not necessarily lead to a smaller exposure risk if the susceptible person locating at the downwind region of the infected person, and people in outdoors are suggested to not only keep distance of greater than 1.5 m from each other but also stand with considerable angles from the prevailing wind direction.
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Affiliation(s)
- Xia Yang
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Zhuhai 519082, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China; Guangdong Provincial Field Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, 510275 Guangzhou, China
| | - Hongyu Yang
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Zhuhai 519082, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China; Guangdong Provincial Field Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, 510275 Guangzhou, China
| | - Cuiyun Ou
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Zhuhai 519082, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China; Guangdong Provincial Field Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, 510275 Guangzhou, China; State Key Laboratory of Green Building in Western China, Xian University of Architecture & Technology, 710055 Xi'an, China
| | - Zhiwen Luo
- School of the Built Environment, University of Reading, Reading, UK.
| | - Jian Hang
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Zhuhai 519082, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China; Guangdong Provincial Field Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, 510275 Guangzhou, China.
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Vadhan JD, Raj KM, Raj SD. Is there a doctor on the plane? A review of in-flight emergencies for the on-board radiologist. Clin Imaging 2021; 76:265-273. [PMID: 34087605 DOI: 10.1016/j.clinimag.2021.04.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/03/2021] [Accepted: 04/09/2021] [Indexed: 10/21/2022]
Abstract
In-flight medical emergencies (IFME) are the acute on-service events involving illness or injury to a passenger with the potential for long-term health compromise. With the continuously rising number of flights available, both domestically and internationally, it is conceivable that the number of IFMEs will similarly continue to rise. Although most of these instances are relatively self-limited, the rare instance of a severe occurrence justifies preparation, both from in-flight staff and healthcare providers traveling on these flights. Given these events' sporadic nature and the variable availability of medical support, all physicians need to understand their in-flight ethical and legal capabilities, the available medical supplies, and the most likely etiologies to manage such situations successfully. Most radiologists rarely utilize the hands-on, clinical skills developed in medical school or internship for emergencies beyond allergic contrast reactions. Therefore, they may not be adept in caring for patients during an IFME. As such, we present a thorough overview and literature review for the radiologist regarding the management of various acute IFMEs, with consideration for ethical and legal precedence and a review of medical equipment available on-board.
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Affiliation(s)
- Jason D Vadhan
- Department of Emergency Medicine, UT Southwestern Medical Center, 5325 Harry Hines Blvd., Dallas, TX 75390, United States of America.
| | - Karuna M Raj
- Department of Radiology, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, United States of America.
| | - Sean D Raj
- Department of Radiology, Baylor University Medical Center, American Radiology Associates, 712 N. Washington, Suite 101, Dallas, TX 75246, United States of America. https://twitter.com/SeanRajMD
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Islam T, Lahijani MS, Srinivasan A, Namilae S, Mubayi A, Scotch M. From bad to worse: airline boarding changes in response to COVID-19. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201019. [PMID: 34007455 PMCID: PMC8080014 DOI: 10.1098/rsos.201019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 04/13/2021] [Indexed: 05/10/2023]
Abstract
Airlines have introduced a back-to-front boarding process in response to the COVID-19 pandemic. It is motivated by the desire to reduce passengers' likelihood of passing close to seated passengers when they take their seats. However, our prior work on the risk of Ebola spread in aeroplanes suggested that the driving force for increased exposure to infection transmission risk is the clustering of passengers while waiting for others to stow their luggage and take their seats. In this work, we examine whether the new boarding processes lead to increased or decreased risk of infection spread. We also study the reasons behind the risk differences associated with different boarding processes. We accomplish this by simulating the new boarding processes using pedestrian dynamics and compare them against alternatives. Our results show that back-to-front boarding roughly doubles the infection exposure compared with random boarding. It also increases exposure by around 50% compared to a typical boarding process prior to the outbreak of COVID-19. While keeping middle seats empty yields a substantial reduction in exposure, our results show that the different boarding processes have similar relative strengths in this case as with middle seats occupied. We show that the increased exposure arises from the proximity between passengers moving in the aisle and while seated. Such exposure can be reduced significantly by prohibiting the use of overhead bins to stow luggage. Our results suggest that the new boarding procedures increase the risk of exposure to COVID-19 compared with prior ones and are substantially worse than a random boarding process.
