Clinical Cases
S. J. Copley, J. P. Kanne, D. M. Hansell in Thoracic Imaging, 2014
Asbestosis usually occurs many (20–30) years after exposure, and a reliable history of nontrivial exposure is mandatory for the diagnosis. Crocidolite is the most fibrogenic form. Histopathologically, early disease is characterised by a peribronchiolar distribution of fibrosis, which is often apparent in the subpleural regions of the lung, but as the disease progresses, distinction from usual interstitial pneumonia (UIP) becomes more difficult. The radiographic features may be identical to those of idiopathic pulmonary fibrosis (IPF), apart from the presence of pleural disease such as pleural plaques and diffuse pleural thickening. Initial features include basal ground-glass and reticular opacities, which may progress to involve the whole lung, including the upper lobes, with volume loss and honeycombing. The HRCT parenchymal features are also often identical to those of UIP, with a basal, subpleural reticular pattern or honeycombing. In very early disease, the peribronchiolar distribution of fibrosis in asbestosis may be apparent as subpleural dots, which can help distinguish it from UIP but, depending on the type of exposure, asbestos-induced disease is often more advanced at presentation. There is controversy over whether parenchymal bands radiating from areas of pleural thickening into the lung parenchyma represent true ‘asbestosis’ or parenchymal changes as a result of pleural thickening. Most authorities favour the latter explanation and suggest that these areas may represent early folded lung or rounded atelectasis (see Question 79).
Atmospheric particulates *
Bev-Lorraine True, Robert H. Dreisbach in Dreisbach’s HANDBOOK of POISONING, 2001
The word asbestos is used for any mineral that breaks down into fibers. The most commonly used form, chrysotile, is fibrous serpentine, a magnesium silicate containing 40% silica. Its fibers are tubular in section and range down to 0.015 μm in diameter, which is invisible in the ordinary microscope. Another form, crocidolite, is fibrous riebeckite, a sodium ferro-ferrisilicate containing 51% silica. Its fibers range down to 0.08 μm in diameter. Amosite is fibrous grunerite, a magnesium ferrosilicate containing 49% silica. Fibers of this form range down to 0.1 μm in diameter. Other forms include anthophyllite and tremolite-actinolite. Uses of the various forms of asbestos in cloth, brake linings, cement products, paper, flooring, gaskets, and paint amount to 3 million tons per year in the USA.
Respiratory medicine
Shibley Rahman, Avinash Sharma in A Complete MRCP(UK) Parts 1 and 2 Written Examination Revision Guide, 2018
The severity of asbestosis is related to the length of exposure. This is in contrast to mesothelioma where even very limited exposure can cause disease. Asbestosis typically causes lower lobe fibrosis. Crocidolite (blue) asbestos is the most dangerous form.
The toxicology of chrysotile-containing brake debris: implications for mesothelioma
Published in Critical Reviews in Toxicology, 2019
Craig A. Poland, Rodger Duffin
Rather than being a single entity, “asbestos” is a collective term for a group of naturally occurring silicate fibers and are broadly classified into serpentine or amphibole. The serpentine group consists only of chrysotile asbestos, a flexible and flowing fiber of thin chrysotile fibrils that can be woven while the amphibole group consists of five different forms of “asbestos”, namely crocidolite, amosite, tremolite, anthophyllite, and actinolite. Crocidolite and amosite asbestos were used commercially to some degree including significant usage in naval and merchant shipping as insulation materials in the form of asbestos filled mattresses, lagging and prior to 1963, sprayed asbestos (Harries 1968). However, of the different forms of “asbestos”, chrysotile was the most extensively used worldwide (Virta 2006). The availability and useful properties of chrysotile, amosite, and crocidolite asbestos fibers promoted their use in many different environments and products. Their lightweight, fireproofing, and insulating capacity made them indispensable in the technological revolution at the beginning of the twentieth century. “Asbestos” fibers such as chrysotile found uses in brake and clutch linings, insulation for fuel tanks for the growing aviation industry, cement boards and roofing tiles in the building industry and even as “artificial snow” sold to the public.
Dimensional determinants for the carcinogenic potency of elongate amphibole particles
Published in Inhalation Toxicology, 2021
Andrey A. Korchevskiy, Ann G. Wylie
Mesothelioma and lung cancer potencies of South Africa riebeckite (crocidolite) and South Africa grunerite (amosite) were derived from Hodgson and Darnton (2000). The updated values of mesothelioma and lung cancer potency for Australia crocidolite were utilized based on the recent personal communication with L. (A.) Darnton (RM = 0.51% was used instead of 0.48% in Hodgson and Darnton (2000), and RL = 4.6% instead of 3.4%). Mesothelioma potency for Na-Ca amphiboles from Libby, MT was quoted based on Korchevskiy et al. (2020) (RM = 0.03%); lung cancer potency value was obtained from L. (A.) Darnton (RL = 0.82%).
Cytotoxicity and genotoxicity of MWCNT-7 and crocidolite: assessment in alveolar epithelial cells versus their coculture with monocyte-derived macrophages
Published in Nanotoxicology, 2020
Célia Ventura, Joana F. S. Pereira, Paulo Matos, Bárbara Marques, Peter Jordan, António Sousa-Uva, Maria João Silva
The crocidolite fibers are a standard reference mineral from the Union for International Cancer Control (UICC, Geneva, Switzerland) and were kindly provided by Dr. Fátima Aguiar from the Environmental Health Department of INSA. Their preparation and characterization have been described in detail (Timbrell and Rendall 1972; Rendal 1970; Timbrell 1970; Kohyama, Shinohara, and Suzuki 1996). A stock solution was prepared at 1 mg/mL in phosphate buffer saline (PBS), pH 7.4 (Gibco). Prior to dilution in culture medium, fibers were passed through a syringe needle to ensure a better uniformity of the suspension.
Related Knowledge Centers
- Actinolite
- Asbestos
- Calcite
- Sodium
- Tremolite
- Relative Density
- Arfvedsonite
- Ankerite
- Mesothelioma