Jill:

This is the Accidental Safety Pro brought to you by HSI. This episode was recorded June 9th, 2021. My name is Jill James, HSI's Chief Safety Officer, and today I'm joined by Dr. Rachael Jones, who is an associate professor in the Department of Family and Preventive Medicine at the University of Utah School of Medicine, and she's also the Director of the Industrial Hygiene Program. Rachael is also Chief Editor of the Annals of Work Exposures and Health, the Journal of British Occupational Hygiene Society. Rachael joins us today from her home in Salt Lake City, Utah. Welcome to the Accidental Safety Pro, Rachael.

Rachael:

Thank you, Jill. It's really a pleasure to be here today.

Jill:

You have such a deep history, work history that is, and I am so excited to dig into many pieces of it. Well, however, if you don't mind, starting from the beginning as to how you got into this field of practice, I would love to hear your story.

Rachael:

Okay, I'm happy to talk about that, Jill. I actually first met an industrial hygienist when I was working at a refinery near my hometown in Northwestern Washington, and I had ... After finishing college at the University of Washington, I wasn't really sure what to do with my career. I had expected to probably go to medical school, but I wasn't ready yet, and so I actually moved to Taipei, Taiwan, and worked as a English language teacher there for several years, and traveled around East Asia. When I decided to come home, I didn't really have any money, so I moved in with my mother who was generous enough to take me back in, and I got a job at the local oil refinery working as a laboratory technician. I was doing product testing and quality control.

Jill:

What was your bachelor's degree in [inaudible 00:02:14] that door opened for you?

Rachael:

Well, I actually had a major in biology and a minor in Chemistry. I guess I was qualified. When I was looking around for jobs at that time in the late '90s in the area, there just weren't very many job seeking degrees in science. They ended up hiring, at the same time, there were four of us who were hired, people with degrees in chemistry or biology or previous experience. They'd hired four women at the same time.

Jill:

Wow. That's remarkable in and of itself, right? Four women in science? That's awesome.

Rachael:

Yeah. It was a really nice lab group at the refinery, and I enjoyed my time working there. But when I was hired, we were hired off cycle of all of the other refinery operators. The industrial hygienists had to meet with us to do respirator fit testing and the non-standard timing. The hygienist was very new to a job, and he had just finished his degree and was just starting out. I'll never forget, this is such an odd experience. He took my coworker and I into the bathroom of a trailer that was on the refinery property to do the ... I think it was a Bitrex respirator fit test, and the whole thing was just so strange being in this tiny little bathroom.

Jill:

Wow.

Rachael:

That was the first time I met a hygienist, and I got to know the hygienist a little bit and learned about the field. I ended up working at that refinery for about six to nine months, and then I decided to move to California and I got a job with the same company at their refinery in the Bay Area. I worked there for about a year, and I also got to know the hygienist at that job and he actually was my neighbor. We were both living in San Francisco at the time. I thought, well, this seems like a career I could do. It has science and technology, but it's also about people and helping organizations be successful. I decided to apply to the graduate school at the University of California, Berkeley to get my master's degree. My plan, at that point, was just to get the master's degree and go back to work as a hygienist. I found the refining industry really fascinating. A good friend of mine was a chemical engineer for another refining company, and I just thought that the industry was really interesting.

Jill:

What do you think about it? What do you think it was for you then that lit that spark?

Rachael:

Well, I was just looking for a new career. I knew I wanted to go to graduate school, I didn't want to work in a laboratory for my whole life. I was looking at maybe going back and doing chemical engineering as another bachelor's degree. At that time, I had pretty much decided I didn't want to be a physician, so I didn't want to go to medical school. I was looking for something that was science oriented and health oriented, and really made a difference for people.

Jill:

People, yeah.

Rachael:

That's why I ended up choosing this. There also was a lot of financial support to get the graduate degree. At UC Berkeley, they have a NIOSH Education and Research Center. We also have one of those centers here at the University of Utah. They provided a lot of financial support to go to school.

Jill:

Even better.

Rachael:

Yeah. It made it much more feasible and less stressful with that support. But when I started school, I was really enjoying it, and I started working with a couple of faculty members. For my summer internship, after my first year, I ended up working on a project with my faculty mentor, Mark Nicas, with the California Department of Occupational Health. They have a group there called HESIS, the Hazard Evaluation Service and Information System, and that group at the time was led by Julia [Kuit 00:06:34], who unfortunately has passed away. But they have a mission of identifying emerging hazards to occupational health in the State of California and communicating the those hazards to workers and employers.

Jill:

Wow.

Rachael:

They create a lot of hazard alerts. But they were struggling because they didn't actually have a system in place to identify where the hazards were in use. For example, if there's a emerging chemical threat, like there was a concern for a period of time about n-hexane exposure in aerosol petroleum solvents used in automotive repair, because it was ... There was also acetone in these projects, and there was an outbreak of peripheral neuropathy at the time, and they were discovering that it was a synergistic effect that the acetone potentiates the effect of n-hexane. Well, you can find auto shops, that's maybe not the best example.

Jill:

Right, right.

