From the conclusion of article linked👆: "Our laser light scattering method not only provides real-time visual evidence for speech droplet emission, but also assesses their airborne lifetime...." 2/
"...This direct visualization demonstrates how normal speech generates airborne droplets that can remain suspended for tens of minutes or longer and are eminently capable of transmitting disease in confined spaces." 3/
From the article: "we estimate that 1 min of loud speaking generates at least 1,000 virion-containing droplet nuclei that remain airborne for more than 8 min. These therefore could be inhaled by others and, according to IAH, trigger a new SARS-CoV-2 infection." 4/
Irony: 'the enclosure was “filled” with speech droplets by someone repeating the phrase “stay healthy” for 25 s. This phrase was chosen because the “th” phonation in the word “healthy” was found to be an efficient generator of oral fluid speech droplets.' 5/
As @ErinBromage notes in this post, 2 metre social distancing will not make confined, unventilated spaces such as classrooms safe. Key passage👇. 6/
erinbromage.com/post/the-risks…
erinbromage.com/post/the-risks…
.@ErinBromage's post describes a number of studies that show that a single Covid-19 infected individual can infect a large proportion of others in a confined space they share for an extended period of time, even if these others are much more than 2 metres away. 7/
In order to render classrooms safe, measures beyond social distancing will be necessary. One such measure, which is the focus of many American universities that hope to re-open their classrooms in the autumn, is extensive testing, tracing & isolation. 8/
E.g., President of Brown Univ: "All campuses must be able to conduct rapid testing for the coronavirus for all students...at regular intervals throughout the year. Testing only those with symptoms will not be sufficient." 9/
brown.edu/news/2020-04-2…
brown.edu/news/2020-04-2…
Given that a significant number of coronavirus infections are likely to remain in the general population in places such as the UK & the US during the coming academic year, testing, tracking & isolation will also need to be supplemented w the wearing of PPE in classrooms. 10/
This short Youtube video, by those who conducted the laser light study mentioned above, provides striking visual evidence👀of the extent to which the wearing of a mask blocks the release of speech generated oral fluid droplets. 11/
See this, plus links, for more on the effectiveness of face masks in reducing Covid-19 transmission when worn by all👇. 12/
theconversation.com/masks-help-sto…
theconversation.com/masks-help-sto…
In France, the wearing of facemasks is now a requirement in secondary schools that have recently re-opened (as well as on public transport). The govt is taking steps to ensure that such masks are widely available. 13/
bbc.co.uk/news/world-eur…
bbc.co.uk/news/world-eur…
Having failed to persuade the government to provide universities with money to make up for the loss in tuition fees from overseas students who will refuse to come to the UK for either risky in person teaching or inferior online provision... 14/
.@UniversitiesUK @UCU @AlistairJarvis @DrJoGrady & @RussellGroup should now call on the government to assist them in ensuring that they can provide sufficient testing, tracing & PPE to make it safe for students & teachers to return to the classroom in the autumn. 15/
If unis & the gov't don't get their act together NOW, overseas students from Asia will abandon their autumn places in the UK & apply for Jan admission to unis in New Zealand & Australia, which have controlled the pandemic far more competently. 16/16
monitor.icef.com/2020/05/austra…
monitor.icef.com/2020/05/austra…
Link to later thread on in person teaching:
