TEXT OF THE LETTER

06 July 2020

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.

Commentary

We appeal to the medical community and to the relevant national and international bodies to recognize the potential for airborne spread of COVID-19. There is significant potential for inhalation exposure to viruses in microscopic respiratory droplets (microdroplets) at short to medium distances (up to several meters, or room scale), and we are advocating for the use of preventive measures to mitigate this route of airborne transmission.

Studies by the signatories and other scientists have demonstrated beyond any reasonable doubt that viruses are released during exhalation, talking, and coughing in microdroplets small enough to remain aloft in air and pose a risk of exposure at distances beyond 1 to 2 m from an infected individual. For example, at typical indoor air velocities, a 5 μm droplet will travel tens of meters, much greater than the scale of a typical room, while settling from a height of 1.5 m to the floor. Several retrospective studies conducted after the SARS-CoV-1 epidemic demonstrated that airborne transmission was the most likely mechanism explaining the spatial pattern of infections e.g.. Retrospective analysis has shown the same for SARS-CoV-2. In particular, a study in their review of records from a Chinese restaurant, observed no evidence of direct or indirect contact between the three parties [10]. In their review of video records from the restaurant, they observed no evidence of direct or indirect contact between the three parties. Many studies conducted on the spread of other viruses, including respiratory syncytial virus (RSV) , Middle-East Respiratory Syndrome coronavirus (MERS-CoV) , and influenza , show that viable airborne viruses can be exhaled and/or detected in the indoor environment of infected patients. This poses the risk that people sharing such environments can potentially inhale these viruses, resulting in infection and disease. There is every reason to expect that SARS-CoV-2 behaves similarly and that transmission via airborne microdroplets is an important pathway. Viral RNA associated with droplets smaller than 5 μm has been detected in air, and the virus has been shown to maintain infectivity in droplets of this size [9]. Other viruses have been shown to survive equally well, if not better, in aerosols compared to droplets on a surface.

The current guidance from numerous international and national bodies focuses on handwashing, maintaining social distancing, and droplet precautions. Most public health organizations, including the World Health Organization (WHO), do not recognize airborne transmission except for aerosol-generating procedures performed in healthcare settings. Hand washing and social distancing are appropriate, but in our view, insufficient to provide protection from virus-carrying respiratory microdroplets released into the air by infected people. This problem is especially acute in indoor or enclosed environments, particularly those that are crowded and have inadequate ventilation relative to the number of occupants and extended exposure periods. For example, airborne transmission appears to be the only plausible explanation for several superspreading events investigated which occurred under such conditions e.g., and others, where recommended precautions related to direct droplet transmissions, were followed.

The evidence is admittedly incomplete for all the steps in COVID-19 microdroplet transmission, but it is similarly incomplete for the large droplet and fomite modes of transmission. The airborne transmission mechanism operates in parallel with the large droplet and fomite routes, e.g. that are now the basis of guidance. Following the precautionary principle, we must address every potentially important pathway to slow the spread of COVID-19.

The measures that should be taken to mitigate airborne transmission risk include:

• Provide sufficient and effective ventilation (supply clean outdoor air, minimize recirculating air) particularly in public buildings, workplace environments, schools, hospitals, and aged care homes.

• Supplement general ventilation with airborne infection controls such as local exhaust, high-efficiency air filtration, and germicidal ultraviolet lights.

• Avoid overcrowding, particularly in public transport and public buildings.

Such measures are practical and often can be easily implemented; many are not costly. For example, simple steps such as opening both doors and windows can dramatically increase airflow rates in many buildings. For mechanical systems, organizations such as ASHRAE (the American Society of Heating, Ventilating, and Air-Conditioning Engineers) and REHVA (the Federation of European Heating, Ventilation and Air Conditioning Associations) have already provided guidelines based on the existing evidence of airborne transmission. The measures we propose offer more benefits than potential downsides, even if they can only be partially implemented.

It is understood that there is not as yet universal acceptance of airborne transmission of SARS-CoV2; but in our collective assessment there is more than enough supporting evidence so that the precautionary principle should apply. In order to control the pandemic, pending the availability of a vaccine, all routes of transmission must be interrupted.

We are concerned that the lack of recognition of the risk of airborne transmission of COVID-19 and the lack of clear recommendations on the control measures against the airborne virus will have significant consequences: people may think that they are fully protected by adhering to the current recommendations, but in fact, additional airborne interventions are needed for further reduction of infection risk.

This matter is of heightened significance now, when countries are re-opening following lockdowns – bringing people back to workplaces and students back to schools, colleges, and universities. 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.

Disclaimer: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of any agency/institution.

Together with the authors, 239 scientists support this Commentary, and their affiliations and contact details are listed in the Supplementary.