Rachael:

Because it's business listing. But you can imagine that these products might be used in many other industries that you're not really fully aware of. The state asked Mark and I to figure out a system by which they could actually collect information and identify employers and work sites where a certain chemical might be used. I did a small study investigating how other states and the federal government and various laws and regulations exist that enabled tracking of chemical use, and I wrote a report for the state, which was actually used to propose a bill, which-

Jill:

Wow.

Rachael:

... would have implemented one of these policies. Unfortunately, the bill was not successful. But some of the work that I did, I'm part of that project, was used by others to write a bill to motivate further research and education around green chemistry in the State of California, and that bill was successful and led to the formation of the Green Chemistry Center at the University of California.

Jill:

Wow. Congratulations. Thank you. You're a detective. You're a scientist obviously, and data is your thing. But it sounds like detective work, right? I mean you're really digging into this.

Rachael:

Yeah, that was totally-

Jill:

Wow.

Rachael:

... detective work on that project, and I cannot take any credit for the Green Chemistry work. That was really spearheaded by Michael Wilson. But it was really exciting, and I got really interested in the idea of doing research and doing things that could make change through legislation or regulation. I decided that I wanted to stay and do a PhD. It also really helped that I liked working a lot with Mark Nicas, and I knew that he would be a great mentor for me for the rest of my studies.

Jill:

Well, it's so fun when you can find a mentor that you can work professional magic with. There's nothing better than that. Right? How fulfilling is that?

Rachael:

Yeah, it's really great. Yeah. When I started my PhD, I actually really wanted to work with low wage workers, and it just wasn't seeming very feasible at the time, and there was this new thing coming out about hazard banding. Well, it's now called hazard banding. At the time, they were thinking about control banding. There were some schemes coming out of Europe and the UK that were looking at ways to estimate exposures and recommend controls with little to no monitoring data. Because I think it's more widely recognized in industrial hygiene practice now, or we acknowledge it more, that we make most of our decisions without actually measuring exposures. The cost of measuring exposures can be quite prohibitive and requires an expert. Many small employers don't have access to that. These tools were being developed to help serve that community of workers and employers.

Jill:

Fascinating.

Rachael:

NIOSH was getting involved with that, and I found it really fascinating. I decided to initiate a little study with existing data that had been collected by NIOSH and were publicly available to evaluate the control banding tools with these data for a couple of tasks. One was bag filling and the other was vapor degreasing. It was really interesting. Mark Nicas didn't love that I was studying this because he didn't think was very quantitative enough. But I found it really fascinating, and it let me meet a lot of people. In fact, the first time I ever spoke at a conference, I got invited to this conference, I think was sponsored by NIOSH. It was in Washington, D.C.. It was my first trip to Washington, D.C..

Jill:

Wow.

Rachael:

I think I was a second year PhD student. I met this little conference there. It's all a small group and I felt so cool.

Jill:

Oh my God. I was just going to say did you feel cool or was it daunting, or ... were your knees shaking? How does this work?

Rachael:

Totally nerve-racking. [crosstalk 00:11:57] I had written out my whole speech, and I was just terrified. I had written it out word for word, and I got up in front of this room of ... It wasn't a big group, maybe 50 to 70 people, and I read my speech word for word and my knees were shaking. My hand was holding the paper was shaking.

Jill:

How was it received?

Rachael:

But nobody booed me, and I think it was received well and I think people were very understanding of the fact that I was still early on in my studies and this was my first experience. Yeah, I think it went pretty well, but I was pretty terrified.

Jill:

Yeah. Isn't that crazy? I think the most intimidated I've ever been at a speaking engagement was I was invited to speak at the Mayo Clinic. I'm from Minnesota, and my co-workers and I were invited to do this presentation at Mayo. I think about it's the world renowned Mayo Clinic, and just walking into one of their conference settings is like, "Oh, my gosh, think about all the people who've spoken here before, and I'm a 20-something-year-old punk. How did I get in this space?" I remember very little other than the setting and the weight of the room because of the history that it had.

Rachael:

Yeah. Yeah. Yeah.

Jill:

[crosstalk 00:13:35]

Rachael:

Now to think about it, I probably would do very limited preparation for a talk like that these days. It becomes second nature and you don't even think about it as very anxiety producing or intimidating at all.

Jill:

Right, because it's your craft and it's muscle memory, and oh, my gosh. Yeah.

Rachael:

Yeah, absolutely. Well, yeah, after I was studying that, it was control banning things, I had an opportunity to actually get involved in a new area called quantitative microbial risk assessment. Mark was part of this center that included a number of universities across the country called the Center for Advancing Microbial Risk Assessment, and it was led by Joan Rose, who's a professor at Michigan State University, and Charles Haas, who's a professor at Drexel University, and it included the University of California, Berkeley, investigators at the University of Arizona and University of Michigan. It was really exciting for me because it was a new area and it was the first time I participated in something that was so interdisciplinary and across many universities.

Part of the project that we were working on at Berkeley was trying to extend a mathematical modeling technique that Mark Nicas had been working on, that describes the transport of contaminants through the air. We were trying to expand the theory of that model to do three dimensional transport of particulates, and then apply it to the transmission of infectious diseases. Quantitative microbial risk assessment is similar in framework to chemical risk assessment, but it's really focused on the exposure that people experience to pathogens and then the likelihood that they're going to get an infection or other subsequent illness from their infection.

Jill:

For our audience who's listening to this now, yes, this is foreshadowing, for the year that has been 2020 and 2021. But yes, please continue.

