Last time I forgot to introduce myself, so I'm Catherine Miller, Occupational Medicine Physician, obviously, Professor at the University of Colorado, past ACOM President, and also previous Medical Director for the Division of Workers' Comp in Colorado, and I've been privileged to work with our presenters here at National Jewish with our Occupational Medicine Residency at the time, and our next presenter, I was very privileged to work with her during her residency time at National Jewish. So let me tell you a little bit about her background. She's an Occupational Pulmonologist and Critical Care Physician. She completed training in Internal Medicine at Boston University Medical Center, and then subsequently completed Pulmonary and Critical Care Fellowship and Occupational Medicine training in Colorado, University of Colorado. She joined the faculty in the Division of Environmental and Occupational Health Services at National Jewish in Denver in 2016, as well as the Division of Pulmonary and Critical Care at the Rocky Mountain Regional VA Medical Center in Aurora in 2017, where her practice includes evaluation and management of occupational and environmental lung diseases. Her research interests include exposure-related lung disease, with a particular focus on deployment-related respiratory diseases, such as asthma in military service members who have deployed in Iraq and Afghanistan. She currently serves as the Site Director for the VA Eastern Colorado Post-Deployment Cardiopulmonary Evaluation Network Center, one of five specialty centers offering local and regional evaluations for deployment-related respiratory disease. And I also just want to mention, so we're going to have a panel discussion with everyone at the end from both sections, because we really want to not just show you this fascinating research, but really tie together the idea of what are the concepts in occupational medicine practice that make us special, different, and what are we contributing to the world. So these are just some of the examples. Dr. Krach? Thank you so much. Thank you so much, Dr. Miller. So good morning. It's really great to be with you all here today to talk to you all about a group of conditions called Southwest Asia Deployment-Related Respiratory Diseases, or DRRDs, as I will refer to them throughout today's presentation. Before we get started, here are my disclosures. Funding for my work includes a Career Development Award at the VA. I receive research and salary support from VA and DOD funding sources. Also in my work at the VA, our site has received funding for creation of a post-deployment cardiopulmonary evaluation network center. Opinions, interpretations, conclusions, and recommendations are my own and are not necessarily endorsed by the VA or DOD. Next I'll give you some background about DRRDs that have been described in the medical literature. And before we really get into some of how we have impacted this field and the understanding of disease, I think it's important to have a little bit of background before we jump into that. So I'll kind of take you to where we are at right now, and then we'll step back and take a look at how we've all contributed. So over the past 30-plus years, more than 3.5 million people have deployed to Southwest Asia, as well as nearby regions, as shown by the labels of the countries where military personnel have deployed. Our United States military personnel and contractors have deployed not only as part of several military operations, but also peacetime operations, as you can see depicted on this timeline. Deployment to Southwest Asia locations is associated with complex inhalational hazards that may include burn pit emissions, as many of you have already heard about, but also many other inhalational hazards. You can see examples of the first two hazards on this slide. First, if you look up at the top right, you'll see a bulldozer spreading out debris and trash in a so-called burn pit. So this is an area where trash generated by military operations is disposed and burned. The image at the bottom right shows a sandstorm rolling into a military site. Deployed personnel also report exposure to a number of other hazards, as you can see outlined on this slide, including industrial fires and pollutants, such as the sulfur mine fire in Iraq in 2004. Also cigarette smoke. Many military service members report nuance at smoking or an increase in smoking when deployed. Vehicular diesel exhaust appears to be fairly ubiquitous during deployment. IEDs and other types of blasts and fires. Temperature humidity extremes, microbial and allergenic agents, as well as job-specific exposures. So when we think about construction battalions, construction work, a lot of that is happening overseas oftentimes in austere environments where there are other hazards as well. So next couple of slides, I have a couple of pictures for you. So this is just some of the debris generated by a blast. This is dusty conditions, really just from a helicopter taking off in the Helmand province of Afghanistan, known to be a pretty dusty region. We think about combat medics, but also this is a dusty medical rescue. So often they're doing their jobs with their inherent risks, but in these types of austere conditions where air quality is often poor. And then apart from some of these environmental conditions and some of the other exposures I mentioned, we talk about burn pits, but there's also widespread trash combustion that's been reported. So this is another detail that somebody had. Apart from their regular job, they may spend a couple of days a week, a couple of hours during deployment, or maybe this is a daily task for some, where in these 55-gallon drums, that contain feces and other waste, a fuel accelerator is added and it's stirred until it's gone. So there's really a multitude of different kinds of exposures that someone who has deployed overseas may face. And then one that, while we talk about more in the post-911 era, these exposures, going back to the first Gulf War, people have been reporting these kinds of issues. And burn pits, although in the scope of this talk I'm really talking about Southwest Asia, are not unique to just this region. And actually going back to 1991, while there were shared exposures during the first Gulf War era and post-911 era, the 1991 oil well fires were widespread for a period of several months during 1991 that appear to be more unique to the first Gulf War era, or at least the scope of them, as this was a problem for several months. So with a little bit of that background kind of aside, although there were reports of respiratory symptoms as well as what is now termed chronic multi-symptom illness during the first Gulf War era, there have been increasing reports of respiratory symptoms and lung disease in those who have deployed to Afghanistan, Djibouti, Iraq, and other parts of Southwest Asia. So observational studies include case reports, case series, case control studies, and other epidemiologic studies that have shown reports of eosinophilic lung disease, asthma, sinonasal disease, and bronchiolitis. And what we've come to understand is that there's really a spectrum of upper airway and lower airway respiratory diseases. Something that also we have discovered, and several people have published about this, including our group, there are several patterns of lung disease that have been identified on lung biopsy as well, apart from just some of the things that I mentioned before. So emphysema hyperinflation, which you can see in the left panel, also bronchiolitis or inflammation of the