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Affiliation(s)
- T. Islam
- Department of Computer Science, University of West Florida, Pensacola, FL, USA
| | - M. Sadeghi Lahijani
- Department of Computer Science, Florida State University, Tallahassee, FL, USA
| | - A. Srinivasan
- Department of Computer Science, University of West Florida, Pensacola, FL, USA
| | - S. Namilae
- Department of Aerospace Engineering, Embry-Riddle Aeronautical University, Daytona Beach, FL, USA
| | - A. Mubayi
- Arizona State University, Tempe, AZ, USA
| | - M. Scotch
- Arizona State University, Tempe, AZ, USA
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32
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De Angelis G, Lohmeyer FM, Grossi A, Posteraro B, Sanguinetti M. Hand hygiene and facemask use to prevent droplet-transmitted viral diseases during air travel: a systematic literature review. BMC Public Health 2021; 21:760. [PMID: 33879112 PMCID: PMC8056366 DOI: 10.1186/s12889-021-10814-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/12/2021] [Indexed: 01/09/2023] Open
Abstract
Background Transmission of viral diseases (e.g., influenza A H1N1) via respiratory droplets takes place mainly in confined spaces, including in aircraft during commercial air travel. The adoption of hygiene measures may help to prevent disease spread aboard aircraft. This review summarizes the evidence on hand hygiene and the use of facemasks as viral disease prevention measures in aircraft. Methods A literature search was performed in the PubMed, Scopus, and Web of Science databases up to 10 June 2020, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. A population, intervention, comparison, outcomes, and study design (PICOS) approach was used to define the review question. Results We included four studies published between 2007 and 2020, all targeting influenza virus disease, in the qualitative synthesis. Three studies used mathematical models to simulate single- or multiple-direction flights, and two of them showed that facemask (e.g., N95 respirator) use considerably reduced infection probability. In the third study, hand cleaning by 20 to 60% of people at any time in all airports (including on aircraft) reduced the measure of airports’ power to spread the disease across the globe by ~ 24 to 69%. The fourth study was a case-control study designed to trace an influenza outbreak in two flights during the 2009 influenza A H1N1 pandemic. The study showed that none (0%) of nine infected passengers compared to 15 (47%) of 32 healthy control passengers in the aircraft cabin during one of these flights wore a facemask (odds ratio, 0.0; 95% confidence interval, 0.0–0.7). In contrast, both case and control passengers appeared to be equally compliant in self-assessed hand hygiene. Conclusions Facemask use combined with hand hygiene may minimize the chance of droplet-transmitted virus spread by air travelers. Thus, it is necessary that hygiene measures become an integral part of standard procedures in commercial air travel. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-021-10814-9.
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Affiliation(s)
- Giulia De Angelis
- Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, Rome, Italy.,Dipartimento di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo A. Gemelli 8, 00168, Rome, Italy
| | | | - Adriano Grossi
- Dipartimento di Scienze della Vita e Sanità Pubblica, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Brunella Posteraro
- Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, Rome, Italy.,Dipartimento di Scienze Mediche e Chirurgiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Maurizio Sanguinetti
- Dipartimento di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Università Cattolica del Sacro Cuore, Rome, Italy. .,Dipartimento di Scienze di Laboratorio e Infettivologiche, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo A. Gemelli 8, 00168, Rome, Italy.
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Guo Y, Qian H, Sun Z, Cao J, Liu F, Luo X, Ling R, Weschler LB, Mo J, Zhang Y. Assessing and controlling infection risk with Wells-Riley model and spatial flow impact factor (SFIF). SUSTAINABLE CITIES AND SOCIETY 2021; 67:102719. [PMID: 33520610 PMCID: PMC7834120 DOI: 10.1016/j.scs.2021.102719] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/31/2020] [Accepted: 01/12/2021] [Indexed: 05/13/2023]
Abstract
The ongoing COVID-19 epidemic has spread worldwide since December 2019. Effective use of engineering controls can prevent its spread and thereby reduce its impact. As airborne transmission is an important mode of infectious respiratory disease transmission, mathematical models of airborne infection are needed to develop effective engineering control. We developed a new approach to obtain the spatial distribution for the probability of infection (PI) by combining the spatial flow impact factor (SFIF) method with the Wells-Riley model. Our method can be combined with the anti-problem approach, in order to determine the optimized arrangement of people and/or air purifiers in a confined space beyond the ability of previous methods. This method was validated by a CFD-integrated method, and an illustrative example is presented. We think our method can be helpful in controlling infection risk and making the best use of the space and equipment in built environments, which is important for preventing the spread of COVID-19 and other infectious respiratory diseases, and promoting the development of sustainable cities and society.
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Affiliation(s)
- Yong Guo
- Department of Building Science, Tsinghua University, Beijing, China
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
| | - Hua Qian
- School of Energy and Environment, Southeast University, Nanjing, China
| | - Zhiwei Sun
- Department of Building Science, Tsinghua University, Beijing, China
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
| | - Jianping Cao
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, China
| | - Fei Liu
- Hubei Provincial Hospital of Integrated Chinese and Western Medicine, Wuhan, China
| | - Xibei Luo
- Hubei Provincial Hospital of Integrated Chinese and Western Medicine, Wuhan, China
| | - Ruijie Ling
- Hubei Provincial Hospital of Integrated Chinese and Western Medicine, Wuhan, China
| | | | - Jinhan Mo
- Department of Building Science, Tsinghua University, Beijing, China
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
| | - Yinping Zhang
- Department of Building Science, Tsinghua University, Beijing, China
- Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Beijing, China
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Schultz M, Soolaki M. Analytical approach to solve the problem of aircraft passenger boarding during the coronavirus pandemic. TRANSPORTATION RESEARCH. PART C, EMERGING TECHNOLOGIES 2021; 124:102931. [PMID: 33519129 PMCID: PMC7834413 DOI: 10.1016/j.trc.2020.102931] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 11/15/2020] [Accepted: 12/13/2020] [Indexed: 05/10/2023]
Abstract
The corona pandemic significantly changes the processes of aircraft and passenger handling at the airport. In our contribution, we focus on the time-critical process of aircraft boarding, where regulations regarding physical distances between passengers will significantly increase boarding time. The passenger behavior is implemented in a field-validated stochastic cellular automata model, which is extended by a module to evaluate the transmission risk. We propose an improved boarding process by considering that most of the passengers are travel together and should be boarded and seated as a group. The NP-hard seat allocation of groups with minimized individual interactions between groups is solved with a genetic algorithm. Then, the improved seat allocation is used to derive an associated boarding sequence aiming at both short boarding times and low risk of virus transmission. Our results show that the consideration of groups will significantly contribute to a faster boarding (reduction of time by about 60%) and less transmission risk (reduced by 85%) compared to the standard random boarding procedures applied in the pandemic scenario.
