It Is Time to Address Airborne Transmission of Coronavirus Disease 2019 (COVID-19)

Clinical Infectious Diseases INVITED COMMENTARY

Lidia Morawska1 and Donald K. Milton2 1International Laboratory for Air Quality and Heath, WHO Collaborating Centre, Queensland University of Technology, 2 George Street, Brisbane, QLD 4001 Australia, and 2Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Maryland, USA Downloaded from https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa939/5867798 by guest on 15 November 2020

Keywords. airborne transmission; airborne infection spread; coronavirus; COVID-19; SARS-CoV-2 virus.

We appeal to the medical community transmission was the most likely mech- on hand washing, maintaining social and to the relevant national and inter- anism explaining the spatial pattern of distancing, and droplet precautions. Most national bodies to recognize the potential infections [6]. Retrospective analysis has public health organizations, including the for airborne spread of coronavirus dis- shown the same for severe acute respira- World Health Organization (WHO) [16], ease 2019 (COVID-19). There is signifi- tory syndrome coronavirus 2 (SARS- do not recognize airborne transmission cant potential for inhalation exposure to CoV-2) [7–10]. In particular, a study in except for aerosol-generating procedures viruses in microscopic respiratory drop- their review of records from a Chinese performed in healthcare settings. Hand lets (microdroplets) at short to medium restaurant observed no evidence of direct washing and social distancing are ap- distances (up to several meters, or room or indirect contact between the 3 parties propriate but, in our view, insufficient to scale), and we are advocating for the use [10]. In their review of video records from provide protection from virus-carrying of preventive measures to mitigate this the restaurant, they observed no evidence respiratory microdroplets released into route of airborne transmission. of direct or indirect contact between the the air by infected people. This problem Studies by the signatories and other 3 parties. Many studies conducted on the is especially acute in indoor or enclosed scientists have demonstrated beyond any spread of other viruses, including respira- environments, particularly those that are reasonable doubt that viruses are released tory syncytial virus (RSV) [11], Middle crowded and have inadequate ventilation during exhalation, talking, and coughing East Respiratory Syndrome Coronavirus [17] relative to the number of occupants in microdroplets small enough to remain (MERS-CoV) [8], and influenza [2, 4], and extended exposure periods (as graph- aloft in air and pose a risk of exposure at show that viable airborne viruses can be ically depicted in Figure 1). For example, distances beyond 1–2 m from an infected exhaled [2] and/or detected in the in- airborne transmission appears to be the individual ([1–4]). For example, at typical door environment of infected patients only plausible explanation for several indoor air velocities [5], a 5-μm droplet [11, 12]. This poses the risk that people superspreading events investigated that will travel tens of meters, much greater sharing such environments can poten- occurred under such conditions [10], and than the scale of a typical room, while tially inhale these viruses, resulting in others where recommended precautions settling from a height of 1.5 m to the infection and disease. There is every related to direct droplet transmissions floor. Several retrospective studies con- reason to expect that SARS-CoV-2 be- were followed. ducted after the severe acute respiratory haves similarly, and that transmission The evidence is admittedly incom- syndrome coronavirus 1 (SARS-CoV-1) via airborne microdroplets [10, 13] is an plete for all the steps in COVID-19 epidemic demonstrated that airborne important pathway. Viral RNA associated microdroplet transmission, but it is simi- with droplets <5 μm has been detected larly incomplete for the large droplet in air [14], and the virus has been shown and fomite modes of transmission. The

Received 26 June 2020; editorial decision 30 June 2020; to maintain infectivity in droplets of this airborne transmission mechanism op- accepted 6 July 2020; published online July 6, 2020. size [9]. Other viruses have been shown erates in parallel with the large droplet Correspondence: L. Morawska, Australia (l.morawska@ qut.edu.au). to survive equally well, if not better, in and fomite routes [16] that are now the Clinical Infectious Diseases® 2020;XX(XX):1–4 aerosols compared to droplets on a sur- basis of guidance. Following the precau- © The Author(s) 2020. Published by Oxford University Press for face [15]. tionary principle, we must address every the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: [email protected]. The current guidance from numerous potentially important pathway to slow DOI: 10.1093/cid/ciaa939 international and national bodies focuses the spread of COVID-19. The measures

INVITED COMMENTARY • cid 2020:XX (XX XXXX) • 1 may think that they are fully protected by adhering to the current recommendations, but in fact, additional airborne interventions are needed for further re- duction of infection risk. This matter is of heightened signifi- cance now, when countries are reopening following lockdowns: bringing people back to workplaces and students back

to schools, colleges, and universities. Downloaded from https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa939/5867798 by guest on 15 November 2020 We hope that our statement will raise awareness that airborne transmission of COVID-19 is a real risk and that control measures, as outlined above, must be added to the other precautions taken, to reduce the severity of the pandemic and save lives.

Supplementary Data Supplementary materials are available at Clinical Infectious Diseases online. Consisting of data provided by the authors to benefit the reader, the posted materials are not copyedited and are the sole responsibility of the authors, so ques- tions or comments should be addressed to the corresponding author. Figure 1. Distribution of respiratory microdroplets in an indoor environment with (A) inadequate ventilation and (B) adequate ventilation. Notes Acknowledgment. Together with the authors, 239 scientists support this Commentary, and that should be taken to mitigate airborne Ventilating, and Air-Conditioning their affiliations and contact details are listed in transmission risk include: Engineers) and REHVA (the Federation the Supplementary Data. The following scientists contributed to for- of European Heating, Ventilation and Air mulating this commentary. Linsey C. Marr, • Provide sufficient and effective venti- Conditioning Associations) have already William Bahnfleth, Jose-Luis Jimenez, Yuguo lation (supply clean outdoor air, min- provided guidelines based on the existing Li, William W. Nazaroff, Catherine Noakes, Chandra Sekhar, Julian Wei-Tze Tang, Raymond imize recirculating air) particularly evidence of airborne transmission. The Tellier, Philomena M. Bluyssen, Atze Boerstra, in public buildings, workplace envir- measures that we propose offer more Giorgio Buonanno, Junji Cao, Stephanie onments, schools, hospitals, and aged benefits than potential downsides, even if J. Dancer, Francesco Franchimon, Charles care homes. they can only be partially implemented. Haworth, Jaap Hogeling, Christina Isaxon, Jarek Kurnitski, Marcel Loomans, Guy B. Marks, • Supplement general ventilation with It is understood that there is not as yet Livio Mazzarella, Arsen Krikor Melikov, Shelly airborne infection controls such as universal acceptance of airborne trans- Miller, Peter V. Nielsen, Jordan Peccia, Xavier local exhaust, high efficiency air filtra- mission of SARS-CoV2; but in our col- Querol, Olli Seppänen, Shin-ichi Tanabe, Kwok Wai Tham, Pawel Wargocki, Aneta Wierzbicka, tion, and germicidal ultraviolet lights. lective assessment there is more than Maosheng Yao. • Avoid overcrowding, particularly in enough supporting evidence so that the The following scientists reviewed the docu- public transport and public buildings. precautionary principle should apply. In ment. Jonathan Abbatt, John Adgate, Alireza Afshari, Kang-Ho Ahn, Francis Allard, Joseph order to control the pandemic, pending Allen, Celia Alves, Meinrat O. Andreae, Isabella Such measures are practical and often the availability of a vaccine, all routes of Annesi-Maesano, Ahmet Arısoy, Andrew P. Ault, can be easily implemented; many are transmission must be interrupted. Gwi-Nam Bae, Gabriel Bekö, Scott C. Bell, not costly. For example, simple steps We are concerned that the lack of rec- Allan Bertram, Mahmood Bhutta, Seweryn Bialasiewicz, Merete Bilde, Tami Bond, Joseph such as opening both doors and win- ognition of the risk of airborne trans- Brain, Marianna Brodach, David M. Broday, dows can dramatically increase air flow mission of COVID-19 and the lack of Guangyu Cao, Christopher D. Cappa, Annmarie rates in many buildings. For mechanical clear recommendations on the control Carlton, Paul K. S. Chan, Christopher Chao, Kuan-Fu Chen, Qi Chen, Qingyan Chen, David systems, organizations such as ASHRAE measures against the airborne virus will Cheong, Per Axcel Clausen, Ross Crawford, Derek (the American Society of Heating, have significant consequences: people Clements-Croome, Geo Clausen, Ian Clifton,

