Looking for scientific articles on the generation of aerosol particles from coughs.
Physical properties such as droplet size distribution, droplet density, number of droplets, composition of droplets (eg. watery or mucus-laden), air ejection velocity, air volume produced, angle from the vertical at which we typically cough.
Can you help?
Molly you might want to liaise with The Cystic Fibrosis Foundation about this.
There are a lot of variables.
Germs Can Be Spread in the Air
Droplets containing germs are released into the air when a person coughs or sneezes. These tiny droplets can travel as far as 6 feet and can spread germs by landing on surfaces or in another person’s eyes, nose, or mouth.
In rare instances, remains of these small droplets can be suspended in the air for hours and may be carried by air currents farther away than larger droplets. Other people can breathe in these droplets.
At a CF care center, the team works to prevent the spread of dangerous germs between people with CF by taking infection prevention and control measures. These include frequent cleaning of hands, wearing gowns and gloves, and helping people with CF keep a safe 6-foot distance from each other when they visit the care center and when they are admitted to the hospital.
https://www.youtube.com/watch?v=MC8PttCaGTo
air flow during cough simulation using computational fluid dynamics CFD
27 Mar 2020
https://www.youtube.com/watch?v=DKJ-jVs06Ms
sneezing
https://www.youtube.com/watch?v=__DdHLS-MIQ
Sneezing and Coughing Covid 19.
https://www.youtube.com/watch?v=bFxgVkslD-k
The physics of the sneeze
moll, go here:
http://www.hon.ch/med.html
And search on “cough aerosols”. Lots of papers to look at.
(The search box is a bit hard to find, it’s over on the left and quite small)
Is this the sort of thing you are after?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5516269/
Also search in PubMed on the same search term
https://www.ncbi.nlm.nih.gov/pmc/
Thanks skipper & buffy.
> https://www.youtube.com/watch?v=MC8PttCaGTo
Love this.
buffy said:
moll, go here:http://www.hon.ch/med.html
And search on “cough aerosols”. Lots of papers to look at.
(The search box is a bit hard to find, it’s over on the left and quite small)
Some good stuff here. eg.
“The simulated cough has a 4.2 l volume and is based on coughs recorded from influenza patients. In one configuration, the simulator produces a cough aerosol containing particles from 0.1 to 100 µm in diameter with a volume median diameter (VMD) of 8.5 µm and a geometric standard deviation (GSD) of 2.9. In a second configuration, the cough aerosol has a size range of 0.1–30 µm, a VMD of 3.4 µm, and a GSD of 2.3. The total aerosol volume expelled during each cough is 68 µl.”
“Currently, the term droplet is often taken to refer to droplets >5 μm in diameter that fall rapidly to the ground under gravity, and therefore are transmitted only over a limited distance (e.g. ≤1 m). In contrast, the term droplet nuclei refers to droplets ≤5 μm in diameter that can remain suspended in air for significant periods of time, allowing them to be transmitted over distances >1 m. Droplet nuclei are the dried-out residual of droplets”.
The above claim is one that is very much in need of independent confirmation – the date of the reference to droplet nuclei is as far back as 1955. I personally think that dehydration kills the viruses so want to see proof either way.
“their average cough aerosol volume was 38.3 picoliters (pL) of particles per cough (SD 43.7). The number of particles produced per cough was average 75,400 particles/cough, SD 97,300. The average number of particles expelled per cough varied widely from patient to patient, ranging from 900 to 302,200 particles/cough. When the subjects had influenza, an average of 63% of each subject’s cough aerosol particle volume in the detection range was in the respirable size fraction (SD 22%)”
I notice that there are extreme differences between different papers. >5 micron vs 0.5 micron for starters.
mollwollfumble said:
Thanks skipper & buffy.> https://www.youtube.com/watch?v=MC8PttCaGTo
Love this.
buffy said:
moll, go here:http://www.hon.ch/med.html
And search on “cough aerosols”. Lots of papers to look at.
