3D Simulation Shows the Spread of a Cough

3D Simulation Shows the Spread of a Cough title=
3D Simulation Shows the Spread of a Cough
35 Comments
Reads 7729

Photo/Video: FMI/AALTO/VTT/UH/CSC

By edhat staff

Researchers in Finland released a 3D simulation of how rapidly a cough can spread through a supermarket.

According to the study, aerosol particles emitted from the respiratory tract when coughing, sneezing or talking can remain in the air longer than originally thought. These particles can carry pathogens such as the coronavirus (COVID-19) further spreading the disease.

In the 3D model, a person coughs in a corridor with indoor ventilation airflow conditions, resembling a grocery store aisle. A cloud is emitted to represent the cough that travels in the air around the individual before spreading to the next aisle and throughout the store. It takes several minutes for the cloud to spread and disperse.

“Someone infected by the coronavirus can cough and walk away but then leave behind extremely small aerosol particles carrying the coronavirus. These particles could then end up in the respiratory tract of others in the vicinity,” stated Aalto University Assistant Professor Ville Vuorinen.

Researchers state based on their preliminary results it is important to avoid busy public indoor spaces. This also reduces the risk of droplet infection, which remains the main path of transmission for coronavirus.

The Centers for Disease Control and Prevention (CDC) recommends using cloth face coverings, especially in areas of significant community-based transmission such as grocery stories and pharmacies, as well as maintaining physical distancing.

"We now know from recent studies that a significant portion of individuals with coronavirus lack symptoms (“asymptomatic”) and that even those who eventually develop symptoms (“pre-symptomatic”) can transmit the virus to others before showing symptoms.  This means that the virus can spread between people interacting in close proximity—for example, speaking, coughing, or sneezing—even if those people are not exhibiting symptoms," according to the CDC. 

Cloth face coverings fashioned from household items or made at home from common materials at low cost can be used as an additional, voluntary public health measure. The cloth face coverings recommended are not surgical masks or N-95 respirators.  Those are critical supplies that must continue to be reserved for healthcare workers and other medical first responders, as recommended by current CDC guidance.

Login to add Comments

35 Comments

Show Comments
giftedinSB Apr 14, 2020 12:34 PM
3D Simulation Shows the Spread of a Cough

This is disturbing, but very valuable work. Hard to believe that the particles spread that far and stay in the air for 7 full minutes.

a-1586894648 Apr 14, 2020 01:04 PM
3D Simulation Shows the Spread of a Cough

If it's truly this bad, shouldn't we keep locked down until a cure? I mean, if this is still a deadly disease and it's so easily spread, then masks and socially distancing should be required until we have a means of combating the virus.

Chip of SB Apr 14, 2020 01:28 PM
3D Simulation Shows the Spread of a Cough

I think it's up to everyone to make up their own minds. Stay isolated if you are worried, or go back to normal if you are willing to accept the risks. You are free to choose. I would encourage those who are inclined to go back to normal life to try to be respectful of those who wish to continue isolating to the extent possible. However, regardless of your perspective I don't think it's fair to try to impose your preferred approach on others.

a-1586896482 Apr 14, 2020 01:34 PM
3D Simulation Shows the Spread of a Cough

CHIP - I kind of agree, but at the same time, if people start going out and about to risk it now, then we're back at square one. Accepting the risk is one thing, but if you get it, you can now spread it to those who did not want to risk it - co-workers, family, friends. This is what's frustrating. We need to get back to work and life as normal, but if it means spreading this disease, then it's pointless.

a-1586898522 Apr 14, 2020 02:08 PM
3D Simulation Shows the Spread of a Cough

This is such a poorly thought out concept. At first it makes sense - if you want to isolate at home, go ahead. I'm going to take my chances. Seems simple enough.

