tech

Supercomputer shows humidity affects aerosol spread of coronavirus

12 Comments
By Rocky Swift

A Japanese supercomputer showed that humidity can have a large effect on the dispersion of virus particles, pointing to heightened coronavirus contagion risks in dry, indoor conditions during the winter months.

The finding suggests that the use of humidifiers may help limit infections during times when window ventilation is not possible, according to a study released on Tuesday by research giant Riken and Kobe University.

The researchers used the Fugaku supercomputer to model the emission and flow of virus-like particles from infected people in a variety of indoor environments.

Air humidity of lower than 30% resulted in more than double the amount of aerosolised particles compared to levels of 60% or higher, the simulations showed.

The study also indicated that clear face shields are not as effective as masks in preventing the spread of aerosols. Other findings showed that diners are more at risk from people to their side compared to across the table, and the number of singers in choruses should be limited and spaced out.

There has been a growing consensus among health experts that the COVID-19 virus can be spread through the air. The U.S. Centers for Disease Control and Prevention (CDC) revised its guidance this month to say the pathogen can linger in the air for hours.

The Riken research team led by Makoto Tsubokura has previously used the Fugaku supercomputer to model contagion conditions in trains, work spaces, and class rooms.

Notably, the simulations showed that opening windows on commuter trains can increase the ventilation by two to three times, lowering the concentration of ambient microbes.

"People's blind fear or unfounded confidence against the infection of COVID-19 is simply because it is invisible," Tsubokura said.

© Thomson Reuters 2020.

©2020 GPlusMedia Inc.

12 Comments
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The fear-mongering is more dangerous than the virus.

-6 ( +7 / -13 )

The fear-mongering is more dangerous than the virus.

Yes, the families of the million dead, and the million(s) more to die need to shut up and stop fear-mongering. Why can't they die quietly without kicking up a fuss?

6 ( +14 / -8 )

"People's blind fear or unfounded confidence against the infection of COVID-19 is simply because it is invisible," Tsubokura said.

..and because of all the confusing information we’re fed by zealous media pushing an agenda. I’d be lots less stressed if we had all the facts and nothing but the facts.

6 ( +8 / -2 )

You normally don’t need a supercomputer for such simple common sense considerations and 4th-grader mathematics calcifications.

-3 ( +2 / -5 )

You normally don’t need a supercomputer for such simple common sense considerations and 4th-grader mathematics calcifications.

Which is not what this was used for. Models are not made with the purpose of making considerations, but to corroborate that they actually line up with reality.

Scientific advancement comes not only from discovering new exciting things that nobody ever thought about, it also comes from people dedicating their efforts to corroborate what we think is actually correct or not. Even studying something already proven true can be of benefit if it can put a numeric value.

We think humidity influence spreading of the virus, epidemiological data and experiments with other viruses points very strongly to this, but we had no direct evidence of this actually happening, now we have, and even know how much the humidity is likely to change the aerosols. People no longer have to wonder if they have to dial up the levels to a 100% to have an effect.

Fear is fueled by ignorance, discovering something, even if it is dangerous, means less fear, reduces the unknowns used by the actual people that want to instigate fear.

3 ( +6 / -3 )

You normally don’t need a supercomputer for such simple common sense considerations

I disagree. A well programmed and calibrated computer will go a long way in proving or disproving common sense as it can take or observe stuff common sense will forget. And that can offer a more rational explanation about the spread or not of the virus.

The fear-mongering

Telling people how to evaluate the level of risk and how they can reduce risk is not fear-mongering.

9 ( +10 / -1 )

I would like more information. To my way of thinking, the virus should be more infectious with higher humidity, and less infectious with low humidity, but apparently I have it all backwards. How is it that the virus is less of a problem in areas of high humidity?

3 ( +3 / -0 )

I've been hearing for months that the virus is less stable under high humidity. Also, your airways offer much greater protection against infection under humid conditions.

So I just bought a humidifier for my office...

2 ( +2 / -0 )

so ... typhoons protect Japan from COVID ?

0 ( +1 / -1 )

To my way of thinking, the virus should be more infectious with higher humidity, and less infectious with low humidity, but apparently I have it all backwards. How is it that the virus is less of a problem in areas of high humidity?

In general viruses "live" while they are in solution, surrounded by things dissolved in the water, like salts, ions, proteins, etc. being exposed to those other molecules can make the virus grow "old" until it deactivates, their surface can get damaged by ions, or changes in the pH, or enzymes from the saliva, etc. Without a cell to infect the viruses just keep getting damaged over time without any chance to increase their numbers.

In that aspect they are in the opposite situation than bacteria, that can use what is in the water to feed and produce more bacteria.

Another important reason according to this research is that in high humidity big droplets remain big and heavy, so they drop quickly to the ground and stop being part of the aerosol. With low humidity the droplets dry up and become smaller, lighter and can float around for much longer time, so indirectly the virus becomes more infective since it can reach other people more easily.

6 ( +7 / -1 )

Thanks!

2 ( +2 / -0 )

What virusrex said. The virus envelope is actually 'lipid bilayer cell membrane' in which are embedded membrane proteins (the 'corona') whose active shapes are maintained by interaction with H₂O. The liquid droplets which carry the viruses will shrink fairly quickly in a 'dry' atmosphere increasing the ease of deep pulmonary penetration and increasing effective concentration of particles in any droplet which touches susceptible tissue, besides the increased air residency time. Increased humidity will allow droplets to stay large and to possibly grow from ambient absorption decreasing penetrance and particle concentration at any given site of opportunity. 'Mist' making type humidifiers might be the most effective in producing 'diluting' aerosols and, if an otherwise harmless 'lipid bilayer disrupter' of some sort could be added to such aerosols, perhaps an effective anti-virus tactic for large spaces could be developed. Just suggestin'...

0 ( +1 / -1 )

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