Episode Transcript
Stephenie Langston:
Hi everyone, thank you for joining us on today’s Knowledge Network session. Today we have Ralph Stewart. Ralph is a certified industrial hygienist and is a chemical hygiene officer. He has managed laboratory health and safety programs at Cornell and the University of Vermont. He is currently the Membership Chair of the Division of Chemical Health and Safety of the American Chemical Society.
He has previously served as CHAS program chair, the President of the Campus Consortium for Environmental Excellence and is on the editorial board for the Journal of Chemical Health and Safety. He has received numerous awards and has been named to the CSHEMA Hall of Fame. Ralph holds a bachelor’s degree in geology from Cornell University and a master’s in environmental engineering from the University of Vermont. Please, join me in welcoming Ralph as we begin our conversation on COVID-19 and classroom ventilation. Hi, Ralph.
Ralph Stuart:
Good morning. So, I’m going to talk about today some of the work we’ve been doing at Keene State College. I am the currently the Environmental Safety Manager and Chemical Hygiene Officer at Keene State, which is a small liberal arts college in the southwest corner of New Hampshire. We have about 3000 students, but the secret is that we have about 300 environmental, health, and safety majors in the undergraduate [program]. It’s one of the larger undergraduate health and safety majors in the country, and so I get to work with undergraduate students on very practical problems, and this is an interesting example of that opportunity. We have been looking at the ventilation of our classrooms on campus and trying to assess, how we can best assess COVID risk concerns associated with classrooms. And so, that’s what I’m going to go over today. The project started last fall. So, obviously COVID hit last spring. There was a lot of confusion, a lot of hesitation about exactly the best way to manage the situation. The fundamental challenge is that we have what would be considered a biosafety level three agent ubiquitous in the environment, now. The COVID virus is transmissible through respiration, and in the traditional laboratory setting anyway, that would be considered a BSL-3 agent. When I was at Cornell, we had about 4000 laboratories, we had about 1,500 bio laboratories, we had 12 BSL-3 laboratories. And there was a very significant difference between a standard biological laboratory and a BSL-3 laboratory, it has to be designed from the ground up to be a BSL-3 laboratory. And obviously, no campuses in the country (or in the world, probably) built their classrooms to be BSL-3 rooms. So, we began to think about how to manage this risk associated with COVID transmission, particularly in classrooms, given the architecture and the engineering that we have inherited from 100 years of campus operations. Fortunately, for me, in my work at Cornell, in addition to looking at BSL-3 laboratories, I looked at a wide variety of chemistry laboratories, all sorts of laboratories. Cornell has an extremely diverse group of science laboratories, and so, I got to see a lot of different settings, and my primary work at Cornell was to develop a control banding system for laboratories to identify which laboratories could handle higher level ventilations or routine level ventilations or specialized ventilations in order to conserve energy. So, the work I did at Cornell directly plays into the work I’m going to describe today. We are basically trying to divide our classrooms into three groups: well ventilated classrooms, moderately ventilated classrooms, and poorly ventilated classrooms. The reason we were doing this is, I think that Keene State followed pretty much what everybody else did in the country. The first thing we did when we came back for the fall is reduced the occupancy levels of our classrooms. We could reduce the occupancy levels to about 38% of what they were in 2019, in order to enable six-foot distancing between students in the classroom. We started investing in room air cleaners, HEPA filters that could be used to reduce the amount of particles in the air, and we began to think about our classroom scheduling practices. The idea of back-to-back-to-back-to-back classes in the same classroom raises concerns about the inability of some ventilation systems to clear the air between classes, so we decided to look at all those issues as part of this work.
Stephenie Langston:
From my own personal experience working in an academic setting as well as talking to colleagues, when COVID hit, just having data in general to go off to help you make decisions on “What do we need to reduce the class size to, what is the appropriate scenario for each kind of lab or classroom setting?”—that was something that I think people struggled with a lot, because typically, when we’re making judgments, as EH&S professionals, we’re gathering data, and if the data is not there (especially with COVID-19), that makes it extremely (I would say) exhausting to a point to do your job. So, I think this is a really interesting idea.