The problem is that if any significant portion of people stop abiding by social distancing, stay at home (as much as you possibly can) orders, wearing masks/gloves/doing frequent handwashing, then those who choose NOT to abide end up sabotaging things for EVERYONE. Right now activities like going to the grocery store are low risk, even for high risk people. These are not optional activities, these are things necessary to sustain life. What happens when any significant % of the population start eschewing best practices to "go back to normal" is the virus picks up, starts spreading again, and the currently LOW RISK activities become HIGH RISK for everyone.

a-1586898592 Apr 14, 2020 02:09 PM
3D Simulation Shows the Spread of a Cough

And my comment below is in reference to CHIP, not 1:04 PM. So 1:04 PM the answer is, yes, you are correct. Chip is wrong. He doesn't get that his live free or die mentality may not cause only himself to die, but others, too. And that is wrong.

a-1586910399 Apr 14, 2020 05:26 PM
3D Simulation Shows the Spread of a Cough

Reasonable, Chip, for you to be willing to accept the risks, but, imo, not reasonable to inflict those risks on others in public places, such as grocery stores or other essential activity places.

Get over it Apr 14, 2020 06:24 PM
3D Simulation Shows the Spread of a Cough

Not if a cure is a year or more out... Sadly 2 people have died so far in Santa Barbara County. That's out of 446,499 people. That's a .0004% death rate. Any death is terrible, obviously. If the people in our country can't work for a year however, that death rate is going to skyrocket and not from Covid-19.

LnOfan Apr 15, 2020 05:55 AM
3D Simulation Shows the Spread of a Cough

Accepting the risks? Like the risks of moving the virus along and prolonging the virus? Currently normal life is what will keep the virus around. Unfortunately, it is unlikely that everyone wanting a sense of normalcy back will be respectful of others. 1:34 said it beautifully.

mtndriver Apr 15, 2020 08:37 AM
3D Simulation Shows the Spread of a Cough

That’s a pretty self-centered view, CHIP. If it was possible for you to live with high risk without endangering others, that would be one thing. But the truth is, we need to protect others by our behavior. That’s just good citizenship right now.

ChillinGrillin Apr 14, 2020 01:12 PM
3D Simulation Shows the Spread of a Cough

It's remarkable how many people still aren't following social distancing. Even with signs everywhere at markets and marking tape on the ground, I've had to dodge oblivious people every time I go out.

a-1586895924 Apr 14, 2020 01:25 PM
3D Simulation Shows the Spread of a Cough

CHILLIN - I've noticed the same, especially since they've told us to wear masks! People put on their masks and think they can carry on as normal. NO. I had people brushing past me, reaching over me, etc at the store wearing masks. Masks alone won't protect you! You need to still keep your distances.

a-1586896470 Apr 14, 2020 01:34 PM
3D Simulation Shows the Spread of a Cough

Personally, I think it's going to cause more harm and panic. The study looks at small (<20 um) aerosolized particulates. The presence of aerosolized virus does not necessarily equate to a high risk of airborne transmission. The majority of evidence still indicates that COVID-19 is primarily transmitted through droplets and not through aerosolized particulates. Even according to the study, experts in infectious disease and virology are still examining the results. I'd say this was released prematurely for sake of pretty pictures. If people believe there are clouds of virus floating around, behavior will change for the worse. Be smart and be safe.

PitMix Apr 14, 2020 02:14 PM
3D Simulation Shows the Spread of a Cough

From NPR discussion: "Now, citing Santarpia's results along with other studies, a committee of independent experts convened by the National Academies of Sciences, Engineering, and Medicine has weighed in, in response to a question from the White House Office of Science and Technology Policy about whether the virus "could be spread by conversation in addition to sneeze/cough-induced droplets."

"Currently available research supports the possibility that SARS-CoV-2 could be spread via bioaerosols generated directly by patients' exhalation," says a letter from the committee chair. By bioaerosols, they are referring to fine particles emitted when someone breathes that can be suspended in the air rather than larger droplets produced through coughs and sneezes.

sbdude Apr 14, 2020 03:43 PM
3D Simulation Shows the Spread of a Cough

The presence of viruses in the atmosphere is not necessarily an indicator of the danger of getting it. No one knows the virus density in either aerosols or droplets needed to actually infect someone with Covid. You might model the presence of viruses in the atmosphere at a particular place and you might even have a machine that can detect them, but until it is known at what level of density do those viruses actually pose a danger, then just saying they're there isn't particularly helpful.