Rachael:

You probably don't remember this, but at the time in [inaudible 00:16:00] I say, 2005, 2006, there was this well-known case, it made a lot of headlines because I think people hadn't really thought this happened anymore. But there was this case where there was actually a CDC employee with active pulmonary tuberculosis who had been flying around Europe on airplanes as a passenger.

Jill:

Well, no, I do not remember this. I wish I could say I did. Gosh. Okay.

Rachael:

Well, it is a footnote in the history of QMRA. Our center decided that we would model this and determine how likely it was, because at the time, and I think this is still the policy, that if you have a patient with an infectious disease like TB, who's traveling on an airplane, the CDC policy is to notify the passengers that are within three rows of the infected person, and tell them that they may have been exposed and to seek follow-up medical care. There was a question of why three rows? Airplanes are really complicated and there's people moving around. This incident actually spurred a lot of research about particulate transport in airplanes, including work that was funded by the Federal Aviation Administration. It became this whole area of specialization because the airflow is super complicated. In our analysis, we used a relatively simple model and found that you are at highest risk when you're within three rows, but that there is risk at other spots in the airplane and-

Jill:

Depending on how the air is moving, I suppose?

Rachael:

Yeah, and depending on how the passengers move around. There's been much more sophisticated work looking at contact sequences and turbulent jets formed by people walking down the aisle way, and how that disrupts the overall airflow in the airplane. The airplanes are really fascinating and complicated environments. But yes, you can get outbreaks of a number of infectious diseases in airplanes, not just tuberculosis and influenza, but also norovirus outbreaks. They're working on procedures to try to make materials in airplanes easier to clean or more likely to cause the pathogens to lose infectivity as well. Anyway, it was my dissertation research, was about this modeling work and I did these particle transport experiments, which I always tell my students that, when we're doing similar experiments now, that I understand. I can empathize with their suffering.

Jill:

I can't imagine. I am so grateful for this work already. I'm just thinking, gosh, I feel like I'm ... This is going to make my first plane ride post-COVID so much more interesting having had this conversation. Or terrifying, I'm not sure yet. Yeah.

Rachael:

Yeah. Well, after graduating, I moved to Chicago and was a postdoctoral fellow at the University of Illinois Chicago School of Public Health for a couple of years, and then became an assistant professor there. One of the first big projects that I worked on actually was related to infectious diseases. Because OSHA at the time was working on developing an infectious diseases standard, and this standard has since been put on hold, but hopefully will be revived soon.

Jill:

Right. How many years ago was this, Rachael, about?

Rachael:

In around 2010.

Jill:

Yeah, okay.

Rachael:

2010 to 2013. By the time I came on board, OSHA had been working on the standard for about a decade.

Jill:

Yeah. Every once in a while, which is all the time, people say, "How do I keep up with all this OSHA stuff? Everything changes so fast." Right. Okay.

Rachael:

It takes a long time to develop and promulgate a standard at OSHA.

Jill:

That's right. That's right. That's right.

Rachael:

It's a very complicated process, both from the administrative political side, but also from the scientific side and assembling-

Jill:

Yes.

Rachael:

... the evidence that there's a need for the regulation, to demonstrate that the regulation will have a beneficial impact or what the range of possible impacts are, and then to get feedback and insight from all the stakeholders. It's an immensely complex process, and I admire the OSHA personnel with the dedication to carry-

Jill:

[crosstalk 00:21:01] yeah.

Rachael:

... forward and move these things forward over the years, because my attention span is certainly not that long. [inaudible 00:21:07]

Jill:

It's awesome. Rachael, before you continue with this part of the story, for anyone who's listening who may not be in NIH or maybe new to safety, you said in infectious agents. Would you mind defining infectious agent, put it in the context of workplace safety for the listening audience?

Rachael:

Absolutely. An infectious agent, in a general sense, would be anything that's capable of causing an infection in a susceptible person. Classically, that would be a virus or a bacteria. I think the most studied infectious agents from an occupational health perspective had been bloodborne pathogens, like hepatitis and HIV, which motivated the Bloodborne Pathogens Standard at OSHA. I would say, also, tuberculosis has been widely recognized as a problem for healthcare workers. But now there's a recognition that there are many other pathogens, both endemic pathogens, like seasonal influenza or rhinovirus that occur regularly throughout the population from year to year, but also from emerging pathogens like COVID or SARS-CoV-2 would be the pathogen, COVID-19, the disease, or Ebola virus. It'd be another example of a emerging pathogen that poses a risk for healthcare workers.

Jill:

And other workers depending on ... Well, as we've seen in the last year, depending on exposures. Yeah, yeah.

Rachael:

Absolutely. My work has been focused on health care workers. But yeah, any workers who come into contact with these agents, whether it's because they are potentially serving individuals in a grocery store or restaurant, or even working in water treatment plants, where you might get sewage material that's contaminated with infectious organisms. There's a lot of different setting where people encounter pathogens.

Jill:

Thank you. Thank you for that. I appreciate it. Yeah. So you're in Illinois?

Rachael:

I'm in Illinois. Yeah.