Ralph Stuart:
Well, that that’s one part of it. The other part of it is, that you may remember last year at this time there was a lot of speculation (scientifically, but also politically, but also technically, but also at the public level) in what the best approach to controlling the transmission of COVID was, and the advice that people generated depended and lot on what their personal expertise was. So, chemists, medical people, engineers, EHS professionals, and politicians all had different perspectives on the same question. So, there was a lot of conflicting advice going back and forth. So, what happened at Keene state, is we sort of gave up. We said, “Okay, we’re just not holding classes after spring break.” We closed down. I was teaching a class at that point. The whole second half of the semester we just did by zoom. It was a sudden change in the way I was teaching (obviously), given the classroom and zoom, and it was a real stressor for everybody. And then we took the summer to sort of think about what we had learned during the spring break, and these are the three key items we came up with: decreasing the occupancy, getting air cleaners in the rooms, and evaluating concerns about over-scheduling. So, as I said, there are many different technical perspectives on the question, and I come at it as a certified industrial hygienist. Industrial hygienists think about ventilation in a variety different ways. We recognize that ventilation systems are designed with competing interests in mind. Fundamentally, the standard approach to building a ventilation system is (number one) controlled temperature in the space. So, Ashray has its standards for comfort zones that you need to hit to have 80% of the population happy with the space they’re in, and they’re talking about temperature humidity restrictions. I think it’s 68 to 74, it’s a pretty narrow band, actually. So, tech ventilation systems are (number one) built to control that. Number two, they control odors. So, you have an occupied space. You have people breathing. You have people sweating. You have people working. They create odors, and the primary control around that is just to provide lots of air and dilute those orders away. And number three, since about 1990 all the ventilation designs have really focused on energy costs. So, there’s a competition between those values as a design engineer builds a particular building.
Stephenie Langston:
This may be jumping ahead, but in terms of COVID, in those three competing ideas, was there any one in particular that really pushed forward as “This is going to be more important as we address our COVID issues.”?
Ralph Stuart:
Yes, in a very complex way. So, the fundamental challenge that every campus faces is that it’s buildings are built over time. And every building is a unique story unto itself, and I think that was the challenge we faced in 2020. A lot of the advice that was coming out was based on your laboratory studies of a very specific scenario, or on very generic advice from the various authorities in the field. OSHA, Ashray, ACGIH all had advice coming out, but their advice was not specific enough to be actionable. So, like you said before, data is how you turn advice into action. Because of my experience at Cornell, I had a lot of experience in collecting the data about specific rooms, but very few campuses have that luxury. I also had the luxury of having a lot of free labor to help me do the work. I also have a little bit more time, because in addition to having ten faculty in the safety department, we also have a president who was a former faculty member in the safety department, so I was not put in the position of having to advocate for best practices when it came to COVID protection. The President was already committed to that as a safety professional. She recruited the Chair of the Safety Department to be her primary technical consultant. I was not the project manager. I know that many EHS offices were all of a sudden dumped on with many different responsibilities that they were not staffed for, that they were not technically prepared for, and so I was in a very luxurious position of being able to focus. Since I’m in the physical plant department at Keene State, I was able to focus on our buildings. I did not have to deal with student behavior issues. I do deal with PPE management for campus, but I had a very broad outline of how to do that. So, I did have time to really think about ventilation and move forward in what role that was. So, as I said, the ventilation system is built to control very specific things, it also does not control very specific things. Industrial hygienists spend a lot of time…the origins of industrial hygiene are in dusty environments. If you read some of the early literatures about dusty environments—it’s about silica dust, it’s about lead, it’s about enamel in factories that built bathtubs. So, we have a lot of interest and experience in dealing with particles in the air. The viruses are going to travel more like particles than they are like gas molecules. They are too big to act like gas molecules, and we know (industrial hygienists know) that particles generated in the room are not controlled by dilution ventilation. Direction in the air movement is as important as how much air is moving. And so, in general, it takes a BSL-3 laboratory design to actually think about putting engineers [there], to think about how particles move inside the space. It’s not part of the design process and, like I said, there’s no public spaces that are BSL-3. Well, there are in the hospitals, they do have BSL-3 style ventilation systems for specific rooms, but I think that was one of the high stress points last year at this time, that the hospitals did not have enough of those spaces to handle the patient volume they were facing.
Stephenie Langston:
I remember pictures of the medical technologist really having to gear up quite heavily in PPE at the time, because they’re working at just a clean bench, and that’s all they had access to in their hospitals.
Ralph Stuart:
Right, and the patient care situations too. They were putting infectious COVID patients in average rooms, and so the particle of the COVID… I remember a lot of pictures of patients who were garbed in PPE, not to protect the person, but to protect the people around them. And that was sort of one of the things that I don’t think many non-industrial hygienists appreciated about the situation, that the ventilation system was just not part of the solution. The other aspect of this from an industrial hygiene point of view is that ventilation practices have evolved a lot over the last 30 years because, as I said, since about 1990 we’ve been reducing the amount of fresh air supplied to spaces to control energy costs. And that has led to a lot of indoor air quality problems. Many industrial hygienists of my generation (I started as an industrial hygienist in 1985) spent 10 or 15 years just working through many, many, many indoor air quality problems in whatever organization that we were working with, [i.e.-] office spaces, laboratories, shops. People had concerns about odors, about symptoms, about a wide variety of things, and it took us a long time to develop a standard method for approaching indoor air quality problems. The good news at this point is that one of the key lessons we learned in that process was about communication. We had learned that we have to communicate with the occupants in an ongoing way. In a two-way format, we have to hear from them (what their concerns are). We have to explain to them how we can address those concerns, and sometimes we can address those concerns fairly simply by rearranging offices or identifying a source. Other times, we have to rebuild the building. I went through several adventures where we ended up rebuilding the building to address indoor air quality problems that presented significant concerns. So, just like every campus, Keene State has a mixture of legacy and modern ventilation systems. Keene State was established in 1909. We still have the original building on campus and we have a building from 2015. So, we have every possible ventilation system that you’ve seen over the last hundred years on campus, and we have to address each one in a very specific way.