tiniest airway, the respiratory bronchiole in the lung also. In the middle panel, you can see kind of obliteration of the lumen there. Granulomatous inflammation or granulomatous pneumonitis, where you can see the purple balls of lymphocytes in the lungs, all have been described. While not shown on this slide, peribronchial or metoplasia and pleuritis. So a variety of different kinds of lung injury and inflammation also have been noted. So despite these mounting reports and these multiple studies of respiratory symptoms and illnesses following Southwest Asia military deployment, I mean, some of which date back really to the first Gulf War era, you know, while there's been this mounting evidence, there's really been still in some years, you know, more active debate and controversy about a real causal link between military deployment, some of the exposures and lung disease. In particular, you may have heard in the news about burn pits. And as I've shown you, the exposures from that era are really more complex than just burn pits. And so this really kind of led to this back and forth of, is there really a link between these conditions, especially when many of the studies that we do are not designed where there can be a causal association described. And as I think Dr. Gadadi mentioned earlier, in OEM, the kind of research that may be available to us is not going to be your well-designed randomized control trial. We may be lucky to get cohort studies, but often it is observational studies. So although I think when you look at, you know, this, like on a seesaw, there has been, this just represents, you know, some of the dozens of studies that have reported increasing respiratory symptoms. Many veterans and providers were left with difficulty answering questions when people would ask, you know, is my lung disease or is said condition related to my military deployment? So fast forward to 2021 and the VA started to tackle these concerns, prompting new federal regulations. So the VA secretary announced that if a veteran or military service member had deployed to Southwest Asia, which includes Iraq and other nearby countries, and have been diagnosed with asthma, rhinitis, or sinus disease, these conditions were considered to be service related and more specifically related to Southwest Asia deployment, particular matter exposure. Then in 2022, you may have heard the comedian, entertainer, activist, Jon Stewart, several veterans organizations, and U.S. congressional members discussing something called the PACT Act. So the PACT Act is abbreviated from its longer title, the Sergeant First Class Heath Robinson Honoring Our Promise to Address Comprehensive Toxics Act. So what is the PACT Act? So the VA through this legislation has added more than 20 burn pit and other toxic exposure presumptive conditions based on the PACT Act. So this change expands benefits for Gulf War era and post 9-11 veterans who have deployed to Southwest Asia and includes several countries in the Middle East as well as neighboring countries. And so these cancers listed here, and I won't go through all of them, are now considered presumptively service connected. So if you've had a history of military deployment and you're diagnosed with one of these conditions, you may be eligible to file a claim for this. So moving on and kind of more relevant to today's talk is that there's also a number of PACT Act covered respiratory illnesses. And while the content is here on the slide for you to review, I want to spend a little bit more time about talking about how we got to where we are. It's been three decades and some people have felt that this legislation has been a long time coming and others still in the scientific community think that, you know, these links aren't ironclad as we often see that that's not the case in occupational medicine. So that's what I'm going to spend the next part of this talk really talking about. How have occupational medicine providers helped advance our understanding of deployment related respiratory disease? I would argue that each of us have contributed to this and it's really a multi-prong approach. So I may spend a little bit more time on this slide, but one of the things I would say is that research has obviously been one of the things, just getting case reports out is often what starts things for us. And especially with the example of deployment related respiratory disease, that's what really happens. Starting as early as 2004, there are case reports and epidemiologic investigations looking at some of this. The causation piece has been, you know, difficult and challenging because in occupational medicine research, especially trying to conduct exposure assessment and evaluation in a time where there's military operations ongoing too. And that may not be central or the most concerning issue. So I would argue that using things like Bradford Hill criteria has been very helpful in the occupational medicine world. And I think has helped lead us to this place where we can start to react to our, you know, our service members and think about what needs to be done next for prevention. Thinking and diagnosing these respiratory diseases accurately is important. A lack of consistent case definitions in previous studies contributed to some of the uncertainty early on. So you know, having agreed upon definitions for research and clinical use is important. Also thinking about medical surveillance and exposure assessment. Exposure assessment sometimes in the field may be difficult and there may be challenges to some of it. That's been a big concern in this field where there's actually little data that's publicly available about personal exposure monitoring or area sample monitoring and understanding, you know, burn pit emissions or desert dust particulate matter during certain time periods. And so this is where as occupational medicine providers, our history is important and doing things retrospectively and reconstructing some of the exposure assessment. Although not ideal, it's what we have to work with. And then also thinking about prevention, the hierarchy of controls. So many of our service members and clinicians in the Department of Defense, you know, are seeing these patients first line. And also thinking about kind of at a higher level, the Department of Defense doing things like substituting incinerators for burn pits. Although not a perfect answer that, you know, those kinds of things, these engineering or administrative controls may be helpful for future generations too. And then as occupational medicine clinicians, we're thinking about how to mitigate exposures and, you know, should people be returning to some of these environments, you know, depending on what their current functional status is and what they're likely to be exposed to again. And then another important piece is education. As a small community, we're responsible for doing this, not just for our patients, but risk communication to the public as well. So I wanted to give a couple of selected examples. One of them is the occupational medicine research example. So you know, one of our colleagues was actually on this committee, Dr. Rose too, where the National Academy of Sciences was asked to synthesize some of the information that was out there about respiratory health effects. And the panel had concluded that more research was needed, but they also did report that there was an association between appointment and respiratory symptoms. Although not all the studies were, you know, robust methodology and were lacking exposure assessment that there was some evidence