a-1586904359 Apr 14, 2020 03:45 PM
3D Simulation Shows the Spread of a Cough

I’m curious how much virus is required to infect a person. I read that medical personnel are most at risk because they are in an environment with sick people spewing virus all over the place. They are constantly bombarded with particles, and some will get past their masks. That makes sense. But if I get a tiny dose of virus particles at the supermarket from someone coughing two aisles away, will I for sure be infected? Is there some minimum number of virus particles needed to cause infection? Is one tiny virus sphere enough to colonize my body? I don’t suppose we know yet.

macpuzl Apr 14, 2020 03:57 PM
3D Simulation Shows the Spread of a Cough

We don't know yet, but you will never be able to describe a cutoff level in anything other than statistical terms. For some cases, one virus particle may suffice, although it would be a rare occurrence relative to those with larger doses.

PitMix Apr 14, 2020 04:22 PM
3D Simulation Shows the Spread of a Cough

One of the docs on TV said that the South Koreans had established this rule based on their experience: If you were in close contact with someone for more than 1/2 hr that was later determined to be sick, you should self quarantine. Any time less than 1/2 hr and they didn't require that. So it seems that it takes quite a bit of virus to guarantee you are going to get sick.

sacjon Apr 14, 2020 06:34 PM
3D Simulation Shows the Spread of a Cough

PUG: actually, it's entirely possible they had it in December. Do you know if they traveled to Europe or Asia in December? "New evidence suggests that the earliest cases of COVID-19 were seen in November...." --------https://www.uchicagomedicine.org/forefront/prevention-and-screening-articles/wuhan-coronavirus

Shasta Guy Apr 14, 2020 07:14 PM
3D Simulation Shows the Spread of a Cough

Ever wonder why you can smell someone popping popcorn in a microwave from far away. Same with a BBQ or a cigarette. That’s because you’re inhaling microscopic particles that travelled a non-negligible distance to you. You are also inhaling molecules, but those particles can travel far. In the case of popcorn, it’s an aerosol of tiny oil droplets, whereas the smokes are suspensions of solid matter. That simulation is quite real, and if I were to hear someone cough or sneeze in a grocery store I will leave my cart in place and head to the nearest exit away from the source.

Shasta Guy Apr 15, 2020 06:54 AM
3D Simulation Shows the Spread of a Cough

Super Chemical Freak: it’s good to know there’s another chemist out there. I know enough biochem to get me into trouble, but one of the hats I wear is micro contamination control for semiconductor manufacturing.

Shasta Guy Apr 15, 2020 07:21 AM
3D Simulation Shows the Spread of a Cough

Super Chemical Freak: I have something I’d like you to ponder. From everything I’ve been reading about the virus, one hypothesis is the it interferes with the uptake of oxygen by the hemoglobin molecule. This leads to overall oxygen deprivation causing a catastrophic downward spiral in health. The sudden recovery reported by many who take HCQ is because it restores the ability for hemoglobin to take up oxygen, cause a rapid reoxygenation of the blood. Given your biochemistry background, do you have any thoughts on that mechanism?

ChemicalSuperFreak Apr 15, 2020 08:12 AM
3D Simulation Shows the Spread of a Cough

Hey Shasta, as far I I can tell, choroquine and related analogs are anti-inflammatory. Idealy they would be most active when they bind receptor sites on the host cell or virus, the way antivirals work. If they are working on patients currently, they are ameliorating the flooding of liquid into the lungs, which can cause pneumonia.

ChemicalSuperFreak Apr 15, 2020 08:16 AM
3D Simulation Shows the Spread of a Cough

Oxygen uptake in the lungs is dependent on pH, See Wikipedia for cooperativity and pH binding using the Hill plot.

macpuzl Apr 15, 2020 01:56 PM
3D Simulation Shows the Spread of a Cough

https://healthfeedback.org/claimreview/claim-that-sars-cov-2-binds-to-hemoglobin-in-red-blood-cells-unsupported-and-implausible-andrew-gaiziunas/

Please Login or Register to comment on this.