(The search box is a bit hard to find, it’s over on the left and quite small)
Some good stuff here. eg.
“The simulated cough has a 4.2 l volume and is based on coughs recorded from influenza patients. In one configuration, the simulator produces a cough aerosol containing particles from 0.1 to 100 µm in diameter with a volume median diameter (VMD) of 8.5 µm and a geometric standard deviation (GSD) of 2.9. In a second configuration, the cough aerosol has a size range of 0.1–30 µm, a VMD of 3.4 µm, and a GSD of 2.3. The total aerosol volume expelled during each cough is 68 µl.”
“Currently, the term droplet is often taken to refer to droplets >5 μm in diameter that fall rapidly to the ground under gravity, and therefore are transmitted only over a limited distance (e.g. ≤1 m). In contrast, the term droplet nuclei refers to droplets ≤5 μm in diameter that can remain suspended in air for significant periods of time, allowing them to be transmitted over distances >1 m. Droplet nuclei are the dried-out residual of droplets”.
The above claim is one that is very much in need of independent confirmation – the date of the reference to droplet nuclei is as far back as 1955. I personally think that dehydration kills the viruses so want to see proof either way.
“their average cough aerosol volume was 38.3 picoliters (pL) of particles per cough (SD 43.7). The number of particles produced per cough was average 75,400 particles/cough, SD 97,300. The average number of particles expelled per cough varied widely from patient to patient, ranging from 900 to 302,200 particles/cough. When the subjects had influenza, an average of 63% of each subject’s cough aerosol particle volume in the detection range was in the respirable size fraction (SD 22%)”
I notice that there are extreme differences between different papers. >5 micron vs 0.5 micron for starters.
That’s Zhou Enlai
COVID-19. Transport of respiratory droplets in a microclimatologic urban scenario
https://www.medrxiv.org/content/10.1101/2020.04.17.20064394v1
If you write to the lead author, you may be able to get their references list.
Peak Warming Man said:
mollwollfumble said:
Thanks skipper & buffy.> https://www.youtube.com/watch?v=MC8PttCaGTo
Love this.
buffy said:
moll, go here:http://www.hon.ch/med.html
And search on “cough aerosols”. Lots of papers to look at.
(The search box is a bit hard to find, it’s over on the left and quite small)
Some good stuff here. eg.
“The simulated cough has a 4.2 l volume and is based on coughs recorded from influenza patients. In one configuration, the simulator produces a cough aerosol containing particles from 0.1 to 100 µm in diameter with a volume median diameter (VMD) of 8.5 µm and a geometric standard deviation (GSD) of 2.9. In a second configuration, the cough aerosol has a size range of 0.1–30 µm, a VMD of 3.4 µm, and a GSD of 2.3. The total aerosol volume expelled during each cough is 68 µl.”
“Currently, the term droplet is often taken to refer to droplets >5 μm in diameter that fall rapidly to the ground under gravity, and therefore are transmitted only over a limited distance (e.g. ≤1 m). In contrast, the term droplet nuclei refers to droplets ≤5 μm in diameter that can remain suspended in air for significant periods of time, allowing them to be transmitted over distances >1 m. Droplet nuclei are the dried-out residual of droplets”.
The above claim is one that is very much in need of independent confirmation – the date of the reference to droplet nuclei is as far back as 1955. I personally think that dehydration kills the viruses so want to see proof either way.
“their average cough aerosol volume was 38.3 picoliters (pL) of particles per cough (SD 43.7). The number of particles produced per cough was average 75,400 particles/cough, SD 97,300. The average number of particles expelled per cough varied widely from patient to patient, ranging from 900 to 302,200 particles/cough. When the subjects had influenza, an average of 63% of each subject’s cough aerosol particle volume in the detection range was in the respirable size fraction (SD 22%)”
I notice that there are extreme differences between different papers. >5 micron vs 0.5 micron for starters.
That’s Zhou Enlai
not Sun Yang, son ¿