of that. So these are some of the ways that I think that our community can get involved, serving as occupational medicine expert or, you know, somebody with toxicology experience on a research panel. So moving kind of on a more local example, when we talk about the exposure assessment, I've cited that as something that has really hampered research in this field. To tackle the issue of estimating inhalational exposure intensity, our group, led by Lauren Zell-Baron, who is an occupational epidemiologist at National Jewish Health, looked at something called military occupational specialty codes. So previous occupational lung disease research has found utility in occupational specialty codes. I know this group is fairly familiar with that, or specific industry categories in predicting hazard risk for occupational diseases. Seeing a major gap in the literature, our team looked at the utility of military occupational specialty codes. And as you can see here, we found that symptomatic deployers reported higher exposure intensity to inhalational hazards than was scored by a panel of previously deployed physicians as well as occupational medicine physicians, reflecting that we may, you know, even with things like job exposure matrices and things like that, we may be underestimating some of the exposures that are actually encountered just based on occupational specialty codes. And then along with that, you know, from the same study, we found that combat MOS codes were linked to higher exposure risk, but limitations constrained their use as reliable epidemiologic tools. I think as clinicians, you can kind of synthesize some of this. Like while we saw that these were the, those with combat were the ones that had the highest likelihood of having undergone clinical evaluation, there were definitely some non-combat codes that weren't necessarily reliable predictors of exposure risk. So one example would have been a chaplain. You may not, we may think about them providing religious services, but not thinking about in a combat situation, they may actually be accompanying military personnel on operations and performing last rites or, you know, something to that effect. So I think that this experience and ability to integrate the research, understand the limitations and not be purely scientist is, it's what's really key about occupational medicine, how we can impact the world. So I bring up Bradford Hill criteria because I think this is something that in the general scientific community, people don't think about, but as occupational medicine providers and health experts, we have to sort of do the best with the information and research that's available at the time, right? Sometimes make decisions that are public health protective with not the best, you know, some messy, messy studies. So I bring, I won't go through all of these, but when I talk about consistent, I've highlighted the things where I think there's really a compelling case. In terms of consistency of data, there have been dozens and dozens of reports showing an increase in respiratory symptoms following Southwest Asia deployment. I mean, going back decades and not limited to, although sparser in the non-U.S. literature, even in other countries as well. The strength of the association, this is where some of these studies have been hampered by inadequate exposure assessment, like looking at mixed exposures, deployment, not being able to parse out the specific inhalational exposures, like which thing may be linked with which condition or how they may interact. The relationship in time, we've seen that, you know, there's been an increase post-deployment compared to pre-deployment has stood up in a number of observational studies as well as like a dose response and biological gradient. The coherence of evidence in terms of what we know, like the asthma and sinus nasal disease, that's really where I would say that's probably the strongest signal. And then biological plausibility, I mean, extrapolating what we know from, although more dramatic, like pneumoconiosis, you know, other dust-related lung diseases and air pollution, I don't know that this is a complete surprise that some of this poor air quality is contributing to adverse respiratory outcomes in this population. And then one analogy is that, you know, that I think we've seen is we see a very similar spectrum of respiratory conditions in world trade collapse responders. They were fortunate enough to have a little bit more in terms of some objective occupational health surveillance with annual lung function testing that's not generally available in the military population except for select military occupational specialties. And then experimental evidence, this is where really I think understanding the mechanisms of disease, there needs to be more done on that and studies in progress. So another example of something we can do is medical surveillance. And I won't get into all of the details of this, but Dr. Rose, one of my colleagues who will be speaking earlier, really led this effort over 10 years ago when had convened a group of occupational medicine experts, clinicians, toxicologists, public health experts to kind of provide some guidance even in this time of where there was less certainty than there is now that, you know, these are the kinds of things that we have to have a high index of suspicion for something that might be work-related. So that if people have persistent symptoms, abnormal testing, an excessive decline in their lung function testing, even if normal, or an excessive decline in their exercise capacity or physical fitness testing, that they should be considered for medical surveillance. And also had published a recommended approach to diagnosis, which has really held up over time and still is the mainstay of our approach to deployment-related respiratory disease evaluation. You can see that it really goes from a comprehensive history describing the exposures, because not all exposures are alike for each individual. Not everyone who's deployed overseas has been exposed to burn pits, you know? So it really is, it may be location and time dependent. All the way down to when we don't have answers or people's lung function is deteriorating, considering something like a surgical lung biopsy to help tailor their management. Another example of, yet another example of what we as occupational health experts have done is try to work to standardize the diagnostic evaluation, building on some of those recommendations that Dr. Rose and others have put forth, the VA has created this post-deployment cardiopulmonary evaluation network. So our parent site, the VA Airborne Hazards and Burn Pit Center of Excellence has a network of centers across the country that provide more detailed multi-day evaluation to work up unexplained respiratory disease where maybe local and regional assistance may not be available. And then in terms of research and also diagnostic evaluation, the VA Airborne Hazards and Open Burn Pit Registry may be something that you're familiar with. But there is a registry that veterans and active duty service members can fill out where they can document their exposures and health concerns and complete a physical exam that's performed by an environmental health or occupational health clinicians. I think I see one here in the audience, Irlanda from Phoenix, Arizona, who is one of the more than 40 environmental health physicians across the country doing these exams and helping to understand these exposures. So I put the eligibility criteria for this on here. But this is not only this provides a free evaluation where diagnostic testing is free of cost to the veteran or active duty service member. But beyond that, you know, this kind of, while a registry, we think of it as kind of not the most robust method of research, if linked with clinical data and longitudinal outcomes in the future could actually be quite robust. So these are just, you know, some selected examples of how we've made, I think we as a community have made a difference. And then I wanted to end here with just talking a little bit more about some of the work that we're doing in selected research studies at National Jewish Health, VA, and the University of Colorado. We've participated, I've been lucky to be a member of a team called the Group on Lung Injury from Deployment, led by Dr. Rose at National Jewish Health, that I think really helped to work on some of the things that we're lacking, like identify what are the diseases that we need to worry about, establish case definitions, and think about how to assess inhalational exposures when maybe exposure assessment, a quantitative exposure assessment may be lacking. And then in some of the work that I'm currently doing at the VA, I'm focusing on longitudinal health outcomes and building a prospective cohort. And then as an example of a multi-site study with multidisciplinary approach of occupational medicine experts, asthma specialists, and epidemiologists are actually doing, conducting a clinical trial on deployment-related asthma, where we're looking at an investigational drug to see if this may improve outcomes in asthma control. So those are just some selected examples of how we've made a difference and how it's taken 30 years to get to where we are. There's still a lot more to do, and I'm sure many of you have ideas and questions about that. But thank you for letting me share this with you today. Well, we'll do our question and answer session at the end, like we did last time, so we kind of have an ability to talk about the panel and everything. But I wanted to say, I think that was an incredible summary of Dr. Cuff, because she's really brought up a lot of the issues. When we don't have all the information, yet we are impacting the entire military setup and really helping workers. So our next speaker is Dr. Rose, who I have to thank for being my mentor and helping me as I limped from emergency medicine into occupational medicine. Dr. Rose. Oops, I've got to get her presentation up here. Oops, there we go. I can get it there. Well, I can do it. I didn't have trouble before. There we go. And we go here. It should be here. And here. There we go. Dr. Rose is a professor of medicine in the Division of Environmental and Occupational Health Sciences, the Department of Medicine at National Jewish. She has academic appointments in the Division of Pulmonary Sciences and Critical Care Medicine at the University of Colorado and in the Department of Environmental and Occupational Health at Colorado School of Public Health. She's board certified in internal medicine, pulmonary medicine, and occupational environmental medicine and has a master's degree in public health. Her research and clinical interests focus on occupational lung disease. She has had sustained grant funding for clinical and research programs for the U.S. coal and uranium miners and for military veterans who develop respiratory illnesses following deployment to Iraq and Afghanistan. And you may have heard many other things about her on popular TV at various times. So here we will present Dr. Rose. So thank you all for being here this morning. And thanks to Catherine Miller for conceiving and organizing this symposium. She and I go back a long way. And, in fact, she's had an opportunity to see me make mistakes and learn from my mistakes over time and has really functioned as a mentor to me as well as to all the other speakers here. So thank you for that, Catherine. You know, for me, this symposium has really been an opportunity to look back at several cases and several events that have shaped my career in occupational lung disease. And so I'll share some of those with you. I have no relevant disclosures, but I do get grant funding from the Health Resources and Services Administration for our Miner's Clinic and also from the Alpha Foundation for the Improvement of Mine Safety and Health. So a formative case presented early in my academic career at National Jewish Health when a 24-year-old never smoker competitive cyclist was referred for persistent cough, chest tightness, and worsening shortness of breath. And he reported that his symptoms were worse at the end of his work shift as a lifeguard at an indoor pool. His physical exam showed basilar crackles. He had normal resting lung function, but when we did cardiopulmonary exercise testing on him, he was really profoundly hypoxemic. And he had subtle interstitial abnormalities on his chest imaging. So we took him to fibro optic bronchoscopy, and he had a lung full of lymphocytes. He had a lymphocytic alveolitis. And transbronchial biopsies showed that he had granulomatous inflammation. So we diagnosed hypersensitivity pneumonitis. The most notable thing about his case is that he reported that coworkers had similar respiratory symptoms, and so I arranged for those coworkers to come to my clinic to undergo evaluation. And this indicated that several of the lifeguards where he worked at this indoor pool also had hypersensitivity pneumonitis. We organized with the city where the pool was located to have the ventilation system tested. And what our industrial hygienists found was that the ventilation was terrible. There was complete reentrainment of exhaust air back into this indoor pool. And we said, great, you know, they need to fix the ventilation system. So they closed the pool, fixed the ventilation system, and reopened the pool. And within about two months, the lifeguards who had resumed working there, many of them new lifeguards, reported that they had respiratory symptoms. And so what we realized at that point, we brought them back in for clinical evaluation, and we realized that they, again, had pool-related hypersensitivity pneumonitis, this time with an attack rate of 65%. And so the pool was closed again, and this time we undertook to do much more extensive industrial hygiene evaluation. And what we found out was that, again, working with the health department and the city where the pool was located and our own kind of multidisciplinary team, was that the pipes leading to the water features that fed water into the mushrooms and waterfalls and sprays and fountains that really characterized this beautiful indoor pool were corroded and they were colonized with pseudomonads and other gram-negative organisms that were reflected in high endotoxin levels in the pool. So the reason for showing you this is because it really, again, was one of the earliest examples for me where fixing the ventilation system is a good thing, but source control is really the most important thing in terms of controlling exposures for occupational disease. So this experience then laid the groundwork for our later research on hot tubs, swimming pools, and therapy pools, which we realized could be sources of exposure to these unusual microbial organisms, especially mycobacteria. And the nontuberculous mycobacteria are particularly prevalent and can be released in the breathing zones of pool users, hot tub users, sitting down where the jets are going and where the bubbles come out and burst and release these organisms right into their breathing zone and then can cause immunologic reactions like the ones