On the Job: Identifying Occupational Lung Disease

Podcast Transcript

Raed Dweik, MD:

Hello, and welcome to the Respiratory Exchange podcast. I'm your host, Raed Dweik, Chairman of the Respiratory Institute at Cleveland Clinic. This podcast is intended for healthcare providers and covers topics related to respiratory health and disease. My colleagues and I would be interviewing experts about timeless and timely topics, in the areas of pulmonary, critical care, allergy, sleep, and infectious disease. I hope you enjoy today's episode.

Hello, and welcome to this episode of the Respiratory Exchange podcast. I'm your host, Raed Dweik, chairman of the Respiratory Institute at Cleveland Clinic. My guest today is Dr. Maeve MacMurdo, who directs our occupational lung disease program. Welcome, Maeve.

Maeve MacMurdo, MBChB:

Thank you for having me.

Raed Dweik, MD:

So, our topic today is occupational lung disease. And, let's start just by the basics, and letting us know, what do we mean when we talk about occupational lung diseases? What are we referring to?

Maeve MacMurdo, MBChB:

So, good question. And the answer is really, a whole lot of things. Occupational lung disease is really anything which is work-related, or related to exposures on the job. That can be things like black lung, coal workers' pneumoconiosis, silicosis, but also things like occupational asthma or ILD, which has been triggered or exacerbated by work. So really, it's actually a really broad category. It's hard to narrow it down to just one thing alone.

Raed Dweik, MD:

All right, this is why we're having an episode about it. I guess we'll talk about the details as we go along. So first of all, our audience could be pulmonary physicians, but it could be generalists and other physicians. So why should physicians and other providers care about knowing about occupation lung disease? Why is it important?

Maeve MacMurdo, MBChB:

So, I think, when all people think about occupational lung disease, they really think about it as kind of being a disease of history. It's something which used to exist in the United States, and things have changed, and it's gone away. And the reality is, that that really just isn't the case. We have seen an ongoing frequency and prevalence of things like silicosis. There's been a surge in coal worker's pneumoconiosis.

The reality is that United States is still a major manufacturer. We still have mining, and so workers are still exposed. And when you think about sort of exposure and lag time, the reality is that workers who were exposed in the 40s, 50s, 60s, who are still alive, may only now be showing signs of disease. Things like asbestos, which you think about things that we don't really use anymore. A, still isn't actually banned. It's still in use to some extent in the United States. And B, because of the lag time, we see disease from asbestos usually 30 to 40 years long, after the worker is actually exposed. So even though it may seem like things have gotten better, but in reality, we're still seeing the impact of changes in occupational practices that were occurring back in the sort of 60s and 70s. And so it still occurs. It's still relevant.

And the other thing, not to get on my high horse, but the other thing is that there are still new exposures. We think about these old-fashioned exposures like coal and silica dust, but the reality is that as long as people are working, they're still going to be exposed to things. And as we see these new exposures, we see new diseases. And the only way to figure out these new diseases is really to actually think about, could this be occupational?

The flavor-induced lung epidemic that was found from popcorn lung that was found by a German pulmonologist who saw patients in his practice and went, you know, this isn't right. This doesn't make any sense. So he actually reached out to NIASH, and asked NIASH to investigate, and that led to that being discovered in the first place. Again, I think thinking about work is really important when just thinking about overall lung disease and lung health.

Raed Dweik, MD:

So it's an important part of our history when we see a patient, always to ask about their job. It's not just a theoretical question. It may have clues to why they are here in the first place.

Maeve MacMurdo, MBChB:

Exactly, and it's not just in that job, but also, what have you historically done.

Raed Dweik, MD:

Oh, great point. Not just your current job, but what jobs have you done before.

Maeve MacMurdo, MBChB:

Exactly. A lot of patients are retired, and they won't tell you about what they used to do. But if you probe a little bit, you can get some really interesting detail. Plus, I think it's actually just interesting. I learn a lot about my patients and kind of their overall background from what they used to do for work.

Raed Dweik, MD:

Yeah. I know this also, occupational exposure is regulated. You know, maybe tell us about what OSHA is and what the standards mean and how we're dealing with that.

