We can improve air quality simply and cheaply while we wait for standards to catch up with the evidence.
The ferocious bushfires of 2019 made PM2.5 a household term.
They introduced masks to Australian streets, and we started shutting our windows tight.
Then came the pandemic: more masks and, this time, windows were thrown open.
But in spite of these experiences and the work that’s come out of them, there are still no standards for indoor air quality.
“It’s much better now than it was before the pandemic,” physicist Professor Lidia Morawska told Allergy & Respiratory Republic.
Professor Morawska is world renowned for her work on air quality. She established and runs the International Laboratory for Air Quality and Health at the Queensland University of Technology, advises the WHO on air quality (winning a Planetary Health Award last year), holds a number of international positions and has won numerous awards.
She was prominent in the effort to make the WHO change its stance on covid transmission, which it insisted for two years was via droplet rather than airborne.
Waiting for standards to follow the evidence is frustrating, she said.
“If you remove the virus from the air, you won’t get infected. If I let go the pen which I’m holding in my hand, gravity will take it down. I don’t have to prove that all the time.
“In the future, what we hope is that it wouldn’t be the responsibility of individuals or individual organisations to resolve this. Buildings will be designed such that clean air will be provided like clean water is provided, but it will be some time yet.”
Last year, Professor Morawska and her colleagues published another paper on air quality, this time in Science on the lessons learned about indoor ventilation over the course of the covid pandemic.
“Governments are reading this, and there’s a lot of discussion. A lot is happening behind the scenes, but we hope that we will, in the course of this year, get to the other side in that sense that something’s going to happen and it’s not going to go back where it was”.
How do you know if your waiting room is a health risk?
While we wait for that to happen, there are simple things that will make a difference.
“Before buying anything else, buy a CO2 monitor. Until we know what the situation is, there is no point in starting action, because we don’t know if action is needed,” she says.
Everywhere she goes, Professor Morawska carries a little CO2 monitor in her handbag. It costs around $300.
“It’s a little thing which fits in the palm of my hand and it measures CO2 concentration,” she said.
Outdoors, CO2 makes up 400-500 parts per million. When there are people in an indoor space, that concentration is higher.
Using CO2 as a proxy for ventilation and infection transmission, researchers have worked out that indoor concentration shouldn’t be higher than 800 parts per million, based on a scenario of preventing infection in a classroom of 25 kids where one has covid and they’re in class for an hour.
“People emit CO2 during breathing,” said Professor Morawska. “Emission of CO2 will go hand in hand with emission of pathogens. If CO2 concentration is high, potentially there’s enough pathogens to get infected, particularly if you are spending a longer period of time in that space.”
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In a medical waiting room, where several people are likely to have an infection, and be more vulnerable, the concentration of CO2 should be lower.
“If you are sitting for an hour somewhere as a patient, or a medical person, sitting for the whole day in this environment, you simply inhale that stuff,” she said.
Ideally, you’re aiming for concentration levels as close as possible to the CO2 concentration in the air delivered to the space to begin with.
What can you do to fix high CO2 concentration?
If you’re lucky you’ll have windows that you can open, and the right conditions to do so, which will send CO2 concentrations down, said Professor Morawska.
If you’re in a mechanically ventilated building, chances are there might be appropriate ventilation, but it’s not set at the right level. In these buildings, windows can’t be opened. Air is brought in from outside, filtered and delivered to the spaces within the building, and partly recirculated. In theory, this should mean that you have clean air. But it might not be set to the number of people using the space.
“There’s a big difference between just a receptionist and one patient waiting, and 10 people waiting for a long time.
“So maybe what’s needed in a situation like this is to increase the delivery of clean air. And whoever operates the building should be asked that question.”
In some cases, this does not bring the concentration down, perhaps because the building was not well designed.
“The last resort in a situation like this is to buy an air purifier. There are lots of different designs, but we are talking here about filter-based air purifiers. This device filters the particles from human respiration containing pathogens, and also it’s a double benefit in case of air pollution from outside, in particular situations like bush fires.”
These do not put anything into the air, which can make the situation worse. They simply filter particles out of the air.
The best filters are the ones which are used, so noise levels are a consideration.
An online calculator is available to help work out what filtration you might need for the size of your room and the number of people in it.
We shouldn’t be dragging our feet
“The clock is ticking on this,” Professor Bronwyn King told delegates at the Immunisation Coalition Annual Scientific Meeting in Melbourne earlier this month.
“Pandemic preparedness is really important, and climate change is only getting worse. We’re going to see more fires, believe it or not, more floods, and so we need to make our buildings resilient to both.”
Last year she briefed the Prime Minister on the air quality issue, along with Professor Morawska, who she said was “widely regarded as the world’s best aerosol scientist”.
“She will soon win a Nobel Prize, I’m sure. Please remember her name. She’s brilliant. And we’re very, very lucky to have her here in Australia.”
Professor King practised as a radiation oncologist, but for the past 15 years she’s worked in sustainable finance, urging corporations to stop investing in, lending to and insuring tobacco companies. She said the systemic response to the covid pandemic and the smoke from the 2019-20 bushfires had to be around air quality.
“What many now regard as a real tragedy in public health globally [is] that the airborne nature of covid really wasn’t recognised or spoken about for quite some time,” she said.
Professor King pulled out her CO2 monitor which showed that the air quality of the conference room did not pass the test for safe levels.
“We’re working with a whole range of hotels across the world that have uplifted their indoor air quality, so it is possible.
“And it doesn’t have to be all super scientific. Here’s an air quality monitor for schools. And when the air quality is poor, the canary dies and you’ve got to open some doors and windows, and then he comes back to life.”
A right to safety and access
There isn’t data available on doctors’ waiting rooms, but we do know about hospitals. Right now, they are not safe in terms of air quality, Professor King told the meeting.
“We need to really come back to some basic principles like the Hippocratic Oath – do no harm. There is a charter for healthcare rights as a patient, and every patient has the right to be treated in a safe environment. I personally think we’re in breach of both of those principles at the moment, and we just need to return to the basics and really advance air quality and airborne protections in hospitals. And it won’t just be for covid. It will benefit every single airborne disease.”
Spaces with poor air quality made it difficult for vulnerable people and their families to access healthcare because the risk was too high, she said. It was also a work health and safety issue.
“I’m sure many of you know there’s a big group of doctors … in the UK currently suing the healthcare services where they work for acquiring diseases at work. I’m sure we’re going to see that throughout other parts of the world as well.”
In countries like Australia, we spend 90% of our time in shared indoor spaces, Professor King said.
“The good news is there are solutions. There are temporary, interim solutions, often very cheap, and then there are longer term solutions that we can look at to more comprehensively make sure our buildings are safe.”
