NIOSH RESEARCH IN LIBBY, MONTANA: JOB-RELATED ASBESTOS
AND HEALTH EFFECTS IN MINING AND MILLING OF VERMICULITE
September 21, 2000
Concerns have been voiced about occupational and potential public health risks from exposure to
vermiculite contaminated with asbestos, including potential risks to former miners and to residents of
Libby, Montana, and to workers and consumers who come in contact with vermiculite end-products,
such as insulation and potting soil. The National Institute for Occupational Safety and Health (NIOSH)
has responded to past and current concerns by conducting needed research and disseminating its
Conducting Research and Providing Results to Workers in Libby:
In the 1980s, NIOSH conducted research about job-related exposures and health effects among workers
employed in mining and milling vermiculite in Libby. As is customary, NIOSH shared its findings with
workers, their representatives, and the employer. We also made the results publicly available to the
scientific and public health community.
z Our studies identified asbestos contamination in the vermiculite mined and milled in Libby.
z We also determined, from examination of X-rays from Libby miners, that the miners showed
evidence of adverse health effects associated with asbestos exposure.
z Further, in a study involving review of death certificates of former Libby vermiculite miners, we
identified an excess of deaths from lung cancer and other lung diseases consistent with exposure
z We made our results available in 1985 through meetings in Libby with workers and their
representatives, employer representatives, and members of the community. We also published the
findings in three articles in the American Journal of Industrial Medicine, a peer-reviewed
scientific journal, in 1987, and in articles published in1988 in a supplement to the Annals of
Occupational Hygiene, a British scientific journal. NIOSH further disseminated information about
health effects related to vermiculite m