WHAT IS THE MAJOR SOURCE OF ASBESTOS IN MONTANA?

In Montana, asbestos mining became industrially important in the 20th century. Asbestos and vermiculite, another insulating mineral, were mined in several areas of Montana. There were several asbestos and/or vermiculite mines in Montana, all of them located in the western half of the state.

Vermiculite Mountain, outside of the community of Libby, was the site of Montana’s largest vermiculite mine. It operated from the 1920s until 1990. At one time, Vermiculite Mountain was the source of more than 80% of the world’s vermiculite9-10. Unfortunately, much of the vermiculite obtained from this mine was contaminated with asbestos9.

This ore was shipped across Montana on its way around the world. Cascade County was a railroad transportation hub and some of the ore was processed at a plant in Great Falls.

Many residents of Montana worked in industries which mined, processed, or transported the vermiculite and asbestos ores. There was a large amount of human exposure to these minerals. Constructing homes and workplaces with asbestos insulation and other asbestos products may have also led to exposure.

Many of the people with mesothelioma in Montana lived along rail routes that pass through the population centers in the state. Most people in Montana live in these centers, so it is not necessarily unusual that people affected with mesothelioma would live along these routes as well.

9Agency for Toxic Substances and Disease Registry. ToxFAQ for Asbestos. http://www.atsdr.cdc.gov/tfacts61.html

10United States Environmental Protection Agency. Libby asbestos background. http://www.epa.gov/region8/superfund/libby/lbybkgd.html