Researchers at UCSF and UCLA have found that workers who produce artificial stone are developing a potentially fatal and irreversible lung disease from tiny toxic dust particles. The study is the largest study of this emerging health crisis conducted in the United States.
When synthetic stone is cut, ground and polished, it releases dust into the air that is harmful to the lungs, causing a disease called silicosis. The disease has plagued natural stone miners and cutters for hundreds of years, but artificial stone is far more dangerous due to high concentrations of silica, a natural product in sandstone, as well as harmful polymer resins and dyes added to man-made products.
Since the first case of silicosis caused by engineered stone was reported in the United States in 2015, this growing occupational hazard has sickened and killed workers, primarily young Latino men, at an alarming rate, according to a recent study published in JAMA Internal Medicine.
"The increasing number of silicosis cases and accelerated disease progression among stonemakers over the past decade has changed Americans' understanding of this previously forgotten disease," said study co-author Jane Fazio, MD, a pulmonologist at OliveView-UCLA Medical Center. "Our study shows that morbidity and mortality are severe in a particularly vulnerable group of young Latino immigrant workers who are underinsured and potentially undocumented."
The risk of silicosis from artificial stones was first discovered in Israel in 2012. Since the first U.S. case of silicosis linked to artificial stone was discovered in Texas in 2015, California has become an epicenter of the disease.
Researchers at UCSF and UCLA, working with the UCSF California Laboratory and the California Department of Public Health, identified 52 California artificial stone workers diagnosed with silicosis, 51 of whom were Latino immigrants. Most people were diagnosed between 2019 and 2022. Twenty of the patients were in advanced stages when diagnosed, and 10 had died. Their median age is 45 and their average working experience is 15 years.
One of them is Leobardo Segura-Meza, who was born in Mexico and immigrated to the United States in 2012. He found a job as a stone cutter in Los Angeles 10 years ago and started cutting and polishing at the age of 17.
Despite taking health precautions like wearing a mask and using dust suppression tools, Segura-Mesa went to the emergency room in February 2022 with shortness of breath, and a lung biopsy revealed he had silicosis. Now 27, he has been using an oxygen tank since then and can no longer financially support his wife and three young children.
Although Segura-Mesa has been approved for a lung transplant, he fears his days are numbered. On the waiting list, two fellow stone workers passed away. "Every day I expect the phone to ring and tell me to come to the hospital to get my new lungs," Segura-Mesa said.
The study authors called on public health officials, clinicians and policymakers to take steps to better protect workers from exposure to silica dust, diagnose the disease more quickly, and even ban the use of the product.
"Our paper is a wake-up call," said Sheiphali Gandhi, a pulmonologist at the University of California, San Francisco and a co-author of the study. "If we don't stop it now, we're going to have hundreds and thousands of cases. Even if we stop it now, we'll still be seeing these cases over the next decade because it takes years to develop."
No country has yet banned the product, but Australia has considered and is developing new regulations to help reduce the risk of silicosis through better air monitoring, training and reporting requirements. In California, the Los Angeles County Board of Supervisors is weighing a possible ban, while the state's Department of Occupational Safety and Health, or Cal/OSHA, has begun drafting emergency rules.
The study authors also called for early diagnosis and minimizing further exposure, both of which are challenging due to a lack of access to care and the need for workers to support their families. In the study, 45% of patients continued to work after diagnosis.