A California health surveillance program has confirmed hundreds of cases of silicosis, a life-threatening and incurable lung disease that is sickening people who make quartz countertops.
Health officials reported 592 confirmed cases of silicosis in workers who cut, grind, and polish quartz countertop slabs between January 2019 and June 2026.
The illnesses represent a serious occupational health issue for the people who make a product that has boomed in popularity for American kitchen and bathrooms over the past decade.
Out of the 592 workers who were diagnosed with silicosis, 65 needed lung transplants and 31 people died. The findings were reported in NEJM Evidence by researchers from the California Department of Public Health (CDPH), UCLA, UCSF, and George Washington University.
Silicosis is a lung disesase that occurs when someone inhales fine particles of crystalline silica. The disease has been known for centuries, but up until now it was relatively rare. That all changed when companies began engineering quartz countertops, which may be 90% silica.
Silicosis is a progressive disease that cannot be cured. The risk is especially significant for workers who breathe silica dust when working with quartz countertops or engineered stone.
Engineered stone is manufactured by crushing natural quartz into a find powder and combining it with resin. The finished product is over 90% crystalline silica, which is significantly higher than natural stones like granite, which are usually 10% crystalline silica or less.
That high silica content creates a serious workplace hazard when the slabs are manufactured and installed in bathrooms or kitchens. Cutting, grinding, and polishing the slab can spew fine particles of silica dust into the air where workers breathe it in. The fabrication process can also expose workers to volatile organic compounds and metals, according to the report.
The number of cases of silicosis in California do not reflect the full scale of the issue, either. The researchers warn that there are likely many more cases that have not been identified, especaially in states without systems to track the disease.
California’s effort to track these cases began after a single patient was identified in January 2019. The CDPH identified California’s first known case of silicosis in a quartz countertop fabricator. He was diagnosed with silicosis at age 32 and died from respiratory failure at 38.
That case prompted investigators to screen other employees at the same company. The screening found 5 more workers with silicosis out of 43 employees. Two of those workers later died.
Silicosis was not the only serious health problem identified among the workers. Some patients developed complications including autoimmune disease and tuberculosis. Researchers also found that their disease progressed more rapidly than silicosis associated with other industries.
The growing number of cases led to changes in California workplace safety rules. The findings prompted California’s occupational safety board to adopt an emergency regulation for silica dust in 2023. It became permanent in 2025.
The report also encourages increased awareness about silicosis for healthcare professionals, who should ask patients about dust exposure at work. Patients at risk of silicosis should be screened for the diseaese and counseled on ways to minimize breathing silica dust at work.
Workers who develop silicosis after fabricating quartz or engineered stone countertops may have legal options. A product liability attorney can help affected workers and their families understand their rights and determine what options may be available.