that we saw in the lifeguards and lead to a lymphocytic granulomatous lung disease that in this case is not called lifeguard lung, it's called hot tub lung. So these outbreaks and these cases pointed very early on to me as an occupational medicine doctor the importance of removing affected patients from exposure to offending antigens to avoid scarring in the lung. And you can see here on the left-hand side of the screen is a CT image of a person with hypersensitivity pneumonitis. And the date's missing on the other side, but this is from 2017, and you can see that there's much more scarring, subplural scarring, and fibrosis in the lung in a person who wasn't appropriately removed from the exposure that caused their hypersensitivity pneumonitis. So we as clinicians have to follow HP patients over time to assess the response to therapy because as the lifeguard example shows, we may think that we've solved the problem, but if we don't follow people over time and pay attention if the symptoms recur or persist, then we really aren't often sure that exposure abatement has been successful. And importantly, public health reporting may unmask risk to others who share that same environment. So next I'll share some insights into our work and others' work on fixed airways obstruction from exposure to flavoring chemicals in both workers and consumers. And I'm sure many of you are aware of the fact that in the early 2000s, investigators from NIOSH described eight workers with severe fixed airways obstruction, or FAO. The NIOSH investigators, who were led by Dr. Kay Kreiss, found that there were over three times the rate of fixed airways obstruction in current microwave popcorn employees, and that never smokers within that cohort had almost 11 times the expected rate of airways obstruction. These investigators also showed that there was a correlation between airways obstruction and the highest quartile of estimated exposure to the chemical diacetyl, which is an alpha diketone that confers that buttery note or buttery flavor to microwave popcorn and to many other food substances as well. And these slides show the microwave popcorn mixing room where a substantial number of the workers in the Missouri popcorn plant were exposed to oils and flavorings that then the NIOSH investigators were able to pinpoint to the alpha diketones in the buttery flavoring. Subsequently, there were reports of severe fixed airways obstruction confirmed in multiple workplaces besides the microwave popcorn workers, flavoring workers, diacetyl production workers in Great Britain, and even coffee workers later on who were using flavored coffee materials were shown to be at risk for fixed airways obstruction. So with these concerns, our group at National Jewish Health was asked to provide a respiratory health consultation for small flavoring companies who were members of the trade association of FEMA, the Flavor and Extract Manufacturers Association. We initiated a three-pronged effort that focused on industrial hygiene assessment and sampling, a respiratory protection program, and a medical surveillance program. And what the industrial hygienists showed is using a real-time sampling device during production, they found that there were these transient but rather significant spikes in exposure to diacetyl during powder processing in some of these flavoring companies. So you can see why this would be extremely hard to detect, and if you look at it over an eight-hour time weighted average, it probably wouldn't look like very much, but it was a really high spike in a short period of time during production. So the industrial hygienists, who were led by Dr. John Martini, recommended a number of exposure controls and helped these small flavoring houses implement recommended changes, and these are familiar to all of you as occupational medicine specialists, where they need local exhaust ventilation that's in particular areas of powder and liquid compounding. Process changes, simple things like just adding vessel lids or minimizing turbulence during pouring were important in terms of controlling exposures. There was employee need for training and use of chemicals and labeling of high-priority chemicals, especially those that were transferred from the large barrels into the smaller containers. And we helped a number of these companies put in OSHA-compliant respiratory protection programs and medical surveillance programs as well as ongoing sampling programs to see if the exposure controls were actually efficacious in controlling the exposures. So for our aggregate medical surveillance findings, we basically confirmed what NIOSH had described in the microwave popcorn workers, and what we found is that for flavor production workers, they reported higher than expected rates of cough. We looked at all the different respiratory and systemic symptoms, but the one that really stood out was cough, and they reported very high rates of physician-diagnosed asthma, probably didn't have asthma, they probably had fixed airways obstruction. And as you can see in this graph where we looked at abnormal FEV1s, the younger production workers, who are the ones shown in the front row, the blue and the yellow, were significantly more likely to have airways obstruction and that the risk was highest in the blue and green, which were in the never smokers. And probably the reason why the older workers had lower rates than the younger workers is in part because people who had gotten fixed airways obstruction or who had gotten symptoms had left the workplace earlier, so we were seeing sort of a survivor effect here. But the most unexpected finding was the case of a consumer with so-called popcorn lung, and this case was referred to me as just a routine case of hypersensitivity pneumonitis for assessment with regard to their occupational exposures during my clinic. He was a 53-year-old never smoker with a persistent shortness of breath and cough. He had really severe airflow obstruction with an FEV1 of 49% of predicted, and his chest CT scan, which you can see here, had mild bronchiectasis and air trapping. He underwent a lung biopsy before he was referred for OCMED consultation, and he had granulomatous inflammation, but with this component of fixed airflow, small airways, obliterated bronchiolitis. And he had been treated with steroids, but his lung function continued to worsen. So I took, of course, an extensive occupational history, and there was nothing there. And I took a very extensive residential history because we've been burned a few times where we take a great occupational history, but if you don't take a good residential history for antigen exposures, then, you know, you miss out. I could not find a thing, and I will never forget, you know, looking up, kind of sitting there wondering what was causing this guy's fixed airways obstruction, and I said, you don't eat a lot of buttered popcorn, do you? And he said, I am popcorn. I am a two-pack-per-day user. I'd never heard that except with smokers, right? And it's all I eat for my snack of choice. Suffice it to say that we did a fairly extensive investigation and concluded that there was true public health concern about risks to consumers who were using as much buttered popcorn as this particular patient was. And so we reported this as a sentinel case to the FDA, the EPA, OSHA, and the CDC. What do you do with a consumer, right? And what that led to then was that lower concentrations of diacetyl and other diketones were added to flavored microwave popcorn that are purchased by consumers. So most recently, NIOSH investigators