Maeve MacMurdo, MBChB:

Yeah, so OSHA basically sets regulatory standards for a lot of the exposures in the workplace. Some of it is for OSHA, some of that's for the EPA. They kind of share that responsibility and role. For a lot of what I see, particularly things like beryllium and coal dust, OSHA manages that standard. And they have these final rulings, which basically set allowable limits, the kind of perceived safe limit for workers who are exposed to these compounds.

OSHA also regulates screening and their requirements can change. A good example of this is in 2018, OSHA actually upped their final ruling for beryllium exposure. And so what that means is that workers in industries outside of just primarily beryllium manufacturing, are now being for beryllium-associated disease. And what I'm seeing as an occupational pulmonologist is actually a whole lot of workers who didn't know they had beryllium sensitization, which is basically the precursor for beryllium disease, are now being discovered, along with cases of chronic beryllium disease, which just had been, again, not picked up.

Because when you think about workers and people who are actively working, often they're healthy. They're physically fit. They're physically active. They're the guys who aren't going to complain when they feel a little bit short of breath, or have a little bit of a cough. They're going to go, it's nothing to worry about. But in reality, when you screen these workers, we find disease in these early stages, which is preventable. And potentially treatable. So that's why the OSHA standards and the fact that the OSHA standards are being updated is really important. OSHA looks at the evidence and the guidelines, and they change to kind of, again, try to protect workers as much as they can.

Raed Dweik, MD:

Yeah. And OSHA, just to clarify to our audience, is the Occupational Safety and Health Administration, correct?

Maeve MacMurdo, MBChB:

Absolutely, I love my acronyms.

Raed Dweik, MD:

Like acronyms always kind of get us in trouble, so I just want to clarify to our audience. And, early on, when we started, you mentioned old exposures and new exposures, you know? Can you kind of differentiate and tell us what do you mean by new exposures?

Maeve MacMurdo, MBChB:

Yeah, so again, I think the new exposure stuff is really interesting. I mentioned briefly, the, again, popcorn lung, diacetyl exposure. But also what we're seeing is silica exposure and things like other exposures, which were old exposures. So things we saw of mining, of construction now in new industries. So I think in the media, well, probably 2018, 2019, there was some attention paid to an outbreak of silicosis among engineered stone workers. So engineered stones are a new compound, which is basically a mix of quartz and crystalline silica. So when you cut it, when you grind it, you release huge amounts of silica into the atmosphere. It's great. It's cheap. It looks like marble, but it's not. And so it became really widely utilized really quickly because again, it's the cheaper and nicer, long-lasting version of marble. Why wouldn't you want it?

But the problem is for the workers who are cutting and grinding these compounds, they were getting huge amounts of silica exposure, which really wasn't recognized until we started to see cases of young workers coming in with very, very severe end-stage silicosis. And so engineered stones silicosis, as we're now calling it, has really been this new epidemic of silica, which is occurring not just in the United States, but really across the globe. We're seeing it again in Israel, we're seeing it Australia. Workers who are working with these compounds, who really didn't know they were at risk.

And then I think also, when you're thinking about new exposures, one thing that I try and conceptualize in my research a lot is that there are exposures that we sometimes don't think about as being occupational that really are. So things like air pollution exposure. Workers who work outdoors, like agricultural workers, like construction workers, people who work on the roads. They're all exposed to large amounts of air pollution, and that really is an occupational exposure. Because of their job, they are directly exposed in a way they otherwise wouldn't be.

When you think about things like wildfires in California and just the worsening air quality, you recognize that potentially these workers have really high-level exposures that we're not capturing and really not thinking about. And no one really knows what the health indications are for those working groups, but they could be significant.

Raed Dweik, MD:

Oh, wow, so I didn't think of that. So you're talking about air pollution as an occupational or a specific type of air pollution? Do you think, I wouldn't think of air pollution as an occupational exposure, but I think certain occupations, it may be. Is that what you are saying?

Maeve MacMurdo, MBChB:

Exactly, and I mean, for a lot of occupations, potentially, it may be. Air pollution impacts all of us, but for workers who are outside and aren't protected, they have significantly more exposure to things like particulate matter, so near-traffic pollution. That can be a major drive of respiratory mortality. And again, that's truly an occupational exposure for these workers. They're exposed because of their work.

