Asbestos and Mesothelioma Issues in Libby, Montana

Zonolite Mountain, which is located in Libby, Montana, was the richest known source of vermiculite in the United States. Vermiculite is an ore similar to mica and used for fireproofing, insulation, potting soil, and fertilizer. The Libby vermiculite mine opened in 1924. W.C. Grace purchased the mine in 1963 and operated it until it closed in 1990. Over time, the mineworkers and residents in Libby suffered from abnormally high rates of asbestos-related diseases.

Asbestos contamination in Libby, Montana

Several federal agencies became involved with health issues in Libby, including the Agency for Toxic Substances and Disease Registry (ATSDR) and the Environmental Protection Agency (EPA). The agencies determined that the vermiculite from the Libby mine was contaminated with tremolite and actinolite asbestos. When the vermiculite was actively mined, the ATSDR reported that asbestos contamination in Libby air measured 15 times the current occupational limits.

Effects on the community from asbestos in Libby, Montana

In 2000, local newspaper reports found that Lincoln County, where Libby is located, ranked second in the nation for asbestosis deaths. The ATSDR’s first screening of Libby residents in 2001 revealed that 30 percent of the 1,071 people tested had lung scarring, a type of lung abnormality. Other screenings showed that 48 percent of W.C. Grace employees had lung abnormalities. In 2002, the Center for Asbestos Related Diseases (CARD) reported that out of 1,000 patients with lung abnormalities, around 850 were diagnosed with asbestos-related illness.

The ATSDR, in collaboration with the Montana Department of Public Health and Human Services (MDOHHS), prepared an analysis of asbestos-related deaths in Libby, Montana from 1979 to 1998 and compared these deaths with similar deaths throughout Montana and the United States. They found the following in Libby:

• A 20 to 40 percent increase in malignant and nonmalignant respiratory deaths
• A 40 to 80 times higher than expected asbestosis mortality rate
• A lung cancer mortality rate that was 1.2 to 1.3 times than higher Montana and across the United States
• An elevated mesothelioma mortality rate (but no precise statistical comparison was possible because no national mesothelioma statistics were tracked until 1998)
• Significant elevation in non-malignant, non-infectious respiratory deaths
• Finding of asbestosis and mesothelioma mortality almost exclusively in former workers
• Finding of some lung cancer mortality in former workers at the vermiculite facility

Today, the EPA continues to work with community residents to clean up asbestos contamination in an effort to reduce health issues.