described an unexpected increase in coworkers' pneumoconiosis. I'm pivoting to give you all these examples of lessons learned and mistakes made and opportunities provided over the course of my working career. So more recently than those other two, NIOSH investigators described an unexpected increase in coworkers' pneumoconiosis since 2000, which was reversing the downward trend. If you look along on the left-hand side, you'll see the X-axis is time. And you can see that there was this downward trend in all of the different mining tenures of coal miners. That's what the different lines are. The one on the top, the black line that's a continuous line, is miners who had over 25 years of tenure. And then the others are lower tenure miners. And there was a substantial decline in the rates of coworkers' pneumoconiosis since the passage of the Mine Safety and Health Act in 1970. So, you know, the regulation really made a great difference in terms of prevalence of disease. But if you look at around the year 2000, there was this kind of upswing in the rates of coworkers' pneumoconiosis, particularly in the miners with the longer tenure. And if you look at the graph on the right, what you see is that there was this tremendous upswing when the NIOSH investigators looked at coworkers' pneumoconiosis in miners from central Appalachia. Those states are Kentucky, Virginia, and West Virginia. And there the rates of CWP and what's called RPP, or rapidly progressive pneumoconiosis, were really, really substantial. So working with colleagues from Illinois and West Virginia and from NIOSH as well, we collected lung tissue samples from coal miners with rapidly progressive pneumoconiosis in our clinics. So we just put together a case series of miners who had rapidly progressive massive fibrosis from exposure to coal mine dust and who had lung tissue available and where we could get informed consent for using it. And to our surprise, this lung tissue actually showed findings of silicosis, not the coal macules and coal nodules that are typical for coworkers' pneumoconiosis or black lung. And the explanted lung that's on the left shows that the upper area of the lung has been completely replaced by PMF, by progressive massive fibrosis. But with all those little white studded areas actually being silicotic nodules. And when you look at this lung, then under the microscope, what you can see is that the lung shows silicotic nodules. It does not show all of that black anthracotic pigment and coal macules. The lungs in these miners with RPP, rapidly progressive pneumoconiosis, were showing silicosis. They had silicotic nodules and they had alveolar proteinosis, which is typical histologically for people who have the more accelerated form of silicosis. So with leadership then from Dr. Bob Cohen at University of Illinois in Chicago and again with a group of investigators, we obtained lung tissue samples from the NIOSH National Coal Workers Autopsy Study. So there were all of these stored lung tissue samples from previous autopsies that just really hadn't been looked at for a while. We assembled this panel of seasoned pulmonary pathologists from the U.S., from Canada, and from South Africa, and we had them systematically score the histology of the NICWA samples plus others that we obtained from our clinics and from, you know, whoever gave us cases, basically. And then we had the – we divided them up so that the pathologists were blinded to what the timing of these samples was. But we divided them into two groups, the contemporary co-miners and the historical co-miners. And what we found was that the pathologic features of mature and immature silicotic nodules, and what we call MDAP, or mineral dust alveolar proteomosis, were present in the contemporary co-miners in much higher rates than the historical co-miners. And that, again, implicated excessive exposure to respirable crystalline silica. Working then with collaborators at the U.S. Geological Survey, we did mineralogic analysis, and we found significant associations between the concentrations and the percentage of silica particles and the lung lesions of silicosis in the contemporary miners. So again, using this multidisciplinary team, collaborating with mining engineers at Virginia Tech, we identified possible contributors to this increased silica exposure and these resultant and really severe health effects in U.S. co-miners. And what we think the evidence points to is that there are geological factors, one being the thickness of the coal seam, and you can see that here in the illustration, where most of the really wide coal seams in the United States have now been mined out. But with increased mechanization now, there's an ability to mine thinner coal seams. But the problem with that is that the overburdened rock, you know, the surrounding rock strata is silica-containing, it's, you know, it's stone. So mining practices of mechanization have led to efficient and cost-saving cutting of rock around these thinner coal seams that has probably increased the exposure of miners to respirable crystalline silica. And you know, we're not really sure. There may be changes in ventilation practices, in shift duration, in work week, in adherence to regulations that could be driving some of this increase or surge in co-workers pneumoconiosis. And we think there probably are particle characteristic changes that have occurred over time. In addition to there being maybe more silica, there may be smaller particle sizes in coal mine dust that lead to, you know, more absorption into the lung and fibrosis in the lung because the dust particles make their way down to the lower part of the lung. So our findings support the need to identify optimal monitoring and sampling to assure that coal mine dust exposures are controlled. And our findings also suggested that measuring simply total coal mine dust, which is kind of the approach that MSHA uses now to regulate coal dust exposures, this may be insufficient to protect miners' health. And so that research, this collaborative research, has laid the groundwork for a new MSHA silica rule. This is in the works, but we hope that it will be passed and we expect that a focus on better control of exposure to respirable crystalline silica, similar to what OSHA passed in 2017 with the OSHA silica rule, will then allow for better protection for coal miners. So my interest in the emerging role of respirable crystalline silica in coal miners then laid groundwork for an observation that I just made in 2019. I kept seeing younger people in our occupational lung disease clinic who were presenting with silicosis and who worked as stone fabricators. And I wasn't sure what was going on. But in looking into this further, we found that many of these young workers were working now with engineered or artificial stone, which is a composite of quartz bound by a polymer resin. And engineered stone, and you see it everywhere. You see it in hotels and B&Bs and, you know, any house or bathroom that you now look at often contains this engineered stone, which has over 90% crystalline silica that's bound together by this polymer resin, about which we know very little in terms of the resins conferring some toxicity to the silica. Compared to natural stone, like granite, that contains less than 45% crystalline silica, and if you look at trends in use of engineered stone in the United States, the imports have increased over 800% over that period of time from 2010 to 2018. So again, collaborating with colleagues in California, Texas, and Washington, we identified 18 cases of severe silicosis in