About the Data
Background
Silicosis is an occupational lung disease caused by inhalation of dust containing respirable crystalline silica. Silicosis is a progressive, incurable, and potentially fatal disease. In recent years, silicosis has been identified among young engineered stone (ES) countertop fabrication workers in California. Engineered stone is the most popular countertop material in the United States and is processed at nearly all fabrication operations. [1]
Data Sources for Countertop Fabrication Operations
Definition of Terms
Fabrication operation means a person, entity, business or location undertaking countertop fabrication activities.
Countertop Fabrication Operations in California identified by CDPH
The two boxes on the left and map in the dashboard represent all operations identified in California thus far by CDPH using multiple data sources. Using a subscription database (Reference Solutions from Data Axle), CDPH generated a list of likely countertop fabricators by searching with a set of 8-digit North American Industry Classification System (NAICS) codes and 6-digit Standard Industrial Classification (SIC) codes. For fabricators included in this database, the number of employees per operation was available. To try to determine whether each business was a fabricator of engineered stone (commonly called “quartz”) countertops and whether it was likely still in operation, a team of researchers at CDPH searched for each one on the internet. Businesses that appeared to be showrooms but that also offered fabrication of stone countertops were included as fabricators. If the business had no website or if the information on their website was not adequate to determine whether they fabricated stone countertops, CDPH relied on other sources, such as search engines, review websites, building trade sites, mapping street views, Yellow Pages, Chambers of Commerce sites, etc. to help determine business type and status (for example, changed addresses or closures). Use of these other internet sites also led to the identification of additional fabrication operations. Efforts are ongoing to update the information and to add additional operations as they are found. The list used to populate this database is a best-effort attempt to locate fabrication operations and may be subject to change as businesses relocate, cease operations, or change ownership or as more information becomes available.
Self-reported work history of confirmed engineered stone (ES) silicosis cases
The four boxes on the right in the dashboard represent information reported by confirmed ES silicosis cases about their work history. All operations are included, without confirmation that operations are still in business. Some operations that have closed or that are missing some information may be included in the data for the four boxes on the right, but not in the data for the two boxes on the left. Silicosis is a reportable disease in California. Once a case is reported, public health follow-up is conducted to confirm that the case meets the NIOSH case definition for silicosis: History of occupational exposure to airborne silica dust and EITHER or BOTH of a chest radiograph or other imaging technique interpreted as consistent with silicosis or pathologic findings characteristic of silicosis. In addition to confirmation, follow-up also determines source of exposure. If the silica exposure is associated with countertop fabrication, information about work history and employment is also collected, where possible.
Data Sources for Confirmed ES Silicosis Cases
Case Definition
Confirmed ES-Silicosis case:
- Meets the NIOSH case definition of silicosis (see below).
- Has silica exposures associated with countertop fabrication.
NIOSH Case Definition of Silicosis:
History of occupational exposure to airborne silica dust and either or both: Imaging showing abnormalities interpreted as consistent with silicosis or lung histopathology consistent with silicosis. View Silicosis Reporting Guidelines (NIOSH). Only Confirmed ES cases are displayed on the dashboard, which are a subset of all silicosis cases identified in California.
Data sources for reports of engineered stone silicosis cases:
Silicosis is a reportable disease in California. Title 17 Reportable Condition: The California Code of Regulations, Title 17, Section 2505 requires reporting of certain diseases of public health importance to the local health department. Results are transmitted to CDPH from local health departments via The California Reportable Disease Information Exchange (CalREDIE) or through another pre-determined mechanism if a local health department does not use CalREDIE.
Statewide hospital utilization records from the California Department of Health Care Access and Information (HCAI). Any encounter including a silicosis diagnosis (ICD-10: J62.8) in any of the diagnosis code fields is included in the surveillance system:
- Inpatient Discharge (PDD) Data: nonpublic dataset of inpatient data collected from California-licensed hospitals in California. The dataset consists of a record for each inpatient discharged from a California-licensed hospital, including general acute care, acute psychiatric, chemical dependency recovery, and psychiatric health facilities.
- Emergency Department (ED) encounter data: nonpublic dataset of emergency care data collected from hospital emergency departments. Reportable ED encounters include only those patients who had face-to-face contact with a provider.
- Electronic Case Reporting (eCR)/Reportable Conditions Knowledge Management System (RCKMS): System that enables automated eCR to public health agencies via electronic health records, using previously established criteria. Participating healthcare organizations automatically generate and send an initial case report when trigger criteria, such as diagnosis codes or laboratory results, are met within electronic health records. In the context of silicosis, any healthcare encounter from a participating healthcare organization that includes a silicosis diagnosis in the patient's problem list is sent to CDPH for silicosis surveillance.
- Voluntary reporting by healthcare providers, Tuberculosis Controllers, or community members to CDPH.
- Public health follow-up of mandated medical testing following worksite investigations
- Doctor's First Reports of Occupational Injury or Illness (DFR): all physicians are required to complete a DFR form within five days of initial examination for work-related injuries or illnesses statewide.
Reports received from the above sources receive public health follow-up by Occupational Health Branch staff to determine if they meet the case definition specified above; only those considered confirmed ES-Silicosis cases are included in the dashboard.
Countertop fabrication operations where confirmed ES cases have worked are self-reported by identified cases as part of case follow-up, are included in information provided by case reporters, or are recorded in medical records. Countertop fabrication operation information associated with cases is tracked by the silicosis public health surveillance system.
Data Limitation
These data are likely an underestimate of the true burden of ES-Silicosis in California due to underdiagnosis of silicosis cases, the existence of cases that are not captured by the data sources described above, and lack of information in reports indicating that exposure is associated with engineered stone. While all confirmed ES silicosis cases have documented work history in the countertop fabrication industry, specific fabrication operation details are missing for some cases.
Suggested Citation
California Department of Public Health, Occupational Health Branch, Countertop Fabrication Operations Dashboard, Access Date: MM/DD/YYYY.
Link
Countertop Fabrication Operations in California
[1] McGowan, C. M., Cantley, L. F., Klein, R., & Redlich, C. A. (2025). Work Practices and Respirable Crystalline Silica Exposures in Stone Countertop Fabrication Shops. American journal of industrial medicine, 68(11), 973–987. https://doi.org/10.1002/ajim.70020