2 • cid 2020:XX (XX XXXX) • INVITED COMMENTARY Richard L. Corsi, Benjamin J. Cowling, Francesca Shiraiwa, Jeffrey Siegel, Torben Sigsgaard, Brett 6. Yu IT, Li Y, Wong TW, et al. Evidence of airborne Romana d’Ambrosio, Ghassan Dbaibo, Richard C. Singer, James N. Smith, Armin Sorooshian, transmission of the severe acute respiratory syn- de Dear, Gianluigi de Gennaro, Peter DeCarlo, Jerzy Sowa, Brent Stephens, Huey-Jen Jenny Su, drome virus. N Engl J Med 2004; 350:1731–9. Philip Demokritou, Hugo Destaillats, Joanna Jordi Sunyer, Jason D. Surratt, Kazuo Takahashi, 7. Miller SL, Nazaroff WW, Jimenez JL, et al. Transmission of SARS-CoV-2 by inhalation of respiratory aerosol Domagala-Kulawik, Neil M. Donahue, Caroline Nobuyuki Takegawa, Jørn Toftum, Margaret in the Skagit Valley Chorale superspreading event. Duchaine, Marzenna R. Dudzinska, Dominic A. Tolbert, Euan Tovey, Barbara J. Turpin, Annele medRxiv 2020; doi: 10.1101/2020.06.15.20132027. E. Dwyer, Greg Evans, Delphine K. Farmer, Kevin Virtanen, John Volckens, Claire Wainwright, Accessed 23 June 2020. P. Fennelly, Richard Flagan, Janine Fröhlich- Lance A. Wallace, Boguang Wang, Chia 8. Buonanno G, Morawska L, Stabile L. Quantitative Nowoisky, Manuel Gameiro da Silva, Christian C. Wang, Michael Waring, John Wenger, Charles assessment of the risk of airborne transmis- George, Marianne Glasius, Allen H. Goldstein, J. Weschler, Brent Williams, Mary E. Wilson, sion of SARS-CoV-2 infection: perspective and João Gomes, Michael Gormley, Rafal Górny, Armin Wisthaler, Kazimierz Wojtas, Douglas retrospective applications. medRxiv 2020; doi: David Grimsrud, Keith Grimwood, Charles R. Worsnop, Ying Xu, Naomichi Yamamoto, 10.1101/2020.06.01.20118984. Accessed 23 June N. Haas, Fariborz Haghighat, Michael Hannigan, Xudong Yang, Hui-Ling Yen, Hiroshi Yoshino, 2020. Downloaded from https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa939/5867798 by guest on 15 November 2020 9. Cai J, Sun W, Huang J, Gamber M, Wu J, He G. Roy Harrison, Ulla Haverinen-Shaughnessy, Hassan Zaraket, Zhiqiang (John) Zhai, Junfeng Indirect virus transmission in cluster of COVID-19 Philippa Howden-Chapman, Per Heiselberg, (Jim) Zhang, Qi Zhang, Jensen Zhang, Yinping cases, Wenzhou, China. 2020. Daven K. Henze, Jean-Michel Heraud, Hartmut Zhang, Bin Zhao, Tong Zhu. 10. Li Y, Qian H, Hang J, et al. Evidence for prob- Herrmann, Philip K. Hopke, Ray Horstman, Disclaimer. The views and opinions expressed able aerosol transmission of SARS-CoV-2 in a Wei Huang, Alex Huffman, David S. Hui, Tareq in this article are those of the authors and do not poorly ventilated restaurant. medRxiv 2020; doi: Hussein, Gabriel Isaacman-VanWertz, Jouni necessarily reflect the official policy or position of 10.1101/2020.04.16.20067728v1. Accessed 05 June J.K. Jaakkola, Matti Jantunen, Lance Jennings, any agency/institution. 2020. Dennis Johansson, Jan Kaczmarczyk, George Potential conflicts of interest. The authors: No 11. Kulkarni H, Smith CM, Lee DDH, Hirst RA, Kallos, David Katoshevski, Frank Kelly, Søren reported conflicts of interest. Both authors have Easton AJ, O'Callaghan C. Evidence of respiratory syncytial virus spread by aerosol: time to revisit in- Kjærgaard, Luke D. Knibbs, Henrik N. Knudsen, submitted the ICMJE Form for Disclosure of fection control strategies? Am J Respir Crit Care GwangPyo Ko, Evelyn S.C. Koay, Jen Kok, Nino Potential Conflicts of Interest. Med 2016; 194:306–16. Kuenzli, Markku Kulmala, Kazukiyo Kumagai, 12. Kim SH, Chang SY, Sung M, et al. Extensive viable Prashant Kumar, Kazumichi Kuroda, Kiyoung Middle East respiratory syndrome (MERS) corona- Lee, Nelson Lee, Barry Lefer, Vincent Lemort, References virus contamination in air and surrounding envi- Xianting Li, Dusan Licina, Chao-Hsin Lin, Junjie 1. Morawska L, Johnsona GR, Ristovski ZD, et al. Size ronment in MERS isolation wards. Clin Infect Dis Liu, Kam Lun E. Hon, John C. 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How 15. Lin K, Marr LC. Humidity-dependent decay of J. Olsiewski, Spyros Pandis, Daniel Peckham, far droplets can move in indoor environments: re- viruses, but not bacteria, in aerosols and droplets Tuukka Petäjä, Zbigniew Popiolek, Ulrich Pöschl, visiting the Wells evaporation-falling curve. Indoor follows disinfection kinetics. Environ Sci Technol Wayne R. Ott, Kimberly Prather, Andre S. H. Air 2007; 17:211–25. 2020; 54:1024–32. Prevot, Hua Qian, Shanna Ratnesar-Shumate, 4. Lindsley WG, Noti JD, Blachere FM, et al. Viable 16. World Health Organization. Modes of transmis- James L. Repace, Tiina Reponen, Ilona Riipinen, influenza A virus in airborne particles from sion of virus causing COVID-19: implications for IPC precaution recommendations: scientific brief. Susan Roaf, Allen L. Robinson, Yinon Rudich, human coughs. J Occup Environ Hyg 2015; 12:107–13. 27 March 2020; (No. WHO/2019-nCoV/Sci_Brief/ Manuel Ruiz de Adana, Masayuki Saijo, Reiko 5. 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INVITED COMMENTARY • cid 2020:XX (XX XXXX) • 3 Downloaded from https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa939/5867798 by guest on 15 November 2020

Figure 1 It is Time to Address Airborne Transmission of COVID-19

Understanding the transmission of respiratory infections indoors requires expertise in many distinctly different areas of science and engineering, including virology, aerosol physics, flow dynamics, exposure and epidemiology, medicine, and building engineering, to name the most significant. No one person has expertise in all these areas. However, collectively, the community of the signatories to the Comment understands the characteristics and mechanisms behind the generation of respiratory microdroplets, survival of viruses in the microdroplets, transport of the microdroplets and human exposure to them, and the airflow patterns that carry microdroplets in buildings. We have dedicated our careers working in this multidisciplinary field, and our statement stems from our collective expertise spanning the entire field.

The signatories listed on the first two pages contributed to the writing of this commentary, and all the signatories reviewed the document.

Professor Linsey C. Marr Civil and Environmental Engineering Professor Philomena M. Bluyssen Virginia Tech, USA Faculty of Architecture and the Built Environment Email: [email protected] Delft University of Technology, The Netherlands Email: [email protected] Professor William Bahnfleth Department of Architectural Engineering Dr. Atze Boerstra The Pennsylvania State University, USA REHVA Vice-President Email: [email protected] Federation of European Heating, Ventilation and Air Conditioning Associations Professor Jose-Luis Jimenez The Hague, The Netherlands Department of Chemistry and Cooperative Institute Email: [email protected] for Research in Environmental Sciences (CIRES) University of Colorado at Boulder, USA Professor Giorgio Buonanno Email: [email protected] Department of Civil and Mechanical Engineering University of Cassino and Southern Lazio Professor Yuguo Li Cassino, Italy Department of Mechanical Engineering Email: [email protected] The University of Hong Kong, Hong Kong, China Email: [email protected] Professor Junji Cao Institute of Earth Environment William W. Nazaroff Chinese Academy of Sciences, Beijing, China Daniel Tellep Distinguished Professor Emeritus Email: [email protected] Civil and Environmental Engineering Department University of California, Berkeley, USA Professor Stephanie J. Dancer Email: [email protected] Department of Medical Microbiology, NHS Lanarkshire, School of Applied Sciences Professor Catherine Noakes Edinburgh Napier University, United Kingdom School of Civil Engineering Email: [email protected] University of Leeds, United Kingdom Email: [email protected] Dr. Francesco Franchimon Managing Director and Owner Dr Chandra Sekhar Vital Environments Individual Capacity, Singapore Franchimon ICM, The Netherlands Email: [email protected] Email: [email protected]