Stephenie Langston:
Makes sense. I know the university I worked for previously, every time you walked into a building they had tips and tricks on how to understand the ventilation system and how the engineering controls in the building work differently depending on what year it was built. And it was always, “Okay, which building am I going to? Let me grab the checklist for that one in particular.”
Ralph Stuart:
So, over the summer, we began thinking through “How are we going to have an academic year under COVID?” Basically, this is the system we came up with a Keene State. I think it’s pretty common, with variations across the country. Our primary control is testing individuals to screen out infected individuals. All fall, we had everybody on campus (staff, faculty, students) tested once a week. Through November, it wasn’t too bad. We weren’t getting very many hits. In November hits started, a lot more people started testing positive. Primarily students, primarily students who lived off campus, because habits off campus are a little different than habits on campus. We delayed opening in the spring, because we were very concerned about the holiday season, so we closed down the classes at Thanksgiving. We didn’t open again until February 15, because we wanted to let the virus work its way through the population over the holidays. And now, this semester we are still testing faculty and staff once a week and we are testing students twice a week. Our numbers did go up for a while. They’re coming back down now. I forget what the most recent number is, but we are really focusing. Just like any good industrial hygienists, we have an industrial hygienist president. Just like any good industrial hygienists, our first priority is source control, so we are identifying people. We are supporting them through quarantine and isolation periods to continue participating in class virtually, but we are very focused on this idea of testing individuals and reducing the hazard that way. Our secondary control, as I said before, in classrooms we reduced capacities, so we have six-foot distancing between each student in class. As I walk through the classrooms or the hallways of our class buildings on a routine basis, just to see how people are complying with that, there is a lot of compliance with that. Many faculty are talking to themselves in front of the zoom screen because there’s only one or two (or maybe zero) [students]. The faculty can decide how many students they want in the room, as opposed to operating virtually, because there are a lot of faculty who are in risk groups that COVID is a concern for, so typical distancing is our secondary control. And then our tertiary control (a third level control) is mask wearing for near field exposures, so if you’re within six feet of somebody ventilation’s are not going to make any difference. There’s no way a ventilation system can capture any viruses that are within six feet of another person. That’s where we’re really focusing on mask wearing. And then for far field situations we’re thinking about ventilation supplying fresh air to a space, and cleaning the air that’s in the space already through HEPA filters air cleaning units. Again, my experience over the last year has been that there’s been a lot of confusion about the three different levels of control, how they interact with each other, how they work as a system, how they work in and of themselves. Each one has strengths and weaknesses, but depending on an individual’s personal, technical background, they might focus on one or the other of these. It’s been an interesting challenge at communication to help people understand how things connect with each other.
Stephenie Langston:
I imagine with these varying levels of expertise, and again this came up recently as well, it’s really taking an approach of, like you said before, you’re in a very lucky situation where you have very safety-conscious leadership at your university. But there are other EHS professionals who are having to reach out for the first time to their medical leaders, and they’re biosafety industrial hygienists having to work hand-in-hand with these other leaders to really put forth this team effort so that they can address all of these things in a reasonable and productive way.
