We are still coming to understand the features and characteristics and traits of this virus that has upended the world, but how there has been this open and ongoing question about how you catch it right I mean we know that it’s transmitted in all kinds of ways, but Just how contagious is it and people are wiping down their mail and their packages?
They worry in the parks if people jog too close to them outside and all of that might be vectors of transmission. It looks like it’s possible, but increasingly it seems the main method of transmission.
The way it’s mainly being transmitted is saliva droplets, spread through air being expelled by people with coughs and sneezes NBC News, correspondent, Kerry sander. Did this amazing segment breaking down? What that looks like and how that works, the engineering professors use a dummy to simulate the coughs droplets. We all create one.
The FAU team uses a laser to follow how far those droplets travel. What you’re looking at is a mixture of water and glycerin that creates smoke 10 to 20 microns in size, the same size and weight of the smaller droplets of fluid. We expel when we call the simulation, shows the projection 3 feet traveled in less than 2 seconds.
Within 12 seconds, that’s a 6 feet and in 41 seconds there we go 9 feet and that was a ack off. Would you say there was a heavy heavy car in some tests we saw the COFF travel up to 12 feet increasingly. Masks are commonplace. Remember the use of a mask is to protect other people, not you, it doesn’t stop at a hundred percent, but you can see how it dissipates, a COFF mass, do appear to make a difference for precisely that reason.
In terms of you transmitting it, and this remarkable new study from South Korea shows how prolonged indoor exposure people sitting in close quarters right sort of breathing the air around each other is a main pathway. The virus. This is from a call center in South Korea. Look at the map of people, all the blue chairs are people who got infected and look how clustered together most of them are just sitting right next to each other working, basically, on top of each other joining me now to talk about what we know about coronavirus Transmission is dr
Angela Rasmussen, a fire ologist and associate research scientist at Columbia, University’s Mailman, School of Public Health, so maybe start dr. Rasmussen with a sort of overview about like what are the main vectors like. What do we think is the main thing that is transmitting the virus, the highest Ric’s stuff, and then we can move towards the possible, but not the thing.
That’S driving infection sure Chris, the primary mode of transmission for this virus is respiratory droplets, as you just stated, and that study from South Korea really demonstrates that. So you have a lot of people in one room getting infected while the other rooms on the same floor.
We’Re not as affected that suggests that this is not small particle aerosols that are hanging around in the air circulating through the building and the air conditioning system. This is really transmission of those types of respiratory droplets. Those larger particles from people who are all in the same space together sharing the same space, and we think that largely most of the transmission is driven by this method.
And that makes me I mean, as I we’re sort of learning about this and thinking about what. What the world looks like right after lockdown, you know it makes you think about subway cars and crowded buses. It makes you think about. You know, concert venues, certainly, but even big college lecture classes, someone sits there for an hour. Now I mean it. It really sort of to me puts into focus work workplaces where they don’t have.
You know actual offices, all the places that look like they’re, probably going to be the most high-risk. Is that fair? That’S very fair. I think one of the things that this study really underscores is how effective these physical, distancing and stay-home measures really are for reducing the spread of this illness in an office environment in crowds.
Like you just mentioned, all of those examples appear to be really good circumstances. In which the virus can be transmitted to a variety of people, the good news here it seems to me is is on some is on, is what we’re learning about, or transmission and sunlight, and what the risks are, if you’re say outside in a park, and people Are jogging past and they jog closer than six feet, which happens and it does seem.
Obviously people should stay far away, but it does seem that in general, like being outside and keeping your distance from people is pretty safe. All things considered, I think so I mean the risk is not zero. Certainly anytime, you are exposed to another person’s respiratory droplets.
There is a measurable risk, however, on what we’ve learned about sunlight, as well as all the other variables in the outdoor environment, so wind, humidity, temperature, that sort of thing all of those can affect the amount of virus that you are exposed to and if you’re not Exposed to enough virus to actually initiate an infection, you’re you’re likely to not be infected this.
This gets to the surfaces question and I know that some people, like obviously in work in workplaces like if we go back to that call center. Those surfaces are close to each other, people are maybe sneezing on a keyboard and other person’s using it, but but surfaces of say, packages, mail things like that, I mean again, the risk is not zero.
I don’t want to suggest that to anyone, but that seems further along the spectrum of low risk if we’re sort of categorizing them. Is that fair? I think that’s very fair. It’S really a matter of probabilities, so you have to think what are the odds that your package handler is infected with coronavirus?
They touch it they’re, not touching their hands all over the entire package, they’re touching one part of it. So what are the odds that you’re going to touch that exact same spot? Get enough virus onto your hand, to establish an infection then touch your nose in an amount of time that that virus is still going to be infectious.
Those those odds are fairly good in terms of you not getting infected, so I I think that touching packages touching groceries, things like that are relatively low-risk activities, particularly when, coupled with good hand, hygiene yeah. It really makes you think I mean, I think, that part of it, the outdoor stuff, the packages stuff, is sort of like anxiety, reducing.
But when you try to think about like how a business that has a huge bull – and that looks like that, one in the call center is gon na safely bring everyone back.
Angela, Erasmus and thank you for sharing your expertise and I really appreciate it a pleasure.