Professor Julian Wei-Tze Tang Dr. Charles Haworth Respiratory Sciences Consultant Respiratory Physician, Cambridge University Leicester, United Kingdom Centre for Lung Infection, The Adult Cystic Fibrosis Email: [email protected] Centre, The Lung Defence Clinic, Royal Papworth Hospital, Cambridge, United Kingdom Associate Professor Raymond Tellier Email: [email protected] Department of Medicine McGill University, Canada Email: [email protected]

Dr. Jaap Hogeling Professor Jordan Peccia Managing Director, International Standards Department of Chemical and Environmental ISSO, Netherlands Building Research Institute, The Engineering, Yale University, USA Netherlands Email: [email protected] Email: [email protected] Professor Xavier Querol Associate Professor Christina Isaxon Department of Geosciences Ergonomics and Aerosol Technology Institute of Environmental Assessment and Water Lund University, Lund, Sweden Research, Spanish National Research Council Email: [email protected] Barcelona (IDAEA-CSIC), Spain Email: [email protected] Professor Jarek Kurnitski Department of Civil Engineering and Architecture Professor Emeritus Olli Seppänen Tallinn University of Technology, Estonia Department of Mechanical Engineering Email: [email protected] Aalto University Finland Email: [email protected] Assistant Professor Marcel Loomans Department of the Built Environment Professor Shin-ichi Tanabe Eindhoven University of Technology (TU/e) Department of Architecture The Netherlands Waseda University, Japan Email: [email protected] Email: [email protected]

Professor Guy B. Marks Professor Kwok Wai Tham Director, Centre for Air quality Research and Department of Building evaluation (CAR), Faculty of Medicine National University of Singapore, Singapore University of New South Wales (UNSW), Sydney, Email: [email protected] Australia Email: [email protected] Associate Professor Pawel Wargocki International Centre for Indoor Environment and Professor Livio Mazzarella Energy, Department of Civil Engineering AiCARR Vice President Technical University of Denmark Department of Energy Email: [email protected] Politecnico di Milano, Italy Email: [email protected] Associate Professor Aneta Wierzbicka Ergonomics and Aerosol Technology Professor Arsen Krikor Melikov Lund University, Sweden International Centre for Indoor Environment and Email: [email protected] Energy, Department of Civil Engineering, Technical University of Denmark, Denmark Boya Distinguished Professor Maosheng Yao Email: [email protected] College of Environmental Sciences and Engineering, Peking University, Beijing, China Professor Shelly Miller Email: [email protected] Mechanical Engineering Department University of Colorado Boulder, USA Email: [email protected]

Professor Emeritus Peter V. Nielsen The Faculty of Engineering and Science Department of Civil Engineering Aalborg University, Denmark Email: [email protected]

Co-Signing Scientists:

Professor Jonathan Abbatt Dr. Gwi-Nam Bae Department of Chemistry Center for Particulate Air Pollution and Health University of Toronto, Canada Korea Institue of Science and Technology, Email: [email protected] Republic of Korea Email: [email protected] Dr. John Adgate Department of Environmental and Occupational Dr. Gabriel Bekö Health, Colorado School of Public Health International Centre for Indoor Environment and University of Colorado, USA Energy, Department of Civil Engineering Email: [email protected] Technical University of Denmark, Denmark Email: [email protected] Professor Alireza Afshari Department of the Built Environment (BUILD) Professor Scott C. Bell, Chief Executive Aalborg University, Denmark Translational Research Institute Email: [email protected] Brisbane, Australia Email: [email protected] Professor Kang-Ho Ahn Department of Mechanical Engineering Professor Allan Bertram Hanyang University, Republic of Korea Department of Chemistry Email: [email protected] University of British Columbia, Canada Email: [email protected] Professor Francis Allard LaSIE (Engineering Sciences for Environmental Professor Mahmood Bhutta Issues Laboratory) Department of ENT Surgery, Brighton & Sussex La Rochelle University, France University Hospitals, United Kingdom Email: [email protected] Email: [email protected]

Professor Joseph Allen Dr. Seweryn Bialasiewicz Healthy Buildings Program Australian Centre for Ecogenomics Harvard T.H. Chan School of Public Health, USA The University of Queensland, Australia Email: [email protected] Email: [email protected]

Dr. Celia Alves Professor Merete Bilde Centre for Environmental and Marine Studies, Department of Chemistry University of Aveiro, Portugal Aarhus University, Denmark Email: [email protected] Email: [email protected]

Professor Meinrat O. Andreae Tami Bond, Scott Presidential Chair in Energy Max Planck Institute for Chemistry, Germany Environment and Health Email: [email protected] Department of Mechanical Engineering Colorado State University, USA Professor Isabella Annesi-Maesano Email: [email protected] Epidemiology of Allergic and Respiratory Diseases (EPAR) Department, IPLESP, INSERM and Professor Joseph Brain Sorbonne University, France Department of Environmental Health Email: [email protected] Harvard University, USA Email: [email protected] Professor Ahmet Arısoy Mechanical Engineering Department Professor Marianna Brodach İstanbul Technical University, Turkey Engineering Department, Moscow Architectural Email: [email protected] Institute (State Academy), Russia Email: [email protected] Professor Andrew P. Ault Department of Chemistry Professor David M. Broday University of Michigan, USA Civil & Environmental Engineering Email: [email protected] Technion Institute of Technology, Israel Email: [email protected]