engineered stone workers, many of whom had complications of silicosis, including autoimmune diseases. You know, we don't often think of autoimmune diseases as being exposure related, but the data are now really emerging that autoimmune diseases are probably linked to environmental and occupational exposures. We've really known about this for a long time for the fibrogenic dust. I think that, as a pulmonologist, I just, you know, I use the lung hammer and don't see the autoimmune outcomes as easily, but I'm sensitized to that now because they were so prevalent within this engineered stone worker group. They also had kidney disease, inflammatory kidney disease due to inhalational exposure to the silica, and increase in lung infections, again, especially with non-tuberculous mycobacteria, and so a group of us published that in the MMWR. And in so doing, here in the United States, we became aware that there really is an international outbreak of silicosis in engineered stone workers. It was first reported in Israel. They looked at a lung transplant registry, and they found that many of the people who had undergone lung transplant in Israel were engineered stone workers, and also a great deal of really fine work has been done by investigators in Spain, and more recently in Australia. And so, understanding this, we created an international registry of engineered stone silicosis cases, and in putting our heads together with these other investigators, you know, have really described, again, this very important, very devastating emerging clinical disease with ground glass opacities, not just kind of nodular opacities as we're used to seeing in silicosis, but in something that's much more inflammatory and much more rapidly progressive than what we thought we understood about silicosis based on previous work. So in summary, you know, our work has had an impact, but these Sentinel cases are emblematic of our persistent prevention failures, and especially among the engineered stone workers, and you saw this in the flavoring workers, and, you know, also it's true in smaller coal mines, is that the industries are often smaller, they have fewer resources for exposure control and worker training, and oftentimes now they're vulnerable workers, so-called vulnerable workers, which means that they are, they may be undocumented, they may be non-English speaking, they may be particularly at risk because they lack access to the same rights and benefits that other workers may have, and, of course, with silicosis and with coal workers pneumoconiosis, there is no treatment, but it does require long-term medical care to assess disease progression and to manage all of these complications that can occur. So we have to do more. The burden of occupational lung diseases is still excessive, and I'm turning this over to people like Silpa so that hopefully, and Stella and others who are here in the audience, so that they can continue to tackle these problems that we, in my generation, have probably not done as good a job as we had hoped. The cases are Sentinel. That means that they reflect not only a failure of prevention, but they also reflect that other people may be at risk. So workers are still canaries. I'm particularly concerned about workers now being climate canaries, where workers are exposed to very hot environments and other sequelae of climate change that really bode ill for people who are not working in those environments as well. But workers have new exposures, there are new processes, there are new industries, and those workers will tell us when there are exposure risks to consumers and users. So we as clinicians are key to recognition in public health reporting, and I do want to say that I think it's important that we make sure that our professional societies are strong advocates. So there is the Western Occupational Environmental Medicine Association, which is the affiliate of ACOM, has put forward a proposal for an emergency temporary standard for engineered stoneworkers, and I'm hopeful that ACOM will help put something in place because, you know, when you see this disease and how devastating it is in these young workers, it really reflects how much more we still have to do. And then finally, I hope, if anything, that what I've shared with you today reflects the absolute importance of a transdisciplinary research approach and the need for team science. You know, we as clinicians are good at recognizing things, but we really need to work across disciplines to, you know, take from the bench to the bedside to practice to public health. So thank you. And, of course, there are so many people to thank. John Martini, Bob Cohen, Jeremy Waas, Silpa Kreft, Lauren Zellberen, Camille Moore, Carleen Kuhl, Richard Kraus, and Kathy Peng are part of my very kind of inner team, but many, many other people as well. So if the panelists could all come up so we can do a question and answer. So I really appreciate, let's see if I can use this, yeah, okay. I appreciate everybody and I think that if you look at overall, there were just certain things that particular speakers brought up. So Dr. Rosa, of course, I think brought up two things, one, the flavoring and just applying basic principles that we all learned about removing exposure, protection, all that sort of IH stuff. And then, of course, this newest discovery based on sentinel cases, which we had other examples of. Dr. Silpa, I thought was particularly interesting because here we could, we can never exactly know the exact exposure like we can in Dr. Pacheco's example, where she is actually looking the actual exposures in cannabis. So there's so many ways that we in occupational medicine approach these problems and bring them to the world, bring them to workers, bring them to legislation and changes. So I would like to open it for questions. Does anyone have questions? I'd like the microphone. And also to the panelists, if you want to add things, so we'll be able to pass it around. Good morning. My name is Sean Moser and thank you all for your time. I had a question in reference to the panel about the military operations. In thinking about that and with the other industries that were mentioned, what do you think that the safety culture and overall culture plays in, you know, maybe like it being a rite of passage that you work the burn pit or, you know, it's almost like it expected. I ran into that in the fire service a lot, so I was curious if you had any thoughts on that. I mean, I think that's, you know, just an excellent point that you're bringing up in terms of safety culture. And I know that Dr. Rose probably could add a lot about this too. So I'll start off and then if she has any comments about this as well. But what you bring up, like I think I showed a picture of somebody, you know, stirring trash, right? So usually that's somebody who's, you know, enlisted, you know, in their first one or two years of service. They're the ones that I think anecdotally I've heard, you know, doing this kind of activity day to day. And by their third or fourth deployment, they're like, oh, I was much more senior. I didn't have to do any of that, this deployment. You know, I only had this kind of exposure. And I think that there is that built-in hierarchy and, you know, exposure. Like when we're talking about vulnerable workers, these are some of the ones that we worry about. And I think we see that also in oil and gas workers and, you know, just other fields. So in the safety culture, you know, I think that's variable. I've met some veterans where there was some effort made to decrease exposures