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Digital illustration of human respiratory system showing virus spread through air. Concept of infection, health, and microscopic pathogens. By enterdigital
Event

Assessing the Transmission of Infectious Aerosols in the Indoor Environment: Next Steps for Future Research and Policy

April 4-5, 2024

To take stock of the research gaps needed to understand how airborne transmission occurs and how it may be interrupted, the Johns Hopkins Center for Health Security convened a multidisciplinary group consisting of 24 experts in their respective fields for a 2-day not-for-attribution meeting on April 4-5, 2024, in Baltimore, MD. The goal was to identify current research gaps and develop a list of technical considerations for future research and policy development. The driving question for this meeting was “How may we predict infection risk in indoor environments to support planning, design of engineering controls, and public health policies?” This meeting was sponsored by FluLab.

Publication: coming soon

 

Agenda

Meeting Attendees

Agenda

Objective: This workshop convenes experts from a range of disciplines to discuss the technical considerations related to the prediction of aerosol transmission of airborne pathogens. The goal is to identify current research gaps and develop a list of technical considerations for future research and policy development. The driving question for this meeting is “How may we predict infection risk in indoor environments to support planning, design of engineering controls, and public health policies?”

Day 1: Thursday April 4, 2024 

8:30- 9:00 am  Breakfast available
700 East Pratt Street, Suite 900, Baltimore Maryland 21202 
09:00-9:30 am  

Welcome and Introductions 

  • Gigi Gronvall, Associate Professor, Johns Hopkins Bloomberg School of Public Health, Senior Scholar, Johns Hopkins Center for Health Security
  • Paula Olsiewski, Contributing Scholar, Johns Hopkins Center for Health Security 
09:30-10:30 am 

 Topic 1:  Applications of Airborne Exposure Science
Moderator: Gigi Gronvall, Johns Hopkins Center for Health Security, Department of Environmental Health and Engineering 

This session will focus on the practical applications of airborne infection risk analysis. Speakers will discuss engineering control design, administrative control planning, (such as when to apply infection risk management mode in ASHRAE 241), public health actions and regulatory gaps. Speakers will present for 10-12 minutes, leaving time for clarifying questions before the next discussion section.   

Panelists:

  • Bill Bahnfleth, Professor of Architectural Engineering, Pennsylvania State University
  • Jessica Green, Advanced Research Projects Agency for Health
  • Lew Radonovich, Deputy Director, Respiratory Health Division, Centers for Disease Control and Prevention
  • Kazukiyo Kumagai, Air Quality Section Chief at the California Department of Public Health 
10:30-10:45 am  Coffee Break 
10:45 am-12:00 pm Discussion on Topic 1
The following is an in-depth discussion of Topic 1. Areas for consideration include: What information has not been included? What are the knowledge gaps that may be addressed through research? Where are there areas of agreement, and areas where consensus may be elusive? How generalizable are these conclusions? 
12:00- 12:45 pm Lunch Break
12:45-1:45 pm 

Topic 2: Generation of infectious aerosols
Moderator: Paula Olsiewski, Johns Hopkins Center for Health Security  

This session will focus on the generation of indoor infectious aerosols. While there is a lot of variability, discussion will focus on how much infectious material is produced at the source, how much variability there is from person to person in generating virions or bacteria, the ranges one might expect for different pathogens, and what observations may be generalized across pathogens and environments. Speakers will discuss the generation rates, size distribution, and emission rates of respiratory pathogens; confounding factors related to the pathogen, the host, or the environment; and quanta emission rates. Discussion should also include research gaps and suggestions for addressing them. Speakers will present for 10-12 minutes, leaving time for clarifying questions before the next discussion section. 

Panelists:

  • Don Milton, Professor of Environmental Health, Applied Environmental Health, University of Maryland
  • Lidia Morawska, Distinguished Professor and Australian Laureate Fellow, School of Earth and Atmospheric Sciences, Queensland University of Technology
  • Giorgio Buonanno, Professor Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio 
1:45-2:00 pm Coffee Break
2:00-3:00 pm Discussion on Topic 2: Generation of infectious aerosols
Areas for consideration include: What information has not been included? What are the knowledge gaps that may be addressed through research? Where are there areas of agreement, and areas where consensus may be elusive? How generalizable are these conclusions? 
3:00-3:15 pm Coffee Break 
3:15-4:15 pm 

Topic 3: Fate and Transport of Infectious Particles
Moderator: Gigi Gronvall, Johns Hopkins Center for Health Security, Department of Environmental Health and Engineering 

Building on Topic 2, this session will consider how susceptible hosts are exposed to infectious aerosols emitted by infectors. Speakers will address the aerosol characteristics as measured near and far field; the exposure pathway from the “infector” to “receptor,” and where particle deposition occurs; the effect of air distribution and natural removal mechanisms including deposition and inactivation; engineering controls, including dose response to disinfectants; and research needs to address gaps. Speakers will present for 10-12 minutes, leaving time for clarifying questions before the next discussion section. 

