1/ This paper is very interesting:
https://www.nature.com/articles/s41598-019-38808-z">https://www.nature.com/articles/...

It summarises some of the literature on the aerosolisation of particles during speech and reports impact of increasing speech volume on aerosolisation. Here& #39;s my summary:

2/
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">smaller particles (~1μm) are aerosolised during breathing and talking (N.B. #COVID19 virus is 100-160 nm in size so these particles are big enough to carry the virus)

3/
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">these smaller particles are potentially more infectious than the larger particles (~50μm) produced during coughing and sneezing, because they stay in the air for longer
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">smaller particles have more chance of penetrating deeper into the lungs

4/
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">speech can release a larger numbers of particles compared to coughing (counting aloud produces 2-10x more particles than 1 cough)
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">there is a linear correlation: increasing particle emission with increasing speech volume

5/
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">particles are the same size (~1μm) regardless of speech volume
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">on average speaking loudly resulted in 10x more particle emission than speaking quietly
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">some participants were superemitters but there were no trends for gender, age, BMI

6/
https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔸" title="Small orange diamond" aria-label="Emoji: Small orange diamond">Hypthesised mechanism of action: vocal fold vibration and adduction at the larynx resulting in a & #39;fluid-film burst& #39; mechanism and particle emission

7/
My question is: should we be wearing FFP3 for all SLT assessment and interventions with COVID-19 suspected and positive patients?

What do #wespeechies think?