Episode 3: Understanding Silicosis

Episode 3: Understanding Silicosis

From Dust to Verdict is a podcast dedicated to the new epidemic of accelerated silicosis in artificial stone countertop fabrication workers hosted by James Nevin, a partner at Brayton Purcell LLP. 

In this episode, we dive deep into silicosis, the world’s oldest known occupational disease. From the slaves who built the Egyptian pyramids to 20th-century laborers at the Hawks Nest tunnel, and now to modern-day artificial stone fabrication workers—this preventable disease has devastated countless lives over millennia.

We trace the timeline of silicosis, starting with its early recognition, leading up to a surge of cases in Israel in the late 1990s allegedly tied to artificial stone fabrication. Fast forward to the U.S. in 2024, and we're facing a disturbing epidemic. The California Department of Public Health reports over 330 confirmed cases of accelerated silicosis in artificial stone workers, with dozens needing lung transplants—and many dying waiting for one.

What makes artificial stone especially dangerous to fabricators is its ultra-high silica content (up to 95%) and its nano-sized, toxin-coated particles. When these are inhaled, they scar the lungs’ air sacs, making breathing difficult at first and, with continued exposure, impossible without oxygen supplementation.

Listeners will learn how Respirable Crystalline Silica (RCS) from artificial stone causes damage more aggressively than natural stone. Silicosis is progressive and comes in stages—starting with lymph node silicosis, then simple silicosis, and finally complex silicosis or progressive massive fibrosis (PMF). Many workers exposed to artificial stone move through these stages rapidly, developing severe disease within just a few years or even months.

We explain the limitations of current treatment options. Lung transplants, often seen as a last resort, are not cures—they extend life temporarily, but are inaccessible to many due to strict eligibility, organ shortages, and complex post-surgery medication requirements.

The episode concludes with an alarming discussion of disease prevalence: peer-reviewed studies show silicosis rates in fabrication workers range from 11% to over 50%, with some estimates—including our own data—indicating up to 80% of workers may be affected.

Silicosis isn’t the only concern for artificial stone workers. Artificial stone silica exposure is also linked to lung cancer, COPD, chronic kidney disease, autoimmune disorders like rheumatoid arthritis, and other life-altering diseases like tuberculosis and sarcoidosis.

Silicosis is not a relic of the past. It's a modern crisis affecting artificial stone fabrication workers around the world.

Transcript

James Nevin: Hello everyone. Welcome back to another episode of From Dust Verdict. I'm your host, James Nevin, a partner at the law firm of Brayton Purcell LLP. This podcast is dedicated to the epidemic of accelerated silicosis in artificial stone countertop fabrication workers. In each episode, we explore important topics and issues about this occupational health epidemic as well as the associated lawsuits.

Today in episode 3, we will discuss silicosis. What is it? How do we understand it? 

Silicosis is the oldest occupational disease in history. For example, the Egyptian pyramids were built by slaves. Who, because they had to chisel and quarry the rock for the pyramids, died of silicosis. 

If we fast forward in time to the 1930s in the United States, we have what's known as the Hawks Nest incident. In this incident, we had hundreds of mostly black and migrant workers who died relatively quickly from accelerated silicosis while digging and blasting a tunnel. And then over the next few years, many more thousands of them died as well. 

If we fast forward further in time to 1997 in the country of Israel, we have the first publication in a peer-reviewed journal regarding artificial stone silicosis. Dr. Mordechai Kramer published an article in Chest Magazine, which is an internationally renowned and well-recognized journal. He published an article regarding artificial stone silicosis, and he reported on a cohort of artificial stone fabrication workers who were working with Caesarstone who had developed accelerated silicosis.

If we fast forward again in time to the United States in 2024, we see a massive increase in the use of artificial stone in the United States, and what then followed that was a massive increase in accelerated silicosis among fabrication workers. 