The following scientists contributed to formulating this commentary

Professor Linsey C. Marr
Civil and Environmental Engineering
Virginia Tech, USA
Email: lmarr@vt.edu

Professor William Bahnfleth

Department of Architectural Engineering The Pennsylvania State University, USA Email: wbahnfleth@psu.edu

Professor Jose-Luis Jimenez

Department of Chemistry and Cooperative Institute for Research in Environmental Sciences (CIRES) University of Colorado at Boulder, USA Email: jose.jimenez@colorado.edu

Professor Yuguo Li
Department of Mechanical Engineering

The University of Hong Kong, Hong Kong, China Email: liyg@hku.hk

William W. Nazaroff
Daniel Tellep Distinguished Professor Emeritus
Civil and Environmental Engineering Department
University of California, Berkeley, USA
Email: nazaroff@ce.berkeley.edu

Professor Catherine Noakes School of Civil Engineering University of Leeds, United Kingdom Email: C.J.Noakes@leeds.ac.uk

Dr Chandra Sekhar
Individual Capacity, Singapore
Email: chandra.sc@gmail.com

Professor Julian Wei-Tze Tang
Respiratory Sciences
University Leicester, United Kingdom

Email: jwtang49@hotmail.com

Associate Professor Raymond Tellier Department of Medicine McGill University, Canada
Email: raymond.tellier@muhc.mcgill.ca
Professor Philomena M. Bluyssen
Faculty of Architecture and the Built Environment
Delft University of Technology, The Netherlands

Email: P.M.Bluyssen@tudelft.nl

Dr. Atze Boerstra
REHVA Vice-President

Federation of European Heating, Ventilation and Air Conditioning Associations

The Hague, The Netherlands Email: ab-bba@binnenmilieu.nl

Professor Giorgio Buonanno
Department of Civil and Mechanical Engineering
University of Cassino and Southern Lazio

Cassino, Italy
Email: buonanno@unicas.it

Professor Junji Cao
Institute of Earth Environment

Chinese Academy of Sciences, Beijing, China Email: cao@loess.llqg.ac.cn

Professor Stephanie J. Dancer Department of Medical Microbiology, NHS Lanarkshire, School of Applied Sciences Edinburgh Napier University, United Kingdom

Email: Stephanie.Dancer@lanarkshire.scot.nhs.uk

Dr. Francesco Franchimon
Managing Director and Owner
Vital Environments

Franchimon ICM, The Netherlands
Email: francesco@franchimon-icm.nl

Dr. Charles Haworth

Consultant Respiratory Physician, Cambridge Centre for Lung Infection, The Adult Cystic Fibrosis Centre, The Lung Defence Clinic, Royal Papworth Hospital, Cambridge, United Kingdom Email: charles.haworth@nhs.net
Dr. Jaap Hogeling
Managing Director, International Standards

ISSO, Netherlands Building Research Institute, The

Netherlands

Email: j.hogeling@isso.nl

Associate Professor Christina Isaxon
Ergonomics and Aerosol Technology
Lund University, Lund, Sweden
Email: christina.isaxon@design.lth.se

Professor Jarek Kurnitski

Department of Civil Engineering and Architecture Tallinn University of Technology, Estonia Email: jarek.kurnitski@taltech.ee

Assistant Professor Marcel Loomans Department of the Built Environment Eindhoven University of Technology (TU/e) The Netherlands

Email: m.g.l.c.loomans@tue.nl

Professor Guy B. Marks
Director, Centre for Air quality Research and

evaluation (CAR), Faculty of Medicine
University of New South Wales (UNSW), Sydney,
Australia
Email: g.marks@unsw.edu.au

Professor Livio Mazzarella
AiCARR Vice President
Department of Energy
Politecnico di Milano, Italy
Email: livio.mazzarella@polimi.it

Professor Arsen Krikor Melikov

International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Denmark Email: akm@byg.dtu.dk

Professor Shelly Miller
Mechanical Engineering Department
University of Colorado Boulder, USA
Email: Shelly.Miller@colorado.edu

Professor Emeritus Peter V. Nielsen The Faculty of Engineering and Science Department of Civil Engineering Aalborg University, Denmark Email: pvn@civil.aau.dk

Professor Jordan Peccia
Department of Chemical and Environmental
Engineering, Yale University, USA
Email: jordan.peccia@yale.edu

Professor Xavier Querol
Department of Geosciences

Institute of Environmental Assessment and Water
Research, Spanish National Research Council
Barcelona (IDAEA-CSIC), Spain
Email: xavier.querol@idaea.csic.es

Professor Emeritus Olli Seppänen Department of Mechanical Engineering Aalto University Finland Email: olli1944@gmail.com

Professor Shin-ichi Tanabe
Department of Architecture
Waseda University, Japan

Email: tanabe@waseda.jp

Professor Kwok Wai Tham
Department of Building

National University of Singapore, Singapore Email: bdgtkw@nus.edu.sg

Associate Professor Pawel Wargocki International Centre for Indoor Environment and Energy, Department of Civil Engineering Technical University of Denmark Email: paw@byg.dtu.dk

Associate Professor Aneta Wierzbicka Ergonomics and Aerosol Technology Lund University, Sweden

Email: Aneta.Wierzbicka@design.lth.se

Boya Distinguished Professor Maosheng Yao College of Environmental Sciences and Engineering, Peking University, Beijing, China Email: yao@pku.edu.cn

Co-Signing Scientists:

Professor Jonathan Abbatt

Department of Chemistry
University of Toronto, Canada
Email: jonathan.abbatt@utoronto.ca