or maybe not to work outdoors unless absolutely necessary when air quality was poor. But I think by and large, that was not necessarily the main mission when they were deployed overseas. And so a secondary thought, you know, long-term outcomes were not necessarily a big concern. And then I think we'd sometimes hear there'd be a change in leadership, even in terms of referral patterns or people being evaluated or medical evaluation boards to get a diagnosis. It's like there's a new person in charge at this military base or this person. So all of these people are being sent for evaluation versus two years where there's maybe not any of that going on. But I'll pass it to Dr. Rose, too. Yeah, I don't have much to add except that when we first started doing this work, people pointed out to me that occupational health and safety was not central to our mission. Very nice presentations. My name's Jeff Levine. I'm from Tyler, Texas. And we actually had an experience a number of years ago with a coffee plant in Tyler with diastole lung cases. So I was just wondering, Dr. Rose, you mentioned that there's a disproportionate number of younger individuals who, compared with older, who seem to develop VO from the diastole exposure. Isn't it the case, based upon the issue of vulnerable workers, that these particular jobs in these industries seem to be populated with younger people? They are often a little bit lower-paying jobs, and often they are jobs in an area that's less desirable to work. I know you mentioned that older workers are leaving, and so they're lost to follow-up. But maybe it's the vulnerable worker issue, lower-paying jobs, and so forth, that contribute to the higher burden of it. Yeah, no, really helpful comment, and thanks for making it. I don't think there's any doubt, you know, that workers start low and may be in the highest-risk groups and may also be perhaps a little less seasoned in terms of how to avoid risks. I mean, there are all kinds of reasons why this may affect younger workers, but certainly, you know, being kind of segregated into the higher-risk jobs is a very important part of this. So, yeah, I just wanted to, you know, flashing through all of our data, kind of point out that part of the problem was a healthy worker-survivor effect. But you are absolutely right. We need, you know, we need to be particularly conscientious when we see younger workers in terms of, you know, really paying attention to risk, because they may not. Thank you for the great talks. You guys might not remember me, but I graduated from your program. I'm an active-duty Air Force occupational medicine physician, one of just a handful. We deal with mostly the industrial workforce, our civilian workforce. But when it comes to deployment, lung disease, it seems like there's more that we can do. I think we get, they get four questionnaires when they return from a deployment. From your perspective, is there anything more that the Air Force can do to help with them getting evaluated? I think there is, I think there are a couple of key things. The one that I think that we have been saying for a number of years, a number of occupational physicians is just in terms of medical surveillance, beyond just the questionnaires, having also some objective data. I know people have like run times, but often are on, you know, profile for musculoskeletal injury or something like that. But having lung function testing, I know it's not always the most sensitive test, but over time it can be very helpful, that dynamic assessment, like if you're seeing a big decline. So that's something that is not new. It was what helped us identify issues in the World Trade Center collapse before. When people come and look at some of the research, their first question is like, where's the pre-deployment lung function testing? There is none, unless we have an Air Force firefighter, you know, the few between, or at least targeting some higher risk MOS, you know, or specialty codes, although we know that that's still not completely protective. I just want to point out to the audience that that's Dr. Gabe Pepper, and he was a co-author on our study on military occupational specialty codes, and so, of course, we remember you. And I want to thank you, too, for the question. You know, what can we do? You know, what can the Air Force do? I think, you know, you probably have more insight into that than either one of us does, but I think that our hope is to collect enough of the evidence base so that, you know, people like you who are really, you know, boots on the ground putting, you know, putting things in place, implementing exposure controls and medical surveillance programs, you know, feel like you can do it with the best science possible. But, you know, kudos to you for being in that place to help us do that. Thank you. So, we'll take one more question. Hi. Al Philippi, currently a civilian OEM physician with the Navy Marine Corps Public Health Center, retired active duty OEM physician. I don't have the case experience of evaluating, you know, many people, you know, from burn pit deployment exposures, but a few. And I'm just wondering, do we have prevalence data, you know, for some of these, you know, rhinocytositis diseases and obliterans and so forth, do we have prevalence data? Because I'm kind of interested in that because we've had hundreds of thousands of deployers and I'm just kind of wondering as a question I had. It sounds like there are some, you know, areas where some of that information can be gleaned. But in terms of the total denominator, at least to my understanding, I don't know that we have that level of data. I know that there are some cohorts like the Millennium Cohort that follows Department of Defense personnel as they go through the VA and follows them over time so we can sometimes see the new cases that are rising over time. So, that's probably one of the strongest cohorts that we have that has over 100,000 personnel enrolled and they're following them longitudinally. So, you know, in terms of a hard and fast number, I don't know that there is any one particular good study that shows that. But I think it's because we're lacking the denominator and we don't have all of that information on all of our personnel. No, no, I mean, the answer, no. We don't have prevalence data. I mean, I wish we did, but we don't. You know, your point about many of these conditions being so-called ordinary diseases of life is absolutely true. So, you know, there is this sense of, I'm speaking for myself, this, you know, sense of dismay that I don't really know whether this is a small problem or a large problem. You know, I think that when we have looked at our data vis-a-vis things like number of deployments or location of deployments or frequency of deployments, when we've looked at these kind of really crude surrogates for exposure, there's a bit of a signal there in terms of some of the lung disease risk. But at the end of the day, prevalence is really hard to get your head around. Yeah, and this is one of the things we've been, now that I work in the environmental side at the center, you know, it's one of the things we've talked about is just we really still lack good exposure data, right? I mean, we really don't know what the exposure is. Absolutely. Thank you. Thank you to the audience. And thank you to our great panelists.

occupational lung diseases

hypersensitivity pneumonitis

indoor pool ventilation

exposure source fixing

cannabis cultivation risks

mold exposure

respiratory protection programs

silicosis cases

exposure control

safety culture