Raed Dweik, MD:

And if you're a truck driver, you're on the highway eight hours, nine hours a day, then that's, you're getting the diesel exhaust.

Maeve MacMurdo, MBChB:

Exactly, or if you're working on the roadsides. Say you're doing road construction. Those workers are exposed to road traffic, dust, particulate matter on an extremely high level. And again, no one thinks about that because it's not a classic occupational exposure.

Raed Dweik, MD:

You mentioned firefighters, of course, with the fires. Even, you remember, the 9/11 responders. You know, we think about when they showed up, that a lot of things came out of that. That's an occupational hazard as well.

Maeve MacMurdo, MBChB:

It is. World Trade Center exposures. Firefighters are a really high-risk group. And we're still a lot of actual long-term health impacts from those, again, the increasing prevalence of wildfires. We know that wildfire smoke exposure historically didn't occur for as long as it now occurs. So we're seeing a lot more lung injury.

And then I focus a lot on agriculture workers. Because you think about field work, you're out there day in, day out. You don't stop harvesting because the air quality is bad. And right now, OSHA doesn't actually regulate air quality, but there is some move towards doing it. OSHA is the sort of federal OSHA, but states have their own OSHAs. So things like California, Washington, Michigan, they have their own state-level OSHAs. And these state OSHA can set policy outside of the federal OSHA.

And so California OSHA recently set a new policy basically regulating occupational air pollution exposure for wildfire smoke, targeted primarily agricultural workers who are working out in these fields during these wildfires. And they were seeing extremely high-level particulate matter exposure during those events.

Raed Dweik, MD:

Wow, that's something I haven't thought of traditionally as occupational exposure. But it does make sense the way you describe it. So what you're telling me is the federal form of OSHA is not currently regulating these types of exposure. But some states are starting to do it, like California. Is that the state now?

Maeve MacMurdo, MBChB:

Exactly, and I think what we see historically is that that kind of sets a trend. So often, these regulations will start at the state level and then be embraced by federal OSHA. And so I think hopefully in the future, we'll see a federal air pollution standard, though again, it depends a little bit on a lot of things. Developing a federal standard takes a long time, and it's hard. You've got to get a lot of people all on the same page, and you have a lot of discussion about what is truly a safe standard. I think the air pollution, we struggle to answer that question even in a sort of population level.

Raed Dweik, MD:

Yeah. So you really opened our minds today to kind of different levels of thinking of ways of occupational exposures. Additional ones like coals and silica and beryllium. The new ones, like engineering silicosis. But now you are telling me the environment could be. 

So that's really expanding the definition of what occupational is. So with all those things, there's so many things to think about. How do you come about evaluating a patient who shows up either for an occupational reason, or now you are telling me we have, even when they are not coming for that reason, we have to keep that high in your mind. So how do you appreciate a new patient when you see them in your clinic?

Maeve MacMurdo, MBChB:

It's really all about the history. And it's a nice chance to actually really ask what people actually do for a living and what that means. So most of my visit is really spent going through where you were born, where you grew up. What you did during high school. Whether you were deployed. And then really going through, not just your most current job, but all the jobs you've worked along the way. What kind of PPE you wore, what kind of task you did in that job. Because all of those things actually impacts your overall risk. So it's not just what job you did, but it's kind of the conditions in which you did it.

If you think about, potentially, again, mining. If you're mining on the coal seam, versus if you're driving a truck for the coal mine, that's a different exposure in the same general job. Similarly, if you had a great company who supplied really good PPE and really great about making you wear it, that's a different exposure than the company who, again, didn't enforce PPE or didn't offer PPE. So it's not just the work you did, but really the working conditions.

Raed Dweik, MD:

Yeah, that's a great point. So what's the point, then? Why would you need to find out? Is there something we can do about it? Why would we want to know if someone has occupational lung disease versus another etiology, other symptoms?