Dr. John Adgate
Department of Environmental and Occupational
Health, Colorado School of Public Health
University of Colorado, USA
Email: john.adgate@cuanschutz.edu

Professor Alireza Afshari
Department of the Built Environment (BUILD)
Aalborg University, Denmark
Email: aaf@build.aau.dk

Professor Kang-Ho Ahn

Department of Mechanical Engineering Hanyang University, Republic of Korea Email: khahn@hanyang.ac.kr

Professor Francis Allard

LaSIE (Engineering Sciences for Environmental Issues Laboratory)

La Rochelle University, France Email: francis.allard@univ-lr.fr

Professor Joseph Allen
Healthy Buildings Program

Harvard T.H. Chan School of Public Health, USA Email: jgallen@hsph.harvard.edu

Dr. Celia Alves

Centre for Environmental and Marine Studies, University of Aveiro, Portugal Email: celia.alves@ua.pt

Professor Meinrat O. Andreae

Max Planck Institute for Chemistry, Germany Email: m.andreae@mpic.de

Professor Isabella Annesi-Maesano

Epidemiology of Allergic and Respiratory Diseases

(EPAR) Department, IPLESP, INSERM and
Sorbonne University, France
Email: isabella.annesi-maesano@inserm.fr

Professor Ahmet Arısoy

Mechanical Engineering Department İstanbul Technical University, Turkey Email: arisoyah@itu.edu.tr

Professor Andrew P. Ault
Department of Chemistry
University of Michigan, USA
Email: aulta@umich.edu
Dr. Gwi-Nam Bae

Center for Particulate Air Pollution and Health
Korea Institue of Science and Technology,
Republic of Korea
Email: gnbae@kist.re.kr

Dr. Gabriel Bekö

International Centre for Indoor Environment and Energy, Department of Civil Engineering Technical University of Denmark, Denmark Email: gab@byg.dtu.dk

Professor Scott C. Bell, Chief Executive Translational Research Institute Brisbane, Australia

Email: scott.bell@tri.edu.au

Professor Allan Bertram

Department of Chemistry

University of British Columbia, Canada Email: bertram@chem.ubc.ca

Professor Mahmood Bhutta
Department of ENT Surgery, Brighton & Sussex
University Hospitals, United Kingdom
Email: m.bhutta@doctors.org.uk

Dr. Seweryn Bialasiewicz
Australian Centre for Ecogenomics

The University of Queensland, Australia
Email: seweryn@uq.edu.au

Professor Merete Bilde
Department of Chemistry

Aarhus University, Denmark
Email: bilde@chem.au.dk

Tami Bond, Scott Presidential Chair in Energy
Environment and Health
Department of Mechanical Engineering

Colorado State University, USA
Email: Tami.Bond@colostate.edu

Professor Joseph Brain
Department of Environmental Health
Harvard University, USA

Email: brain@hsph.harvard.edu

Professor Marianna Brodach
Engineering Department, Moscow Architectural
Institute (State Academy), Russia

Email: brodatch@abok.ru

Professor David M. Broday

Civil & Environmental Engineering Technion Institute of Technology, Israel Email: dbroday@technion.ac.il
Professor Guangyu Cao
Department of Energy and Process Engineering

Norwegian University of Science and Technology,
Norway
Email: Guangyu.cao@ntnu.no

Professor Christopher D. Cappa
Department of Civil and Environmental Engineering

University of California, Davis, USA
Email: cdcappa@ucdavis.edu

Professor Annmarie Carlton Department of Chemistry, University of California, Irvine, USA Email: agcarlto@uci.edu

Professor Paul K.S. Chan

Department of Microbiology, Faculty of Medicine
The Chinese University of Hong Kong,
Hong Kong, China

Email: paulkschan@cuhk.edu.hk

Professor Christopher Chao
Faculty of Engineering, The University of Hong
Kong, Hong Kong, China

Email: cyhchao@hku.hk

Associate Professor Kuan-Fu Chen
Clinical Informatics and Medical Statistics Research
Center and Department of Emergency Medicine,
Chang Gung University and Chang Gung Memorial

Hospital, Taiwain
Email: kfchen@mail.cgu.edu.tw

Professor Qi Chen

College of Environmental Sciences and Engineering
Peking University, Beijing, China
Email: qichenpku@pku.edu.cn

Professor Qingyan Chen

Mechanical Engineering, Purdue University, USA Email: yanchen@purdue.edu

Dr. David Cheong
Individual Capacity, Singapore
Email: davidalice2005@yahoo.com.sg

Dr. Per Axcel Clausen

New Technologies, National Research Centre for the Working Environment, Denmark Email: pac@nrcwe.dk

Professor Ross Crawford
Orthopaedic Surgeon, The Prince Charles Hospital

Medical Robotics, Queensland University of
Technology, Brisbane, Australia
Email: r.crawford@qut.edu.au

Professor Derek Clements-Croome Department of Built Environment Reading University, United Kingdom Email: d.j.clements-croome@reading.ac.uk

Professor Geo Clausen
Department of Civil Engineering
Technical University of Denmark, Denmark

Email: gc@byg.dtu.dk

Dr. Ian Clifton

Department of Respiratory Medicine, Leeds Teaching Hospitals NHS Trust, United Kingdom Email: i.clifton@nhs.net

Dean Richard L. Corsi

Maseeh College of Engineering and Computer Science, Portland State University, Oregon, USA Email: rcorsi@pdx.edu

Professor Benjamin J. Cowling

School of Public Health, The University of Hong Kong, Hong Kong, China Email: bcowling@hku.hk

Professor Francesca Romana d’Ambrosio Department of Industrial Engineering University of Salerno, Italy Email: fdambrosio@unisa.it

Professor Ghassan Dbaibo

Center for Infectious Diseases Research American University of Beirut, Lebanon Email: gdbaibo@aub.edu.lb

Professor Richard de Dear

School of Architecture, Design and Planning The University of Sydney, Australia Email: Richard.Dedear@sydney.edu.au

Professor Gianluigi de Gennaro
Department of Biology

University of Bari Aldo Moro, Italy
Email: gianluigi.degennaro@uniba.it

Dr. Peter DeCarlo
Environmental Health and Engineering
Johns Hopkins University, USA

Email: pdecarl1@jhu.edu

Professor Philip Demokritou Department of Environmental Health TH Chan School of Public Health Harvard University, USA

Email: pdemokri@hsph.harvard.edu

Dr. Hugo Destaillats
Indoor Environment Group
Lawrence Berkeley National Laboratory, USA
Email: HDestaillats@lbl.gov

Professor Joanna Domagala-Kulawik Department of Pneumonology and Allergy Medical University of Warsaw, Poland Email: domagalakulawik@gmail.com

Lord University Professor Neil M. Donahue Center for Atmospheric Particle Studies Carnegie Mellon University, USA Email: nmd@andrew.cmu.edu

Professor Caroline Duchaine

Biochemistry, Microbiology and Bio-Informatics Department, Université Laval, Canada Email: caroline.duchaine@bcm.ulaval.ca

Professor Marzenna R. Dudzinska Department of Indoor and Outdoor Air Quality Lublin University of Technology, Poland Email: m.dudzinska@pollub.pl

Professor Dominic E. Dwyer

Director, New South Wales Health Pathology Public Health Pathology, NSWHP-ICPMR

University of Sydney, Westmead, Australia Email: dominic.dwyer@sydney.edu.au

Professor Greg Evans P.Eng. FCAE, FAAAS Southern Ontario Centre for Atmospheric Aerosol Research

University of Toronto, Canada Email: greg.evans@utoronto.ca

Associate Professor Delphine K. Farmer Department of Chemistry

Colorado State University, USA Email: delphine.farmer@colostate.edu

Kevin P. Fennelly, MD, MPH, ATSF
Pulmonary Branch, Division of Intramural Research
NHLBI / NIH, USA
Email: Kevin.Fennelly@nih.gov

Professor Richard Flagan

Departments of Chemical Engineering and Environmental Science and Engineering California Institute of Technology, USA Email: flagan@caltech.edu

Dr. Janine Fröhlich-Nowoisky
Multiphase Chemistry

Max Planck Institute for Chemistry, Germany Email: j.frohlich@mpic.de

Professor Manuel Gameiro da Silva ADAI, LAETA, Department of Mechanical Engineering, EfS Initiative

University of Coimbra, Portugal Email: manuel.gameiro@dem.uc.pt

Dr. Christian George
IRCELYON, CNRS, France

Email: christian.george@ircelyon.univ-lyon1.fr

Associate Professor Marianne Glasius Department of Chemistry Aarhus University, Denmark Email: glasius@chem.au.dk

Professor Allen H. Goldstein

Department of Environmental Science, Policy, and Management

University of California at Berkeley, USA Email: ahg@berkeley.edu

Professor João Gomes
Chemical Engineering Department

ISEL – Lisbon Polytechnic, Portugal
Email: jgomes@deq.isel.ipl.pt

Dr. Michael Gormley

Institute for Sustainable Building Design Heriot- Watt University, Edinburgh, United Kingdom Email: m.gormley@hw.ac.uk

Professor Rafal Górny

Department of Chemical, Aerosol and Biological Hazards, Central Institute for Labour Protection – National Research Institute, Poland Email: ragor@ciop.pl

Professor Emeritus David Grimsrud Founding Editor, Indoor Air Journal University of Minnesota (Retired), USA Email: grimsrud@earthlink.net

Professor Keith Grimwood
School of Medicine
Griffith University, Brisbane, Australia
Email: k.grimwood@griffith.edu.au

Professor Charles N. Haas
Civil, Architectural & Environmental Engineering
Drexel University, USA
Email: haas@drexel.edu

Professor Fariborz Haghighat
Building, Civil and Environmental Engineering

Concordia University, Canada
Email: Fariborz.Haghighat@concordia.ca

Professor Michael Hannigan Department of Mechanical Engineering University of Colorado, USA Email: hannigan@colorado.edu
Professor Roy Harrison

School of Geography, Earth & Environmental Sciences,

University of Birmingham, United Kingdom Email: r.m.harrison@bham.ac.uk

Professor Ulla Haverinen-Shaughnessy, D. Sc. Civil Engineering; Indoor Air Program