The California Department of Public Health now maintains an online silicosis dashboard in which they chronicle the current number of confirmed cases of silicosis in artificial stone fabrication workers, as well as additional details like their age and whether they've received a lung transplant or not, and the counties that they're found in. So according to the California Department of Public Health--they have chronicled approximately 336 artificial stone fabrication workers who have developed accelerated silicosis as of July 2025. And of those, 41 have received a lung transplant. 35 are on the transplant list waiting for a lung transplant and 19 have died waiting for a transplant. And approximately eight have been found to be ineligible for a transplant, but they need one. The average age of diagnosis is 46. Though there's many patients who are significantly younger than that, and approximately 98% of the fabrication workers are Latino who have developed artificial stone silicosis. 

So that's the brief background on the historical context of silicosis. Now, to understand silicosis a little more, we need to understand how it causes disease. And to do that we need to understand, first off, what actually is causing disease. 

So, silicosis at its core, is caused by Respirable Crystalline Silica, or RCS for short. And, in short, this means that silica is simply very small particles that, the most common way that we can think about it is beach sand is very large silica. RCS is much smaller than beach sand. 

RCS, or Respirable Crystalline Silica, is an ingredient in natural stone. It is also an ingredient in artificial stone with significant differences. And so, the main differences between the silica that's in natural stone and artificial stone is threefold. One is extremely high content in artificial stone (up to 95% silica) versus varying ranges for [natural] stone, which can range as low as 1% silica. 

Secondly, the RCS that is in artificial stone is intentionally pulverized to a nano size in the manufacturing process before it is put into artificial stone slab. And so, the silica in the artificial stone is not only much higher content, it's much smaller. 

And then, the third component of artificial stone silica is the other 5 to 10% of the ingredients in artificial stone are various other metals and toxins and volatile organic compounds that are used basically in the resins and in the coloring agents to make the artificial stone mimic the look of natural stone.

And so, the artificial stone RCS that is released in addition to being high content and nano-size is also coated with these other resins that are all also toxic. And so, this sort of toxic soup of specialized RCS that is released from artificial stone is causing accelerated silicosis. 

So, the way that silica, whether it be from natural stone or artificial stone, or something else, causes silicosis, is it first has to be breathed in.

And so, we breathe in through our nose and our mouth and the air gets down into our lungs and gets down into what's called our terminal bronchioles. One way to think about it is like an upside-down oak tree, and as the branches of that tree get farther and farther out from the base, they get thinner and thinner and thinner.

That's pretty much what the lungs look like. And at those tips of the bronchioles, at the terminal bronchioles, we have what's called our alveolar air sacs, and the average adult human male has about 500 million of these. These alveolar air sacs is where our breathing occurs. So, as we breathe in, the oxygen in the air that we breathe is diffusing across the alveolar air sacs into our capillaries to be transported around our body to, for example, metabolize our muscles. That process then releases carbon dioxide, which then goes back to the lungs through the alveolar air sacs to be breathed out, in and out. Oxygen and carbon dioxide going back and forth.

The problem with silicosis is these alveolar air sacs become scarred over by the RCS. And therefore, the scarred over alveolar air sac can no longer do its job. So traditionally in a trade, such as a miner or a sand blaster, or a natural stone countertop fabrication worker, a worker might, after many decades of working--maybe with a mask, maybe without a mask, maybe working dry, maybe working wet. But after many, many decades, they might develop chronic silicosis.

And this is an example of what chronic silicosis looks like under an X-ray on the left and on the right side under a CT scan. And it requires a specialized radiologist to review a specialty scan to determine if the worker has chronic silicosis.

Now in the United States, since legislation, starting in the 1930s and that was strengthened in the 1970s, the United States, up until recently, chronic silicosis was relatively rare. But in the globe as a whole, there was still probably around 100 thousand cases of chronic silicosis diagnosed every year.