Ralph Stuart:
I talked to colleagues on other campuses where the team approach was more of a challenge than an asset, and it’s something I think people have learned over time. But given the high stakes for everybody at both the individual level of not wanting to be sick and at the institutional level of wanting to stay in business, there are a lot of opinions about the best way to move forward, and this is what we’ve done at Keene State. It’s worked pretty well. Our numbers of infected students are much lower than for the other two campuses that I have classes going on at [within] the New Hampshire system. We also had the luxury of having a fairly small campus. I was pleasantly surprised when I got the Keene State that our buildings have been well maintained over the years. We still have buildings that are considered legacy buildings, but in general there’s been significant renovation to almost all of our buildings in the last 20 years and we have fairly modern systems. There’s a few buildings that don’t have that in place, but then most of our buildings [have] the net modern ventilation systems. So, the Swiss cheese model I showed in the previous slide alludes to the fact that there are holes in any particular layer of protection, and this particular slide starts to thinking about what are the holes in the ventilation layer. So, moving forward, we expect ongoing concerns around COVID for (we don’t know) years probably. Years that we’ll have to be considering COVID and that means that the ventilation system is going to need to be continuously evaluated for how it’s managing particles, in particular. And so, there’s three key concerns I’m aware of in the ventilation system. Number one, as I mentioned before, airborne particles moving differently than gases. Gases move by diffusion and in a fairly predictable way, and you can expect them to be well-mixed in a room. In general, when I do CO2 studies for occupancy in classrooms, I don’t see a lot of difference between one side of a classroom and the other. With particles, that’s not the case. I see that, depending on where the particle releases, very specific areas of the room will have many more particles than other areas of the room. So, that’s the number one challenge. So, related to that challenge, what we’re concerned about is super spreader events. So, some of the most famous super spreader events are situations where an infectious individual (who’s doesn’t know that they are infectious) is in a public setting that is upwind of other people, so the ventilation system has air blowing past the infectious individual to other individuals and in those situations you can have dozens of people become infected, particularly if they are there for a period of time (an hour or hour and a half if they were at dinner or something). So, in those situations infectious individuals may create or may be part of a super spreader event that the ventilation system helped make happen, just by the direction of the air movement in the room. Then the third possibility is that, if there is not a lot of air exchange in the room to move the virus particles, then the link of highest particles can stay in the air for a significant amount of time. It doesn’t appear that we know very much yet of what size virus particles are. The viruses themselves are pretty small, but they’re often attached to either liquid particles are solid particles and how the particles move can’t depend a lot on the size and the shape and all sorts of other aspects of the particle that it is attached to. So, there’s a lot of interesting questions, which until 2020 were theoretical questions, and now they’re very practical questions about how can the ventilation system can control particles in the air.
Stephenie Langston:
You’ve mentioned that we’re going to have to deal with COVID for quite some time, for a number of years. But I imagine that all of the data you’re collecting for COVID and classroom air quality also applies to other viruses, as well. I’ve had conversations where it’s much different than two years ago. If you had the flu, or onset of flu, some people still didn’t think twice about going into the office to work with the flu and not wearing any kind of mask or PPE, but now that’s really changed with COVID. You’re not allowed to come into work whatsoever with a fever or temperature and there’s a lot more restrictions when it comes to going into work sick. So, I imagine that this research that you’re doing is also going to apply to other viruses as well, in terms of how you deal with it, how you look at indoor air quality, and classroom ventilation (for quite some time), [and] for broader applications as well.
Ralph Stuart:
Yes, and that’s a really interesting challenge because design engineers have a very set specific set of criteria (which I described before), and if we add to that criteria infection control, that’s going to change a lot of things. It’s going to change a lot of budgets and a lot of timelines for installation of new systems. So, addressing those different concerns about the holes in the Swiss cheese, there’s three strategies I’m taking to assess those three hazards. Number one, trying to understand the direction of air movement in our classroom spaces, as well as the speed. So, I’m very specifically focusing on classrooms, because that’s our most public space where random people come and go the most. I haven’t done this kind of work in their dorms or our office spaces, because of (number one) time. I’ve been doing this for about five months for classrooms and I’m trying to develop a more streamlined approach for other spaces. But for now, we’re strictly focusing on classrooms. So, I have to figure out what direction air is moving in the classrooms, and again this is very specific not only to the building but also just each room within the building, because many buildings have different shaped classrooms. So, the shape of the classroom makes a big difference in the direction of the air moving in the classroom. Secondly, on the terms of super spreader concerns and infectious individuals, we try to minimize air turbulence. So, having turbulent air means that they particles in the air are going to move very unpredictably. They may move in a very specific direction towards a vulnerable target, or they may move in a very random direction and just spread across the whole classroom. So, if you have a person (who is infectious) who is sneezing in the classroom, depending on where they are within the directionality of the space, they may be a super spreader, they may not be a super spreader. Everybody may get it, nobody may get it. Then the third hole [is], we’re trying to provide clearance time between classes so that classrooms are not used back-to-back-to-back. In fact, we’ve established for the fall semester that we’re going to have an hour at lunch and an hour at dinner when classes will not be held at Keene State, just so we have a clearance time for all our classrooms. We’re providing HEPA filters, HEPA air cleaners, we have used ionization air cleaning technologies in a few spaces where we couldn’t use HEPA air cleaners, and I’m monitoring CO2 levels on a daily basis in our classroom buildings to identify potential problem areas. So, this is how we’re collecting the data, trying to convert it into useful information for upper management. We organize our buildings into poorly ventilated spaces, moderately ventilated spaces, and well ventilated spaces. Our well ventilated spaces (well, the top three) have all been renovated over the last 10 to 15 years. We have good control of the ventilation system, it can be immediately swapped out before we open classes, and we immediately swapped out to Merv 13 filters in the space. We left them in 100% fresh air as much as possible. The moderately ventilated spaces include older ventilation systems (or more modern ones). [For example,] the living/learning space is a 2015 building, but because it was built for LEAD standards it doesn’t have very much air going into it. So, it’s interesting that modern spaces have limitations on ventilation that are different than some slightly older spaces. And then we have the legacy buildings, the poorly ventilated buildings are the legacy buildings, and some of these are original and just had space heaters in the space, they didn’t even have a ventilation system. And so, those are the ones that we really focus on in terms of providing air cleaning and other strategies to.