Professor Guangyu Cao Professor Derek Clements-Croome Department of Energy and Process Engineering Department of Built Environment Norwegian University of Science and Technology, Reading University, United Kingdom Norway Email: [email protected] Email: [email protected] Professor Geo Clausen Professor Christopher D. Cappa Department of Civil Engineering Department of Civil and Environmental Engineering Technical University of Denmark, Denmark University of California, Davis, USA Email: [email protected] Email: [email protected] Dr. Ian Clifton Professor Annmarie Carlton Department of Respiratory Medicine, Leeds Department of Chemistry, Teaching Hospitals NHS Trust, United Kingdom University of California, Irvine, USA Email: [email protected] Email: [email protected] Dean Richard L. Corsi Professor Paul K.S. Chan Maseeh College of Engineering and Computer Department of Microbiology, Faculty of Medicine Science, Portland State University, Oregon, USA The Chinese University of Hong Kong, Email: [email protected] Hong Kong, China Email: [email protected] Professor Benjamin J. Cowling School of Public Health, The University of Hong Professor Christopher Chao Kong, Hong Kong, China Faculty of Engineering, The University of Hong Email: [email protected] Kong, Hong Kong, China Email: [email protected] Professor Francesca Romana d'Ambrosio Department of Industrial Engineering Associate Professor Kuan-Fu Chen University of Salerno, Italy Clinical Informatics and Medical Statistics Research Email: [email protected] Center and Department of Emergency Medicine, Chang Gung University and Chang Gung Memorial Professor Ghassan Dbaibo Hospital, Taiwain Center for Infectious Diseases Research Email: [email protected] American University of Beirut, Lebanon Email: [email protected] Professor Qi Chen College of Environmental Sciences and Engineering Professor Richard de Dear Peking University, Beijing, China School of Architecture, Design and Planning Email: [email protected] The University of Sydney, Australia Email: [email protected] Professor Qingyan Chen Mechanical Engineering, Purdue University, USA Professor Gianluigi de Gennaro Email: [email protected] Department of Biology University of Bari Aldo Moro, Italy Dr. David Cheong Email: [email protected] Individual Capacity, Singapore Email: [email protected] Dr. Peter DeCarlo Environmental Health and Engineering Dr. Per Axcel Clausen Johns Hopkins University, USA New Technologies, National Research Centre for Email: [email protected] the Working Environment, Denmark Email: [email protected] Professor Philip Demokritou Department of Environmental Health Professor Ross Crawford TH Chan School of Public Health Orthopaedic Surgeon, The Prince Charles Hospital Harvard University, USA Medical Robotics, Queensland University of Email: [email protected] Technology, Brisbane, Australia Email: [email protected] Dr. Hugo Destaillats Indoor Environment Group Lawrence Berkeley National Laboratory, USA Email: [email protected]

Professor Joanna Domagala-Kulawik Dr. Christian George Department of Pneumonology and Allergy IRCELYON, CNRS, France Medical University of Warsaw, Poland Email: [email protected] Email: [email protected] Associate Professor Marianne Glasius Lord University Professor Neil M. Donahue Department of Chemistry Center for Atmospheric Particle Studies Aarhus University, Denmark Carnegie Mellon University, USA Email: [email protected] Email: [email protected] Professor Allen H. Goldstein Professor Caroline Duchaine Department of Environmental Science, Policy, and Biochemistry, Microbiology and Bio-Informatics Management Department, Université Laval, Canada University of California at Berkeley, USA Email: [email protected] Email: [email protected]

Professor Marzenna R. Dudzinska Professor João Gomes Department of Indoor and Outdoor Air Quality Chemical Engineering Department Lublin University of Technology, Poland ISEL - Lisbon Polytechnic, Portugal Email: [email protected] Email: [email protected]

Professor Dominic E. Dwyer Dr. Michael Gormley Director, New South Wales Health Pathology Public Institute for Sustainable Building Design Health Pathology, NSWHP-ICPMR Heriot- Watt University, Edinburgh, United Kingdom University of Sydney, Westmead, Australia Email: [email protected] Email: [email protected] Professor Rafal Górny Professor Greg Evans P.Eng. FCAE, FAAAS Department of Chemical, Aerosol and Biological Southern Ontario Centre for Atmospheric Aerosol Hazards, Central Institute for Labour Protection - Research National Research Institute, Poland University of Toronto, Canada Email: [email protected] Email: [email protected] Professor Emeritus David Grimsrud Associate Professor Delphine K. Farmer Founding Editor, Indoor Air Journal Department of Chemistry University of Minnesota (Retired), USA Colorado State University, USA Email: [email protected] Email: [email protected] Professor Keith Grimwood Kevin P. Fennelly, MD, MPH, ATSF School of Medicine Pulmonary Branch, Division of Intramural Research Griffith University, Brisbane, Australia NHLBI / NIH, USA Email: [email protected] Email: [email protected] Professor Charles N. Haas Professor Richard Flagan Civil, Architectural & Environmental Engineering Departments of Chemical Engineering and Drexel University, USA Environmental Science and Engineering Email: [email protected] California Institute of Technology, USA Email: [email protected] Professor Fariborz Haghighat Building, Civil and Environmental Engineering Dr. Janine Fröhlich-Nowoisky Concordia University, Canada Multiphase Chemistry Email: [email protected] Max Planck Institute for Chemistry, Germany Email: [email protected] Professor Michael Hannigan Department of Mechanical Engineering Professor Manuel Gameiro da Silva University of Colorado, USA ADAI, LAETA, Department of Mechanical Email: [email protected] Engineering, EfS Initiative University of Coimbra, Portugal Email: [email protected]

