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EPA Finalizes Libby Amphibole Asbestos Health Assessment/Risk assessment shows EPA cleanup has reduced cancer and non-cancer risks in Libby and Troy

Release Date: 12/08/2014
Contact Information: Lisa McClain-Vanderpool, EPA Region 8 303-501-4027 Cathy Milbourn (for IRIS assessment questions) 202-564- 7849 202-564-4355

DENVER – The U.S Environmental Protection Agency (EPA) announced the release of its final Integrated Risk Information System (IRIS) health assessment today for Libby Amphibole Asbestos (LAA). This assessment analyzes the potential cancer and non-cancer human health effects from inhalation exposure to LAA, and includes the final Toxicological Review of LAA. In addition, using the toxicity values as well as exposure data collected in Libby and Troy, Montana, EPA has developed a draft site-wide Human Health Risk Assessment for the Libby, Montana Superfund site, which quantifies the risks of exposure to LAA for residents and workers.

“EPA’s scientific evaluation shows that our cleanup approach is working and we are reducing health risks for residents in Libby,” said Shaun McGrath, EPA’s Regional Administrator. “We look forward to working with the community to use this important science in identifying the final set of cleanup actions.”

The risk assessment shows that EPA’s indoor and outdoor cleanups have been effective in reducing both the cancer and non-cancer risks in Libby and Troy. The asbestos air concentrations in Libby today are about 100,000 times lower than when mine and processing facilities were in operation, making the air quality in Libby similar to other Montana cities. The information will be used to identify how exposures can be reduced to protect human health now and in the future.

The IRIS health assessment includes an estimate of the amount of LAA that a person can breathe every day for a lifetime that is likely to not result in adverse non-cancer health effects. This is the first such estimate regarding non-cancer effects for any type of asbestos. The assessment also finds that LAA is carcinogenic to humans when inhaled and provides a quantitative estimate of cancer risk.

EPA plans a broad discussion with the community over the next months on the risk assessment and options for cleanup and long-term management of the remedy. The agency expects to issue a plan for cleanup of the site early next year that will be available for public comment before a remedy is selected.

EPA is hosting the following public sessions locally this week to present information and answer questions about the toxicity values and draft risk assessment:

  • Tuesday, Dec. 9, 7 to 9 p.m.; City of Libby Ponderosa Room; 952 E. Spruce Street, Libby, Mont.
  • Wednesday, Dec. 10, 7 to 9 p.m., Kootenai Senior Center, 304 Third Street, Troy, Mont.
  • Thursday, Dec. 11, 7 to 9 p.m., City of Libby Ponderosa Room, 952 E. Spruce Street, Libby, Mont.

EPA has been working in Libby since 1999. The Libby, Montana site was placed on the Superfund National Priorities List in 2002. In 2009, EPA and the U.S. Department of Health and Human Services announced a public health emergency at the Superfund site. Removal actions have now been completed at more than 2,000 properties at the site, including the most contaminated areas. Studies show that those actions have reduced exposures and risks to residents.

EPA’s IRIS program evaluates information on health effects that may result from exposure to environmental contaminants. These high quality, science-based health assessments are used to inform decisions to protect human health. The IRIS database contains crucial information on chemical substances and their impacts on human health. Governments and private entities use data from IRIS in conjunction with exposure information to help characterize the public health risks of environmental contaminants. These characterizations are then considered in risk management decisions to protect human health.

To access the final toxicity assessment, draft risk assessment and other documents on EPA’s Web site, visit:

For more information about the final IRIS assessment for Libby Amphibole Asbestos and for IRIS, visit: