IRIS Toxicological Review of Libby Amphibole Asbestos (Interagency Science Consultation Draft)
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This draft health assessment of the toxicity of Libby amphibole asbestos was prepared by staff in both EPA’s Region 8 Office and ORD/NCEA. The assessment is focused on a specific type of asbestos found as a consequence of the mining and processing of vermiculite in Libby, Montana. The assessment will be included on EPA's IRIS data base when finalized. The project supports OSWER and Region 8 site clean-up and related risk management initiatives at the Libby Superfund site. As with all IRIS assessments, the development of this external peer review draft document required internal EPA review and OMB/interagency review. After an independent external peer review, the draft final document will undergo a second round of EPA and OMB/interagency review before being finalized and then included on the IRIS data base.
Libby Amphibole asbestos is a complex mixture of amphibole fibers, both mineralogically and morphologically. The mixture primarily includes tremolite, winchite, and richterite fibers with trace amounts of magnesioriebeckite, edenite, and magnesio-arfvedsonite. These fibers exhibit a range of morphologies (e.g. prismatic, ascicular, asbestiform)(Meeker et al., 2003).
|Aug 2007||The Libby Amphibole Asbestos assessment was initiated in 2007. It was nominated for assessment by the IRIS Program because it supports OSWER and Region 8 site clean-up and related risk management initiatives at this Superfund site. An assessment for Libby Amphibole Asbestos is not currently on IRIS.|
|May 2011||EPA hosted an interagency science consultation on the draft IRIS Toxicological Review of Libby Amphibole Asbestos.|
|Aug 2011||EPA released the External Review Draft for public review and comment, and announced the public listening session would be held on October 6, 2011. [Federal Register Notice Aug 25, 2011]|
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