Quantifying Proximity, Confinement, and Interventions in Disease Outbreaks: A Decision Support Framework for...

Area of Science:

• Environmental Science
• Public Health
• Aerosol Science

Background:

• Infectious disease transmission, particularly airborne pathogens like SARS-CoV-2, poses significant public health challenges.
• Understanding pathogen transport in human environments is crucial for effective mitigation strategies.

Purpose of the Study:

• To introduce and define the Effective ReBreathed Volume (ERBV) metric for quantifying airborne pathogen transport.
• To analyze the influence of particle size, proximity, and confinement on pathogen rebreathing.
• To evaluate the effectiveness of ventilation and filtration in reducing airborne pathogen transmission.

Main Methods:

• Defined Effective ReBreathed Volume (ERBV) as a metric for airborne pathogen transport.
• Calculated ERBV for exhaled particle diameters of 1, 10, and 100 μm.
• Modeled pathogen transport considering proximity and confinement in enclosed spaces.
• Assessed the impact of ventilation and filtration on ERBV for different particle sizes.

Main Results:

• Confinement, rather than proximity, dominates rebreathing in enclosed spaces after 10-15 minutes for particles ≤100 μm when 2m distancing is maintained.
• Ventilation and filtration reduced ERBV for 1 μm particles by 13-85% in residential and office settings.
• These interventions reduced ERBV for 10 μm particles by 3-50%, with minimal impact on 100 μm particles due to surface deposition.

Conclusions:

• The ERBV metric provides a quantitative framework for assessing airborne pathogen transport and comparing different scenarios.
• Understanding size-dependent ERBV is essential for identifying transmission modes and selecting effective interventions.
• This framework supports informed mitigation decisions for emerging infectious threats.