Starting in 2002, the California Department of Public Health (CDPH)–formerly California Department of Health Services (CDHS)–conducted evaluations of the public health implications from vermiculite contamination at various facilities accross the State of California.
What is vermiculite?

Vermiculite is a mineral used in construction and consumer materials, and agricultural, horticultural, and industrial products (more information). Between the early 1920s and 1990, as much as 80% of the vermiculite ore processed and/or sold worldwide came from a mine near Libby, Montana. This vermiculite ore was contaminated with asbestos-like fibers. Exposure to asbestos has been linked to several types of cancers, inlcuding lung, bronchus, mesothelioma, peritoneum, retroperitoneum, and pleura, as well as to noncancer health conditions such as asbestosis. There are some studies that suggest a link between asbestos exposure and cancers of the digestive system, respiratory system, and intrathroriacic organs.
CDHS’s involvement at sites where vermiculite was used
As part of its efforts to address the public health impact of asbestos exposure from the Libby vermiculite ore, the federal Agency for Toxic Substances and Disease Registry (ATSDR) funded CDPH to evaluate existing data on cancer and mortality (cause of death) in communities near facilities in California that received vermiculite ore.
The objectives of this project were 1) to determine whether the occurrence of asbestos-related cancers or disease is higher in these communities than in the U.S. population, and 2) to work with local health and environmental agencies and other stakeholders to inform the community and other interested parties about the findings and conclusions of the review.
Based on proximity or residential neighorhoods to the 30 sites in California that received Libby vermiculite, CDPH reviewed cancer and mortality data for 9 sites. ATSDR combined California data with other state data to look for mortality and cancer incidence patterns in communities around vermiculite facilities. In addition, ATSDR and CDPH produced reports that try to assess past and current exposure for each of the 9 sites.
Popping facilities in California that used Libby vermiculite (links to ATSDR webpages)
- W.R. Grace & Company Plant, Santa Ana, Orange County
- W.R. Grace, Newark, Alameda County
- W.R. Grace, Glendale, Los Angeles County
Gypsum manufacturing facilities in California that used Libby vermiculite (links to CDPH webpages)
- Georgia Pacific Gypsum (formerly Domtar Gypsum), Antioch, Contra Costa County
- U.S. Gypsum (formerly the Flintkote Facility), Fremont, Alameda County
- National Gypsum, Long Beach, Los Angeles County
Other facilities that used Libby vermiculite (links to Health Consultation reports)
- Pryor Giggey Co., Whittier, Los Angeles County [9/28/07]
- Germain’s Seed Company, Vernon, Los Angeles County [5/11/07]
- A-1 Lube, Glendale, Los Angeles County [5/4/07]