Stephenie Langston:
It’s interesting (when you have just space heaters) how you’re going to have to pay attention to those areas much more, because to me that’s…Being from Florida, every building has an AC system and things like that, but I imagine in New Hampshire it’s not a requirement to have an A.C. system, it doesn’t get nearly as hot. I think my mind is kind of just thinking about all the things that you would have to do to make sure that that space is safe and clean, especially (I imagine) timing between when those classes started and ended was key as well, just to make sure that you had to clean and even just let things kind of settle a little bit.
Ralph Stuart:
Well, if you know down here, these two buildings are our legacy buildings and have no ventilation system. When the windows are open, they’re very well ventilated. And so, September and October last semester we have very few concerns about ventilation, but when you get to February/March, these two buildings go over to this column, because they have the windows closed to protect the building. You don’t want it to be 32 degrees inside the building. The radiators are really so old and clunky that you’re going to get to eighty-five, no matter what you do. So, every building has its own story (is the key point here), and you can see that I’m very fortunate and I have an assortment of about 15 buildings near that I’m focusing on. Most campuses, you’re looking at 75 to 100 buildings, if you’re talking just about classroom buildings. Add dorms and you can get up to the 200 building range for a larger campus. I’m not sure how I would approach this kind of work in those settings. I have ideas, but I don’t know exactly if it would work or not.
Stephenie Langston:
Yeah, and I think that was going to be one of my questions. Coming from a large university, it would be wonderful to have this this kind of information, especially timing-wise. [For example,] windows open it’s fine, and then windows closed it moves to this area. So, how would somebody who maybe comes from a university that doesn’t have any idea, how would you even begin to recommend they get started in gathering this kind of information?
Ralph Stuart:
So, when I was at Cornell, the group I was working with wrote three papers about the work that we were doing there. This was a control banding for chemical laboratories. We came up with a process based on a lot of research (both literature research and physical research in different rooms). We came up with a process of control banding that was based on three criteria. So, we would walk into a laboratory, we would look at the chemistry going in the laboratory (the intended chemistry). An organic lab is obviously very different from a biochemistry lab, and very different from an engineering lab. And so, you’re looking at the chemistry—what’s the chemical inventory? Do they have appropriate and adequate fume hood space, flammable storage cabinets, all that kind of stuff? So, you get a sense of the chemistry (number one), and if we felt that the chemistry was manageable, that was our first criteria. Second criteria was the shape of the room and the ventilation effectiveness. So, we basically did about 60 or 70 rooms, where we went in and did the CO2 testing. I just described in another paper and got a sense of how those of us who are doing the work intuitively develop a professional judgment about [whether a] room is likely to be effectively ventilated throughout or there may be dead spots in the room. That was really the question. And then, the third piece was housekeeping. Some laboratories are very strict about their housekeeping practices, and other laboratories not so much. And so, you can walk into a laboratory and in a minute and a half, identify housekeeping issues. Those three concerns helped us to determine “should this laboratory for chemical purposes have six air changes in an hour or eight air changes an hour?” What we found is that about 80% of the labs could have six air changes in an hour, but the 20% that needed eight air changes in an hour were totally unpredictable. We would be walking through a food sciences building and we will be saying, “Six, six, and six.” and then all sudden you walk into this room and there’s a faculty member who’s trying all sorts of new stuff with all sorts of weird chemistry, and he’s just totally different from everything else that is going on in the building and he needs eight air changes in an hour. What I learned is, you can’t just say, “Well this building is biology, it’s not going to be a problem.” There’s always a biologist who’s heavy duty into very exotic chemistry, and you have to visit their lab and get a sense of both the chemistry and the housekeeping and ventilation effectiveness of the space in order to make a determination. Now, in COVID world, we’re talking about particles not chemicals, we have to think about a different approach to this. This is the beginnings, this is the kind of research I was doing at Cornell for chemicals. This is the way I approach it at Keene State when it comes to particles in classrooms. So, that’s sort of where the inspiration for this work came from.
Stephenie Langston:
Okay, well maybe we’ll get to this later on, maybe I should save this question for later, but it’s on my mind now. With these buildings (we’ve talked about [how] the virus particles are very different than gas particles, they’d be centrally located to a certain area of the room, rather than evenly spread across) did you have any situations where you felt like you could better prepare faculty and things like that, where you could move desks or move even podiums where they were speaking? I didn’t know if you had approached that in any of these spaces as well.
