EI2 Asks: Jenny Houlroyd, DrPH, Discusses Silicosis and Engineered Stone Manufacturing

Jenny Houlroyd is the Occupational Health group manager of the Safety, Health, and Environmental Services (SHES) program, which is part of Georgia Tech’s Enterprise Innovation Institute. On May 16, 2024, she gave a presentation at the conference Preventing Silicosis – An Ancient Disease in Modern Times: Silicosis Caused by Artificial Stone in the U.S., hosted by the Center for Occupational and Environmental Health at the University of California, Los Angeles. As June is National Safety Month, Houlroyd, a national expert on the disease, discusses the prevalence of silicosis in the manufacturing of engineered stone and explains why keeping workers safe is essential to growing Georgia’s economy.

Jenny Houlroyd, CIH, MSPH. DrPH

Why is manufactured stone more hazardous to work with than natural stone?

A natural stone slab typically has a concentration of silica that’s 40% or less. It’s comprised of lots of different minerals. Engineered stone or quartz countertops can be 90% — and reaching towards 100% — silica. They take silica, crush it, mix it with polyester resins and other minerals, and then compress it under either high heat or pressure to make the slabs.

When the slabs get to the fabricator, the workers at these countertop fabrication shops have to cut or grind on it a second time, making some of dust produced into nano-sized particles. Not only does it become nano-sized, but it becomes charged and reactive, and there is a growing body of research these demonstrates this dust causes more inflammation in the lungs when compared to a natural stone slab. There’s some interaction, and they’re not quite sure what it is yet, but they think it’s a combination of the polyester resins, the nano-sized silica particles, and the other minerals present that’s leading to this aggressive development of silicosis. So, it’s very different than a natural stone slab.

You recently completed your doctorate in public health (DrPH). What was the focus of your dissertation?

I did my dissertation on respirators because they are the last line of defense for a lot of workers. If we don’t get that right, then we’re going to have workers at high risk of being exposed to inhalation hazards on the job.

How does that tie into your work around silicosis?

I have been with SHES since 2005, and over the course of the 18 years I have been going to stone fabrication shops. I have watched these stone fabrication shops go from being able to control the exposure to silica when fabricating countertops with the use of wet methods to now, when fabricating engineered stone slabs, needing to upgrade their employees’ respiratory protection to a powered air purifying respirator. I would classify engineered stone as a really toxic product. When you have something that’s high-risk, you have to prepare for any of those systems to fail and have backup measures. However, now we are asking employers to purchase not only additional equipment to control the dust exposure, but we are also asking them to invest in these expensive respiratory protection devices. The stakes are very high if these respirators are not the right size, fitted properly, and the employees understand how to clean and store the respirators.

When I go out to these shops, most of the workers in this industry are relying on respirators as their primary source of protection, and they need a lot more to protect them from that hazard. Personal protection equipment (PPE) is the last line of defense, and safety needs to be addressed from all angles. That’s what’s known as the hierarchy of controls: elimination, substitution, engineering controls, administrative controls, and then we get to personal protective equipment. In fact, Australia banned the fabrication of engineered stone because they determined that the only option to protect workers from developing silicosis is to eliminate the hazard, when using the framework of the hierarchy of controls.

So, the farther upstream that you can stop the problem, the less you rely on the last line of defense to keep people safe?

Yes. At the industrial sites where they’re doing the fabrication of the stone countertops, they’ll use polishing tools that have water-fed systems to keep the dust down. In this case, the engineering control is using the wet method.

The administrative control would be educating the workers, making them aware that they need to use enough water flow, and educating them that when they use the tools at certain angles the exposure risk may increase. Where we run into problems is when, let’s say if it’s cold out and the workers don’t want their hands to get cold, the workers need to understand that they cannot just turn the water off to keep their hands from getting cold, because then they will be polishing dry and exposed to significantly higher levels of silica dust.

Then the personal protective equipment, which in this case would be the respirators, are designed to make sure that if something does get in the air, the workers are still protected. An employer is required to buy the personal protective equipment for the employees. However, for a variety of reasons, we are seeing workers not being provided the protections they should have to prevent disease.

When did the dangers of engineered stone become evident?

The product was first introduced in 1970s in Italy, and then it slowly gained popularity and marketed globally. In the early 2000s in Israel, they started noticing that younger men were having more lung transplants than should be happening, and they were able to tie it to one of the engineered stone companies. Since then, we’ve been seeing outbreaks crop up as the popularity of the material has been exploding. There have identified outbreaks in Israel, Italy, Spain, Australia, and now they’re identifying cases here in the U.S., in particular in California.

When did this issue start to become a concern in Georgia?

I didn’t start noticing the material at fabrication shops here in Georgia until about 2017. But since then, we’ve been seeing it nonstop, and the latency period for silicosis with this exposure to the engineered stone is between seven and 10 years. Note that latency for silicosis when working with countertops would normally be 30 or 40 years — and, actually, people shouldn’t get silicosis at all, because it’s completely preventable.

But we’re seeing a much more accelerated rapid progression, and the diseases is very often complicated with a comorbidity of an autoimmune disorder. They’re seeing workers being diagnosed with not just silicosis, but silicosis and rheumatoid arthritis or scleroderma or a variety of other autoimmune diseases.

The reason why we’re aware of the outbreak in California is because of brave and astute doctors that raised their hand and said that there are young men dying of a disease that is completely preventable and this shouldn’t be happening. When they found cases, they talked to each other and got the state health department involved.

Was that the impetus for this conference you attended at UCLA?

Yes. The stakeholders in California were there to discuss policy options and to figure out how to handle the growing epidemic. From my perspective, I’m worried that there are cases here in Georgia, and we just haven’t identified them yet. We need to figure out how to gather the stakeholders here. Then our next step is determining what to do once we identify cases. Silicosis is a progressive, irreversible lung disease. The only treatment is a lung transplant.

At the conference in Los Angeles, the keynote speaker was an Australian pulmonary doctor by the name of Dr. Ryan Hoy. He explained all the different ways they tried to manage the growing outbreak of engineered stone silicosis patients in Australia through policy changes before finally landing on the conclusion that the only way to prevent the disease was to ban engineered stone countertops. This ban goes into effect this month.

I would love to see our country follow the hierarchy of controls by either finding a safer substitution or alternate product and eliminate this dangerous product from the market.

How does this issue affect the general public in Georgia?

Manufacturing industries and businesses are booming here in Georgia, and if we want to keep growing our economy, we need to do it in a way that keeps our workers healthy and safe, which includes implementing safety and health controls. I hope that safety and health professionals can be invited to the table to give feedback and constructive criticism on how we can keep our workers safe on job. For the countertop industry, this includes protecting the workers fabricating countertops and also making consumers aware that the choices they make when selecting a countertop may have a direct impact on the health of a worker.

I think there is dignity in safe work. People should have the right to go to work and come home in the same condition or better condition than they went to work that day. My dad got sick with brain cancer from exposure on the job, and he died two years ago. Unfortunately, his story is representative of many people who go to work each day just to feed their family, who are not aware of the hazards for a variety of reasons, and then find themselves sick as a result of just trying to make a living.

It would be a wonderful world if we could all purchase items that were manufactured in a way that did not cause harm to the workers making them. I would feel proud purchasing things if I could say that they were ethically fabricated. If we want to be strong as a society, we need to have a strong workforce, a sustainable workforce, a workforce that can contribute to the growth of the economy. The way we do that is by creating safe jobs.