Maeve MacMurdo, MBChB:

Another really good question. And the answer is, it matters for a couple of reasons. One, a lot of these occupational lung diseases, if they're caught early, can potentially be, again, slowed down. We think about this term exposure removal. Basically, taking the worker out of the workplace, away from the exposure. For things like beryllium, coal dust basilica. We think that removing you from exposure can potentially slow down progression, so again, improve your outcomes.

And additionally, while we think about occupational lung disease kind of being this untreatable behemoth, the reality is that some things, like chronic beryllium disease, like having a lung disease, they are treatable. There are treatments that you can target if you catch it early. If you catch it late, when it's fibrotic and scarred, we have limited treatment options. But again, if- when we catch it early in the inflammatory phase, there are treatments we can offer which can potentially reverse damage, and they can promote better quality of life.

There is also some role for the antifibrotics that's increasingly being made clear. So again, it shows some benefit for patients who had occupational lung disease. They really weren't the primary cohort. There's some clinical trials now that are ongoing looking at basically, of coal workers' pneumoconiosis and some antifibrotic therapy. So there's some interest there in potentially starting those treatments and seeing if that can potentially improve outcomes.

Raed Dweik, MD:

So as I remember is removal from exposure is the primary way. Is that usually too late? Or is still your first line of treatment for these individuals, is to get them out of the line of exposure as early as possible.

Maeve MacMurdo, MBChB:

It can still make a difference. Even if you're catching it late, exposure removal can still help. And obviously, that's challenging, right? Workers work these jobs. Often, they're skilled jobs that are well-paid. So it's not as easy as it sounds. I say exposure removal, but in reality, it's lot more of a risk/benefit discussion with the worker themselves. Because it is a tough conversation to have. But it does make a difference, and it can make a difference.

Raed Dweik, MD:

Yeah, that's a great way to put it. So now if somebody out there, a general internist or a pulmonologist sees a patient that they suspect or believe somebody has occupational lung disease, is that something they can handle on their own? Should they refer them to you or somebody who's specializing in occupational disease? What do you recommend the approach to be?

Maeve MacMurdo, MBChB:

I think if you're ever concerned and don't know, it's always worth referring to occupational pulmonologists for an evaluation. A lot of time, I'll see patients for sort of a one-time visit. It's an occupational visit. And then get them back to their referring provider for ongoing care. But if it's a concern of a question about it, I think it's helpful to get an answer that's clear as it can be.

And we can't always say with 100 percent certainty this isn't or is an occupational. But we can provide guidance in kind of the likelihood. And I think for a lot of workers, in particular, that can be really helpful. Not just for the worker themselves, but also thinking, if they're still working, there are potentially other workers who are also exposed. So really figuring it out can impact not just your patient's life, but the lives of the workers around them.

Raed Dweik, MD:

That's good. Anything else? Look, we covered lot of ground here. And I want to maybe just touch base on one of these, you know, each one of it could have its own podcast, I can imagine, all these occupational lung diseases, the old and the new. One unique one that you and I have been involved in is chronic beryllium disease. Because unlike the other ones, it seems to be more, like, immune-mediated than, like, direct lung disease. Can you talk about that and how something like beryllium disease is different than the traditional, you know, occupational lung diseases?

Maeve MacMurdo, MBChB:

Absolutely. So beryllium is actually really interesting. It's got a long history. And basically, what we know is that workers who are exposed to beryllium, kind of through luck of the draw can develop something called beryllium sensitization. As if turning on a switch. Their immune system is activated, meaning they're at risk for developing chronic beryllium disease. Not all workers who are sensitized are going to go on to develop disease. So some workers can each be sensitized their entire life, and never deal with current beryllium disease. Other workers, because sensitized, and develop disease straight away. And figuring out who's going to develop disease and who's going to progress is really sometimes pretty challenging. It's not always clear.

I think beryllium's really interesting because it's one where you can screen for. And knowing that a worker is sensitized is actually important in thinking about exposure removal. Because, like I talked about, if you can remove them from exposure, the risk of progressing to chronic beryllium disease potentially goes down. And so screening for beryllium is really, really beneficial and really important, which is why OSHA updated the standard, recognizing that beryllium sensitization can occur at really even low levels.