Ralph Stuart:
We haven’t gotten to that level of detail yet at Keene State. We did run into a couple situations at Cornell where that specifically came up. It was based around air movement in laboratories that were surprises because the fume hoods were put in such a place that they sucked essentially all the air in their neighborhood into them, so there was an odor problem. They would say, “Well, it’s right next to the fume hood, it shouldn’t be a problem, right? The fume hood is capturing it.” The fume hood does not capture anything that’s not inside the fume hood very well. And so, we did some testing and we showed that the air movement in that particular laboratory essentially avoided the source of the odor, just because of the shape of the room and the way it was laid out. So, you’re one step ahead of me. It is interesting, as we do the work at Keene State, podiums do seem to make sense as the center point of the room, right? They do seem to be the center point of the ventilation system as well. How we’re responding to that actually is sort of in the next slide here. So, I mentioned we’re optimizing our class schedule by reviewing class occupancies and reducing back-to-back scheduling, but we also put out about 100 air filters. So, we have a universe of probably 75 to 80 classrooms on campus that we’re monitoring. I knew early last year, about this time the last year, that air cleaners were going to be important. They were also very scarce at that point, so we bought 50 of them for specific classrooms on campus, including the childcare center. We have a daycare center with (well, this year they’re running at half capacity), but with a lot of kids in there. So, they were a high priority for protection. We have a very active music department and they have a lot of spaces where they’re singing and playing. Obviously, they socially physically distance their practices and they’re outside as much as possible to practice, but we put a lot of air cleaners in their spaces. And then the naturally low ventilated buildings are places where we put the air cleaners. So, those were our top priority for the air cleaners to go in. Then over the fall semester break, we had had been able to get 50 more air cleaners. We put them into our other classrooms to control what particle accounts there. Again, this is similar to what I was explaining about the Cornell Chemistry Lab situation. [At] Keene State, the question is not what the airflow needs to be, but how many air cleaners do you need in the room. So, some of our classrooms have two, some have three, some have four. [You] can’t get more than four or you run into noise problems. So, we go and look at the room, we look at what’s available, how it might impact noise, and based on that we’ve deployed about 100 air filters into about 70 spaces. Fortunately for us, our two biggest classroom buildings are modern enough that they don’t really benefit from air cleaners. There are a few air cleaners in them on faculty request. So, as I said, faculty can request classroom air cleaners. I provide that. I go and look at the classroom, and if I think there’s value added, then I will provide an air cleaner for them. The data on whether air cleaners make a difference (from a risk point of view) when it comes to the COVID virus is not entirely clear, because HEPA filters are very good for cleaning air coming into a space, but the source of the problem is not the air coming in, it is the air that’s in there and if there’s an infectious individual. And so, if that infectious individual doesn’t happen to be next to an air cleaner, it may not make any difference to that hazard (the risk level) in that particular room. I mentioned [before], we do have some ionization units as well. The data on them is even less convincing, but there are certain situations, [such as] the music recital hall, [where] we just could not provide enough air cleaners. We put the ionization unit into the ventilation system to try to alleviate that [lack]. I haven’t seen a lot of data either in the literature or at Keene State that convinces me the ionization units are doing a lot for us. The system that’s developing now is based on air cleaners and spaces, and then the additional thing we’re doing is monitoring CO2 levels. So, CO2 tells us about the occupancy level, how many people are in the space relative to the amount of ventilation they’re getting in there, the amount of fresh air. You can see classes happen and the ventilation goes up. These particular rooms are about below 600 (which is pretty low). Anything over 1000 is when people start getting nervous about it, but the key point here is that these are the particle numbers for the same classrooms at the same time. To me, I don’t see a lot of correspondence between the number of particles in the space and the number of people in the space, they are not really well connected. We’ve been working the numbers, trying to figure out [if] there [is] a correlation between CO2 and particles. What’s the best way to measure the particles, given that we don’t know which of these particle sizes (so, this is 10 microns, five microns, two and a half microns) are most likely to contain a virus, an infectious particle? So how do we assess the risk associated with more people in the room if CO2 and particle size do not correspond to each other?
Stephenie Langston:
The thing that’s really interesting is that you still see an influx in the various particle sizes, even when there’s low occupancy in these classrooms. I can start to gather that in a research-controlled lab you could find a way to tag the virus and see how it traveled and things like that. In the classroom setting that is really not an option. So, I’m wondering if you have any guesses as to what would better tie to deciding how to measure these virus particles.
Ralph Stuart:
That’s the million dollar question, right there. We are planning on having students come back for fall semester full force. Whether we will able to maintain the testing program I described, given the financial requirements to maintain the testing program…So, right now, these particles (I’m pretty confident) are not infectious, because we don’t have infectious individuals on campus. When we know who they are, we get them off campus. If we don’t do testing of the population, [students] are potentially infectious. So, being in the classroom on [a certain] day [could be] a whole lot worse than being in the classroom on [a different] day. I don’t see patterns yet. If you compare classroom-to-classroom-to-classroom, you can see sort of common-sense patterns. For example, having air filters and air cleaners in a room will cut down the length of time for the particles to decay back to background by about a half. So, usually about an hour for a particle to return to the background (in general, it’s about a half hour). There are obviously lots of curlicues and disclaimers around this, but that’s what our preliminary data is showing, that we can get back to background quicker when we have air cleaners in the room. Which makes sense, but that data is very specific to the room and case, it’s not a principal yet.
Stephenie Langston:
This is kind of going back to that measurement. Given that the virus likely travels through aerosol or even on liquid particles (I think I’ve seen that research as well), would it be helpful to measure water vapor or things like that in the air as well?
Ralph Stuart:
That’s an interesting issue as well. I haven’t seen data, but there is speculation that COVID virus will survive longer in drier air. In New England, in the winter, our classrooms tend to be about 10% relative humidity. Between 5 and 10% because you’re taking outdoor air, heating it up, and delivering it at 70 degrees (when it was 20 degrees outside.) So, it’s very dry air, and the very dry air is where the people are (where the potentially infectious individual is,) so COVID may be happier there. Humidity is interesting, but it’s very hard to control. At UBM and at Cornell both, there’s a lot of concern about humidity control for animal rooms. It’s very difficult to do. I don’t know what the situation is in Florida, you can probably get up to 40% humidity in January; you can’t do that in Vermont or Ithica.
Stephenie Langston:
I think it’s 100% humidity all year round.
Ralph Stuart:
There’s a lot of moving variables here. I saw yesterday in the paper that there is a commercial product coming out to collect and analyze COVID particles in the environment. It was not a product yet, it was just a technology that’s in development and they didn’t mention any prices associated with it. I imagine the collection device may not be all that expensive, but I imagine the lab work is fairly expensive. I’m hoping that in the next year or two we have a lot of opportunity to explore these a lot further now that the value of this (both the science and the technical data) is much more clear to everybody.
Stephenie Langston:
What I’ve found really interesting, and I’ve noticed this trend throughout my career (especially at the beginning of my career), [is that] there was a lot of focus on translational medicine, getting benchwork. Your research focused on what kind of therapies or medicine (or something like that) you could develop from that bench research. But I’ve actually seen the shift, especially with COVID, back to just basic science research. Understanding the virus particle, the size, the shape, how it moves, and even things like measuring air quality—these are all basic science research, things that maybe don’t translate into medicine, but it does provide tools, and I think that’s a really important step for scientists and labs and even EH&S professionals. It’s great to get to the point where you have a lucrative drug that you can sell or something like that, but in order to get to that point and provide protection, you really these foundational pieces of knowledge to move forward. So, I think that that shift has been really interesting, and I think COVID really highlighted that for me in particular.
Ralph Stuart:
Well, that actually is a great example of that, right? I mean, without all the basic science that has been developed over the last decade, we would not have not delivered a vaccine in a year. It’s just amazing when you think about it from a scientific point of view, but in the vaccine case they still have the benefit of working with very specific cultures, medical culture [and] public health culture. The COVID situation in the field [includes] competing cultures, science culture, engineering culture, and public health culture. You have all these different groups, industrial hygienists and the EHS field in general, work with these field people in very specific ways, and all of a sudden they may not be comfortable or may not be used to working with each other. They gain comfort over time as they understand the limits of their personal expertise and how that impacts other people, but it’s really been fascinating to watch those cultural issues arise.
Stephenie Langston:
I’ve had several conversations with people who work in sustainability, and what I’ve seen is that sustainability is really still a relatively young career in terms of having a set of regulations or set policies to follow. Whereas safety is, to me, the foundation of how sustainability can build. I even talked about the risk matrix with a colleague who works in sustainability and he said, “Oh, this is a fantastic way to think about it going forward.” And, as you know, there’s a lot of tools that EH&S professionals have developed, and when you start tying in these [different] groups, you can really learn a lot from each other and how to approach [things], because there is a lot of wide-ranging knowledge [among] environmental, health and safety professionals. You have your bio safety professionals, you have your industrial hygienists, and they are typically used to working collaboratively (to a certain extent) to solve a problem. And so, I think it’s a great model of teamwork (when it works well), of how to solve a complex problem with varying levels of expertise.
Ralph Stuart:
The other challenge we’re seeing in 2020/2021 is the rush to press. With pre-prints, the Twitter-verse, the media scarfing up a sentence in a press release that’s out of context, there’s just the rush to try to proclaim something that (if you look at the data) is just not there. I think that’s something that a lot of people have not really…That’s an ongoing challenge.
Stephenie Langston:
I agree.