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Affiliation(s)
- Michael Schultz
- Institute of Logistics and Aviation, Dresden University of Technology, Germany
| | - Majid Soolaki
- School of Mechanical and Materials Engineering, University College Dublin, Ireland
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35
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Chen Q. Can we migrate COVID-19 spreading risk? FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING 2021; 15:35. [PMID: 32874703 PMCID: PMC7453368 DOI: 10.1007/s11783-020-1328-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Indexed: 05/04/2023]
Abstract
It is well recognized that Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus could be spread through touch and large droplets. However, we may have under-estimated the disease transmission by small droplets or aerosols that contain SARS-CoV-2 virus. Social distancing in public transport vehicles, such as airplanes, is not feasible. It is also not possible to wear masks in restaurant. This paper recommended wearing masks in airplanes and use partition screens in the middle of a table in a restaurant to reduce the infectioncausedbySARS-CoV-2virus. Advanced ventilation systems, such as personalized ventilation and displacement ventilation, are strongly recommended for transport vehicles and buildings.
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Affiliation(s)
- Qingyan Chen
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 USA
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36
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Li J, Huang C, Wang Z, Yuan B, Peng F. The airline transport regulation and development of public health crisis in megacities of China. JOURNAL OF TRANSPORT & HEALTH 2020; 19:100959. [PMID: 33020730 PMCID: PMC7527282 DOI: 10.1016/j.jth.2020.100959] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 05/10/2023]
Abstract
BACKGROUND The Civil Aviation Administration of China (CAAC) declares the airline transport regulation in January 2020 to help retard the spread of the novel coronavirus disease in China. This study is to examine the effect of airline transport regulation on confirmed cases of the novel coronavirus disease in megacities in China. METHODS This study combines the multi-source data from the health data platform DXY, the airline data platform Airsavvi, the China Economic Internet Statistical Database and the China Railway website. The megacities whose airports have a passenger throughput of over 30 million per year (11 megacities: Wuhan, Beijing, Shanghai, Guangzhou, Chengdu, Shenzhen, Kunming, Xi'an, Chongqing, Hangzhou, Nanjing) are included in the analysis. The regression analysis is conducted in this study. RESULTS The curvilinear relationship between the limitation on air traffic and confirmed cases of the novel coronavirus disease is identified (coefficient of the linear term = -4.650, p-value < 0.01; coefficient of the quadratic term = 4.089, p-value < 0.01). CONCLUSIONS This study confirms the effectiveness of airline transport regulation in suppressing the development of this pandemic. The limitation on air traffic is found to negatively affect the confirmed cases in China's megacities. However, such effect marginally recedes as the strength of limitation intensifies. It suggests that comprehensive policy intervention is in need and air traffic can be one of important determinants that affect the epidemic development.
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Affiliation(s)
- Jiannan Li
- International School of Business & Finance, Sun Yat-sen University, Guangzhou, China
| | - Chulan Huang
- School of Tourism Management, Sun Yat-sen University, Guangzhou, China
| | - Zhaoguo Wang
- School of Economics and Management, Shenyang Agricultural University, Shenyang, China
| | - Bocong Yuan
- School of Tourism Management, Sun Yat-sen University, Guangzhou, China
| | - Fei Peng
- School of Tourism Management, Sun Yat-sen University, Guangzhou, China
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Peng S, Chen Q, Liu E. The role of computational fluid dynamics tools on investigation of pathogen transmission: Prevention and control. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 746:142090. [PMID: 33027870 PMCID: PMC7458093 DOI: 10.1016/j.scitotenv.2020.142090] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 08/28/2020] [Accepted: 08/28/2020] [Indexed: 05/17/2023]
Abstract
Transmission mechanics of infectious pathogen in various environments are of great complexity and has always been attracting many researchers' attention. As a cost-effective and powerful method, Computational Fluid Dynamics (CFD) plays an important role in numerically solving environmental fluid mechanics. Besides, with the development of computer science, an increasing number of researchers start to analyze pathogen transmission by using CFD methods. Inspired by the impact of COVID-19, this review summarizes research works of pathogen transmission based on CFD methods with different models and algorithms. Defining the pathogen as the particle or gaseous in CFD simulation is a common method and epidemic models are used in some investigations to rise the authenticity of calculation. Although it is not so difficult to describe the physical characteristics of pathogens, how to describe the biological characteristics of it is still a big challenge in the CFD simulation. A series of investigations which analyzed pathogen transmission in different environments (hospital, teaching building, etc) demonstrated the effect of airflow on pathogen transmission and emphasized the importance of reasonable ventilation. Finally, this review presented three advanced methods: LBM method, Porous Media method, and Web-based forecasting method. Although CFD methods mentioned in this review may not alleviate the current pandemic situation, it helps researchers realize the transmission mechanisms of pathogens like viruses and bacteria and provides guidelines for reducing infection risk in epidemic or pandemic situations.
