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Inorganic Particulates in Human Lung: Relationship to the Inflammatory Response
Published in William S. Lynn, Inflammatory Cells and Lung Disease, 2019
Victor L. Roggli, J. P. Mastin, John D. Shelburne, Michael Roe, Arnold R. Brody
The term asbestos encompasses a number of naturally occurring silicate mineral fibers in the serpentine and amphibole series.56 Chrysotile, the sole representative of the serpentine type of asbestos mineral, is a fibrous magnesium silicate consisting of a curled sheet which spirals around a central capillary. The fibers of chrysotile are typically curly or wavy (Figure 3A). The amphibole series has five recognized members: crocidolite (blue asbestos), amosite (brown asbestos), anthophyllite, tremolite, and actinolite. The amphibole minerals occur as double chains of linked silica tetrahedra which are crosslinked with various bridging cations, the identity of which is useful in the chemical identification of the various types of amphibole. For example, amosite contains iron (Fe+ +) as well as smaller amounts of magnesium and manganese, whereas crocidolite contains iron (Fe+ +, Fe + + +) and sodium as well as smaller amounts of magnesium. The amphiboles are typically straight fibers (Figure 3B). Asbestos may be associated with various contaminants, including trace metals such as nickel, chromium, cobalt, and aluminum, and various hydrocarbons (either as natural contaminants or as a result of processing and storage).56
Occupational respiratory diseases
Published in Louis-Philippe Boulet, Applied Respiratory Pathophysiology, 2017
Louis-Philippe Boulet, Marc Desmeules
We design by the name of “asbestosis” a group of complex hydrated silicates in a fibrous state. They include two main families: serpentine asbestosis and amphiboles [5]. Serpentine asbestosis—Chrysotile (white asbestosis): these long fibers are flexible, resistant to fire and have been used in the production of asbestosis textiles. This form of asbestosis was often found in mining industry in Quebec since 1878, where chrysotile constitutes more than 90% of industrial asbestosis.Amphiboles asbestosis: this group includes five varieties of rigid fibers that are easy to break but have an excellent resistance to acids. They include anthophyllite, amosite, crocidolite, actinolite, and tremolite.
Malignant Pleural Mesothelioma
Published in Dongyou Liu, Tumors and Cancers, 2017
Raúl Barrera-Rodríguez, Carlos Pérez-Guzmán
About 70% of MPM cases have a history of direct or indirect exposure to asbestos (including the serpentine chrysotile and members of the amphibole family—amosite, crocidolite, tremolite, anthophyllite, and actinolite). Other agents and factors related to MPM consist of the nonasbestos fiber erionite (seen only in Cappadocia, Turkey), beryllium, therapeutic radiation, and possibly processes that lead to intense pleural scarring such as prior plombage therapy for tuberculosis. Simian virus 40 (SV40) and inactivated nuclear deubiquitinase BRCA1-associated protein 1 (BAP1) may have a role in the pathogenesis of MPM [2].
Dimensional determinants for the carcinogenic potency of elongate amphibole particles
Published in Inhalation Toxicology, 2021
Andrey A. Korchevskiy, Ann G. Wylie
Dimensional characteristics of fibers are essential for various regulatory criteria and laboratory methods of exposure evaluation. During occupational assessments, the asbestos dose is measured by the membrane filter method which records the number of particles longer than 5 µm with a length to width ratio of three or more visible by phase-contrast light microscopy (PCM). Resolution by the PCM method employed is ∼0.3 μm, but experiments have shown fibers of amphibole with widths as small as 0.1–0.15 μm are visible by this method (Rooker et al. 1982; Kenny et al. 1987; Pang et al. 1988).1 NIOSH describes particles counted in an exposure assessment as elongate mineral particles (EMP), although they are still referred to as fibers in their analytical protocols (NIOSH 1994, 2011). By formal ruling in 1992, EMPs from fragmented tremolite, actinolite, grunerite, riebeckite, and anthophyllite (cleavage fragments) derived from crushing rock or excavating soil are not covered under Occupational Safety and Health Administration (OSHA) regulations for asbestos (OSHA 1992) even though they meet the NIOSH EMP definition. However, all federal regulations of asbestos specify the asbestiform variety of these minerals.
An updated evaluation of potential health hazards associated with exposures to asbestos-containing drywall accessory products
Published in Critical Reviews in Toxicology, 2019
Neva F. B. Jacobs, Kevin M. Towle, Brent L. Finley, Shannon H. Gaffney
The amphibole anthophyllite was reportedly measured in one study of drywall accessory products (Rohl et al. 1975); the anthophyllite mineral was presumably present as a trace contaminant of industrial talc. It is unclear whether this analysis actually identified asbestiform anthophyllite because the methods used did not permit distinction between asbestiform and non-asbestiform structures. To our knowledge, there are no published mesothelioma or lung cancer NOAEL values for asbestiform anthophyllite. However, numerous animal studies involving intrapleural injections of various asbestos fiber types have found that anthophyllite exhibited a lower potency for inducing mesothelioma than other amphiboles, and, in some studies, lower than even chrysotile (Wagner et al. 1973; Smith and Hubert 1974; Wagner et al. 1974; Wagner 1976; Pylev 1980). Hence, even if trace levels of asbestiform anthophyllite amphibole were truly present in some joint compound products, it is unlikely that these fibers pose a risk of asbestos-related disease.
Empirical model of mesothelioma potency factors for different mineral fibers based on their chemical composition and dimensionality
Published in Inhalation Toxicology, 2019
Andrey Korchevskiy, James O. Rasmuson, Eric J. Rasmuson
The mesothelioma potency of anthophyllite is generally unknown and may depend on the morphology of the fibers in specific deposits. In the study of the Finland cohort of anthophyllite miners, four cases of malignant pleural mesothelioma were found among the cohort of 999 miners (Karjalainen et al. 1994). The Finnish authors stated that mesothelioma risk caused by anthophyllite was ‘higher than among chrysotile miners and almost as high as among amosite miners’ (Meurman et al. 1994). This statement is consistent with our modeling results. According to both of our models, Finnish anthophyllite seems to be 1.3 (Fe2O3 model) to 1.5 (total Fe model) times less potent than amosite, and respectively 62.5–66 times more potent than Quebec chrysotile.