Composition, Fe<sup>3+</sup>/∑Fe, and crystal structure of non-asbestiform and asbestiform amphiboles from Libby, Montana, U.S.A.

Gunter, Mickey E.; Dyar, M. D.; Twamley, Brendan; Foit, Franklin F.; Cornelius, S. B.

doi:10.2138/am-2003-11-1240

Cited by 56 publications

(43 citation statements)

References 23 publications

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“…Meeker et al [3] conducted the first comprehensive study on Libby asbestos to determine the mineralogy and morphology of both fibrous and non-fibrous amphiboles, supporting the earlier results of Wylie and Verkouteren [41] and Gunter et al [42]. They described the Libby AA as winchite, richterite, tremolite, and magnesioriebeckite, with the majority of structures displaying a gradient of morphologies between prismatic crystals and asbestiform fibers.…”

Section: Discussionmentioning

confidence: 58%

Libby Amphibole Contamination in Tree Bark Surrounding Historical Vermiculite Processing Facilities

Elashheb¹,

Spear²,

Hart³

et al. 2011

JEP

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Section: Discussionmentioning

confidence: 58%

Libby Amphibole Contamination in Tree Bark Surrounding Historical Vermiculite Processing Facilities

Elashheb¹,

Spear²,

Hart³

et al. 2011

JEP

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“…Libby was at one time the site of the world's largest vermiculite mine accounting for almost 80% of the world's vermiculite production [3]. The unprocessed vermiculite ore reportedly contained an estimated 0-5% amphibole, both asbestiform and nonasbestiform varieties [2,3,114,[133][134][135]. Epidemiological studies conducted in the 1980s found a high incidence of asbestosrelated disease among the mine workers.…”

Section: Libby Mtmentioning

confidence: 99%

“…Nearly all of the amphiboles found in Libby are not regulated minerals, and at a minimum, the vast majority of the amphiboles in the soil and air are not asbestiform [114,134,135]. A recent study conducted by the USGS in Libby noted that the amphibole minerals in Libby continue to present formidable challenges to the analyst, to anyone attempting to classify these materials using existing regulatory definitions, and particularly to those attempting to extrapolate those morphological features and chemical compositions to potential health risks [114].…”

Section: Libby Mtmentioning

confidence: 99%

Naturally occurring asbestos—A recurring public policy challenge

Lee

Strohmeier

Bunker

et al. 2008

Journal of Hazardous Materials

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“…These amphibole fibers, which have been chemically and physically characterized in detail, contain six amphibole fiber types, including winchite, richterite, and tremolite (Gunter et al, 2003;Meeker et al, 2003;Wylie & Verkouteren, 2000). Prior to elutriation, fibers were dispersed in sterile water by cup-horn sonication (Misonix, Framingdale, NY).…”

Section: Amphibole Fibermentioning

confidence: 99%

Separation and Characterization of Respirable Amphibole Fibers from Libby, Montana

Webber

Blake

Ward

et al. 2008

Inhalation Toxicology

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The vermiculite mine in Libby, Montana, was in operation for over 70 yr and was contaminated with asbestos-like amphibole fibers. The mining, processing, and shipping of this vermiculite led to significant fiber inhalation exposure throughout the community, and residents of Libby have developed numerous pulmonary diseases such as lung cancer and mesothelioma. The present study describes the separation of Libby 6-mix into respirable and nonrespirable size fractions by means of aqueous elutriation. The elutriator, designed to separate fibers with aerodynamic diameters smaller than 2.5 μm (respirable) from larger fibers, used an upward flow rate of 3.4 × 10 −4 cm s −1 . The resultant respirable fraction constituted only 13% of the raw Libby 6-mix mass, and less than 2% of the fibers in the elutriated fraction had aerodynamic diameters exceeding 2.5 μm. Surface area of the elutriated fibers was 5.3 m −2 g −1 , compared to 0.53 m −2 g −1 for the raw fibers. There were no detectable differences in chemical composition between the larger and smaller fibers. Such harvesting of respirable fractions will allow toxicological studies to be conducted within a controlled laboratory setting, utilizing fiber sizes that may more accurately simulate historical exposure of Libby residents' lungs. Importantly, this work describes a method that allows the use of material enriched in more uniform respirable material than raw Libby 6-mix, making comparisons with other known fiber preparations more valid on a mass basis.Vermiculite historically extracted from Zonolite Mountain near Libby, Montana, was contaminated with a toxic form of naturally occurring fibrous and asbestiform amphibole, occurring in veins throughout the deposit (Pardee & Larsen, 1929). As a result of nearly 70 yr of mining and processing activities, the Libby area was contaminated with a complex mixture of dust including these amphibole fibers, and many of the homes within Libby are (Wright et al., 2002). High concentrations (>100 million fibers/cm 2 ) of these amphibole fibers have even been found in the bark of Libby trees (Ward et al., 2006). Asbestos exposures have led to considerable health problems in the community, including reduced pulmonary function, elevated autoimmune responses, and increased mortality from lung cancer, malignant mesothelioma, and fibrosis (McDonald et al., 2004;Pfau et al., 2005;Whitehouse, 2004).The form of asbestos in Libby's contaminated vermiculite has been characterized as belonging to the amphibole (double-chain silicate) mineral group, including both regulated (tremolite) and unregulated (primarily winchite and richterite) fibers (Meeker et al., 2003). These various fibers within Libby amphibole asbestos differ in their relative proportions of cations (Mg, Ca, Fe, Na, K). On the basis of their diverse chemical composition, Libby amphibole fibers are distinct from the more typical and well-characterized and -studied amphibole fibers. According to Meeker et al. (2003), most of the Libby particles display characteristics that...

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Composition, Fe³⁺/∑Fe, and crystal structure of non-asbestiform and asbestiform amphiboles from Libby, Montana, U.S.A.

Cited by 56 publications

References 23 publications

Libby Amphibole Contamination in Tree Bark Surrounding Historical Vermiculite Processing Facilities

Libby Amphibole Contamination in Tree Bark Surrounding Historical Vermiculite Processing Facilities

Naturally occurring asbestos—A recurring public policy challenge

Separation and Characterization of Respirable Amphibole Fibers from Libby, Montana

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Composition, Fe3+/∑Fe, and crystal structure of non-asbestiform and asbestiform amphiboles from Libby, Montana, U.S.A.

Cited by 56 publications

References 23 publications

Libby Amphibole Contamination in Tree Bark Surrounding Historical Vermiculite Processing Facilities

Libby Amphibole Contamination in Tree Bark Surrounding Historical Vermiculite Processing Facilities

Naturally occurring asbestos—A recurring public policy challenge

Separation and Characterization of Respirable Amphibole Fibers from Libby, Montana

Contact Info

Product

Resources

About

Composition, Fe³⁺/∑Fe, and crystal structure of non-asbestiform and asbestiform amphiboles from Libby, Montana, U.S.A.