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Affiliation(s)
- Shanbi Peng
- School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu 610500, China
| | - Qikun Chen
- School of Engineering, Cardiff University, CF24 0DE, UK.
| | - Enbin Liu
- School of Petroleum Engineering, Southwest Petroleum University, Chengdu 610500, China
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Shen J, Duan H, Zhang B, Wang J, Ji JS, Wang J, Pan L, Wang X, Zhao K, Ying B, Tang S, Zhang J, Liang C, Sun H, Lv Y, Li Y, Li T, Li L, Liu H, Zhang L, Wang L, Shi X. Prevention and control of COVID-19 in public transportation: Experience from China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115291. [PMID: 32829124 PMCID: PMC7833563 DOI: 10.1016/j.envpol.2020.115291] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/13/2020] [Accepted: 07/17/2020] [Indexed: 05/09/2023]
Abstract
Due to continuous spread of coronavirus disease 2019 (COVID-19) worldwide, long-term effective prevention and control measures should be adopted for public transport facilities, as they are increasing in popularity and serve as the principal modes for travel of many people. The human infection risk could be extremely high due to length of exposure time window, transmission routes and structural characteristics during travel or work. This can result in the rapid spread of the infection. Based on the transmission characteristics of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and the nature of public transport sites, we identified comprehensive countermeasures toward the prevention and control of COVID-19, including the strengthening of personnel management, personal protection, environmental cleaning and disinfection, and health education. Multi-pronged strategies can enhance safety of public transportation. The prevention and control of the disease during the use of public transportation will be particularly important when all countries in the world resume production. The aim of this study is to introduce experience of the prevention and control measures for public transportation in China to promote the global response to COVID-19.
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Affiliation(s)
- Jin Shen
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Hongyang Duan
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Baoying Zhang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Jiaqi Wang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - John S Ji
- Environmental Research Center, Duke Kunshan University, Kunshan, Jiangsu, 215316, China; Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Jiao Wang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Lijun Pan
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Xianliang Wang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Kangfeng Zhao
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Bo Ying
- 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, Jiangsu, 211166, China
| | - Jian Zhang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Chen Liang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Huihui Sun
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Yuebin Lv
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Yan Li
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Tao Li
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Li Li
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Hang Liu
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Liubo Zhang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Lin Wang
- China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, 100021, China
| | - Xiaoming Shi
- 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, Jiangsu, 211166, China.
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Yang X, Ou C, Yang H, Liu L, Song T, Kang M, Lin H, Hang J. Transmission of pathogen-laden expiratory droplets in a coach bus. JOURNAL OF HAZARDOUS MATERIALS 2020; 397:122609. [PMID: 32361671 PMCID: PMC7152903 DOI: 10.1016/j.jhazmat.2020.122609] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 03/25/2020] [Accepted: 03/27/2020] [Indexed: 05/04/2023]
Abstract
Droplet dispersion carrying viruses/bacteria in enclosed/crowded buses may induce transmissions of respiratory infectious diseases, but the influencing mechanisms have been rarely investigated. By conducting high-resolution CFD simulations, this paper investigates the evaporation and transport of solid-liquid mixed droplets (initial diameter 10 μm and 50 μm, solid to liquid ratio is 1:9) exhaled in a coach bus with 14 thermal manikins. Five air-conditioning supply directions and ambient relative humidity (RH = 35 % and 95 %) are considered. Results show that ventilation effectiveness, RH and initial droplet size significantly influence droplet transmissions in coach bus. 50 μm droplets tend to evaporate completely within 1.8 s and 7 s as RH = 35 % and 95 % respectively, while 0.2 s or less for 10 μm droplets. Thus 10 μm droplets diffuse farther with wider range than 50 μm droplets which tend to deposit more on surfaces. Droplet dispersion pattern differs due to various interactions of gravity, ventilation flows and the upward thermal body plume. The fractions of droplets suspended in air, deposited on wall surfaces are quantified. This study implies high RH, backward supply direction and passengers sitting at nonadjacent seats can effectively reduce infection risk of droplet transmission in buses. Besides taking masks, regular cleaning is also recommended since 85 %-100 % of droplets deposit on object surfaces.
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Affiliation(s)
- Xia Yang
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou, PR China
| | - Cuiyun Ou
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou, PR China
| | - Hongyu Yang
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou, PR China
| | - Li Liu
- Department of Building Science, School of Architecture, Tsinghua University, Beijing, 100084, PR China
| | - Tie Song
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, PR China
| | - Min Kang
- Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, PR China
| | - Hualiang Lin
- Department of Epidemiology, School of Public Health, Sun Yat-sen University Guangzhou, PR China
| | - Jian Hang
- School of Atmospheric Sciences, Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China.
