Asbestosis, silicosis, sick building syndrome

- So occupational lung diseases, once again, are diseases of the lung that are somehow related to some work-related or some occupational exposure. And I'm gonna talk about three types of occupational lung diseases. And the first type of occupational lung disease, we're gonna talk about is called asbestosis, asbestosis. And asbestosis is caused by asbestos exposure, right. And what fields does that occur in? Well, it can occur in-- The exposure can occur in construction. So it can occur in construction. It can also, plumbers can be exposed to asbestos. So it can be seen in plumbers. And finally, it can also be seen in shipyard workers, so people who work on the ship or people in the navy, like that might be a clue to exposure to shipyard environment. Those are some of the fields in which you can be exposed to asbestos and wind up with asbestosis. And asbestosis is really important because it increases, it increases the risk of lung cancer, of lung cancer, primarily. And it also increases the risk of mesothelioma. So it increases the risk of lung cancer, and it increases the risk of mesothelioma. And I guess mesothelioma tends to earn more media recognition, but something that's really important to keep in mind, that it's actually lung cancer that's most likely to arise after exposure to asbestos rather than mesothelioma. So a person exposed to asbestos is more likely to do up lung cancer than mesothelioma. So the second occupational lung disease I'm gonna talk about is silicosis or exposure to silica. What fields does this occur in? Well, silicosis can be seen in sandblasters. Sandblasters. And it can also be seen in silica minors. To be honest, I didn't even know there was such a thing as silica minors until I explored this further. But there is such a thing as silica minors. And silicosis is really, really, important because it increases the risk of tuberculosis. It increases the risk of TB. And the mechanism by which it does this is important, and it's interesting. So I wanted to explore that a little bit further. Let's see, what you see in the orange here are little tuberculous bacilli. Okay, so those are, that's a TB. And we know that TB is handled by our body, right, by macrophages. So there are these big, white blood cells that will engulf the TB bacteria, that will engulf them, that will eat them all up, just like I'm trying to show the macrophages taking up the TB bacilli. So these are the macrophages, right, so the white blood cells that are responsible for protecting our body against this bacteria. And what silica exposure does is it inhibits the function of the macrophages so that the macrophages are no longer able to take up the TB. And so that predisposes a person who's been exposed to silica to developing TB infection. So the third type of occupational lung disease, I'd like to talk about is sick, is sick building, Sick Building Syndrome. These are only three types of occupational lung diseases. I'd really like to point that out that I picked three important ones, but these are not the only ones. So Sick Building Syndrome, where do you get exposed to Sick Building Syndrome? Usually it's seen when you have AC or heating ventilation problems and also when people are exposed to different mold found in older buildings or unkempt buildings. So these three types of occupational lung diseases, actually have a common thread that runs through them. They have a common pathogenesis. I'm gonna scroll down just a touch. I'm gonna bring up back this picture of the lung. And let's say-- For example, let's say that we are inhaling these particles. These are particles of asbestos, called asbestos fibers. Or inhaling silica particles or molds in Sick Building Syndrome. So we inhale these particles and they go and they deposit into the tissue of the lungs. So that's what I'm showing over here. It's being deposited into the tissue of the lungs. And really importantly, we have white blood cells scattered all throughout the tissue of the lung. And these white blood cells will take up any particles, any dust particles also, any silica, any asbestos, any molds, that make their way into the lung. And that's what I'm trying to show. I'm trying to show the white blood cells sort of engulfing these bad particles that can damage the lung. So through the engulfing, through the function of these macrophages or white blood cells, they're sort of engaging in battle in the lung. And by their engaging in battle in the lung, it leads to a sort of environment of inflammation in the lung. So because they're trying to destroy these particles, it leads to this environment of inflammation in the lung. And that inflammation over the course of not days or weeks or months, but over the course of several years, leads to the development of scarring and of fibrosis, so that's really important. So over the course of many years, all this inflammation that's present through the continual inhalation of these particles will lead to fibrosis of the lung. That fibrosis is what's responsible for the lung disease, for the lung manifestation. So difficulty breathing and all the things that happen in occupational lung disease in these three cases is due to fibrosis of the lung. So in asbestosis, silicosis, and in Sick Building Syndrome, you end up with scarring and fibrosis of the lungs. So keep in mind that these are only three types of the many, many, types of occupational lung diseases. And this is the mechanism by which they cause disease, eventually leading to fibrosis of the lungs.