New research has revealed certain physical features increase the spread of COVID-19.
And one of them is pretty surprising!
It's all about velocity
Researchers at University of Central Florida say a full set of teeth could increase the potential to spread viruses by affecting how far droplets travel when a person sneezes.
In other words, being toothless means you are less likely to spread COVID-19.
The study appearing this month in the journal Physics of Fluids used computer-generated models to replicate sneezes in different types of people and determine associations between people's physiological features and how far their sneeze droplets travel and linger in the air.
The scientists found that teeth also restrict the sneeze's exit area and cause droplets to increase in velocity.
One of the authors of the research paper, Michael Kinzel, explains:
Teeth create a narrowing effect in the jet that makes it stronger and more turbulent,They actually appear to drive transmission. So, if you see someone without teeth, you can actually expect a weaker jet from the sneeze from them.
A blocked nose can also increase velocity. This is because a clear nose provides a path in addition to the mouth for the sneeze to exit.
If the nose is blocked, the area that the sneeze can leave is restricted, so the droplets come out with more power and spread further.
The researchers used 3D modelling and numerical simulations to recreate four mouth and nose types: a person with teeth and a clear nose; a person with no teeth and a clear nose; a person with no teeth and a congested nose; and a person with teeth and a congested nose.
When they simulated sneezes in the different models, they found that the spray distance of droplets expelled when a person has a congested nose and a full set of teeth is about 60 percent greater than when they do not.
The results indicate that when someone keeps their nose clear, such as by blowing it into a tissue, that they could be reducing the distance their germs travel.
The researchers also discovered that thinner saliva spreads the virus faster.
For instance, three seconds after a sneeze, when thick saliva was reaching the ground and thus diminishing its threat, the thinner saliva was still floating in the air as a potential disease transmitter.
Scientists have been trying to discover why some people appear to be ‘super-spreaders’ in infecting others, and this is one more piece to place in the jigsaw.
Professor Woolhouse, professor of infectious disease epidemiology at the University of Edinburgh, told the Independent newspaper that science was still working out the question of ‘super-spreaders’. He commented:
One reason could be that some individuals shed large amounts of virus so they are more likely to pass this on. The other theory is that these super-spreaders cope better with the virus and don’t show any symptoms so they are going about as normal and don’t know they have it.
Have a full set of teeth and worried about passing the virus on? Just keep social distancing. In other research, scientists have found that physical distancing is universally effective at reducing the spread of COVID-19.
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