Ralph Stuart:
So, the closing slide I have…It’s important to remember that the ventilation requirement for any particular space depends on how the room is used. The classroom is very different from a lab, and very different from an office. So, there’s a lot of different ways you can approach a particular room. The challenge is, who has the resources to go room by room and come up with the best approach? At Keene State I’m very fortunate, I have a lot of resources relative to the number of rooms I have, and I have a lot of support. When I need specific equipment or something, I’ve gotten a lot of support from our upper management to get it (without asking much about cost). That’s not always the case. It’s very important to understand (this is the industrial hygienist in me coming out) the direction of the movement, as well as the speed. So, capture velocity is a vector, not a scaler. It’s not just how many and how fast, it’s where it’s moving. That means there’s no specific air change rate that is safe or unsafe. Ventilation is just one part of the overall system. You have to make sure in testing that physical distancing and masks are in place to provide protection, and I think that’s the challenge for Fall 2021, in general. Public schools, private schools, higher education, everybody is facing a Fall 2021 where the population may be wanting to revert to 2019, rather than to 2020, and that’s sort of the challenge we’re going to face.
Stephenie Langston:
Wanting to revert back to 2019, like you mentioned earlier, it’s not something that we’re likely going to be able to do for a number of years, especially when we’re just getting started with these vaccine rollout phases for everyone and making it more readily available. I had a question on the top of my mind and it just left me.
Ralph Stuart:
There’s that part of it, then there’s the public health part of it, where we’re seeing all these variations coming out, these variants on the virus. What we know so far is that there are differences in transmissibility. The vaccine seems to be pretty robust against the different variants, but the fact that there are differences in transmissibility and also the fact that the flu went away entirely this year. There was almost no flu, which means that our system in the field was working pretty well. All the standard transmission pathways were cut off pretty well, but COVID was still blossoming at that point. So, there’s something about COVID that’s different, and if it does come back to some kind of endemic background level it’s an ongoing stress for everybody.
Stephenie Langston:
I remembered where my question was going earlier, in terms of looking at these large-scale classroom buildings and approaching it in a more holistic process. I think you mentioned before that you have ideas on how you would tackle larger universities or larger classroom settings. I can envision putting together some kind of matrix where you’re looking at the ventilation system and how old it is and how well it’s functioning, and then testing various classrooms (maybe you pick a classroom on each floor), and then you also take something. SafetyStratus has clients that use this all the time—a risk assessment, that you can easily run data on and say, “Okay, I’m going to look at everything that this individual is using.” [Then] pull that data and start prioritizing from there, maybe targeting points of interest where you think that there may be higher concerns, where you’ll have more interaction between individuals. Maybe the research is different. They’re putting themselves in different situations, like you were saying with the organic chemistry versus biochemistry labs. [Then] creating this matrix that you can work through at your university to pick and choose which classrooms to focus on, and then trying to make broader assumptions based off those smaller observations.
Ralph Stuart:
I think the key is not to get over-anxious and try to do too much at once. We are going to have to wait for science to develop. What I’ve just been showing is fairly tentative, very specific to Keene State’s situation. It is only one part of Keene State, it’s only the classroom scene. It’s not the office scene, it’s not the dorm scene. And the classroom is probably the easiest of those three, because it’s the most well-defined. I have the schedule. I know when people are there. I know how many people are there. My experience at Cornell is that you can develop, like I said, a professional judgment by just wandering buildings, identifying when a building looks like one that requires more investigation, [while another] one is not a high priority. You can do that based on data. I know that other campuses have a lot more data available about their buildings and their ventilation system. It’s not always as easily interchangeable into the data as you need it to be, but there are ways to move forward with this. I think it’s going to be a year or two before the science is really there to tell us which is the most important. To me, the most important thing is getting some kind of relative magnitude of the importance of the different pathways. So, whether ventilation is most important, or whether it’s near-field exposure or far-field exposure or surface exposure or home exposure (because that’s a very different scenario as well.) Those seem to be the case (at least for our students), that home exposure is where it happens. It’s not in the public. When we find seven students that are infectious, it turns out that four of them probably lived together.
Stephenie Langston:
That makes sense, and I think we’ve seen that play out across the news numerous times, which is (I think) an interesting human experience research as well. Thank you so much for this presentation and for hopping on this call. I found the topic really interesting and, like you said, it’s going to be a few years before we have all the data. I’m curious to follow it and to see what other research you’re currently doing to get answers, because, like I said earlier in our call, I really do think that it’s going to be something that plays out for other practices as well. I think I’m more curious, when you’re talking about design of buildings, if infection control will start to play a heavier role in really putting environmentalist and safety professionals together to figure out a compromise of “How do we make our buildings energy efficient, but we keep our people safe at the same time?”
Thank you for joining us for this conversation and presentation.
If you have any more questions for Ralph Stuart, please email them to: ralph.stuart@keene.edu