Professor Roy Harrison Professor David S. Hui School of Geography, Earth & Environmental Department of Medicine & Therapeutics, The Sciences, Chinese University of Hong Kong, University of Birmingham, United Kingdom Hong Kong, China Email: [email protected] Email: [email protected]

Professor Ulla Haverinen-Shaughnessy, D. Sc. Professor Tareq Hussein Civil Engineering; Indoor Air Program Department of Physics The University of Oulu; The University of Tulsa University of Jordan, Jordan Finland & USA Email: [email protected] Email: [email protected] Dr. Gabriel Isaacman-VanWertz Professor Philippa Howden-Chapman Civil and Environmental Engineering Department of Public Health Virginia Tech, USA University of Otago, Wellington, New Zealand Email: [email protected] Email: [email protected] Professor Jouni J.K. Jaakkola Professor Per Heiselberg Center for Environmental and Respiratory Health Department of the Built Environment Research, University of Oulu, Finland Aalborg University, Denmark Email: [email protected] Email: [email protected] Professor Matti Jantunen Professor Daven K. Henze National Institute for Health and Welfare, Finland Department of Mechanical Engineering Email: [email protected] University of Colorado Boulder, USA Email: [email protected] Associate Professor Lance Jennings Pathology and Biomedical Science Dr. Jean-Michel Heraud University of Otago, Christchurch, New Zealand Virology Unit, Email: [email protected] Institut Pasteur de Madagascar, Madagascar Email: [email protected] Professor Dennis Johansson Building Services, Lund University, Sweden Professor Hartmut Herrmann Email: [email protected] Atmospheric Chemistry Department (ACD) Leibniz-Institute for Tropospheric Research Dr. Jan Kaczmarczyk (TROPOS), Germany Department of Heating, Ventilation and Dust Email: [email protected] Removal Technology Silesian University of Technology, Poland Professor Philip K. Hopke Email: [email protected] Public Health Sciences, University of Rochester School of Medicine and Dentistry, USA Professor George Kallos Email: [email protected] Department of Physics National & Kapodistrian University of Athens, Ray Horstman, Greece Beoing (Retired), USA Email: [email protected] Email: [email protected] Professor David Katoshevski Professor Wei Huang Environmental Engineering Department of Occupational and Environmental Ben-Gurion University of the Negev, Israel Health, Peking University, Beijing, China Email: [email protected] Email: [email protected] Professor Frank Kelly Professor J. Alex Huffman School of Public Health Department of Chemistry and Biochemistry Imperial College London, United Kingdom University of Denver, USA Email: [email protected] Email: [email protected] Associate Professor Søren Kjærgaard Department of Public Health Aarhus University, Denmark Email: [email protected]

Associate Professor Luke D. Knibbs Professor Kiyoung Lee School of Public Health Department of Environmental Health Sciences The University of Queensland, Brisbane, Australia Seoul National University, Republic of Korea Email: [email protected] Email: [email protected]

Dr. Henrik N. Knudsen Professor Nelson Lee [MBBS, MRCP, MD, Department of the Built Environment (BUILD) FRCP(Edin), FRCP(Lond), FIDSA] Aalborg University, Denmark Department of Medicine, Division of Infectious Email: [email protected] Diseases, University of Alberta, Canada Email: [email protected] Professor GwangPyo Ko Graduate School of Public Health Dr. Barry Lefer Seoul National University, Republic of Korea Individual Capacity, USA Email: [email protected] Email: [email protected]

Associate Professor Evelyn S.C. Koay Professor Vincent Lemort Yong Loo Lin School of Medicine, Department of Thermodynamics Laboratory Pathology University of Liège, Belgium National University of Singapore, Singapore Email: [email protected] Email: [email protected] Professor Xianting Li Dr. Jen Kok Department of Building Science Centre for Infectious Disease and Microbiology Tsinghua University, Beijing, China Laboratory Services Email: [email protected] NSW Health Pathology-Institute of Clinical Pathology and Medical Research, Australia Professor Dusan Licina Email: [email protected] Civil and Environmental Engineering, EPFL – École Polytechnique Fédérale de Lausanne, Switzerland Professor Nino Kuenzli, MD Email: [email protected] Department of Epidemiology and Public Health and Department of Education and Training, Swiss Dr. Chao-Hsin Lin, PE Tropical and Public Health Institute, Switzerland Environmental Control Systems Email: [email protected] Boeing Commercial Airplanes, USA Email: [email protected] Professor Risto Kosonen Mechanical Engineering, Aalto University, Finland Professor Junjie Liu Email: [email protected] School of Environmental Science and Engineering Tianjin University, China Professor Markku Kulmala Email: [email protected] Institute for Atmospheric and Earth System Research (INAR) / Physics, Faculty of Science Dr. Kam Lun E. Hon, MBBS, MD, FAAP, FCCM University of Helsinki, Finland The Department of Paediatrics & The Hong Kong Email: [email protected] Institute of Integrative Medicine The Chinese University of Hong Kong, Adjunct Professor Kazukiyo Kumagai Hong Kong, China Graduate School of Engineering Email: [email protected] Tokyo University of Science, Japan Email: [email protected] Professor John C. Little Department of Civil and Environmental Engineering Professor Prashant Kumar Virginia Tech, USA Global Centre for Clean Air Research (GCARE) Email: [email protected] University of Surrey, United Kingdom Email: [email protected] Dr. Li Liu Department of Building Science Dr. Kazumichi Kuroda Tsinghua University, Beijing, China School of Medicine, Nihon University, Japan Email: [email protected] Email: [email protected]

