California is poised to become the first state in the country to adopt special measures to protect workers who make kitchen and bathroom countertops out of a popular kind of artificial stone known as "quartz."

That's because more and more countertop workers, almost all Latino men, are coming down with an irreversible lung disease after breathing in dangerous dust while cutting and grinding quartz and other stone materials.

At least ten have died. Others have needed lung transplants.

The disease, silicosis, is caused by silica dust that can fly into the air when a raw slab of countertop material gets cut to fulfill a customer's order. While natural stone like granite contains silica, "engineered stone" made of quartz contains far more, and public health experts have been warning of its increased risk.

In California alone, officials have so far identified 77 sickened workers, says Dr. Sheiphali Gandhi, a pulmonologist at the University of California, San Francisco.

"Things are heading in the direction that we feared. We've had more and more people presenting very severely," she says. "And they're all very young."

She and her colleagues have just published a new report in JAMA Internal Medicine describing dozens of silicosis cases in California's countertop workers.

Almost all were Spanish-speaking Latino men who had emigrated from Mexico, El Salvador, or elsewhere in Central America. The median age was 45.

One of the workers included in the study is Ever Ramón, who began coughing and struggling with phlegm after 16 years of fabricating countertops. In a workplace safety video, speaking in Spanish, he broke down as he described the day he learned that his lungs were badly damaged.

"I never imagined that my work would harm me so much," he said.

The federal government places a limit on how much airborne silica a worker can be exposed to, and dust can be controlled using wet cutting techniques, adequate ventilation, and respirators.

But in 2019 and 2020, safety officials in California examined its countertop industry and found that about 72% of the 808 fabrication shops operating in the state were "likely out of compliance with the existing silica standard," putting hundreds of workers at risk of developing silicosis.

As a result, California's Occupational Safety & Health Standards Board just voted to fast-track the development of new regulations to keep workers from breathing in dust while fabricating countertops from materials with a high silica content.

In an email to NPR, a spokesperson for Cal/OSHA said that it had "advised the Board that it plans to hold an advisory committee in August and hopes to have an Emergency Temporary Standard proposal to the Board within 3-4 months."

The Los Angeles County Board of Supervisors is even considering a ban on this type of countertop material.

Occupational health experts say there's no reason to believe this problem is confined to countertop makers in California. Since the first U.S. case of silicosis in this industry emerged in Texas in 2014, other sickened workers have been found in Colorado and Washington.

One recent case report from Florida recounted severe disease in a 39-year-old undocumented immigrant from Guatemala who had been exposed to silica through "manual labor regarding stone cutting of quartz for fabrication of countertops."

"This is something that we've had, if you will, flashing warning lights about for some time," says David Goldsmith, an occupational and environmental epidemiologist at George Washington University.

An estimated 100,000 people work in this industry across the United States. One study did silicosis screening on the 43 employees of "an engineered stone countertop fabrication facility" and found that 12 percent had the disease.

If workers are undocumented or lack insurance, they may be reluctant to seek medical care, says Goldsmith, and doctors who aren't expecting to see silicosis can misdiagnose it as pneumonia or tuberculosis.

So while the new report of cases in California is a "very serious finding," he says, "I am certain that this is an underestimate of the severity of the problem in California. And, by inference, it's an underestimate of the severity of the problem in the whole United States."