Jill:

[crosstalk 00:23:23]

Rachael:

The infectious diseases standard is a programmatic standard that would require ... It's focused on the healthcare sector, but that's very broadly defined in the proposed standard or the draft language. What I was asked to do, because I had been working in this area of exposure modeling and quantitative microbial risk assessment, was to help support that cost benefit analysis. Because we don't really track a lot of common infectious diseases among healthcare workers, and so we don't really know how many infections are really work related. For example, if you're a nurse or a teacher, or anyone who works with people, you have some risk of getting infected from influenza, for example, just because you're going about your normal daily life, and you're in contact with family and friends and people in the community, but you also encounter people with this disease in your work, right?

A sick patient or a sick child. Because the disease is so common, it's really hard to know if any particular incident of infection is because of work or because of home and personal life. We don't really track things like flu or norovirus very much in workers. We decided to approach this with modeling. We had this task to accomplish, and that was to estimate the current burden and the burden that would likely occur if the regulation became law, if the proposed language became law. We used a quantitative microbial risk assessment approach, and we were tasked to consider a wide variety of different infectious diseases, including influenza, tuberculosis, and norovirus, infections from methicillin resistant, Staphylococcus aureus, vaccinia.

We have this long list. We've published a couple of the studies in the peer-reviewed literature focused on influenza and tuberculosis. But it was a really fascinating study because we had to figure out not only ... To figure out how many workers get sick, you have to figure out how many times a worker is exposed. Then you have to know [crosstalk 00:25:49] how many people in the public are sick, and how many of them actually seek health care, and what kinds of health care do they seek? When they go to seek health care, who do they encounter that they might expose? Right? Because if you go to see your primary care provider, for example, you interact with the receptionist, the medical assistant, the primary care provider who might come in and out of your room a couple of times, and then maybe you get sent to the laboratory or the pharmacy or whatever.

You could quickly, with one sick patient, result in a number of potential exposure opportunities for healthcare workers. We tabulated how many exposures they have, then we tried to figure out what is actually the magnitude of exposure or risk of infection from each of these individual exposures, and then we aggregated that to a national annual level. I worked very closely with one of my former students on this project, [Yu Lin Zhu 00:26:52], and it was really fascinating. But we found out that there's a lot about these processes that we really don't know, both in terms of how you figure out how many exposures there are, but also in the process of trying to describe how the exposure occurs and quantitatively characterize that exposure.

Jill:

Then, like you said, you have to compare this to what would happen in non-work settings so you know where the risk is the highest? [crosstalk 00:27:25]

Rachael:

Well, we were very ... One of the things about risk assessment that's nice is that you're looking at a very specific exposure scenario. All of the estimates and analysis that you're doing are really focused just on the workplace in this category.

Jill:

Got it. Okay.

Rachael:

We found, for example, that the kind of incidents that you would expect for influenza among healthcare workers in acute care facilities was about equivalent to the incidents that is observed in the general population, suggesting that they experienced about twice the average risk for getting influenza. Yeah.

Jill:

Then you did that for a whole myriad of infectious diseases?

Rachael:

Yeah, a myriad of infectious diseases.

Jill:

Oh, my God.

Rachael:

It took us three years.

Jill:

I was going to say how long did this take it? Yeah, okay.

Rachael:

It took about three years of Yu Lin working nearly full time and me part time to try to get this done. We submitted this giant report to OSHA along the way. Then we have published some of the work. Now, some diseases, actually, we couldn't really do a risk analysis for because a key element was missing, and that was the dose response function. The dose response function describes the probability that you're going to get an infection given a certain dose. For example, if you inhale 10 viruses, the probability that you get infected might be 20%, or 0.2. If you inhaled 50 viruses, it might be 0.6. For those, the dose response function is actually really difficult to obtain because for a lot of pathogens, we don't want to expose people to the organism just to figure this out.

Jill:

[crosstalk 00:29:23]

Rachael:

They do studies in animals, and then you wonder, okay, well, do people really respond like the monkey or-

Jill:

The same, yeah.

Rachael:

... the ferret or the mouse? Right, in the same way? Then it's not really convenient to expose animals in exactly the same way that people experience exposures. You can make an animal inhale an aerosol. Okay, that works pretty well. But one of the other key routes that we're concerned about is contact transmission, and that's when you would get something on your hands, for example, and touch it to your face. Well, that's really hard to reproduce in an animal.

Jill:

Sure.

Rachael:

Or even droplet spray exposure, which is the event that somebody coughs and sneezes large particle right on to you. Again, not all animals with a disease that causes coughing in human will cough, and then even if they do cough, is it really like a human's cough? There's a lot of gaps in our knowledge with respect to dose response functions, and that's actually been a bit of a struggle with COVID. Although, my understanding is that they are beginning some human studies with COVID-19. That will be very interesting.

Jill:

Wow. Okay.

Rachael:

Yeah. Yeah.

Jill:

Wow. Okay. It's interesting.

Rachael:

Yeah. Yeah. The COVID human studies, I think, are more oriented to better understand vaccination and vaccine related immunity rather-

Jill:

Sure.

Rachael:

... than infectivity. But about five years ago, there was an initiative to do human infectivity studies with influenza, and this work was all done in the UK. But unfortunately for the investigators, none of the people got sick. Fortunate for the parti-

Jill:

But not for the science.

Rachael:

But not for the science.

Jill:

Oh man. Who signs up for that gig?