Dr. Janet M. Macher, ScD MPH Professor Edward Nardell School of Public Health, Alumna Department of Global Health Equity, Brigham & University of California, Berkeley, USA Woman's Hospital, Harvard University School of Email: [email protected] Medicine and School of Public Health, USA Email: [email protected] Associate Professor Ebba Malmqvist Occupational and Environmental Medicine Professor Athanasios Nenes Lund University, Sweden School of Architecture, Civil and Environmental Email: [email protected] Engineering, École Polytechnique Fédérale de Lausanne, Switzerland Dr. Corinne Mandin Email: [email protected] Department of Health and Comfort Scientific and Technical Center for Building, France Emeritus Adjunct Professor Mark Nicas Email: [email protected] School of Public Health, University of California, Berkeley, USA Professor Ivo Martinac Email: [email protected] Division of Sustainable Buildings, Building Services and Energy Systems Professor Zhi Ning KTH Royal Institute of Technology, Sweden Division of Environment and Sustainability Email: [email protected] The Hong Kong University of Science and Technology, Hong Kong, Hong Kong, China Professor Dainius Martuzevičius Email: [email protected] Faculty of Chemical Technology Kaunas University of Technology, Lithuania Professor Jianlei Niu Email: [email protected] Fellow of ISIAQ, ASHRAE, and IBPSA Faculty of Construction and Environment Dr. Mark J. Mendell The Hong Kong Polytechnic University, Hong Kong, Indoor Environment Department Hong Kong, China Lawrence Berkeley National Laboratory, USA Email: [email protected] Email: [email protected] Dr. Hidekazu Nishimura Professor David Miller Virus Reserch Center, Clinical Research Division Department of Chemistry Sendai Medical Center, National Hospital Carleton University, Ottawa, Canada Organization, Japan Email: [email protected] Email: [email protected]

Assistant Professor Claudia Mohr Professor Colin O'Dowd MAE MRIA Department of Environmental Science Centre for Climate & Air Pollution Studies Stockholm University, Sweden National University of Ireland Galway, United Email: [email protected] Kingdom Email: [email protected] Dr. Luisa T. Molina Department of Earth, Atmospheric and Planetary Professor Bjarne W. Olesen Sciences International Centre for Indoor Environment and Massachusetts Institute of Technology, USA Energy, Technical University of Denmark, Denmark Email: [email protected] Email: [email protected]

Professor Glenn Morrison Dr. Paula J. Olsiewski Environmental Sciences and Engineering Alfred P. Sloan Foundation, USA University of North Carolina, Chapel Hill, USA Email: [email protected] Email: [email protected] Professor Spyros Pandis Dr. Roya Mortazavi Chemical Engineering Department Atmospheric and Oceanic Sciences University of Patras, Greece McGill University, Canada Email: [email protected] Email: [email protected] Professor Daniel Peckham Leeds Institute of Medical Research University of Leeds, United Kingdom Email: [email protected]

Professor Tuukka Petäjä Emeritus Professor Susan Roaf Institute for Atmospheric and Earth System Institute for Sustainable Building Design, EGIS Research (INAR) / Physics Heriot Watt University, Edinburgh, United Kingdom Faculty of Science, University of Helsinki, Finland Email: [email protected] Email: [email protected] Professor Allen L. Robinson Professor Zbigniew Popiolek Department of Mechanical Engineering Department of Heating Ventilation and Dust Carnegie Mellon University, USA Removal Technology Email: [email protected] Silesian University of Technology in Gliwice (Politechnika Ślaska), Poland Professor Yinon Rudich Email: [email protected] Department of Earth and Planetary Sciences Weizmann Institute, Israel Professor Ulrich Pöschl Email: [email protected] Multiphase Chemistry Department Max Planck Institute for Chemistry, Germany Professor Manuel Ruiz de Adana Email: [email protected] Department of Applied Thermodynamics University of Cordoba, Spain Dr. Wayne R. Ott Email: [email protected] Department of Civil and Environmental Engineering Stanford University, USA Dr. Masayuki Saijo Email: [email protected] Department of Virology National Institute of Infectious Diseases, Japan Professor Kimberly Prather Email: [email protected] Distinguished Chair in Atmospheric Chemistry Scripps Institution of Oceanography Professor Reiko Saito University of California, San Diego, USA Division of International Health Email: [email protected] Graduate School of Medical and Dental Sciences Niigata University, Japan Professor Andre S. H. Prevot Email: [email protected] Laboratory of Atmospheric Chemistry Paul Scherrer Institute, Switzerland Professor Paulo Saldiva Email: [email protected] Department of Pathology University of São Paulo, Brazil Professor Hua Qian Email: [email protected] School of Energy and Environment Southeast University, China Professor Tunga Salthammer Email: [email protected] Department of Material Analysis and Indoor Chemistry Dr. Shanna Ratnesar-Shumate Fraunhofer WKI, Braunschweig, Germany Department of Pathology and Microbiology Email: [email protected] University of Nebraska Medical Center, USA Email: [email protected] Professor Joshua L. Santarpia Department of Pathology and Microbiology James L. Repace, MSc. University of Nebraska Medical Center, USA President, Repace Associates, Inc. Secondhand Email: [email protected] Smoke Consultants, USA Email: [email protected] Nohl Professor John H. Seinfeld Department of Chemical Engineering Professor Tiina Reponen California Institute of Technology, USA Department of Environmental and Public Health Email: [email protected] Sciences University of Cincinnati, USA Email: [email protected] Distinguished Professor Emeritus Gary S. Settles Mechanical Engineering Professor Ilona Riipinen Pennsylvania State University, USA Department of Environmental Science Email: [email protected] Stockholm University, Sweden Email: [email protected]