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40
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Chen J, He H, Cheng W, Liu Y, Sun Z, Chai C, Kong Q, Sun W, Zhang J, Guo S, Shi X, Wang J, Chen E, Chen Z. Potential transmission of SARS-CoV-2 on a flight from Singapore to Hangzhou, China: An epidemiological investigation. Travel Med Infect Dis 2020; 36:101816. [PMID: 32645477 PMCID: PMC7336905 DOI: 10.1016/j.tmaid.2020.101816] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND Between January 24, 2020 and February 15, 2020, an outbreak of COVID-19 occurred among 335 passengers on a flight from Singapore to Hangzhou in China. This study aimed to investigate the source of the outbreak and assess the risk of transmission of COVID-19 during the flight. METHOD Using a standardized questionnaire, we collected information on the travelers' demographic characteristics and illness before, during, and after the flight. We also collected data on factors potentially associated with COVID-19 transmission during the flight. RESULTS A total of 16 COVID-19 patients were diagnosed among all passengers; the overall attack rate was 4.8%. The attack rate among passengers who had departed from Wuhan was significantly higher than that among those who had departed from other places. One passenger without an epidemiological history of exposure before boarding developed COVID-19. During the flight, he was seated near four infected passengers from Wuhan for approximately an hour and did not wear his facemask correctly during the flight. CONCLUSIONS COVID-19 transmission may have occurred during the flight. However, the majority of the cases in the flight-associated outbreak could not be attributed to transmission on the flight but were associated with exposure to the virus in Wuhan or to infected members in a single tour group.
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Affiliation(s)
- Junfang Chen
- HangZhou Center for Disease Control and Prevention, Hangzhou, China
| | - Hanqing He
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Wei Cheng
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Yan Liu
- HangZhou Center for Disease Control and Prevention, Hangzhou, China
| | - Zhou Sun
- HangZhou Center for Disease Control and Prevention, Hangzhou, China
| | - Chengliang Chai
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Qingxin Kong
- HangZhou Center for Disease Control and Prevention, Hangzhou, China
| | - Wanwan Sun
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Jiaqi Zhang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Song Guo
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Xuguang Shi
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Jinna Wang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Enfu Chen
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China.
| | - Zhiping Chen
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China.
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You R, Lin CH, Wei D, Chen Q. Evaluating the commercial airliner cabin environment with different air distribution systems. INDOOR AIR 2019; 29:840-853. [PMID: 31172603 DOI: 10.1111/ina.12578] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/25/2019] [Accepted: 05/29/2019] [Indexed: 05/05/2023]
Abstract
Ventilation systems for commercial airliner cabins are important in reducing contaminant transport and maintaining thermal comfort. To evaluate the performance of a personalized displacement ventilation system, a conventional displacement ventilation system, and a mixing ventilation system, this study first used the Wells-Riley equation integrated with CFD to obtain the SARS quanta value based on a specific SARS outbreak on a flight. This investigation then compared the three ventilation systems in a seven-row section of a fully occupied, economy-class cabin in Boeing 737 and Boeing 767 airplanes. The SARS quanta generation rate obtained for the index patient could be used in future studies. For all the assumed source locations, the passengers' infection risk by air in the two planes was the highest with the mixing ventilation system, while the conventional displacement ventilation system produced the lowest risk. The personalized ventilation system performed the best in maintaining cabin thermal comfort and can also reduce the infection risk. This system is recommended for airplane cabins.
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Affiliation(s)
- Ruoyu You
- Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, China
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA
| | - Chao-Hsin Lin
- Environmental Control Systems, Boeing Commercial Airplanes, Everett, Washington, USA
| | - Daniel Wei
- Boeing Research & Technology, Beijing, China
| | - Qingyan Chen
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA
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Abstract
BACKGROUND Air travel is associated with the spread of influenza through infected passengers and potentially through in-flight transmission. Contact tracing after exposure to influenza is not performed systematically. We performed a systematic literature review to evaluate the evidence for influenza transmission aboard aircraft. METHODS Using PubMed and EMBASE databases, we identified and critically appraised identified records to assess the evidence of such transmission to passengers seated in close proximity to the index cases. We also developed a bias assessment tool to evaluate the quality of evidence provided in the retrieved studies. RESULTS We identified 14 peer-reviewed publications describing contact tracing of passengers after possible exposure to influenza virus aboard an aircraft. Contact tracing during the initial phase of the influenza A(H1N1)pdm09 pandemic was described in 11 publications. The studies describe the follow-up of 2,165 (51%) of 4,252 traceable passengers. Altogether, 163 secondary cases were identified resulting in an overall secondary attack rate among traced passengers of 7.5%. Of these secondary cases, 68 (42%) were seated within two rows of the index case. CONCLUSION We found an overall moderate quality of evidence for transmission of influenza virus aboard an aircraft. The major limiting factor was the comparability of the studies. A majority of secondary cases was identified at a greater distance than two rows from the index case. A standardized approach for initiating, conducting, and reporting contact tracing could help to increase the evidence base for better assessing influenza transmission aboard aircraft.
