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A study published in Interface suggests that pre-adolescent children exhibit lower aerosol particle volume emissions than adults for breathing, speaking, singing and shouting.
Prof Jonathan Reid, Director of Bristol Aerosol Research Centre (BARC) and Professor of Physical Chemistry at the University of Bristol, said:
“In this new study, particle exhalation rates reported are consistent with our own measurements on adolescent children (aged 12-14, https://doi.org/10.1098/rsfs.2021.0078) rising from 5 to 40 to 80 particles / s when considering breathing, speaking and singing, respectively, at intermediate loudness.
“Particle exhalation rates from speaking and singing were recorded at consistently greater loudness from adults than pre-adolescent children, and so comparing directly the reported numbers for speaking and singing is not straightforward. This makes factors of 3-4 increase difficult to attribute and may, as the authors suggest, partially explain the differences reported, particularly given the necessary limitations of cohort size.
“Despite this, lower particle exhalation rates for pre-adolescent children may be entirely consistent with their anatomical and physiological differences to adults. However, as we and others have shown, particle exhalation rates can increase by a factor of more than 30 when you compare soft speaking with shouting, and loudness is a key factor controlling how much aerosol individuals exhale.
“In addition, there are many other factors important for understanding transmission by inhalation, including variations in viral load, room ventilation and duration of activity.”
‘Pre-adolescent children exhibit lower aerosol particle volume emissions than adults for breathing, speaking, singing and shouting’ by Mario Fleischer et al. was published in Interface at 00:01 UK time on Wednesday 23 February.
DOI: doi.org/10.1098/rsif.2021.0833
Declared interests
None received.