Welcome back everyone, to Inside Infection Control, our video blog here at CDC's Project Firstline.
I'm Abby Carlson. I'm an infectious diseases doctor at the CDC,
and it's wonderful to have you back with us here today.
Many of us have been hearing about how important ventilation is.
But you might be asking, what is ventilation and why does it matter?
Ventilation, essentially, is the movement of air in and out of spaces.
It's important to understand, because good ventilation can help move things
that we don't want to breathe in, like virus, out of the air.
That's why it's important to have the best possible air movement
and air quality in healthcare.
It can help reduce the risk that germs will spread,
particularly the ones that cause COVID-19.
But how?
Well, remember that we talked in another episode about our respiratory droplets,
and how some of them can move and float in the air for a while.
Many of them are going to drop to the ground or land on surfaces pretty quickly.
But what about the ones that don't?
What about those that stay in the air? What happens to them?
Well, in the outdoors, they get carried away pretty quickly.
They are outdoors.
They could also be killed, like by sunlight or by drying out,
so they can't make you sick anymore.
You can think of it like this-- let's imagine that respiratory droplets
are like droplets of food coloring.
Now let's imagine that we drop a little bit of that food coloring in the ocean.
You wouldn't actually do this, of course, but picture it in your head.
You're dropping a little bit of droplets, just like you're breathing out some droplets
if you're infected with COVID-19.
It's so little, and it gets carried away so quickly in the ocean
that the ocean doesn't turn a different color,
and you can barely see where the food coloring was for more than a few seconds.
That's like those respiratory droplets being breathed out outside.
The droplets are very quickly carried away, and you don't worry about breathing them in,
because they spread so fast and essentially disappear.
On the other hand, if you put that drop of food coloring in a glass jar of water,
one that's full of water and isn't moving,
so the water is not coming into the jar, it's not coming out of the jar,
it's just sitting there.
You'll see that food coloring when you drop it in, and the whole jar is going to turn a color.
That jar is like a room without ventilation.
Just like the food coloring in the jar, when somebody who's infected with COVID-19
breathes out into a room,
that virus that's being carried by those respiratory droplets
are going to stay for a little while, and won't have anywhere to move.
But, imagine we now take this jar and we put a system together that takes out old water,
the color of water that the food coloring is in, and puts in new water.
Then what?
Slowly, depending on how fast the new water comes in and how fast we take that old water out,
that color is going to go away.
And eventually we'll have nice clean water again.
It's the same thing with ventilation.
When old air with droplets is pulled out and new clean air is pushed in,
eventually we have nice clean air in the room.
But what if you don't have a system that's moving air like that?
What can you do then?
Well, in those cases, you may see that rooms are going to be cleaned by a filter instead,
like a HEPA filter that is put in a corner.
So, you don't change the air in the room,
but you're just trying to clear it of those respiratory droplets.
Almost as if we were to drop something in the jar
that pulled all the food coloring out of the water and cleaned it up again.
You could see how doing these things to improve the air and the movement of the air
will help keep the virus from spreading.
The fewer virus particles the air, the less likely you are to breathe them in,
or that will land on your eyes or a surface that you might touch.
So, ventilation is important.
And it's one of the many tools that we have to keep infections like COVID-19 from spreading.
As always, thanks for joining us.
Be sure to follow up with us on Facebook, Twitter, and YouTube,
or you can check us out on our website, CDC.gov/ProjectFirstline
and we will see you back here with the next episode.