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43
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Yan Y, Li X, Shang Y, Tu J. Evaluation of airborne disease infection risks in an airliner cabin using the Lagrangian-based Wells-Riley approach. BUILDING AND ENVIRONMENT 2017; 121:79-92. [PMID: 32287972 PMCID: PMC7111330 DOI: 10.1016/j.buildenv.2017.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 04/28/2017] [Accepted: 05/08/2017] [Indexed: 05/03/2023]
Abstract
An urgent demand of assessing passengers' exposure risks in airliner cabins was raised as commercial airliners are one of the major media that carrying and transmitting infectious disease worldwide. In this study, simulations were conducted using a Boeing 737 cabin model to study the transport characteristics of airborne droplets and the associated infection risks of passengers. The numerical results of the airflow field were firstly compared against the experimental data in the literature to validate the reliability of the simulations. Airborne droplets were assumed to be released by passengers through coughing and their transport characteristics were modelled using the Lagrangian approach. Numerical results found that the particle travel distance was very sensitive to the release locations, and the impact was more significant along the longitudinal and horizontal directions. Particles released by passengers sitting next to the windows could travel much further than the others. A quantifiable approach was then applied to assess the individual infection risks of passengers. The key particle transport information such as the particle residence time yielded from the Lagrangian tracking process was extracted and integrated into the Wells-Riley equation to estimate the risks of infection. Compared to the Eulerian-based approach, the Lagrangian-based approach presented in this study is more robust as it addresses both the particle concentration and particle residence time in the breathing zone of every individual passenger.
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Affiliation(s)
- Yihuan Yan
- School of Engineering, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia
| | - Xiangdong Li
- School of Engineering, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia
| | - Yidan Shang
- School of Engineering, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia
| | - Jiyuan Tu
- School of Engineering, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia
- Key Laboratory of Ministry of Education for Advanced Reactor Engineering and Safety, Institute of Nuclear and New Energy Technology, Tsinghua University, PO Box 1021, Beijing 100086, China
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44
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Jang HS, Lim H, Jeon JY. Control of interior surface materials for speech privacy in high-speed train cabins. INDOOR AIR 2017; 27:670-679. [PMID: 27637472 DOI: 10.1111/ina.12339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Accepted: 09/10/2016] [Indexed: 06/06/2023]
Abstract
The effect of interior materials with various absorption coefficients on speech privacy was investigated in a 1:10 scale model of one high-speed train cabin geometry. The speech transmission index (STI) and privacy distance (rP ) were measured in the train cabin to quantify speech privacy. Measurement cases were selected for the ceiling, sidewall, and front and back walls and were classified as high-, medium- and low-absorption coefficient cases. Interior materials with high absorption coefficients yielded a low rP , and the ceiling had the largest impact on both the STI and rP among the interior elements. Combinations of the three cases were measured, and the maximum reduction in rP by the absorptive surfaces was 2.4 m, which exceeds the space between two rows of chairs in the high-speed train. Additionally, the contribution of the interior elements to speech privacy was analyzed using recorded impulse responses and a multiple regression model for rP using the equivalent absorption area. The analysis confirmed that the ceiling was the most important interior element for improving speech privacy. These results can be used to find the relative decrease in rP in the acoustic design of interior materials to improve speech privacy in train cabins.
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Affiliation(s)
- H S Jang
- Department of Architectural Engineering, Hanyang University, Seoul, Korea
| | - H Lim
- Department of Architectural Engineering, Hanyang University, Seoul, Korea
| | - J Y Jeon
- Department of Architectural Engineering, Hanyang University, Seoul, Korea
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Xu C, Nielsen PV, Liu L, Jensen RL, Gong G. Human exhalation characterization with the aid of schlieren imaging technique. BUILDING AND ENVIRONMENT 2017; 112:190-199. [PMID: 32287969 PMCID: PMC7111220 DOI: 10.1016/j.buildenv.2016.11.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/17/2016] [Accepted: 11/18/2016] [Indexed: 05/08/2023]
Abstract
The purpose of this paper is to determine the dispersion and distribution characteristics of exhaled airflow for accurate prediction of disease transmission. The development of airflow dynamics of human exhalation was characterized using nonhazardous schlieren photography technique, providing a visualization and quantification of turbulent exhaled airflow from 18 healthy human subjects whilst standing and lying. The flow shape of each breathing pattern was characterized by two angles and averaged values of 18 subjects. Two exhaled air velocities, u m and u p , were measured and compared. The mean peak centerline velocity, u m was found to decay correspondingly with increasing horizontal distance x in a form of power function. The mean propagation velocity, u p was found to correlate with physiological parameters of human subjects. This was always lower than u m at the mouth/nose opening, due to a vortex like airflow in front of a single exhalation cycle. When examining the talking and breathing process between two persons, the potential infectious risk was found to depend on their breathing patterns and spatial distribution of their exhaled air. Our study when combined with information on generation and distributions of pathogens could provide a prediction method and control strategy to minimize infection risk between persons in indoor environments.
