Clean indoor air

Suman Majumdar:

So most people think of air pollution as an outdoor problem. Exhaust fumes, factory smoke. Why is indoor air more important? What's actually inside the air in our homes, our workplaces and our public spaces that we should know about?

Lidia Morawska:

Well, there are lots of reasons, several of them, why indoor air is even more important than outdoor air. First of all, we spend most of our lives indoors, more than 90% of times we are inside. Secondly, air from outside penetrates indoors. So everything which is outside, or in terms of composition, will come indoors for some fraction of this. So we have outdoor air pollution indoors as well. But in addition to this, there are indoor sources, and in particular, if ventilation is not adequate, so concentrations of these pollutants from the indoor sources keep accumulating, including pathogens which we emit if we're infected. So we have everything from outdoor anything emitted indoors, pathogens, and we spend most of our time there. So this is the issue.

Suman:

So can the air inside typical building be worse than the outside?

Lidia:

Air inside can definitely be worse in situations when, in addition to what comes from inside, there are sources indoors. And those sources could be combustion sources, but could be any other sources, like sources of volatile organic components from products which we have indoors. So if this accumulates, then indoor air is worse than outdoor air.

Suman:

What are some of the consequences of poor indoor air quality on the health or society broadly?

Lidia:

Similar to the consequences of air pollutants full stop. So when we are talking about the consequences, for example, of exposure to particulate matter, whether it's from inside or outside, the consequences are the same. And basically there's no organ in our body, which is not affected by particulate matter. So the consequences are similar.

Suman:

Are there specific impacts on people's health that we know about from poor air? Is it as bad as having poor water?

Lidia: 

Different, but as bad, clearly as bad. As I said, there's no organ in our body, which is not affected by air pollution. There are short-term impacts, long-term impacts, and mortality, morbidity, full stop impacts are serious.

Suman:

So knowing this, what can we do to improve air quality?

Lidia:

This is, of course, a big question how to improve air quality, but the first and the most important point is to control emissions. Because if we can control emissions, if there's less pollution in the air, then there's less impact. So we are talking about reducing emissions from any combustion sources, transition to clean energies, particularly in terms of outdoor operating sources, vehicles, industry and so on, but the same of indoor sources. Any products which we bring inside and operate inside should be as least emitting as possible. The problem is that we don't have sufficient regulations in terms of what the products emit. Ventilation on removing from indoor air pollutants, which are emitted indoors. And finally, humans as a source. We emit, as I mentioned, pathogens if we are infected, but we emit also other products, in particular carbon dioxide. And the concentration of carbon dioxide can increase significantly and can have lots of impacts, one of them, even if it's not a health impact, it's an impact on cognition and performance.

Suman: 

You were one of the most influential scientists in the world on the issue of indoor air quality. And last year you won the Prime Minister's Prize for Science. You also played a key role in challenging the official dogma that respiratory diseases like colds and flus and particularly COVID spread through droplets that land on surfaces. And you challenged that very publicly. Can you describe what fundamentally changed in our understanding of how these airborne diseases are transmitted?

Lidia:

When the pandemic started, the dogma, prevailing dogma, was that infection is transmitted through surfaces. So there are those big droplets which don't stay in the air, they land on the surfaces, and therefore the most important is to clean the surfaces, clean hands. So we would see people in supermarkets with gloves and not masks. We knew, and by we, I mean scientists, scientists and the big fraction of medical community as well understood this very well, that the most important is the other particles with the pathogens which are in the air, they are much smaller. So it's not that big, big droplets we sometimes see when somebody's picking is overexcited, but the much smaller particles which can stay suspended in the air for much longer. We had evidence for this for a very long, long time. But to persuade this and make this accepted by the World Health Organization and by national public health authorities, this was the challenge. But the evidence was there and present this evidence such that it is or forced the evidence that was the challenge.

Suman:

So now we're a few years on. What is the work you're doing that's continuing to influence the science and the policy around indoor equality

Lidia: 

Well, there are science, technologies and policies. In terms of science, as a scientist, I would always say more science is needed. That's what apparently scientists say all the time. And of course, there are many scientific areas which need to expand. But in general, we have science which is needed to influence implementation and policies. We also have technologies, many technological solutions, which are necessary for implementation for clean air. What's needed are in particular policies and in particular regulations in relation to clean indoor air. We have policies regarding outdoor emissions, outdoor emission sources, be it emissions from vehicles, which we import from outside, power plants, industries and so on. We also have for outdoor air, we have air quality standards. For indoor air, we have only construction codes, national construction codes, which are not about the performance and emissions, but we don't have standards for air quality indoors. And that's what's desperately needed. And that's what our focus now is to explain that it's needed and also that it is possible to introduce standards like this because we have science and we have technologies.

Suman:

For someone who's watching this, thinking about air quality in their own home, in their workplace, what are some important things they can do today?

Lidia:

Well, the first most important thing is to realize that this is a problem. Even so you don't see pollutants in the air, well, if you see that that's a real problem, but even if you don't see pollutants, they are there. So understanding that pollutants could be there, that's the first important point. And then thinking in terms of where do they come from? Are you operating a source which is emitting them? So in indoor environment, well, we all cook. If we cook without a hood, so any emissions, whether from the fuels which we use for cooking or from the process of cooking, spread around the kitchen, around the home. So use a hood. But we also bring and deliberately introduce sources. For example, candles. Why do we use candles? There is a combustion source and we sit at the table and emit this. So thinking about this, what is a source and whether we need to operate this source. So it's very, very important. And the same, of course, applies to workplace, our offices or schools. Of course, the sources are different because we don't necessarily cook in our office. But we are the source, particularly if we share the office or meeting room with others. So we are the source. So thinking about ventilation, thinking about how to make sure that we are not affecting each other by our emissions or any source specific. So just be alert to potential sources. This is very important.

Suman:

Are there ways that people can understand what's in the air and things they can do about poor air?

Lidia:

Well, there are lots of ways. You can read about this and there's plenty literature about this. So there is no doubt about this. But there are also lots of small tools like monitors.

Lidia:

Buying a monitor, like, for example, a CO2 monitor, which you can have in the palm of your hand or in your handbag or in your pocket and just measure the concentrations of CO2, but also other pollutants. So this is one of the best ways to kind of start learning. And that's that aha moment. Oh, yes, really. It is this high here. Oh, it's lower here. That's very important as well.

Suman: 

And what about for parents or people that go to school and children? How do they make the air, indoor air quality inside a school or a childcare centre better and take this issue seriously?

Lidia:

Well, schools are a particularly difficult environment. One of the problems is that the majority of schools in Australia are naturally ventilated, which means they depend on opening windows. If the windows are closed because it's too cold, too hot, too noisy, too unsafe, or for any other reasons, there's basically no ventilation. If there's no ventilation, anything emitted in this environment, and these are emissions from children, from staff, but also emissions of the products. There are lots of products like art products, which emit pollutants. There's lots of dust brought to the schools. So understanding that that's the problem in this kind of environment is the starting point. But then parents influencing the schools to take active measures against this. So indeed, if you can open the window, open that window. But otherwise, there are other measures to lower the concentration of pollutant. And taking those measures is very important.