So very much not an eradicated disease, but very much reduced in the United States, at least. That has all changed with artificial stone. The first stage of silicosis is called lymph node silicosis. This is the most minor stage. Most treating doctors are going to miss it, but if you have a specialist who reviews a HRCT, they will find lymph node silicosis. And lymph node silicosis is a silicosis in the lymph nodes.

And the lymph nodes are these sort of drainage nodes of our body that run throughout our body. And, you know, the most common example would be if we have a really bad cold, the lymph nodes on the sides of our throat might swell up or behind our ear. Those are lymph nodes. 

Well, we also have lymph nodes in our lungs. And silica, one of the first scarring diseases that it causes in the lungs, is scarring of the lymph nodes. So, lymph node silicosis. This disease doesn't cause any impairment. A worker's not going to know that they have it, but a specialty doctor looking at this knows that this is a marker of extreme exposure to RCS, most typically from artificial stone. And it's an indication that the worker has already been exposed to far too much [silica] and that they need to be provided with either state of the art safety equipment or be given the opportunity to change professions. Now if exposure were to cease in lymph node silicosis a large majority of those workers would not go on to develop the next level of silicosis.

The next level of silicosis is simple silicosis. Simple silicosis, again, is diagnosed by a specialist looking at a high resolution CT. It can sometimes be diagnosed by regular CT or by chest x-ray, but those devices will typically miss it, and so an HRCT is recommended. Simple silicosis, again, in a traditional worker, like a sand blaster or a natural stone fabrication worker, is something that would typically not be developed until after many decades, and the disease may simply stay at that rate.

Unfortunately, what we're finding with artificial stone fabrication workers is lymph node silicosis is quickly transitioning to simple silicosis, which is then quickly transitioning to a next level. So, with simple silicosis, a worker may or may not experience symptoms. They may experience shortness of breath, cough, fatigue. They may think that they have asthma or pneumonia or some other problem, or they may feel perfectly fine. 

So, in an artificial stone fabrication worker, simple silicosis is typically going to quickly progress to complicated silicosis, also known as progressive massive fibrosis, or PMF. 

So similar to lymph node silicosis and simple silicosis, complicated silicosis or complex silicosis is best diagnosed via an HRCT scan or a biopsy. A treating doctor who has experience with silicosis may diagnose it with a chest x-ray or a regular CT scan. But quite often those scans may be found to be negative even in someone with complex silicosis. And so that's why an HRCT or high-resolution CT reviewed by an expert  B-reader radiologist is the best method for diagnosis along with pathology or a biopsy. So, a biopsy would be the treating doctor would typically go in via the throat, down into the lungs and take a sample, and the pathologist would review it under a microscope and make a determination.

Typically, a worker with complex silicosis may also have pneumonia or a treating doctor may misdiagnose their complex silicosis as pneumonia. They may often have tuberculosis, or they may be misdiagnosed with tuberculosis, when in fact it's complex silicosis. Any combination is quite normal of those diseases.

And so, the difficulty with complex silicosis, with progressive massive fibrosis is the worker is suffocating. And so the only treatment is oxygen, and oxygen is not a cure. It's simply just a way to get more oxygen into those alveolar air sacs. So, recall we talked about before that silicosis is a scarring disease where those alveolar air sacs get scarred over and no longer function. And so, a worker with complex silicosis with progressive massive fibrosis, a large majority of their air sacs are scarred over and not working. And so, oxygen helps because it increases the oxygen concentration in the alveolar air sacs that are still working because it's providing a higher amount of oxygen than is in the normal air.

The problem, of course, is that the worker is now tethered to 24/7 oxygen and essentially becomes immobile, you know, their mobility is the length of the oxygen cord, that is attached to either their tank or a concentrator. 

So, with traditional silicosis, that you might find in a different type of worker other than an artificial stone fabrication worker, whether the worker has lymph node silicosis or simple silicosis or chronic silicosis, or even complex silicosis, that is a very slow disease progression in a typical worker. 