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Affiliation(s)
- Chunwen Xu
- College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao 266580, China
- Department of Civil Engineering, Aalborg University, Aalborg 9000, Denmark
| | - Peter V. Nielsen
- Department of Civil Engineering, Aalborg University, Aalborg 9000, Denmark
| | - Li Liu
- Department of Civil Engineering, Aalborg University, Aalborg 9000, Denmark
| | - Rasmus L. Jensen
- Department of Civil Engineering, Aalborg University, Aalborg 9000, Denmark
| | - Guangcai Gong
- College of Civil Engineering, Hunan University, Changsha 410082, China
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46
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Li X, Liu T, Lin L, Song T, Du X, Lin H, Xiao J, He J, Liu L, Zhu G, Zeng W, Guo L, Cao Z, Ma W, Zhang Y. Application of the analytic hierarchy approach to the risk assessment of Zika virus disease transmission in Guangdong Province, China. BMC Infect Dis 2017; 17:65. [PMID: 28086897 PMCID: PMC5234119 DOI: 10.1186/s12879-016-2170-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 12/24/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An international spread of Zika virus (ZIKV) infection has attracted global attention in 2015. The infection also affected Guangdong province, which is located in southern China. Multiple factors, including frequent communication with South America and Southeast Asia, suitable climate (sub-tropical) for the habitat of Aedes species, may increase the risk of ZIKV disease transmission in this region. METHODS An analytic hierarchy process (AHP) method was used to develop a semi-quantitative ZIKV risk assessment model. After selecting indicators, we invited experts in related professions to identify the index weight and based on that a hierarchical structure was generated. Then a series of pairwise comparisons were used to determine the relative importance of the criteria. Finally, the optimal model was established to estimate the spatial and seasonal transmission risk of ZIKV. RESULTS A total of 15 factors that potentially influenced the risk of ZIKV transmission were identified. The factor that received the largest weight was epidemic of ZIKV in Guangdong province (combined weight [CW] =0.37), followed by the mosquito density (CW = 0.18) and the epidemic of DENV in Guangdong province (CW = 0.14). The distribution of 123 districts/counties' RIs of ZIKV in Guangdong through different seasons were presented, respectively. CONCLUSIONS Higher risk was observed within Pearl River Delta including Guangzhou, Shenzhen and Jiangmen, and the risk is greater in summer and autumn compared to spring and winter.
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Affiliation(s)
- Xing Li
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Tao Liu
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Lifeng Lin
- Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Tie Song
- Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Xiaolong Du
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Hualiang Lin
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Jianpeng Xiao
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Jianfeng He
- Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Liping Liu
- Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Guanghu Zhu
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Weilin Zeng
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Lingchuan Guo
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China
| | - Zheng Cao
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, No. 511 Kehua Street, Tianhe District, Guangzhou, 510640, China
| | - Wenjun Ma
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, No. 511 Kehua Street, Tianhe District, Guangzhou, 510640, China.
| | - Yonghui Zhang
- Guangdong Provincial Center for Disease Control and Prevention, No. 160 Qunxian Road, Panyu District, Guangzhou, 511430, China.
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Goeijenbier M, van Genderen P, Ward BJ, Wilder-Smith A, Steffen R, Osterhaus ADME. Travellers and influenza: risks and prevention. J Travel Med 2017; 24:taw078. [PMID: 28077609 PMCID: PMC5505480 DOI: 10.1093/jtm/taw078] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/14/2016] [Indexed: 02/03/2023]
Abstract
BACKGROUND Influenza viruses are among the major causes of serious human respiratory tract infection worldwide. In line with the high disease burden attributable to influenza, these viruses play an important, but often neglected, role in travel medicine. Guidelines and recommendations regarding prevention and management of influenza in travellers are scarce. Of special interest for travel medicine are risk populations and also circumstances that facilitate influenza virus transmission and spread, like travel by airplane or cruise ship and mass gatherings. METHODS We conducted a PUBMED/MEDLINE search for a combination of the MeSH terms Influenza virus, travel, mass gathering, large scale events and cruise ship. In addition we gathered guidelines and recommendations from selected countries and regarding influenza prevention and management in travellers. By reviewing these search results in the light of published knowledge in the fields of influenza prevention and management, we present best practice advice for the prevention and management of influenza in travel medicine. RESULTS Seasonal influenza is among the most prevalent infectious diseases in travellers. Known host-associated risk factors include extremes of age and being immune-compromised, while the most relevant environmental factors are associated with holiday cruises and mass gatherings. CONCLUSIONS Pre-travel advice should address influenza and its prevention for travellers, whenever appropriate on the basis of the epidemiological situation concerned. Preventative measures should be strongly recommended for travellers at high-risk for developing complications. In addition, seasonal influenza vaccination should be considered for any traveller wishing to reduce the risk of incapacitation, particularly cruise ship crew and passengers, as well as those participating in mass gatherings. Besides advice concerning preventive measures and vaccination, advice on the use of antivirals may be considered for some travellers.
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Affiliation(s)
- M Goeijenbier
- Institute for Tropical Diseases, Havenziekenhuis, Rotterdam, The Netherlands
| | - P van Genderen
- Institute for Tropical Diseases, Havenziekenhuis, Rotterdam, The Netherlands
| | - B J Ward
- Research institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - A Wilder-Smith
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Institute of Public Health, University of Heidelberg, Germany
| | - R Steffen
- Epidemiology, Biostatistics and Prevention Institute, WHO Collaborating Centre for Travelers Health, University of Zurich Travel Health Centre, Zurich, Switzerland
| | - A D M E Osterhaus
- ARTEMIS One Health Research Institute Utrecht, The Netherlands.,Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine, Hannover, Germany
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You R, Chen J, Lin CH, Wei D, Chen Q. Investigating the impact of gaspers on cabin air quality in commercial airliners with a hybrid turbulence model. BUILDING AND ENVIRONMENT 2017; 111:110-122. [PMID: 32287968 PMCID: PMC7117005 DOI: 10.1016/j.buildenv.2016.10.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 05/05/2023]
Abstract
It is not clear whether turning on the gaspers in the cabins of commercial airliners actually improves the air quality. To answer this question, this study first developed a hybrid turbulence model which was suitable for predicting the air distribution in an aircraft cabin with gaspers turned on. Next, the investigation validated the model using two sets of experimental data from a cabin mockup and an actual airplane. This study then used the validated model to systematically investigate the impact of gaspers on cabin air quality in a seven-row section of the fully-occupied, economy-class cabin of Boeing 767 and 737 airplanes. The CFD calculations formed a database consisting of 9660 data points that provide information about SARS infection risk. It was found that the distribution of opened gaspers can influence the infection risk for passengers. Even though the gasper supplies clean air, it is possible for it to have a negative impact on the passengers' health. Statistically speaking, the overall effect of turning on the gaspers on the mean infection risk for the general population was neutral.
