HAMILTON — As COVID-19, influenza, and RSV continue to infect Ontarians and strain our health-care system, the Ontario Society of Professional Engineers says cleaning the air is a critical step in reducing airborne illness and other harmful pollutants.
Health officials in Ontario, Canada, and beyond agree that ventilation is an important tool in reducing the spread of COVID-19.
In Spring 2022, the OSPE formed an advisory group on indoor-air quality: its members have expertise in such areas as ventilation, filtration, the use of ultraviolet light, air quality, occupational health and safety, and infectious diseases. Now, that group has published new guidance on creating safer indoor air, masking, and the spread of COVID-19.
TVO.org speaks with the advisory group’s chair, Toronto engineer Joey Fox — a specialist in heating, ventilation, and air-conditioning automation in schools — about why he thinks it’s important to monitor ventilation and what individuals can do to make spaces safer.
TVO.org: When did the advisory group form and why?
Joey Fox: June 3 is when they officially announced it, but it was created through the spring of 2022. The main reason is because of COVID-19, and now we see it with influenza and RSV — we need to address indoor-air quality if we’re going to move forward. It’s been this blind spot in the past few years that needs to be fixed if we’re going to move on.
TVO.org: If people look at these recommendations and think, “What do engineers have to do with fighting airborne infections?” — what would you say to that?
Fox: When it comes to airborne diseases, you care about the air you’re breathing and, specifically, indoor air. This has been an indoor pandemic. Outdoors spread happens, but it’s much lower-risk. When it comes to making sure your indoor air is safe, it’s the engineers who are supposed to design it. Ventilation is the main tool used to improve indoor-air quality, and that’s fully within the realm of engineering. So engineers need to be the ones to take the lead and explain how we should be using these tools in order to provide safe indoor environments.
Agenda segment, Nov. 18, 2022: What can Ontarians expect from COVID-19 this winter?
TVO.org: The recommendations that you’ve put together — who do you see them being for?
Fox: They’re for all public spaces. When people are out in public, they should be protected. They should be in safe environments. It’s an equity issue. It’s a health and safety issue. It’s a public-health and societal issue. Right now, really, the priorities are: Schools — we have a moral obligation to our kids to provide them with a safe environment. And we also need to address long-term care immediately. There are still tons of outbreaks. The failure to address indoor-air quality and mitigate the airborne spread of COVID in long-term care has had drastic effects on our society, and this can be dealt with. Those are really high priorities. Employers have a very good incentive to keep their employees healthy and very productive, so office environments are also places where it would be really good to have this initial focus.
Ventilation is the main tool used to improve indoor-air quality, and that’s fully within the realm of engineering.
TVO.org: Let’s look at some of the recommendations that the group’s put forward. One of the big ones was targeting six equivalent air changes per hour in occupied spaces. Can you break down what an equivalent air exchange is, and then we can talk about why six?
Fox: An air exchange is you take the amount of air and the volume of the room and you remove it and supply fresh air. That’s an air change. An equivalent one means it can also be done by filtering the air or it can be done by disinfecting the air (so the virus will still be in the air, but it won’t be able to infect people). If the room is 100 metres cubed, and you supply 100 metres cubed of air, that is non-infectious. So it’s been disinfected or all the viruses have been filtered out of it or you just supply outdoor air, fresh air — those are all different ways to provide an equivalent air exchange.
Ventilation has the best overall health benefits, but it’s also sometimes the most difficult to do. It’s the most expensive. The others are equally acceptable options.
TVO.org: And why the target of six air changes per hour?
Fox: There’s always the question: What should the value be? Six air exchanges per hour has been used for a very long time, going back through the U.S. Centers for Disease Control to what would be a good basic level for mitigation of airborne diseases. It’s also the standard in Canadian health-care systems.
TVO.org: Is that achievable, do you think, in most spaces?
Fox: Absolutely. It’s very achievable using the different tools that we’ve laid out. Whether it’s adding filtration (filtration is usually the easiest one to just upgrade) or a proper focus on ventilation and improving the system, those two ways are very achievable. Ultraviolet light is not a commonly used tool, but that also can help you achieve that.
TVO.org: I know you haven’t done a formal survey, but you know a lot about different buildings and, in your job, you go around different places. Do you think that a lot of public spaces are currently getting six air changes, or is that more something that we need to work toward?
Fox: We need to work toward it. There are buildings that have upgraded their ventilation, and it’s very possible they do have it. But, for the most part, we don’t know. That’s one of the reasons one of the recommendations is to monitor the carbon-dioxide levels so you will know how much ventilation you’re getting, and you can easily verify how much filtration you’re getting, so you’ll know what the targets are. As part of a societal push to improve indoor-air quality, we need to focus on the poor places, not the places that have really good air quality. The first step is knowing what the air quality is in different places.
Agenda segment, Nov. 11, 2022: Why are Ontario kids getting sick?
TVO.org: The second recommendation is for facility operators to bring buildings in line with ASHRAE [the American Society of Heating, Refrigerating and Air-Conditioning Engineers] and CSA Group standards. Could you explain a little bit more about what those mean and how commonly those are met?