Rachael:

Well, it turns out that people will do quite a bit of things for compensation, right? You can get incentives. There have been quite a number of studies trying to figure out the infectivity of norovirus. In these studies, they'll have human participants who agree to drink a glass of water containing norovirus in some concentration.

Jill:

Man. No, thank you.

Rachael:

Right, and then potentially experience acute gastroenteritis for a couple of days. I think the compensation is on the order of $1,000 to participate in a study like this.

Jill:

Thank you to brave souls who choose to do that.

Rachael:

Yes, yes. I appreciate their contributions. Yeah, yeah. But after we finished all this risk analysis for OSHA, I got really curious to try to do some experiments or observation studies and gather data about how workers are really exposed in health care. I applied for and was awarded a grant from the CDC Prevention Epicenter Program when I was still in Chicago. It was called the UIC Epicenter for Prevention of Healthcare Associated Infections. We had a number of aims, but one of the major aims of the study was actually to conduct observation and exposure assessment research in an acute care hospital for providers to patients with infectious diseases. What we did in that study was we would recruit participants who had tested positive for influenza or a virus that causes the common cold, like rhinovirus or parainfluenza, and we would recruit them to this study.

Then we would camp out outside their room. We set up some air monitoring equipment in the patient room, and we would swap the surfaces looking for respiratory viruses. Then we would recruit the health care providers that were going into the patient room to deliver patient care. On some of those providers, we would observe them. We'd simply observe them and record the surfaces that they touched and the personal protective equipment that they used and how they took it off. Some participants agreed to wear air sampling devices, and so we would measure viruses in their breathing zone. Then some participants agreed to let us swab their face and hands after providing care to see if there was virus on their body and clothing. A lot of this work was led by my former PhD student, Lynn [Fan 00:34:18].

They did this work over two long winter. For almost two years, they were collecting data. We did demonstrate that there is respiratory virus in the breathing zone of health care providers during these patient care activities, that it is in the respirable size range, so it can be inhaled, and that you can find the virus on the cheeks and on the scrubs of the health care workers after they take off their personal protective equipment.

Jill:

Wow. In the year that we've had, was any of this research then useful, or is it because it's a completely different pathogen you're like, these are ... Okay, I'm not a scientist, obviously. Forgive me if this is a really dumb question. But all the struggles of why can't we know more? Why can't wait no more? I'm listening to you say how many years you worked on this, and then something brand new drops on the planet's lap. Yeah. Is your former research useful or were there any apples to apples comparisons?

Rachael:

Well, I think it's useful. There's actually a lot of-

Jill:

[crosstalk 00:35:41] Yeah.

Rachael:

There's a lot of conflict in this field and disagreement. I say conflict, not that people are in fisticuffs. But there's a lot of, I think, legitimate intellectual disagreement in the field. But I think there's a couple of areas that I would highlight that speak to whether or not the research that we do with seasonal influenza is relevant. I would say that the evidence from the relatively limited research we have about respiratory virus suggests that respiratory viruses are more alike than they are different in how they are transmitted. I think that the data that we have about influenza, for example, is relevant to SARS-CoV-2 or SARS-1 or MERS, that as we collect more data about more diseases, I see greater similarities than I see differences.

The types of similarities have to do with the fact that they tend to all be emitted from the respiratory tract. They may be replicating in slightly different locations in the respiratory tract, but we have a pretty good understanding now that breathing, talking and a variety of medical procedures can aerosolize respiratory secretions. That's just a general phenomenon, whether you're sick or with an infectious disease or not, and that we see these viruses in these respiratory secretions. One of the challenges has been that, and this is an area of vigorous debate, is how do you classify these disease transmission processes? The CDC dogma is that you have an airborne infectious disease, a droplet transmission or indirect contact transmission, and you can have multiple routes relevant for a disease. But the definitions of these transmission groups is really based on very old data. These definitions haven't been updated since they were first introduced in the 1940s and '50s, so they came into common usage around that time.

Jill:

Wow.

Rachael:

There's a distinction that's made where an airborne infectious disease is a disease that involves the inhalation of what hygienists would refer to as respiratory sized particles, but that you are far away when this happens, right? Somebody emits a particle and it floats out their room and down the hall. There are some diseases that clearly are only transmitted through the inhalation of respirable particles such as tuberculosis, which are initiate infection in the alveolar and lower regions of the lung. It has to be respirable to get there. Droplet transmission, on the other hand, is this idea that you're just spraying large droplets onto somebody's face and facial mucous membrane, and they just land on the lips and in the nostrils, and then they can initiate infection. Well-

Jill:

[crosstalk 00:38:53] yeah.

Rachael:

Yeah. Hygienists have knowledge of aerosol science and are usually, when we talk about this community, like, "Well, that's a weird distinction to make." Clearly, when somebody coughs, there are things that are large that might project on the face, but there are also things in that cough that are released that are respirable. You can really have both of these things at the same time. Lisa Brosseau and I wrote about this in 2015. We had a paper called Aerosol Transmissible Diseases, where we made the argument that the distinction between airborne and droplet really wasn't supported anymore by current evidence, and that there were quite a number of diseases for which this paradigm worked. Now, we weren't the only people to write about this. There have been several other groups over the years and individuals. I can't claim that we created something entirely novel.

Jill:

Let's claim it because Lisa Brosseau is also a fellow Minnesotan, and so I say you should claim it. This piece, this body of work and the similarities, does that help, in your opinion, shore up the aerosol standard that you're talking about with OSHA? Does that help you focus and ... What's the word I'm looking for? I guess does it help prove the case that the standard is needed? Well, obviously, we know we need it, but how it would work and what the mitigation efforts could be based on some of this work that you've done?

Rachael:

Are you referring to the proposed ETS?

Jill:

Yeah. No. Well, it could be that. I'm sorry, the infectious diseases standard. Yeah.

Rachael:

The infectious diseases standard actually was a programmatic standard. It didn't prescribe that a disease was transmitted in a certain way or that an employer had to do a specific thing because of a disease. What that standard specified was that the employer would have to assess the hazards and the potential routes of exposure, and then implement a plan that would prevent exposures that were deemed unacceptable. That standard really did refer to guidance from the CDC and HIPAC, the Healthcare Infection Prevention Advisory Committee, which meets regularly and reviews how disease transmission is classified for common diseases in healthcare. I think the infectious diseases standard differed a lot to CDC and conventional practice.

I think many of us are hopeful that, in any kind of forthcoming potential emergency temporary standard for COVID-19, or if the infectious diseases standard is revived under the Biden administration, to move forward to rulemaking that they might be a little more assertive and thinking about or challenging the CDC paradigm because it has real implications for how we protect workers. As a hygienist, we consider protecting the respiratory tract of workers to mean wearing a respirator. A respirator is really the only device that will keep healthcare workers and other workers from inhaling respirable infectious particles. You can't acknowledge that the disease is transmitted through an aerosol, and then say, "Oh, that's okay. You don't then have a-"

Jill:

A respirator. Right, right. It doesn't make sense. I just want to take just one second before we talk about ways to protect employees. You were talking ... I mischaracterized the infectious disease standard and called it something else. Pardon me. Then you mentioned OSHA's ETS. If people who are listening to this recording and have listened to many of mine, you'll know what we're talking about. But for anyone who just dropped into this episode, and is like, "What are Jill and Rachael talking about? What is an OSHA ETS?" [inaudible 00:43:20] background and help me fill this in, Rachael, is that ...

The Biden administration asked OSHA to determine if they were going to promulgate an emergency temporary standard by March 15th to protect employees from COVID-19 in the workplace. March 15th has come and gone. However, we know that there's text written for an emergency temporary standard, it's been named Subpart U, and it's under ... Let's see, what would we call that, Rachael? With the Office of Management and Budget? It's being reviewed at this point and open for public comment. Am I getting all that correct?

Rachael:

I think so.

Jill:

Yeah. Yeah. So we keep waiting?

Rachael:

Keep waiting. I think that this whole debate about face coverings being used in COVID-19 has been a real challenge for the hygiene community. Early in the pandemic, I was not a big fan of face coverings for workers for a couple of reasons. One, the evidence that we had at the time suggested that they didn't filter out particles very well, and so it was really unclear how much protection the wearer would get. Two, workers in my views want ... Two, I guess, I didn't really anticipate that the COVID pandemic would be as catastrophic as it has been. I was anticipating that maybe we'd have another episode like H1N1 one from 2009 or prior emerging respiratory infectious diseases where you get some kind of localized outbreaks, but that it doesn't really spread to the general public.

COVID-19 has been much more catastrophic than I anticipated. I guess the third reason I felt was that if you're actually protecting workers, then you should provide them the best protection available, which was respirators. Now, of course, there was a shortage of respirators early in the pandemic that I felt probably should have been resolved sooner-

Jill:

Amen.

Rachael:

... than it has been.

Jill:

Great.

Rachael:

That is persistent, I think, as a barrier. Now that we think about what to do going forward, we have to also acknowledge that no one loves to wear a respirator.

Jill:

Right. Yeah. You were talking about the thing that protects people is a respirator, and of course, obviously, the right respirator for the hazard that's presenting and fitted correctly and all of that. Is there anything else from your research that's an equivalent protection? Say, ventilation or filtration, or is that just a helpful aid?

Rachael:

Well, certainly we would always prefer to have engineering controls, and there are designs for local exhaust ventilation systems, and then in healthcare facilities, they have airborne infection isolation rooms, which do substantially curtail pathogen concentrations or aerosol concentrations in the area. Local exhaust ventilation is really nice because by capturing it at the source, you are really able to prevent airborne contamination as well as surface contamination. There are some designs NIOSH, more than a decade ago, proposed designs for what they called a ventilated headboard, which is basically instead of having a headboard of the head of your bed, you would have a bank of filters going to a exhaust system.

Those I think were really fundamentally designed for emergency hospitals. They're a little bit maybe bulky to put in a conventional hospital room. But they certainly have good performance at capturing respiratory particles generated by patients. Here at the University of Utah, we have a grant from the Department of Defense right now to develop a portable battery operated filtration aerosol containment device that could be used to provide respiratory isolation for patients, but also to capture particles that might be generated during aerosol-generating medical procedures.

Jill:

Sure.

Rachael:

During the pandemic, there's been a lot of people looking at designs like that, whether they're acrylic glass boxes with some circles through which you can put your hands that keep the splash down, or more complicated the devices with ventilation or suction, like the device that we're seeking to develop.

Jill:

Are there other entities who are doing this same sort of research for other work environments? You're really focused on healthcare. Thank you so much. It's so important for all the lives that were lost in this pandemic in health care. Are there other researchers who are doing this work for other places of employment?

Rachael:

I'm sure there are. I am not familiar with the full extent of it. I know there's been quite a bit of investigation about various options for preventing disease transmission in the meatpacking industry, because that industry in particular was very severely impacted by COVID with many workers losing their lives as a result of workplace exposures. That environment is very challenging because of the design of the processing lines, which put workers in such close physical proximity, and it's really such a complicated engineered environment, right? With a lot of temperature and humidity controls and complicated HVAC systems. I think one of the challenges that we've had in a lot of businesses or worksites is that HVAC systems are optimized for efficiency in terms of heating and cooling costs and delivery of air. They're pretty finely tuned machines. They're difficult to modify.

Even to increase the filtration capacity can cause the system to be out of balance. I think that that is an area where we need to think about how can we design HVAC system for this going forward, for this circumstance going forward, or look at the value of local or portable filtration devices? I have seen at least one study that demonstrates that by operating a portable HEPA filter device, you can reduce virus concentration. We certainly know from studies of childhood asthma that filtration devices in the home can reduce the presence of allergens and reduce asthma severity. But we haven't really linked those kinds of filtration devices yet to infectious diseases, although we can show that they will reduce particle concentrations or virus concentrations in the air. But that's hard to know where to put one. What is the optimal location is a very complicated question, given the variation in airflow in different kind of occupied-

Jill:

Yeah. Not every business, or shall we say no business nearly, have professionals who would be adept at knowing that. Yeah. Let me get back to the respirator again, because it's easy. Yeah, it's complex and easier. You were saying you weren't into the face coverings to begin with, and obviously, you've done a lot of work with respirators and knowledge there. What's that progression been like, and what do you know now about respirators or emerging technology even?

Rachael:

Yeah. For general face coverings, I think the evidence that has emerged is that if you're testing filtration and fit, it's really highly variable and pretty much unpredictable because there's so many designs and so many different fabrics that people can use that it's really hard to know when you go to buy a face covering at the store what it's going to mean. Now there is a recommended guideline in the European Union now for that kind of performance of face coverings.

Jill:

Wow.

Rachael:

Yeah. We reviewed those kinds of standards in a recent paper in the Annals of Work Exposures and Health, Dave Rempel and I, building on some work done by this group called N95DECON, which has been quite an amazing group of people that came together. We can talk about them in a minute. But to finish the question on respirators, there is also a move to try to develop criteria for some kind of intermediate device that would be more comfortable to wear than N95 filtering facepiece respirator. You'll have lower performance, but perform better than a cloth face covering or a surgical mask, and then actually be tested to a standard. I've been in a few conversations about that, and I think at this point there are some recommendations or suggestions for what could be a standard. But we really don't know as a group how good they should perform or how well they should perform?

Jill:

What's acceptable.

Rachael:

Right. What is an acceptable level of performance? Because we don't really know what is an acceptable level for risk? How many infections can we tolerate among workers? Clearly, as a national society, we can tolerate a lot of illness and a lot of death. But if we actually go to thinking about how well should workers be protected, I don't think we really know if it's okay, if one in 100 workers get sick, one in 1,000 workers, one in 10,000. Workers, we don't really have consensus about what that risk should be. Then since we don't know a whole lot about the infectivity of the organisms, it's hard to then also relate that level of risk to what would be an acceptable virus concentration in the air, right?

We choose respirators based on the contaminant concentration in the air, trying to get that exposure to certain level. We're just a bit behind, I would say, in the infectious disease arena relative to chemicals in that we haven't really had the conversations as a society or a professional community about what kind of risk we're willing to tolerate.

Jill:

Yeah, yeah.

Rachael:

But going to N95DECON.

Jill:

Yeah. Yes, please.

Rachael:

N95DECON is a group of volunteers who coalesced very early in the pandemic with the goal of collating and disseminating information about respirators to the general public and to workers groups. I've been very peripherally involved in the group and attended a few meetings, but it was amazing the democratic collaborative process that they use. Right now that group is in the transition phase of archiving all of their materials. But they developed a wide range of informational graphics and about how to use respirators. They wrote briefs, summarizing literature about respirator decontamination and reuse methods. I would encourage everybody who's interested in this topic to check out their website. It's n95decon.org.

Jill:

Okay. Interesting. I'm writing that down. We'll make sure that gets into the show notes. So happy people are doing that. Rachael, at this point in your career and based on, gosh, everything that you've done in your body of work thus far as we're starting to wind down our time together, what happened to your career in 2020? Did the volume go from an eight to way blow past 10? What's this been like? Because there can't be very many people like you in the country. I'm guessing you probably all know one another who have specialties like you do. Yeah. What's this been like? Yeah.

Rachael:

A busy year. I've done some press. I haven't done a huge amount of press.

Jill:

You've done a lot of journal articles, though, as well, and keynote addresses. Yeah?