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Affiliation(s)
- Ruoyu You
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Jun Chen
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Chao-Hsin Lin
- Environmental Control Systems, Boeing Commercial Airplanes, Everett, WA 98203, USA
| | - Daniel Wei
- Boeing Research & Technology, Beijing 100027, China
| | - Qingyan Chen
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
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Vidotti HGM, Sticca MG, Silva TNRD, Menegon NL. Trabalho e saúde dos comissários de bordo: uma revisão. REVISTA BRASILEIRA DE SAÚDE OCUPACIONAL 2016. [DOI: 10.1590/2317-6369000116015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Resumo Introdução: com o aumento do número de voos e passageiros, as tarefas atribuídas aos comissários de bordo tornam-se mais complexas, podendo gerar sobrecarga e prejuízo à saúde e ao desempenho desses trabalhadores. Objetivos: identificar e sistematizar os artigos publicados em periódicos científicos, sobre o impacto de fatores físicos, ambientais e organizacionais do trabalho dos comissários de bordo na saúde desses trabalhadores. Método: revisão sistemática da literatura, em português e inglês, utilizando as palavras-chave "aeronave", "cabine", "transporte aéreo", "comissário de bordo" e "trabalho", nas bases de dados ScienceDirect, PubMed, Scopus, ProQuest e SciELO, considerando o período de 1983 a 2013. Resultados: 65 artigos atenderam aos critérios de inclusão. Verificou-se um predomínio de trabalhos com foco em fatores físicos e/ou relacionados à saúde/doença e em fatores relacionados à satisfação no trabalho e poucos estudos abordando a organização do trabalho. Conclusão: os estudos encontrados analisaram os fatores presentes nas situações de trabalho de comissários de bordo de forma isolada. Não foram encontrados estudos que adotassem uma metodologia de análise das situações de trabalho que possibilitasse estabelecer inter-relações entre os fatores determinantes da carga de trabalho desses trabalhadores e os impactos para sua saúde.
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Browne A, Ahmad SSO, Beck CR, Nguyen-Van-Tam JS. The roles of transportation and transportation hubs in the propagation of influenza and coronaviruses: a systematic review. J Travel Med 2016; 23:tav002. [PMID: 26782122 PMCID: PMC7539332 DOI: 10.1093/jtm/tav002] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/10/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND Respiratory viruses spread in humans across wide geographical areas in short periods of time, resulting in high levels of morbidity and mortality. We undertook a systematic review to assess the evidence that air, ground and sea mass transportation systems or hubs are associated with propagating influenza and coronaviruses. METHODS Healthcare databases and sources of grey literature were searched using pre-defined criteria between April and June 2014. Two reviewers screened all identified records against the protocol, undertook risk of bias assessments and extracted data using a piloted form. Results were analysed using a narrative synthesis. RESULTS Forty-one studies met the eligibility criteria. Risk of bias was high in the observational studies, moderate to high in the reviews and moderate to low in the modelling studies. In-flight influenza transmission was identified substantively on five flights with up to four confirmed and six suspected secondary cases per affected flight. Five studies highlighted the role of air travel in accelerating influenza spread to new areas. Influenza outbreaks aboard cruise ships affect 2-7% of passengers. Influenza transmission events have been observed aboard ground transport vehicles. High heterogeneity between studies and the inability to exclude other sources of infection means that the risk of influenza transmission from an index case to other passengers cannot be accurately quantified. A paucity of evidence was identified describing severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus transmission events associated with transportation systems or hubs. CONCLUSION Air transportation appears important in accelerating and amplifying influenza propagation. Transmission occurs aboard aeroplanes, at the destination and possibly at airports. Control measures to prevent influenza transmission on cruise ships are needed to reduce morbidity and mortality. There is no recent evidence of sea transport accelerating influenza or coronavirus spread to new areas. Further investigation is required regarding the roles of ground transportation systems and transport hubs in pandemic situations.
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Affiliation(s)
- Annie Browne
- Division of Epidemiology and Public Health, University of Nottingham, Nottingham, UK, Field Epidemiology Service, Public Health England, Bristol, UK and
| | - Sacha St-Onge Ahmad
- Division of Epidemiology and Public Health, University of Nottingham, Nottingham, UK
| | - Charles R Beck
- Field Epidemiology Service, Public Health England, Bristol, UK and School of Social and Community Medicine, University of Bristol, Bristol, UK
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