With artificial stone workers, what we're finding is the process is accelerated, so we have accelerated silicosis, and so the worker is quickly going through the stages from lymph to simple to complex with progressive, massive fibrosis in an accelerated fashion.

And so, a disease that might take decades in a typical worker, and in fact, the worker typically would not live long enough to develop the disease. In an artificial stone worker, the accelerated silicosis is developing within months to a few years.

With accelerated silicosis, in artificial stone workers, in addition to that, we see what's called acute silicosis, also sometimes known as PAP. 

Now, acute silicosis is very similar to complex silicosis with progressive massive fibrosis. The main difference is with acute silicosis or PAP, the worker also develops fluid in their lungs, which makes it even harder to breathe because in addition to the scarred over alveolar air sacs, now their lungs have to contend with the fact that they're filled with fluid, right? Like someone might have with severe pneumonia.

The second aspect of acute silicosis is that it develops very fast. And so an artificial stone worker due to the very high levels of nano-sized silica, coated with other toxins, the sort of witches brew toxic soup that is exposing these workers, they can develop acute silicosis within only a few weeks or months of exposure.

So, whether the worker has complex silicosis or accelerated silicosis or acute silicosis, or a combination of any of those three, as I mentioned, that the only treatment is oxygen. There is no real cure. You could potentially call it a cure, but it's not fully a cure, which is a lung transplant.

There's multiple problems with lung transplants being the cure for accelerated or acute or complex silicosis. The first problem is, quite simply, a donor needs to die with compatible lungs for a patient who qualifies to get the transplant in the first place. 

Secondly, the worker has to have access to competent medical care and specialized medical care because there's very few medical facilities that can even perform lung transplants. So, for example, in Southern California, there are three lung transplant possibilities. UCLA, USC Tech and Cedars Sinai. There's one in San Diego. But, for example, there's none in Orange County. There's none in San Bernardino. So a worker has to be able to have access to medical care at a facility that can provide lung transplants in the first place, a donor has to die with compatible lungs, and the worker has to get on the transplant list, which means they have to qualify, which they have to be sick enough to need it, but not so sick that they won't survive the transplant.

So, if a worker has access to a lung transplant facility and they qualify for a lung transplant, which means they're sick enough, but they're not too sick and they don't have any comorbidities, such as being overweight ,or having HIV, or having diabetes or significant cardiac problems, and a donor lung becomes available, then they may be lucky enough to have a lung transplant.

The lung transplant surgery itself is a radical surgery. Many patients don't survive the surgery. Assuming they survive the surgery, it's many weeks to a few months of recovery from that surgery. And then most of us think of an organ transplant as sort of a one and done thing. And that might work with, say, a liver transplant or a kidney transplant. With your lungs, your body does not want those replacement lungs, and it immediately starts to try to reject those lungs. And so, the lung transplant recipient has to take numerous medications. No exaggeration, around 50 different medications a day, including medications that are immunosuppressants to suppress the body's ability to reject those lungs.

And even with those medications, the body over time is going to be successful in rejecting those lungs, such that on average, let's say five years on average, and with some people it may be two or three years, with some people it may be seven or 10 years, but on average about five years--the body is going to be successful in rejecting those lungs. And then the worker is either going to die or they're going to need a second lung transplant. And so, you can imagine if you're a worker and you're 30 years old and you are lucky enough to meet all their criteria to actually get a lung transplant and you survive the lung transplant, well then, you're going to need a second lung transplant at around 35 years old. Five years after that at 40, it's unheard of for someone to get a third lung transplant. So best case scenario, if you are a 30-year-old worker who needs a lung transplant, your best-case scenario is that you're going to live to around 40 years old. So, that is why I say that lung transplant is not really a cure. It's a life extender and it's a very difficult life that the worker patient has, where they need to spend most of their time trying to keep their body from rejecting those lungs. So, the lung transplant as a supposed solution to accelerated or acute silicosis for an artificial stone fabrication worker, it's just not an effective solution. 