Rachael:

Yes. I've written a couple of articles related to COVID, including a risk assessment for healthcare workers and a review article with David Rempel about respirators and face covering testing methods and another review about aerosol transmission, potential for COVID-19 with an international group led by a man from the Chinese CDC. It has been a really interesting time. We also have been successful with research funding, and we're working on a project right now for NIOSH about the emission of respiratory aerosols through the exhalation valves of respirators because that was a concern, that you would have people who were asymptomatic with COVID-19 wearing an elastomeric respirator, for example, and then shedding virus into the environment.

We're doing a study on that right now, and we also have this project from the Department of Defense to develop an aerosol containment device. I did get involved somewhat with the response at the University of Utah Health System, which was very proactive, I think, in terms of developing strategies and implementing strategies to try to protect their personnel, including the use of various local exhaust ventilation systems. When we had a shortage of respirators, the university, my colleagues at the Center for Medical Innovation developed a powered air purifying respirator for use until they could acquire new ones.

Jill:

Fascinating.

Rachael:

Yeah. It's been really interesting to see all the innovation that's going on in the field. I'm hoping that the unfortunate severity of the COVID-19 pandemic will lead to some greater, longer lasting changes in how we think about disease transmission and protecting workers, including healthcare workers. It's very dispiriting, I think, as an occupational health person that even though I focus on healthcare workers, that was really the main focus for our occupational health response nationally, and it left so many other workers at risk, who had to continue coming to work every day so that the rest of our community could be sustained. I think that we as an occupational health profession, but also as a larger society, need to really think about what that says about us and how we can do better going forward to ensure that everybody has equity in their work and has a safe and healthful working experience.

Jill:

Yeah. Yeah, amen to that. Yeah. Your work continues. It's not like this is done. I had asked you before when we were speaking before we recorded how you feel about the loose use of the terms our post-pandemic world.

Rachael:

Yeah, yeah. I don't know if we're really post-pandemic yet. I think that [crosstalk 00:59:57] at least in the US, we may be able to believe that if we don't look too far outside our borders. But it's still going on globally and more severe in some countries than it ever has been before, and I think that there's a lot of implications that we need to consider in terms of what we do in the US, what we do globally, how we treat workers who are in lower wage jobs.

Jill:

That's right.

Rachael:

I'm hoping that that gives us an opportunity to make some systemic changes in-

Jill:

Yeah. Care for one another better globally, yeah, and within our borders. Rachael, as people have been listening to our conversation today, and I'm so grateful for it, if there are industrial hygienists listening, or aspiring industrial hygienists listening, do you have any advice, words of wisdom, for people who are listening to you and thinking, "Oh, my God, what you can do with this career? I want more, I want to learn more," what would you say?

Rachael:

Well, I think it's a really exciting career. I direct the industrial hygiene program here at the University of Utah. We offer master's and PhD degrees, and I used to direct the program at the University of Illinois at Chicago, which also offers master's and PhD degrees. I think that there is great opportunities. I'm always impressed at the ability of our students and the variety of career paths that they choose after they complete their graduate degrees, and it's so exciting to see them just thriving in their careers. What drew me to it is often what I hear others echo as well, is that it's a great career because it has the science and technology, you get to learn about processes and how things are made and how the world works, and you get to do those things by also doing something that really has a direct positive impact on individuals and organizations.

I just feel like it's super exciting. More and more students are going into jobs where there's also the intersection between industrial hygiene or occupational health and environmental issues, whether that's in this area of green chemistry and sustainability, or also just thinking holistically about air quality and water quality and how the workplace interfaces with the ambient environment. I also think that that's a very exciting area.

Jill:

Yeah, yeah.

Rachael:

I encourage people to get into the profession. It's also nice that people who are in the profession are promoted and move through the ranks in their careers and earn a good living. NIOSH education and research centers can help to make going to school affordable as well.

Jill:

Oh, that's a good tip. That's a good tip. Yeah. Thank you. Thank you so much for everything that you've shared today, and thank you for your work, the whole body of your work and all that it's done for so many of us that had no idea who's behind some of these things.

Rachael:

Well, it's not just me. Yeah. I must say I've tried to acknowledge-

Jill:

Yes, you certainly have. Yes.

Rachael:

But also, research is always a team effort, and-

Jill:

Yes.

Rachael:

... I'm always eternally grateful to my talented students and research associates and other research personnel that have worked with me, because when I say we, it's usually them doing all the work. I can't be successful without their success. That's one of the most satisfying things about being in academics and being a researcher, is seeing how your students and mentees develop through their career. I've really benefited from mentorship at different points in my career development, and it's a big priority of mine to help make sure that my students have the same opportunities.

Jill:

Yeah. Part of the legacy. Absolutely part of the legacy. Thank you so much, Rachael.

Rachael:

Thank you, Jill.

Jill:

Thank you all for spending your time listening today. More importantly, thank you for your contribution toward the common good making sure your workers, including your temporary workers, make it home safe every day. If you'd like to join the conversation about this episode or any of our previous episodes, you can follow our page and join the Accidental Safety Probe community group on Facebook. If you aren't subscribed and want to hear past and future episodes, you can subscribe in iTunes, the Apple Podcast app or any other podcast player that you'd like. We'd love it if you could leave a rating and review us on iTunes. It really helps us connect the show with more and more health and safety professionals. Special thanks to Will Moss, our podcast producer. Until next time, thanks for [inaudible 01:05:30]