Raed Dweik, MD:

Yeah so I think, to me, what strikes me about it is that, just the body's reaction is different. You know, it's more of an immune response, the immune system responding, as opposed to just direct injury to the lung, which makes it, again, different for screening, et cetera, like that.

Maeve MacMurdo, MBChB:

Exactly, and it kind of goes along with something called hard middle lung disease, which is also, so, similar, again, triggered by cobalt in an immune-mediated process. So I think we always think about the lung disease, as occupational lung diseases as being scarring diseases. But they also, it's an immune-mediated component. And those ones are really interesting, because they can be treated and caught early.

Raed Dweik, MD:

Yeah, I'd like to highlight here that maybe asbestos exposure because I know while it's declining, as you said, it's still there. You know, there are still houses with asbestos. They're still used in manufacturing. But long lag period before asbestos shows up. So it could be, like, could be 20, 30 years or longer. Can you comment on that a little bit?

Maeve MacMurdo, MBChB:

Yeah, so actually, we're seeing the peak of mesothelioma cases now. So when you think about asbestos, we know that the asbestosis, which is the scarring, the sort of pneumoconiosis form of disease, and the mesothelioma, the pleural cancer, both have a really long lag time. So workers who are exposed when they are in their 20s and 30s are gonna develop their in their 60s, 70s. And so what we see is that even though use is really decreased, the peak is really happening now. And it's gonna probably persist for quite some time. We're gonna see another 10, 12 years, where we're going to have high levels of asbestos-related lung disease.

Raed Dweik, MD:

Yeah, which kind of again, raises the point you mentioned earlier about the importance of occupational history. You should go back to as far as you can go because these diseases, especially things like asbestos have a long, really long lag time. It's not what you were exposed to last year. It what you exposed to 20, 30, 40 years ago.

Maeve MacMurdo, MBChB:

Exactly, and for a lot of those guys who have asbestos-related lung disease, the exposure occurred during deployment, which people don't often mention. People forget that they were deployed.

Raed Dweik, MD:

Yeah.

Maeve MacMurdo, MBChB:

Or don't count as being work. Because again, for a lot of these guys, it was sort of voluntary and sort of not.

Raed Dweik, MD:

Yeah, that's a good point.

Maeve MacMurdo, MBChB:

Really got to dig sometimes and go, but were you deployed? And they go, oh, yeah, for four years. That counts.

Raed Dweik, MD:

Yeah, that's a great point. I'm glad you brought it up. Anything else you like to add? I think this is chock full of information about occupational lung disease. Anything else you'd like to add?

Maeve MacMurdo, MBChB:

No, I mean, I could talk about this for hours, as you can probably tell, but I just think it's really important that people be aware of it. It's really easy to miss occupational lung disease or not think about it. But it does have important implications for just the patient, and also just, it's important to know about. It's not going away. It's still around. It's not going to go away anytime soon.

Raed Dweik, MD:

Wonderful, I just want to summarize with a view takeaways to our audience here. That occupational lung disease have not gone away. You know, we'd like to think that it's with industrial ingenuity and controls that they've gotten better, that they're really still there. Not only that, but new exposures, like engineered stones, et cetera, we're getting exposed to the popcorn you mentioned. And that still, the most important tool in finding that out is getting a good occupational history. Not only of your current job, but of your previous job. And also not just jobs, but the conditions in those jobs. And really to close by the fact, if you are not sure, always think of referring your patient to an occupational lung disease clinic. Is that fair?

Maeve MacMurdo, MBChB:

That is absolutely fair.

Raed Dweik, MD:

Okay, wonderful. So thank you, Maeve, for joining us today, and for our audience thank you again for joining us. Again, this is your host, Raed Dweik, MD, chairman of the Respiratory Institute at Cleveland Clinic. And my guest today was Dr. Maeve MacMurdo, who runs Occupational Lung Disease at Respiratory Institute at the Cleveland Clinic, and that was the topic of our discussion today. Thank you and have a great day.

Thank you for listening to this episode of the Respiratory Exchange. For more stories and information from Cleveland Clinic Respiratory Institute, you can follow us @clevecliniclungs, or follow me at @raeddweikmd. Thank you.