Silicosis Among Immigrant Engineered Stone (Quartz) Countertop Fabrication Workers in California

Abstract

ImportanceSilicosis associated with inhalation of respirable crystalline silica among engineered stone countertop fabrication workers is an emerging health concern.ObjectiveTo describe clinical, socioeconomic, and occupational characteristics of patients diagnosed with silicosis associated with engineered stone in California.Design, Setting, and ParticipantsThis case series included reported cases of silicosis associated with fabrication of engineered stone countertops, as identified by statewide surveillance by the California Department of Public Health (2019-2022). Data analysis was performed from October 2022 to March 2023.ExposuresPatient interviews and medical record abstractions were used to assess occupational exposure to respirable crystalline silica, including duration of work tenure and preventive measures undertaken.Main Outcomes and MeasuresDemographics, clinical characteristics, health care utilization, and clinical outcomes were obtained, including vital status, hypoxia, and lung transplant.ResultsThis case series identified 52 male patients meeting inclusion criteria; median (IQR) age was 45 (40-49) years, and 51 were Latino immigrants. Ten (19%) were uninsured, and 20 (39%) had restricted-scope Medi-Cal; 25 (48%) presented initially to an emergency department. A delay in diagnosis occurred in 30 (58%) patients, most commonly due to alternative initial diagnoses of bacterial pneumonia (9 [30%]) or tuberculosis (8 [27%]). At diagnosis, 20 (38%) patients had advanced disease (progressive massive fibrosis) with severely or very severely reduced forced expiratory volume in 1 second in 8 (18%) and 5 (11%), respectively. Of the cases, 10 (19%) were fatal; median (IQR) age at death was 46 (38-51) years, and 6 patients (12%) were alive with chronic resting hypoxia. Eleven were referred for lung transplant: 3 underwent transplant with 1 fatality; 7 were declined transplant, with 6 fatalities; and 1 died prior to listing. Median (IQR) work tenure was 15 (10-20) years; 23 (45%) reported use of water suppression for dust mitigation, and 25 (48%) continued to fabricate stone after being diagnosed with silicosis.Conclusions and RelevanceIn this case series performed in California, silicosis associated with occupational exposure to dust from engineered stone primarily occurred among young Latino immigrant men. Many patients presented with severe disease, and some cases were fatal.

Workers at Risk of Silicosis—Ongoing Overexposure and Lack of Medical Surveillance—Reply

“…In Reply We agree with the comments from Wagner and Michaels regarding prioritization of disease prevention through increased resources for the federal Occupational Safety and Health Administration (OSHA) inspections . Additionally, employers have a responsibility to uphold and implement the requirements of the 2016 Respirable Crystalline Silica Standard, which Hodgson and Smith of OSHA detailed in their letter.…”

“…Hodgson and Smith state that the OSHA National Emphasis Program on Respirable Crystalline Silica in 2022 provided clear evidence of exposure above the permissible exposure limit (PEL) among one-quarter of those sampled. Similarly, analysis of data from the California Special Emphasis Program (occupational exposure to respirable crystalline silica, cut stone, and stone product manufacturing) showed that from January 2019 to February 2020, 25% of individuals and 51% of shops sampled had exposures above the PEL . This suggests that the existing 2016 OSHA silica standard is not preventing overexposure.…”

Preventing the Continuing Tragedy of Silicosis—Reply

“…In Reply We thank Wagner and Michaels for their thoughtful comments regarding the recently reported resurgence of silicosis among engineered stone workers in California, many of whom had severe disease . The correspondents highlight the tragic and preventable nature of these cases, and Occupational Safety and Health Administration enforcement constraints from severely limited resources and inadequate penalties for violations.…”

Preventing the Continuing Tragedy of Silicosis

“…The identification of 52 cases in California alone suggests there are hundreds of these cases across the country, yet few cases have been reported elsewhere. Physicians asking patients about current and past workplace exposures and informing a national occupational disease surveillance program could help address this problem.…”