Characterization of expiration air jets and droplet size distributions immediately at the mouth opening
By Chi H. Chao, M. Wan, Lidia Morawska, Zoran D. Ristovski, M. Hargreaves, Kerrie L. Mengersen, S. Corbett, Y. Li, X. Xie, D. Katoshevski. Journal of Aerosol Science, 2008
847 citations recorded by the source corpus.
Size distributions of expiratory droplets expelled during coughing and speaking and the velocities of the expiration air jets of healthy volunteers were measured. Droplet size was measured using the interferometric Mie imaging (IMI) technique while the particle image velocimetry (PIV) technique was used for measuring air velocity. These techniques allowed measurements in close proximity to the mouth and avoided air sampling losses. The average expiration air velocity was 11.7 m/s for coughing and 3.9 m/s for speaking. Under the experimental setting, evaporation and condensation effects had negligible impact on the measured droplet size. The geometric mean diameter of droplets from coughing was 13.5 μm and it was 16.0 μm for speaking (counting 1–100). The estimated total number of droplets expelled ranged from 947 to 2085 per cough and 112–6720 for speaking. The estimated droplet concentrations for coughing ranged from 2.4 to 5.2 cm−3 per cough and 0.004–0.223 cm−3 for speaking.
Subfields: Aerospace Engineering, Pulmonary and Respiratory Medicine
View Paper: https://www.semanticscholar.org/paper/e647ccf66fb4f1e2e14dc3d62e4d352843abc0be
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In Pulmonary and Respiratory Medicine
Citations in the corpus
- Estimation of airborne viral emission: Quanta emission rate of SARS-CoV-2 for infection risk assessment (2020, positive): “particle image velocimetry (Chao et al., 2009) and, above all, increasingly accurate particle counters (Morawska et al.”
- The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission (2020, background): “However, the possible role of small speech droplet nuclei with diameters of less than 30 μm, which potentially could remain airborne for extended periods of time (1, 2, 8, 9), has not been widely appreciated.”