Median age at death: 52.
That number comes from the first peer-reviewed tally of California’s engineered-stone silicosis outbreak, published in NEJM Evidence on August 12 by researchers at the California Department of Public Health, UCLA, UCSF and George Washington University. From January 2019 through June 2026 they identified 592 silicosis cases among workers fabricating quartz countertops. Sixty-five required lung transplants. Thirty-one died.
The shape of the curve
Forty-seven cases from 2019 through 2022. Five hundred seventy-one from 2023 onward. That isn’t a trend, it’s a wall.
Engineered stone is more than 90% crystalline silica, against roughly 30% for granite. Cutting and polishing it releases respirable silica at concentrations that overwhelm controls designed for natural stone. Median age at diagnosis is 46. Latino men are about 98% of cases, roughly half of them in Los Angeles County.
“Silicosis among these workers is progressing much more rapidly than silicosis we’ve seen in other occupations,” said David Michaels, a George Washington University professor, former OSHA assistant secretary of labor and a co-author of the study. “The percentage of workers who have either received lung transplants or who are awaiting lung transplants is astoundingly high.”
Enforcement isn’t remotely keeping pace. A petition from the Western Occupational & Environmental Medical Association states that Cal/OSHA has cited 94% of the shops it inspected and ordered emergency shutdowns at 20% of them. But those roughly 140 inspections cover about 10% of an estimated 1,342 fabrication operations in the state.
The Cal/OSHA Standards Board approved that petition in late May 2026. Staff are now drafting emergency regulations that would prohibit fabricating engineered stone countertops in California outright, following Australia’s national ban.
Note: CDPH’s live surveillance, current through August and cited by the Los Angeles Times, runs higher than the study’s cutoff figures at 32 deaths, 72 transplants and 51 workers referred for transplant evaluation.
Why this is a GC problem, not a public health story
Quartz is still the best-selling countertop material in the United States. If California bans fabrication, specs get stranded mid-project, substitutions get negotiated late, and a category that residential and multifamily builders lean on daily gets repriced.
Then there’s the exposure question. If 94% of inspected shops draw citations, the base rate says the average fabrication sub in your chain is out of compliance. That’s a liability that runs uphill to whoever hired them.
Michaels went further than California: “It’s become clear that this product cannot be manufactured safely and economically. This is a product that we do not need that is damaging the lungs of hundreds of workers and probably thousands of workers across the country.” Other state-plan states will read the same study. Federal OSHA’s 2016 silica standard was written before engineered-stone fabrication existed at this scale.
Practical version: silicosis surveillance is becoming a subcontractor qualification question. Residential and mixed-use projects carry the most exposure, including student and multifamily work like Rowan in Denver.