So next in understanding what exactly is silicosis, particularly in artificial stone fabrication workers, is we need to understand the incidence of disease. In other words, how many stone fabrication workers are getting or will get accelerated silicosis? So, there's been numerous published peer reviewed studies throughout the world starting in 2011 and up through 2023, where various groups of artificial stone workers have been studied, different size groups, some smaller, some larger, and amount of time spent fabricating stone. And various tools were utilized most typically either a chest x-ray or regular CT scan. And the studies noted the prevalence rate. 

So, among those studies, the lowest prevalence rate is just over 11%. Now, 11% to a lay person may seem low. It’s actually quite high. An example would be if we look at only one in 10, heavy two pack a day smokers is going to get lung cancer, or 10%. Yet we still look at that from an epidemiological point of view as an epidemic.

As another example, the traditional asbestos insulators, that group of workers, approximately 10% of them got mesothelioma. Again, that was considered epidemic levels. So again, if we look here at the prevalence studies for artificial stone fabrication workers developing silicosis, the lowest finding is 11% and the finding ranges up to 54%. Meaning, if you look at a particular fabrication shop, over half those workers are going to get silicosis. 

Our own data indicates that the prevalence of artificial stone silicosis in fabrication workers is actually even higher than that. We're finding up to 80% of fabrication shop workers have some level of silicosis. And so, if you extrapolate that out to the number of fabrication shops and fabrication workers, in any particular state or county throughout the country, whether you're looking at Los Angeles or you're looking at California, or you're looking at Florida. And so if we look at our own data showing that the rate of artificial stone accelerated silicosis in fabrication workers is as much as 80%, and we extrapolate that out across the country and think about how many fabrication shops there are in the US and how many fabrication workers there are in the US, we can expect a significant amount of workers, who have no idea that they are working with this product that is going to cause fatal disease, are going to develop silicosis over the next several years.

In addition to silicosis, including the various types of silicosis that artificial stone causes, artificial stone fabrication workers are also at an increased risk for several other diseases. And the first one is lung cancer and quite simply silica and the other components of artificial stone, in addition to being toxins that cause scarring, there are also carcinogens that cause cancer. And so, the process of breathing in that toxic soup into the lungs, the same way that it gets into the lungs to cause the scarring diseases, it can cause lung cancer. 

Other diseases caused by artificial stones include chronic obstructive pulmonary disease. That's a difficult one because if anyone was a smoker, well, COPD, is very commonly caused by cigarettes as well.

Other diseases caused by artificial stone include chronic kidney disease or CKD and various autoimmune diseases--the most common of which is rheumatoid arthritis or RA. 

Exposure to artificial stone also causes sarcoidosis. Now, sarcoidosis is a disease that is different from silicosis, but very similar. And so often a worker could be misdiagnosed with sarcoidosis and actually what they have is silicosis. Or the worker could be diagnosed with sarcoidosis, and they also have silicosis. Some specialists have coined a new termed of “silio-sarcoidosis” to note the combination of the two in workers.

And additionally, workers with silicosis are at increased risk for tuberculosis or TB. So, a worker with silicosis can have tuberculosis on top of that. Also, many workers with silicosis are misdiagnosed as having tuberculosis when they may have never even had that disease--what they had was silicosis. 

Silicosis can also leave workers subject to various other bacterial and fungal infections of the lungs.

So today we covered what is the history of silicosis and what is silicosis, particularly in the context of artificial stone disease. In our next episode, we'll cover various safety mechanisms and how a worker or a fabrication shop can utilize various safety mechanisms to try to prevent silicosis. What works, and more importantly, what doesn't work.

Thank you for tuning into this episode of From Dust to Verdict. I'm your host, James Nevin from the law firm of Brayton Purcell LLP. Remember to like and subscribe, and for anyone who speaks Spanish, I encourage you to check out the Spanish language version of this podcast hosted by my good friend Charlie Velasco Ariza.

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