Fox: So this is not specifically about protecting people from COVID or other airborne diseases. This is a general health issue. There are other pollutants in the air. A common one is called volatile organic compounds. These are different gases in the air that are bad to inhale. Usually, things that have strong chemical smells are volatile organic compounds, so ventilation is still needed to protect people. The necessity for our committee was really because of the pandemic and ensuring people have safe environments. You can see the drastic effect the pandemic had on our health-care system. But our goal was not to limit ourselves to that.
We wanted to make sure all aspects of indoor-air quality are dealt with. All the other pollutants need to be dealt with through ventilation. ASHRAE is the main society that sets these standards, and the building code references ASHRAE standards for what’s required for new construction. These standards are to deal with other pollutants. We recommend that places also have that safety level for all other pollutants, not just airborne diseases.
CBC Marketplace tested several portable HEPA units.
TVO.org: Let’s also talk about filtration. You recommend operators upgrade filters to MERV-13 or higher and use portable HEPA filters or DIY Corsi-Rosenthal boxes. The MERV-13 filter is a better filter for the ventilation system, right?
Fox: Right. In ventilation systems, usually we have lower-rated filters. They protect the equipment and the space from dust and larger particles. But when it comes to the smaller particles, which are more hazardous for people — and those include viruses — we don’t use filters to protect people. We don’t use filters for people’s health in general. So MERV-13 are better filters that do remove those tiny particles.
The COVID virus doesn’t just float by itself. It’s inside a respiratory particle. When you breathe out, you have respiratory particles that float in the air, and, if you’re infectious, they can contain live virus. When people breathe it in, that’s how they get infected. MERV-13 filters can remove them. HEPA filters are even more efficient at removing them.
TVO.org: With HEPA filters, I think most people would think of those boxes that take in the air and filter it. And then the Corsi-Rosenthal box is the do-it-yourself version of that, where you set up the fan and the filters?
Fox: Precisely. Fancy handling units in hospital settings can sometimes use HEPA filters, a type of filter that’s extremely efficient, but the vast majority of places can’t really use them inside the air-handling unit. But there are lots of portable devices and, of course, the boxes that are do-it-yourself. It generally outperforms all the portable HEPA filters, and it’s much cheaper.
The best resource I know of is Clean Air crew cleaning. They have a great page discussing how to how to build them and all the information you need. They use just a much bigger fan. They take up a lot more space, but it allows them to clean air at a higher rate, and the actual pieces of equipment are much cheaper.
TVO.org: Another one of the report recommendations involves UV technology. My understanding is that it’s newer. Is that the case?
Fox: No — there are different ways UV can be used. The way we’re recommending right now for widespread deployment has been used for 80 years. It has decades’ worth of research, but it’s still not being used in Canada. It’s extremely efficient technology. It reduced measles spread in schools by 75 per cent. It reduced influenza spread in a hospital by 90 pent. It was used in a hospital with COVID patients. And there was no transmission in rooms that used upper-room UV. These are fixtures on the wall, and they shine UV light into the room but make sure that it doesn’t shine down on people. It shines above everyone’s head into the upper room, and it’s able to disinfect air at a very high rate doing that.
A diagram illustraing upper-room UV in action. (Centers for Disease Control)
TVO.org: What would an upper-room space be in a school?
Fox: So, the ceiling heights in most commercial buildings are nine feet, or 2.7 metres, and people are usually under two metres high, so the upper room is above everyone’s head. That’s the area where you could shine UV light. Usually around seven to nine feet up high, or above two metres. The lower room is where all the people are, so the people stay unexposed in the lower room, and the upper room is what’s exposed to the UV light.
TVO.org: So it’s not a separate room; it’s just the upper room within whatever space people are in.
Fox: It’s the upper part of the room.
TVO.org: You said it’s not something that we use in Canada.
Fox: Correct. It’s partly people being unaware of it. And, at the beginning of the pandemic, there were a lot of these ultraviolet devices that hit the market. They weren’t regulated. A lot of UV is used in different ways. A lot of these devices weren’t necessarily safe (not the upper-room UV devices, as none of them really hit the market in Canada). So the government has decided to regulate it, which is good.
TVO.org: I want to ask you about some of those newer ones that hit the market during the pandemic. I bought a portable HEPA unit, and it’s got a UV setting. And I remember it was reviewed by CBC Marketplace, and one of the experts who looked at it said the UV is probably not doing anything.
Fox: These devices can be used in different ways. If you have a HEPA filter, the HEPA filter removes 99.95 per cent of particles. So do you need the UV for the other 0.05 per cent? That’s not helpful to use. Often, inside these units, you’re passing the air through it very quickly. Some companies make them and test them carefully to make sure that it is disinfecting, but sometimes the air just goes so quickly through. The UV light doesn’t have time to really disinfect the air.
And, a lot of the time, the UV light is not used to disinfect the air. It’s used in a different way, which puts particles out into the air. It causes a chemical reaction, and this actually can be bad for you. So, if you have a HEPA filter with UV light, it’s probably best to disable the UV part of it.
The Peterborough Public Library lends carbon-dioxide monitors out. (Peterborough Public Library)
TVO.org: You’ve mentioned a few times how important carbon-dioxide monitoring is. For people who are who are unfamiliar with it, this is the process by which you can measure how much carbon dioxide there is in a space, and that gives you an idea as to how good the ventilation is?
Fox: Carbon dioxide comes from people. We breathe it out. There’s carbon dioxide in the atmosphere, but we breathe it out at a much higher concentration. If you have a poorly ventilated space, the carbon-dioxide levels will rise and increase, and you’ll be sharing more air. Carbon dioxide can pretty much tell you how much percentage of air you are breathing comes from someone else, how much of your air is backwash. We don’t drink from other people’s glasses and drink their backwash, but we do share air with other people. The better the ventilation, the more of this carbon dioxide is removed from the space and the more fresh outdoor air you will be breathing in.
TVO.org: And using that information can give you a better idea of what measures you should be applying or improving?
Fox: Right. There are many different ways to use carbon-dioxide monitoring. If you want to achieve a certain level of protection for people — let’s say six equivalent air changes per hour — some of that has to come from ventilation. To know how much is coming from ventilation, you should be monitoring the carbon dioxide. Ongoing monitoring can ensure the equipment is running properly. Carbon-dioxide monitoring can tell you if there are any issues that need to be addressed.
TVO.org: Do you see a world where, as we are already measuring humidity and temperature, we also start monitoring carbon dioxide?
Fox: Absolutely. Especially, again, focusing primarily on schools to ensure our kids are in a healthy environment and on long-term care, to make sure they’re safe. Knowing the carbon-dioxide levels would be the first step in providing a safe environment.
TVO.org: In addition to putting out these recommendations, you also released some guidance on COVID-19 transmission and about masking. Now that, once again, health officials have been making so-called strong recommendations on masking in indoor public spaces, what do people need to remember?
Fox: Recommendations still don’t clearly state that respirators are the proper choice to be used when you’re masking. COVID is an airborne disease. Respirators are designed to protect you from airborne diseases. Surgical masks are not, and cloth masks aren’t either. Wearing these masks at the beginning of the pandemic was understandable, because we didn’t have the respirators available. We now have many high-quality Canadian-manufactured respirators that are available. If we’re going to learn to live with this, and people want to protect themselves by masking, they should be using the appropriate face covering for that.
Peterborough's medical officer of health recommends higher-quality masks in a March 2022 video.
TVO.org: We discussed the importance of monitoring and actually checking to see how well air-quality measures are working. How important is it that it’s not just facility operators, but also occupants in a building who know about their air quality?
Fox: It’s unfortunate, because it shouldn’t be occupants. People shouldn’t need to advocate for themselves. People shouldn’t need to worry. When you go to a restaurant, you don’t worry about the water you’re drinking. People shouldn’t need to worry about the air they’re breathing. However, people generally don’t know, and we’ve kind of worked on the honour system, which has not been successful. Having more public knowledge about this, public displays of carbon-dioxide levels so people can see what the air they’re breathing is like — this is an important step moving forward as a society.
The first step is knowing what the air quality is in different places.
TVO.org: A lot of people who are reading this might be preparing to do some hosting for holiday parties. Are these recommendations the sort of things that individuals can try to apply to private spaces, such as their homes, when they’re trying to keep people safe?
Fox: Yeah. Homes generally don’t have good levels of mechanical ventilation. The best tools you have are windows and HEPA filters. So open up your windows as much as possible — even just cracking them open can help. But the more they’re open, the better. And HEPA filters can just be placed throughout the space to clean the air. Those are the two most effective tools you have at home.
TVO.org: What’s next for the advisory group?
Fox: We put out our core recommendations. There’s a much more detailed document that will be coming out. We haven’t dealt with all aspects of indoor-air quality, but we intend to deal with many more just to provide comprehensive guidance. There will be a longer document that we will be publishing in the future.
Agenda segment, Nov. 23, 2022: Can Canada's health-care system survive the next crisis?
TVO.org: Was there anything that we didn’t talk about or that you wanted to add?
Fox: One of the recommendations is to avoid the use of additive air cleaners. There are a lot of these technologies on the market. A lot of companies are able to make claims, and it’s not necessarily backed up by the evidence as being safe and effective. I know some schools are using these technologies. There are plans now to possibly implement them in different public spaces, including transportation. We need to avoid using these. We need to focus on what works, which is ventilation (bringing outdoor air), filtration (passing the air through a filter to remove the particles), and UV to disinfect the air. We should be avoiding all these additive technologies.
TVO.org: That’s because they may be less proven or not known to be safe?
Fox: Correct. It’s both. A lot of the time, they do experiments in smaller chambers, and when it actually comes to applying it to the real world, the evidence isn’t there for them being effective. When you put different chemicals or radicals out into the space, it can create by-products. So there are safety concerns about some of these technologies.
If we want to try to make the most of this, we should be focusing on things that we know work and that we know are safe. There continues to be this lack of understanding about how COVID spreads and how we need to shape our society to allow people to forget about this, move on, and not have to worry. We’re still not there yet.
This interview has been condensed and edited for length and clarity.
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