Associate Professor Siegfried Schobesberger Professor Brent Stephens Department of Applied Physics Department of Civil, Architectural, and University of Eastern Finland, Finland Environmental Engineering, Email: [email protected] Illinois Institute of Technology, USA Email: [email protected] Associate Professor Paul T. J. Scheepers Radboud Institute for Health Sciences Professor Huey-Jen Jenny Su Radboudumc, The Netherlands Institute of Environmental Health Sciences Email: [email protected] National Cheng Kung University, Taiwan Email: [email protected] Professor Max H. Sherman, Lawrence Berkeley National Laboratory (Retired), Professor Jordi Sunyer USA Childhood and Environment, ISGlobal, Spain Email: [email protected] Email: [email protected]

Professor Alan Shihadeh Professor Jason D. Surratt Maroun Semaan Faculty of Engineering & Department of Environmental Sciences and Architecture, American University of Beirut, Lebanon Engineering, Gillings School of Global Public Health Email: [email protected] University of North Carolina at Chapel Hill, USA Email: [email protected] Professor Manabu Shiraiwa Department of Chemistry Professor Kazuo Takahashi University of California, Irvine, USA Department of Clinical Laboratory Medicine Email: [email protected] International University of Health and Welfare, Japan Professor Jeffrey Siegel Email: [email protected] Department of Civil & Mineral Engineering University of Toronto, Canada Professor Nobuyuki Takegawa Email: [email protected] Department of Chemistry Tokyo Metropolitan University, Japan Professor Torben Sigsgaard Email: [email protected] Deptartment of Public Health Aarhus University, Denmark Professor Jørn Toftum Email: [email protected] Department of Civil Engineering Technical University of Denmark, Denmark Dr. Brett C. Singer Email: [email protected] Sustainable Energy and Environmental Systems Department Distinguished Professor Margaret A. Tolbert Lawrence Berkeley National Laboratory, USA Department of Chemistry and CIRES Email: [email protected] University of Colorado, Boulder, USA Email: [email protected] Professor James N. Smith Department of Chemistry Associate Professor Euan Tovey University of California, Irvine, USA Woolcock Institute of Medical Research Email: [email protected] University of Sydney, Australia Email: [email protected] Professor Armin Sorooshian Department of Chemical and Environmental Professor Barbara J. Turpin Engineering, University of Arizona, USA Department of Environmental Sciences and Email: [email protected] Engineering, Gillings School of Global Public Health, University of North Carolina - Chapel Hill, USA Dr. Jerzy Sowa Email: [email protected] Faculty of Building Services, Hydro and Environmental Engineering Professor Annele Virtanen Warsaw University of Technology, Poland Department of Applied Physics Email: [email protected] University of Eastern Finland, Finland Email: [email protected]

Professor John Volckens Dr. Kazimierz Wojtas Department of Mechanical Engineering Faculty of Environmental and Power Engineering Colorado State University, USA Cracow University of Technology, Poland Email: [email protected] Email: [email protected]

Professor Claire Wainwright Dr. Douglas R. Worsnop Child Health Research Centre Institute for Atmospheric and Earth System The University of Queensland, Brisbane, Australia Research (INAR) / Physics, Aerodyne Research / Email: [email protected] University of Helsinki, USA / Finland Email: [email protected] Dr. Lance A. Wallace US EPA (Retired), USA Professor Ying Xu Email: [email protected] Department of Building Science Tsinghua University, Beijing, China Professor Boguang Wang Email: [email protected] Institute for Environmental and Climate Research Jinan University, Guangzhou, China Associate Professor Naomichi Yamamoto Email: [email protected] Environmental Health Sciences Seoul National University, Republic of Korea Professor Chia C. Wang Email: [email protected] Aerosol Science Research Center National Sun Yat-sen University, Taiwan Professor Xudong Yang Email: [email protected] Department of Building Science Tsinghua University, Beijing, China Professor Michael Waring Email: [email protected] Department of Civil, Architectural and Environmental Engineering, Drexel University, USA Dr. Hui-Ling Yen Email: [email protected] School of Public Health The University of Hong Kong, Hong Kong, China Professor John Wenger Email: [email protected] School of Chemistry & Environmental Research Institute, University College Cork, Ireland, United Professor Emeritus Hiroshi Yoshino Kingdom Department of Architecture and Building Science Email: [email protected] Tohoku University, Japan

Email: [email protected] Professor Charles J. Weschler Environmental & Occupational Health Sciences Institute Dr. Hassan Zaraket Rutgers University, USA Department of Experimental Pathology, Email: [email protected] Immunology, and Microbiology, Faculty of Medicine, American University of Beirut, Lebanon Professor Brent Williams Email: [email protected] Department of Energy, Environmental, & Chemical Engineering Professor Zhiqiang (John) Zhai Washington University in St. Louis, USA Department of Civil, Environmental and Architectural Email: [email protected] Engineering University of Colorado at Boulder, USA Professor Mary E. Wilson Email: [email protected] Global Health San Francisco and Harvard Chan School of Public Professor Junfeng (Jim) Zhang Health, University of California, USA The Nicholas School of the Environment Email: [email protected] Duke University, USA Professor Armin Wisthaler Email: [email protected] Department of Chemistry University of Oslo, Norway Professor Qi Zhang Email: [email protected] Department of Environmental Toxicology University of California, Davis, USA Email: [email protected]

Professor Jensen Zhang Department of Mechanical and Aerospace Engineering Syracuse University, USA Email: [email protected]

Professor Yinping Zhang Department of Building Science Tsinghua University, Beijing, China Email: [email protected]

Professor Bin Zhao Department of Building Science, School of Architecture, Tsinghua University, Beijing, China Email: [email protected] Professor Tong Zhu College of Environmental Sciences and Engineering Peking University, Beijing, China Email: [email protected]