Episode #10 - Ventilation & COVID-19

VGS   Ventilation. What role does it play in keeping your homes, your offices, your schools, and you safe from COVID-19? Hello and welcome to Science in 5.

I'm Vismita Gupta-Smith. And these are WHO’s conversations in science. We are talking to Dr. Maria Neira today and she's going to talk about the role that ventilation plays in keeping your indoor spaces safe from COVID-19. Welcome, Maria.

MN   Hello. Thank you.

VGS   My first question to you: how important is ventilation? And how does it make our indoor spaces safe from COVID-19?

MN   Ventilation represents a very important aspect, a very important factor to prevent the virus from spreading indoors. So, something as simple as natural ventilation means opening the doors, opening the windows, can provide this type of renewal of the healthy air we want to breathe. And let me give you an example. Whenever it's possible in public spaces or in buildings, ensure a natural ventilation, opening the windows. And, in places like and in settings like schools or working in places or touristic places, what we are recommending is to increase the rate of air change, increase the rate of ventilation by natural ways or mechanical ones, always trying to avoid the recirculation of the air. And when you cannot avoid it, then having filters that are properly and regularly maintained and changed as needed. Please don't forget that ventilation is very important but it's not the only measure. So, this has to be a one intervention part of a package of interventions to prevent COVID-19 from being spread.

VGS   Maria, most indoor spaces around the world depend on opening doors and windows. So, how can we be sure that enough outdoor air is circulating indoors?

MN   Of course, we need to consider the space size. I mean, how big is the room or the space we want to ventilate? The occupancy rate. How many people are occupying that room? And, the activities that are carried out in that space. And, of course, there are formulas to calculate all of that. But essentially what we know is to renew the air. And to give you an example, if in one hour you renew, you change your air six times, I think that will provide quite a sensible way of making sure that we are reducing or preventing the spread of the virus indoors.

VGS   Maria, it’s not always possible, in heavily-polluted settings, to open doors and windows. How should we manage outdoor air pollution, preventing that, as well as preventing COVID-19 and keeping our houses better ventilated?

MN   Together with COVID-19, we very much concerned by air pollution.  And as you know, this is a major public health issue still responsible for 7 million premature deaths every year.

So, my answer will be, we need to do whatever is needed to reduce air pollution outdoors by putting in place the different measures and interventions that are available and requesting the authorities to do so. But while this is not possible, we need to make sure that we still ensure some natural ventilation, except, of course, if you are very close to the source of emission, or there are very heavy and very high levels of pollution. But in any case, you can consider as well, depending on your capacity or where you live, you can consider what they call air purifiers, and of course the HEPA filters, that in some residential buildings are already available.

VGS   Thank you, Maria. That was Dr. Maria Neira talking about ventilation and the role that it plays in keeping you safe in your indoor spaces. If you find this content useful, please share it with your colleagues, with your friends and network, and invite them to follow us on our social media channels. Until next time then. Stay safe and stick with science.