Journal ArticleDOI
Quantification of amphibole content in expanded vermiculite products from Libby, Montana U.S.A. using powder X-ray diffraction
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TLDR
In this article, expanded vermiculite with no detectable amphibole was spiked with 100, 500, 1000, 2500, 5000, 7500, and 10 000 ppm Libby amphiboles to determine the detection limit of XRD and to develop a calibration method.Abstract:
Five expanded vermiculite samples known to have originated from the former vermiculite mine near Libby, Montana were analyzed using powder XRD to quantify their amphibole content. An expanded vermiculite with no detectable amphibole based on our XRD methods discussed herein was spiked with 100, 500, 1000, 2500, 5000, 7500, and 10 000 ppm Libby amphiboles to determine the detection limit of XRD and to develop a calibration method. The 110 amphibole peaks were not detectable in the 100 and 500 ppm samples; thus, defi ning the detection limit. The 110 peak areas for the remaining samples were measured and used to form a calibration curve relating peak area to ppm amphibole. Of the fi ve Libby samples, each had detectable levels of amphibole and their amphibole content ranged from 1171 to 9218 ppm. The XRD method provides a bulk measurement of the total amphibole content. To determine the amount of asbestiform amphiboles, morphological considerations obtained by microscopy techniques are required. From the results of a previous polarized light microscopy study, the fi ve expanded vermiculites in this study would contain from 390 to 3073 ppm asbestiform amphiboles and not be subject to regulation on the basis of the 1% rule used by regulatory agencies in the U.S.A.read more
Citations
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Journal ArticleDOI
Amphiboles: Environmental and Health Concerns
TL;DR: Asbestos is something manufactured by humans and that one fiber is enough to kill you if inhaled as discussed by the authors, which is often not based on rational science, but about fear; however, many people still believe that asbestos is made by humans.
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Quantifying carbon fixation in trace minerals from processed kimberlite: A comparative study of quantitative methods using X-ray powder diffraction data with applications to the Diavik Diamond Mine, Northwest Territories, Canada
TL;DR: In this paper, the abilities of three methods of quantitative phase analysis to measure trace nesquehonite (MgCO3·3H2O) in samples of processed kimberlite have been assessed: the method of reference intensity ratios (RIR), the internal standard method, and the Rietveld method with X-ray powder diffraction data.
Journal ArticleDOI
Characterization of chrysotile samples for the presence of amphiboles: the carey canadian deposit, southeastern quebec, canada
TL;DR: In this article, the authors used a powder X-ray diffraction (XRD) method to detect amphiboles in chrysotile-containing samples from the former Carey Canadian Mines.
Journal ArticleDOI
Mechanisms of oxidative stress and alterations in gene expression by Libby six-mix in human mesothelial cells
Jedd M. Hillegass,Arti Shukla,Maximilian B. MacPherson,Sherrill A. Lathrop,Vlada Alexeeva,Timothy N. Perkins,Albert van der Vliet,Pamela M. Vacek,Mickey E. Gunter,Brooke T. Mossman +9 more
TL;DR: Results support a mechanistic basis for the importance of SOD2 in proliferation and apoptosis of mesothelial cells and its potential use as a biomarker of early responses to mesotheliomagenic minerals.
Journal ArticleDOI
Geochemistry in the lung: Reaction-path modeling and experimental examination of rock-forming minerals under physiologic conditions
TL;DR: In this paper, reaction-path modeling for chrysotile, anorthite, K-feldspar, talc, muscovite, kaolinite, albite, and quartz under physiologic conditions in simulated lung fluids is presented.
References
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Journal ArticleDOI
Cohort study of mortality of vermiculite miners exposed to tremolite.
TL;DR: The results of this and case-referent analyses indicate an increased risk of mortality from respiratory cancer in this cohort of about 1% for each fibre year of exposure and in relation to estimated exposure the mortality experienced by the cohort from both lung cancer and mesothelial tumours was higher than in chrysotile mining.
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The morbidity and mortality of vermiculite miners and millers exposed to tremolite-actinolite: Part II. Mortality
Harlan E. Amandus,R. Wheeler +1 more
TL;DR: Results indicated that mortality from nonmalignant respiratory disease (NMRD) and lung cancer was significantly increased compared to the U.S. white male population.
Journal ArticleDOI
The morbidity and mortality of vermiculite miners and millers exposed to tremolite-actinolite: Part I. Exposure estimates
TL;DR: The vermiculite ore and concentrate of a mine and mill near Libby, Montana, was found to be contaminated with fibrous tremolite-actinolite, and all 8-hr TWA job exposure estimates decreased from 1972-1976, and from 1977-1982 were less than 1 fiber/cc.
Journal ArticleDOI
Radiological survey of past and present vermiculite miners exposed to tremolite.
TL;DR: Overall, the data suggest that by retirement age the increase in prevalence of small opacities lies between 5% and 10% per 100 f/ml years, and may be somewhat steeper than for chrysotile miners and millers, but not much so.
Journal ArticleDOI
Composition, Fe3+/∑Fe, and crystal structure of non-asbestiform and asbestiform amphiboles from Libby, Montana, U.S.A.
TL;DR: In this article, compositional data and Fe 3 + /ZFe ratios obtained by electron microprobe and Mossbauer analyses are given for a suite of three amphibole and amphibole-asbestos samples collected from the former vermiculite mine near Libby, Montana.