The University of Oulu; The University of Tulsa Finland & USA

Email: ulla.haverinen-shaughnessy@oulu.fi

Professor Philippa Howden-Chapman Department of Public Health

University of Otago, Wellington, New Zealand Email: philippa.howden-chapman@otago.ac.nz

Professor Per Heiselberg Department of the Built Environment Aalborg University, Denmark Email: pkh@build.aau.dk

Professor Daven K. Henze Department of Mechanical Engineering University of Colorado Boulder, USA Email: daven.henze@colorado.edu

Dr. Jean-Michel Heraud
Virology Unit,

Institut Pasteur de Madagascar, Madagascar Email: jmheraud@pasteur.mg

Professor Hartmut Herrmann

Atmospheric Chemistry Department (ACD)
Leibniz-Institute for Tropospheric Research
(TROPOS), Germany
Email: herrmann@tropos.de

Professor Philip K. Hopke

Public Health Sciences, University of Rochester School of Medicine and Dentistry, USA Email: philip_hopke@URMC.rochester.edu

Ray Horstman,
Beoing (Retired), USA
Email: randshors@gmail.com

Professor Wei Huang

Department of Occupational and Environmental Health, Peking University, Beijing, China Email: whuang@pku.edu.cn

Professor J. Alex Huffman
Department of Chemistry and Biochemistry

University of Denver, USA
Email: alex.huffman@du.edu

Professor David S. Hui
Department of Medicine & Therapeutics, The

Chinese University of Hong Kong,
Hong Kong, China
Email: dschui@cuhk.edu.hk

Professor Tareq Hussein
Department of Physics

University of Jordan, Jordan
Email: t.hussein@ju.edu.jo

Dr. Gabriel Isaacman-VanWertz Civil and Environmental Engineering Virginia Tech, USA Email: ivw@vt.edu

Professor Jouni J.K. Jaakkola

Center for Environmental and Respiratory Health Research, University of Oulu, Finland Email: jouni.jaakkola@oulu.fi

Professor Matti Jantunen

National Institute for Health and Welfare, Finland Email: matti.jantunen@janding.fi

Associate Professor Lance Jennings Pathology and Biomedical Science
University of Otago, Christchurch, New Zealand Email: lance.jennings@cdhb.health.nz

Professor Dennis Johansson

Building Services, Lund University, Sweden Email: dennis.johansson@hvac.lth.se

Dr. Jan Kaczmarczyk

Department of Heating, Ventilation and Dust Removal Technology

Silesian University of Technology, Poland Email: jan.kaczmarczyk@polsl.pl

Professor George Kallos
Department of Physics

National & Kapodistrian University of Athens,
Greece
Email: kallos@mg.uoa.gr

Professor David Katoshevski Environmental Engineering Ben-Gurion University of the Negev, Israel Email: davidk@bgu.ac.il

Professor Frank Kelly
School of Public Health

Imperial College London, United Kingdom Email: fkelly@imperial.ac.uk

Associate Professor Søren Kjærgaard Department of Public Health Aarhus University, Denmark Email: sk@ph.au.dk

Associate Professor Luke D. Knibbs School of Public Health

The University of Queensland, Brisbane, Australia Email: l.knibbs@uq.edu.au

Dr. Henrik N. Knudsen
Department of the Built Environment (BUILD)
Aalborg University, Denmark

Email: hnk@sbi.aau.dk

Professor GwangPyo Ko Graduate School of Public Health
Seoul National University, Republic of Korea Email: gko@snu.ac.kr

Associate Professor Evelyn S.C. Koay

Yong Loo Lin School of Medicine, Department of Pathology

National University of Singapore, Singapore Email: patkoaye@nus.edu.sg

Dr. Jen Kok

Centre for Infectious Disease and Microbiology Laboratory Services

NSW Health Pathology-Institute of Clinical Pathology and Medical Research, Australia Email: jen.kok@health.nsw.gov.au

Professor Nino Kuenzli, MD

Department of Epidemiology and Public Health and Department of Education and Training, Swiss Tropical and Public Health Institute, Switzerland Email: nino.kuenzli@swisstph.ch

Professor Risto Kosonen

Mechanical Engineering, Aalto University, Finland Email: risto.kosonen@aalto.fi

Professor Markku Kulmala

Institute for Atmospheric and Earth System Research (INAR) / Physics, Faculty of Science University of Helsinki, Finland Email: markku.kulmala@helsinki.fi

Adjunct Professor Kazukiyo Kumagai Graduate School of Engineering Tokyo University of Science, Japan Email: kkumagai@rs.tus.ac.jp

Professor Prashant Kumar

Global Centre for Clean Air Research (GCARE)
University of Surrey, United Kingdom
Email: p.kumar@surrey.ac.uk

Dr. Kazumichi Kuroda

School of Medicine, Nihon University, Japan Email: kuroda.kazumichi@nihon-u.ac.jp

Professor Kiyoung Lee

Department of Environmental Health Sciences Seoul National University, Republic of Korea Email: cleanair@snu.ac.kr

