California Artificial Stone and Silicosis (CASS) Project

Investigators: Kristin Cummings, MD, MPH, Robert Harrison, MD, MPH, and Amy Heinzerling, MD, MPH 

California workers who fabricate countertops using artificial stone are at risk of developing accelerated silicosis, a severe, incurable, and potentially fatal lung disease that is completely preventable. The Occupational Health Branch (OHB) of the California Department of Public Health (CDPH) has been instrumental in characterizing this emerging occupational health issue in California. We recently reported two fatal cases of silicosis in Hispanic immigrant countertop fabrication workers in their 30s and documented radiographic silicosis in 12% of their co-workers [Rose, Heinzerling, et al. MMWR 2019Heinzerling et al. AJRCCM 2021]. Investigation of the workplace revealed respirable crystalline silica exposures many times the permissible exposure limit, reflecting the much higher silica content of artificial stone compared to natural stone and the failure to implement well-established exposure controls for this hazard. 

The burden of silicosis in California’s countertop fabrication industry is unknown, but it is likely that these cases and the handful of others that have been reported to OHB represent the tip of the iceberg in an industry that employs at least 9,000 people statewide.  

The overarching aim of this project is to promote respiratory health among vulnerable workers in California’s countertop fabrication industry through education, medical monitoring, and statewide enhanced surveillance. The overall hypothesis of this project is that a multifaceted public health intervention will increase compliance with silica regulations and the detection of silicosis in the contemporary workplaces of California’s countertop fabrication industry.

Specific aims: 

1. Increase awareness in the countertop fabrication industry about the risk of silicosis to workers using artificial stone and methods for effective strategies for prevention. 

2. Facilitate medical monitoring of silica-exposed workers in the countertop fabrication industry. 

3. Enhance public health surveillance of silicosis related to working with artificial stone through increased reporting.  

Project investigators recently partnered with Cal/OSHA to include employer reporting of silicosis cases to CDPH in the new Emergency Temporary Standard on silica. They also petitioned the California Conference of Local Health Officers and the Director of CDPH and received approval to add silicosis to the state’s list of reportable non-communicable conditions in Title 17, California Code of Regulations. 

Recruitment: The CASS Study is recruiting! Learn more below:

Presentations and Publications:

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