Panelists:

  • Yuguo Li, Chair Professor of Building Environment Department of Mechanical Engineering, and Associate Dean of Research, University of Hong Kong
  • Brian Damit, Project Manager and Research Scientist Johns Hopkins Applied Physics Laboratory
  • Jordan Peccia, Professor and Chair of the Department of Chemical and Environmental Engineering, Yale University  
4:15-5:00 pm Discussion on Topic 3: Fate and Transport of Infectious Particles
Areas for consideration include: What information has not been included? What are the knowledge gaps that may be addressed through research? Where are there areas of agreement, and areas where consensus may be elusive? How generalizable are these conclusions? 
5:00 pm Wrap up and instructions for the next day 
6:00-8:00 pm Dinner
Location: Apropoes Restaurant, Baltimore Marriott Waterfront Hotel, 700 Aliceanna Street, Baltimore, MD  21202 


Day 2: Friday April 5, 2024 

08:30-9:00 am  Breakfast Available 
09:00-9:15am  Meeting Begins – what we will accomplish today and goals for this effort
Gigi Kwik Gronvall, Associate Professor, Johns Hopkins Center for Health Security, Department of Environmental Health and Engineering
9:15-10:15 am 

Topic 4: Risk Estimation
Moderator: Paula Olsiewski, Johns Hopkins Center for Health Security 

Speakers will discuss the current models and their limitations, including Wells-Riley and others. They will address the input data requirements, sources of uncertainty, exposure scenarios, and discuss absolute or relative risk. Research needs will be highlighted. Speakers will present for 10-12 minutes, leaving time for clarifying questions before the next discussion section. 

Panelists:

  • Chuck Haas, Chair Professor of Environmental Engineering, Department of Civil Architectural, and Environmental Engineering, Drexel University
  • Ben Jones, Associate Professor, Department of Architecture and Built Environment, University of Nottingham
  • David Fisman, Professor at the Division of Epidemiology and Institute for Pandemic, Dalla Lana School of Public Health, University of Toronto
  • Pawel Wargocki, Professor, Department of Environmental and Resource Engineering, Technical University of Denmark 
10:15-11:00 am  Coffee Break 
11:00-12:00 pm  Discussion on Topic 4: Risk Estimation
Areas for consideration include: What information has not been included? What are the knowledge gaps that may be addressed through research? Where are there areas of agreement, and areas where consensus may be elusive? How generalizable are these conclusions? 
12:00 -12:30 pm  Break to pick up lunch for working lunch (lunch provided)
12:30 - 3:00 pm  

Working towards a paper: 

  • What should the main messages of the paper be? 
  • Who are the most important audiences of this paper? 
  • What are key research needs that need to be addressed, and how should they be prioritized? (Thought experiment: If another pandemic were to emerge, and you were able to go back in time 8 months with an extensive research budget, what would you prioritize? Does this change if it were bacterial or viral pandemic?) 
  • Tour de table 
3:00 pm Adjourn 

Meeting Attendees

  • William (Bill) Bahnfleth, PhD
    Professor of Architectural Engineering
    The Pennsylvania State University
  • Richard Bruns, PhD
    Economist
    Johns Hopkins Center for Health Security
  • Giorgio Buonanno, PhD
    Professor
    University of Cassino and Southern Lazio
  • Brian Damit, PhD
    Aerosol Scientist
    Johns Hopkins Applied Physics Laboratory
  • David Fisman, MD, MPH
    Professor
    Dalla Lana School of Public Health
    University of Toronto
  • Jessica Green, PhD
    Program Manager, Resilient Systems
    ARPA-H
  • Gigi Gronvall, PhD
    Senior Scholar
    Johns Hopkins Center for Health Security
  • Charles Haas, PhD
    LD Betz Professor of Environmental Engineering
    Drexel University
  • Benjamin Jones, EngD
    Associate Professor
    University of Nottingham
  • Georgia Lagoudas, PhD
    Advisor
    Convergent Research
  • Yuguo Li, PhD
    Professor
    The University of Hong Kong
  • Kazukiyo (Kazu) Kumagai, PhD, M.Eng, MPH
    Chief, Air Quality Section
    California Department of Public Health
  • Alexander Linder, MSc
    Senior Analyst
    Johns Hopkins Center for Health Security
  • Don Milton, MD, DrPH
    Professor
    University of Maryland
  • Lidia Morawska, PhD
    Distinguished Professor
    Queensland University of Technology (QUT)
    Director of the International Laboratory for Air Quality and Health
  • William Moss
    Professor
    International Vaccine Access Center
    Johns Hopkins Bloomberg School of Public Health
  • Scott Olesen, PhD
    Lead Data Scientist
    The Center for Forecasting and Outbreak Analytics (CFA)
    U.S. Centers for Disease Control and Prevention (CDC)
  • Paula Olsiewski, PhD 
    Contributing Scholar
    Johns Hopkins Center for Health Security
  • Jordan Peccia, PhD
    Professor
    Yale University
  • Cria Perrine, PhD
    Chief, Epidemiology Branch
    Coronavirus and Other Respiratory Viruses Division
    U.S. Center for Disease Control and Prevention (CDC)
  • Lewis Radonovich, MD
    Deputy Director, Respiratory Health Division
    National Institute of Occupational Safety and Health (NIOSH)
  • Lewis Rubinson, MD, PhD
    VP, Technical Staff
    IQT
  • Julie Schafer, PhD, MPH
    CTO
    Flu Lab
  • Arjun Srinivasan, MD
    Deputy Director for Program Improvement
    Division of Healthcare Quality Promotion U.S. Centers for Disease Control and Prevention (CDC)
  • Pawel Wargocki, PhD
    Professor
    Technical University of Denmark
  • Alex Zhu, MSPH
    Analyst
    Johns Hopkins Center for Health Security