Professor Nelson Lee [MBBS, MRCP, MD, FRCP(Edin), FRCP(Lond), FIDSA] Department of Medicine, Division of Infectious Diseases, University of Alberta, Canada Email: laishunn@ualberta.ca

Dr. Barry Lefer
Individual Capacity, USA
Email: barry.lefer@nasa.gov

Professor Vincent Lemort
Thermodynamics Laboratory

University of Liège, Belgium
Email: Vincent.Lemort@uliege.be

Professor Xianting Li Department of Building Science Tsinghua University, Beijing, China Email: xtingli@tsinghua.edu.cn

Professor Dusan Licina

Civil and Environmental Engineering, EPFL – École Polytechnique Fédérale de Lausanne, Switzerland Email: dusan.licina@epfl.ch

Dr. Chao-Hsin Lin, PE Environmental Control Systems Boeing Commercial Airplanes, USA Email: chao-hsin.lin@boeing.com

Professor Junjie Liu
School of Environmental Science and Engineering

Tianjin University, China
Email: jjliu@tju.edu.cn

Dr. Kam Lun E. Hon, MBBS, MD, FAAP, FCCM The Department of Paediatrics & The Hong Kong Institute of Integrative Medicine

The Chinese University of Hong Kong, Hong Kong, China

Email: ehon@hotmail.com

Professor John C. Little
Department of Civil and Environmental Engineering
Virginia Tech, USA

Email: jcl@vt.edu

Dr. Li Liu
Department of Building Science

Tsinghua University, Beijing, China
Email: liuli_archi@tsinghua.edu.cn

Dr. Janet M. Macher, ScD MPH School of Public Health, Alumna University of California, Berkeley, USA Email: janmacher@berkeley.edu

Associate Professor Ebba Malmqvist Occupational and Environmental Medicine Lund University, Sweden

Email: ebba.malmqvist@med.lu.se

Dr. Corinne Mandin
Department of Health and Comfort

Scientific and Technical Center for Building, France Email: corinne.mandin@cstb.fr

Professor Ivo Martinac

Division of Sustainable Buildings, Building Services and Energy Systems

KTH Royal Institute of Technology, Sweden Email: im@kth.se

Professor Dainius Martuzevičius
Faculty of Chemical Technology

Kaunas University of Technology, Lithuania Email: daimart@ktu.lt

Dr. Mark J. Mendell
Indoor Environment Department

Lawrence Berkeley National Laboratory, USA Email: mmendell@pacbell.net

Professor David Miller
Department of Chemistry

Carleton University, Ottawa, Canada
Email: david.miller@carleton.ca

Assistant Professor Claudia Mohr Department of Environmental Science Stockholm University, Sweden Email: claudia.mohr@aces.su.se

Dr. Luisa T. Molina

Department of Earth, Atmospheric and Planetary Sciences

Massachusetts Institute of Technology, USA Email: ltmolina@mit.edu

Professor Glenn Morrison

Environmental Sciences and Engineering University of North Carolina, Chapel Hill, USA Email: glenn.morrison@unc.edu

Dr. Roya Mortazavi
Atmospheric and Oceanic Sciences

McGill University, Canada
Email: roya.mortazavi@mail.mcgill.ca

Professor Edward Nardell

Department of Global Health Equity, Brigham & Woman’s Hospital, Harvard University School of Medicine and School of Public Health, USA Email: enardell@bwh.harvard.edu

Professor Athanasios Nenes

School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Switzerland
Email: athanasios.nenes@epfl.ch

Emeritus Adjunct Professor Mark Nicas
School of Public Health, University of California,

Berkeley, USA
Email: mnicas@berkeley.edu

Professor Zhi Ning

Division of Environment and Sustainability The Hong Kong University of Science and Technology, Hong Kong, Hong Kong, China Email: zhining@ust.hk

Professor Jianlei Niu
Fellow of ISIAQ, ASHRAE, and IBPSA

Faculty of Construction and Environment

The Hong Kong Polytechnic University, Hong Kong,

Hong Kong, China
Email: jian-lei.niu@Polyu.edu.hk

Dr. Hidekazu Nishimura
Virus Reserch Center, Clinical Research Division
Sendai Medical Center, National Hospital

Organization, Japan
Email: hide-nishimura@mte.biglobe.ne.jp

Professor Colin O’Dowd MAE MRIA Centre for Climate & Air Pollution Studies National University of Ireland Galway, United Kingdom

Email: colin.odowd@nuigalway.ie

Professor Bjarne W. Olesen

International Centre for Indoor Environment and Energy, Technical University of Denmark, Denmark Email: bwo@byg.dtu.dk

Dr. Paula J. Olsiewski
Alfred P. Sloan Foundation, USA
Email: olsiewski@sloan.org

Professor Spyros Pandis Chemical Engineering Department University of Patras, Greece

Email: spyros@chemeng.upatras.gr

Professor Daniel Peckham
Leeds Institute of Medical Research
University of Leeds, United Kingdom
Email: d.g.pecham@leeds.ac.uk

8

Professor Tuukka Petäjä

Institute for Atmospheric and Earth System Research (INAR) / Physics

Faculty of Science, University of Helsinki, Finland Email: tuukka.petaja@helsinki.fi

Professor Zbigniew Popiolek

Department of Heating Ventilation and Dust Removal Technology

Silesian University of Technology in Gliwice (Politechnika Ślaska), Poland

Email: zbigniew.popiolek@polsl.pl

Professor Ulrich Pöschl Multiphase Chemistry Department
Max Planck Institute for Chemistry, Germany Email: u.poschl@mpic.de

Dr. Wayne R. Ott

Department of Civil and Environmental Engineering

Stanford University, USA
Email: wott1@stanford.edu

Professor Kimberly Prather

Distinguished Chair in Atmospheric Chemistry Scripps Institution of Oceanography University of California, San Diego, USA Email: kprather@ucsd.edu

Professor Andre S. H. Prevot Laboratory of Atmospheric Chemistry Paul Scherrer Institute, Switzerland Email: andre.prevot@psi.ch

Professor Hua Qian
School of Energy and Environment
Southeast University, China

Email: qianh@seu.edu.cn

Dr. Shanna Ratnesar-Shumate Department of Pathology and Microbiology University of Nebraska Medical Center, USA Email: sratnesar@gmail.com

James L. Repace, MSc.
President, Repace Associates, Inc. Secondhand
Smoke Consultants, USA
Email: repace1@verizon.net

Professor Tiina Reponen

Department of Environmental and Public Health
Sciences University of Cincinnati, USA
Email: Tiina.Reponen@uc.edu

Professor Ilona Riipinen
Department of Environmental Science
Stockholm University, Sweden
Email: ilona.riipinen@aces.su.se

Emeritus Professor Susan Roaf

Institute for Sustainable Building Design, EGIS Heriot Watt University, Edinburgh, United Kingdom Email: s.roaf@hw.ac.uk

Professor Allen L. Robinson Department of Mechanical Engineering Carnegie Mellon University, USA Email: alr@andrew.cmu.edu

Professor Yinon Rudich
Department of Earth and Planetary Sciences
Weizmann Institute, Israel
Email: yinon.rudich@weizmann.ac.il

Professor Manuel Ruiz de Adana Department of Applied Thermodynamics University of Cordoba, Spain Email: manuel.ruiz@uco.es

Dr. Masayuki Saijo
Department of Virology

National Institute of Infectious Diseases, Japan Email: msaijo@nih.go.jp

Professor Reiko Saito
Division of International Health
Graduate School of Medical and Dental Sciences
Niigata University, Japan
Email: jasmine@med.niigata-u.ac.jp

Professor Paulo Saldiva Department of Pathology University of São Paulo, Brazil Email: pepino@usp.br

Professor Tunga Salthammer

Department of Material Analysis and Indoor Chemistry

Fraunhofer WKI, Braunschweig, Germany Email: tunga.salthammer@wki.fraunhofer.de

Professor Joshua L. Santarpia Department of Pathology and Microbiology University of Nebraska Medical Center, USA Email: josh.santarpia@unmc.edu

Nohl Professor John H. Seinfeld Department of Chemical Engineering California Institute of Technology, USA Email: seinfeld@caltech.edu

Distinguished Professor Emeritus Gary S. Settles Mechanical Engineering

Pennsylvania State University, USA Email: gss2@psu.edu

Associate Professor Siegfried Schobesberger Department of Applied Physics

University of Eastern Finland, Finland Email: siegfried.schobesberger@uef.fi

Associate Professor Paul T. J. Scheepers Radboud Institute for Health Sciences Radboudumc, The Netherlands

Email: Paul.Scheepers@radboudumc.nl

Professor Max H. Sherman,
Lawrence Berkeley National Laboratory (Retired),
USA
Email: MHSherman@lbl.gov

Professor Alan Shihadeh

Maroun Semaan Faculty of Engineering & Architecture, American University of Beirut, Lebanon Email: as20@aub.edu.lb

Professor Manabu Shiraiwa Department of Chemistry University of California, Irvine, USA Email: m.shiraiwa@uci.edu

Professor Jeffrey Siegel
Department of Civil & Mineral Engineering
University of Toronto, Canada
Email: jeffrey.siegel@utoronto.ca

Professor Torben Sigsgaard
Deptartment of Public Health
Aarhus University, Denmark

Email: ts@ph.au.dk

Dr. Brett C. Singer

Sustainable Energy and Environmental Systems Department

Lawrence Berkeley National Laboratory, USA Email: bcsinger@lbl.gov

Professor James N. Smith Department of Chemistry University of California, Irvine, USA Email: jimsmith@uci.edu

Professor Armin Sorooshian

Department of Chemical and Environmental Engineering, University of Arizona, USA Email: armin@email.arizona.edu

Dr. Jerzy Sowa

Faculty of Building Services, Hydro and Environmental Engineering

Warsaw University of Technology, Poland Email: jerzy.sowa@pw.edu.pl

Professor Brent Stephens
Department of Civil, Architectural, and

Environmental Engineering,
Illinois Institute of Technology, USA
Email: brent@iit.edu

Professor Huey-Jen Jenny Su

Institute of Environmental Health Sciences National Cheng Kung University, Taiwan Email: hjsu@mail.ncku.edu.tw

