Resolving the Loss of Intermediate-Size Speech Aerosols in Funnel-Guided Particle Counting Measurements

Bibliographic Details
Title: Resolving the Loss of Intermediate-Size Speech Aerosols in Funnel-Guided Particle Counting Measurements
Authors: Tayeb Kakeshpour, Adriaan Bax
Source: Atmosphere, Vol 15, Iss 5, p 570 (2024)
Publisher Information: MDPI AG, 2024.
Publication Year: 2024
Collection: LCC:Meteorology. Climatology
Subject Terms: airborne transmission, infectious dose, respiratory aerosol, coarse aerosol, superspreader event, inertia deposition, Meteorology. Climatology, QC851-999
More Details: Modeling of airborne virus transmission and protection against it requires knowledge of the amount of biofluid emitted into the atmosphere and its viral load. Whereas viral concentrations in biofluids are readily measured by quantitative PCR, the total volume of fluids aerosolized during speaking, as measured by different researchers using various technologies, differs by several orders of magnitude. We compared collection methods in which the aerosols first enter into a low-humidity chamber either by direct injection or via commonly used funnel and tubing arrangements, followed by standard optical particle sizer measurement. This “collect first, measure later” approach sacrifices the recording of the temporal correlation between aerosol generation and sound types such as plosives and vowels. However, the direct-injection mode prevents inertia deposition associated with the funnel arrangements and reveals far more intermediate-size (5–20 μm in diameter) particles that can dominate the total mass of ejected respiratory aerosol. The larger aerosol mass observed with our method partially reconciles the large discrepancy between the SARS-CoV-2 infectious dose estimated from superspreader event analyses and that from human challenge data. Our results also impact measures to combat airborne virus transmission because they indicate that aerosols that settle faster than good room ventilation rates can dominate this process.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2073-4433
Relation: https://www.mdpi.com/2073-4433/15/5/570; https://doaj.org/toc/2073-4433
DOI: 10.3390/atmos15050570
Access URL: https://doaj.org/article/bd6a1997766844b5b23ec892a08f17d5
Accession Number: edsdoj.bd6a1997766844b5b23ec892a08f17d5
Database: Directory of Open Access Journals
More Details
ISSN:20734433
DOI:10.3390/atmos15050570
Published in:Atmosphere
Language:English