Workers From Nine Vermiculite Plants Exposed to High Levels of Asbestos

Vermiculite Ore Came From W.R. Grace's Zonolite Mine

WASHINGTON, DC - September 30, 2005 - Workers who processed asbestos-contaminated vermiculite shipped from a mine in Libby, Montana were exposed to high levels of asbestos at nine plants throughout the nation, according to the latest report by the federal Agency for Toxic Substances and Disease Registry or ASTDR (ASTDR Media Release, September 22, 2005). The plants were located in Newark, California; Honolulu, Hawaii; Wilder, Kentucky; Marysville, Ohio; Portland, Oregon; New Orleans, Louisiana; Ellwood City and New Castle, Pennsylvania; and Dallas, Texas.

What is Vermiculite and How Is It Processed?

A type of ore resembling mica, vermiculite forms a lightweight material that is used in insulation, fertilizers, potting mixes, and animal feed. Manufacturing plants heat raw water-containing vermiculite to high temperatures until the water becomes steam and flakes of vermiculite expand. The resulting "popped" or "exfoliated" material is inert and fire resistant. If the vermiculite contains asbestos, the asbestos fibers are released in high amounts during the popping process.

From 1963 through 1990, the W.R. Grace company operated a vermiculite mine in Libby that was contaminated with asbestos. The Environmental Protection Agency has identified over 200 processing plants that received this asbestos-containing vermiculite. The ASTDR previously provided reports on 12 of these sites and expects to assess the extent of the asbestos problem at seven other plants by the end of the year.

Groups Affected By Asbestos Vermiculite

Once the most recent ASTDR report was released, Oregon health officials lost no time in issuing warnings about the state's Portland vermiculite plant. Amanda Guay of the Oregon Department of Human Services said that former plant workers could develop lung cancer, mesothelioma, asbestosis, and other asbestos diseases (The Oregonian, September 23, 2005). Family members may have been exposed to asbestos that was carried home on the worker's clothes or shoes. She urged former vermiculite plant workers and their families to get medical checkups with doctors who are knowledgeable about asbestos diseases.

The ATSDR made similar recommendations for former workers and household members at the nine plants. In addition, the agency urges these groups to learn more about asbestos exposure and to quit any tobacco use. Taken together, asbestos exposure and smoking greatly increase the risk of developing lung cancer.

The ATSDR report also said that residents near the vermiculite plants may have been exposed to asbestos if they handled or played in waste rock, a by-product of vermiculite exfoliation. At some vermiculite plants, workers or people in the community may have brought waste rock from the plant to their homes. This waste rock was used in gardens, as fill, or as driveway surfacing material.

Learning about Asbestos

You can find details about each site on the ASTDR web site. The list of sites will be updated as more information becomes available. To learn about the cleanup in Libby, see:

  • W.R. Grace to Pay $250 million for Asbestos Cleanup
  • Town of Libby Suffered From Zonolite Mine Operation
  • Has the EPA Cleaned Up Libby's Asbestos Problem