Professor Jordi Sunyer

Childhood and Environment, ISGlobal, Spain Email: jordi.sunyer@isglobal.org

Professor Jason D. Surratt

Department of Environmental Sciences and Engineering, Gillings School of Global Public Health University of North Carolina at Chapel Hill, USA Email: surratt@unc.edu

Professor Kazuo Takahashi
Department of Clinical Laboratory Medicine
International University of Health and Welfare,
Japan

Email: takahashikz@iuhw.ac.jp

Professor Nobuyuki Takegawa
Department of Chemistry
Tokyo Metropolitan University, Japan
Email: takegawa@tmu.ac.jp

Professor Jørn Toftum

Department of Civil Engineering
Technical University of Denmark, Denmark
Email: jt@byg.dtu.dk

Distinguished Professor Margaret A. Tolbert Department of Chemistry and CIRES University of Colorado, Boulder, USA Email: tolbert@colorado.edu

Associate Professor Euan Tovey Woolcock Institute of Medical Research University of Sydney, Australia Email: euan.tovey@sydney.edu.au

Professor Barbara J. Turpin

Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina – Chapel Hill, USA Email: bjturpin@email.unc.edu

Professor Annele Virtanen Department of Applied Physics University of Eastern Finland, Finland Email: annele.virtanen@uef.fi

Professor John Volckens
Department of Mechanical Engineering

Colorado State University, USA
Email: john.volckens@colostate.edu

Professor Claire Wainwright
Child Health Research Centre

The University of Queensland, Brisbane, Australia Email: claire.wainwright@health.qld.gov.au

Dr. Lance A. Wallace
US EPA (Retired), USA
Email: lwallace73@gmail.com

Professor Boguang Wang

Institute for Environmental and Climate Research Jinan University, Guangzhou, China Email: tbongue@jnu.edu.cn

Professor Chia C. Wang

Aerosol Science Research Center National Sun Yat-sen University, Taiwan Email: chiawang@mail.nsysu.edu.tw

Professor Michael Waring

Department of Civil, Architectural and Environmental

Engineering, Drexel University, USA
Email: msw59@drexel.edu

Professor John Wenger
School of Chemistry & Environmental Research

Institute, University College Cork, Ireland, United
Kingdom

Email: j.wenger@ucc.ie

Professor Charles J. Weschler
Environmental & Occupational Health Sciences

Institute
Rutgers University, USA
Email: weschlch@rwjms.rutgers.edu

Professor Brent Williams

Department of Energy, Environmental, & Chemical Engineering

Washington University in St. Louis, USA Email: brentw@wustl.edu

Professor Mary E. Wilson
Global Health
San Francisco and Harvard Chan School of Public

Health, University of California, USA
Email: mewilson@hsph.harvard.edu

Professor Armin Wisthaler
Department of Chemistry
University of Oslo, Norway
Email: armin.wisthaler@kjemi.uio.no

Dr. Kazimierz Wojtas

Faculty of Environmental and Power Engineering Cracow University of Technology, Poland Email: kaz_wojtas@o2.pl

Dr. Douglas R. Worsnop

Institute for Atmospheric and Earth System Research (INAR) / Physics, Aerodyne Research / University of Helsinki, USA / Finland Email: worsnop@aerodyne.com

Professor Ying Xu
Department of Building Science
Tsinghua University, Beijing, China

Email: xu-ying@mail.tsinghua.edu.cn

Associate Professor Naomichi Yamamoto Environmental Health Sciences

Seoul National University, Republic of Korea Email: nyamamoto@snu.ac.kr

Professor Xudong Yang Department of Building Science Tsinghua University, Beijing, China Email: xyang@tsinghua.edu.cn

Dr. Hui-Ling Yen

School of Public Health

The University of Hong Kong, Hong Kong, China Email: hyen@hku.hk

Professor Emeritus Hiroshi Yoshino

Department of Architecture and Building Science

Tohoku University, Japan

Email: yoshino@sabine.pln.archi.tohoku.ac.jp

Dr. Hassan Zaraket

Department of Experimental Pathology,

Immunology, and Microbiology, Faculty of Medicine,

American University of Beirut, Lebanon

Email: hz34@aub.edu.lb

Professor Zhiqiang (John) Zhai

Department of Civil, Environmental and Architectural Engineering

University of Colorado at Boulder, USA Email: john.zhai@colorado.edu

Professor Junfeng (Jim) Zhang

The Nicholas School of the Environment

Duke University, USA

Email: junfeng.zhang@duke.edu

Professor Qi Zhang

Department of Environmental Toxicology University of California, Davis, USA Email: dkwzhang@ucdavis.edu
Professor Jensen Zhang
Department of Mechanical and Aerospace

Engineering
Syracuse University, USA
Email: jszhang@syr.edu

Professor Yinping Zhang
Department of Building Science

Tsinghua University, Beijing, China
Email: zhangyp@tsinghua.edu.cn

Professor Bin Zhao
Department of Building Science, School of
Architecture, Tsinghua University, Beijing, China

Email: binzhao@tsinghua.edu.cn

Professor Tong Zhu

College of Environmental Sciences and Engineering
Peking University, Beijing, China
Email: tzhu@pku.edu.cn