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Chemistry of Contaminants
Published in Daniel T. Rogers, Environmental Compliance Handbook, 2023
The term asbestos describes a variety of fibrous, nonflammable minerals with flexibility and high tensile strength. Their unique properties were used mostly between the 1940s and 1970s in fireproof insulation, vinyl flooring, pipe insulation, ceiling tiles, brake linings, and roof coatings. Chrysotile, a serpentine mineral, is also known as “white asbestos” and makes up about 95% of asbestos found in buildings in the United States. The other asbestos minerals—crocidolite, amosite, anthophyllite, tremolite, and actinolite—are amphiboles that aren't commonly used in commercial products (USEPA 2021o). Asbestos usually occurs in the form of very thin elongated fibers. If asbestos is disturbed, the fibers may create an airborne dust, which, when inhaled, can penetrate tissues deep within the lungs and cause asbestosis, mesothelioma, and lung cancer. The US Occupational Safety and Health Administration and Environmental Protection Agency make no distinction between the two kinds of asbestos—chrysotile and amphibole. OSHA began regulating workplace asbestos in 1970, around the time when miners and construction workers, who worked with the fibrous material, began reporting serious lung disease. At that time, the United States used about 800,000 metric tons of asbestos per year. OSHA published the Asbestos Standard for the Construction Industry, which outlined four categories of asbestos contamination and specified precautions and disposal techniques for each class. For instance, if asbestos insulation is removed (Class 1), contractors and supervisors trained in asbestos removal must be onsite wearing respirators and protective clothing (USEPA 2021o).
Introduction
Published in Shishir Sinha, G. L. Devnani, Natural Fiber Composites, 2022
Mineral fibers, primarily occurring or moderately altered fibers extracted from mineral deposits, are classified into the succeeding categories. Asbestos is a collection of mineral compounds that assuredly transpire as bunches of fibers in the ecological system. These are heat resilient, flame resilient, and poor conductors of electrical energy. Asbestos is a silicate mineral with silicon dioxide in its chemical pattern. There are various forms of asbestos: chrysotile and amphibole. Amphibole is composed primarily of five fibroid minerals. Grunerite, fibrous riebeckite, fibrous tremolite, fibrous actinolite, and fibrous anthophyllite are the five types of asbestos. The second significant variety of asbestos discovered in construction products is fibrous amosite. It is occasionally known as “brown” asbestos. The native occurrence of magnesium and iron gives it a specific color. It was commonly utilized in insulating materials as a flame decelerant (Kelse & Thompson, 1989). Crocidolite, commonly referred to as bluish asbestos, is the type of asbestos less commonly employed for commercialization (Gualtieri & Tartaglia, 2000). Tremolite is formed through the metamorphic rocks of dolostone and quartz-rich deposits. The color of magnesium silicate tremolite is milky white, but when the ferrous component increases, the color changes to deep green. It is poisonous at elevated temperatures and converts to diopside (Orden, 1964). Actinolite, for example, is originated from the gibberish word aktis, which means “ray” or “gleam.” Actinolite is mainly encountered in metamorphisms such as aureoles and hard intruding igneous rocks. Metamorphic rocks are magnesium affluent, and dolostone shales produce anthophyllite. White asbestos is a kind of serpentine asbestos. It's a sheet silicate mineral that's incredibly soft and rubbery. It is one of the most often utilized types of chrysotile. This fiber is made up of long cylindrical tubes that are extremely strong (Orden, 1964).
Health and Safety
Published in Kenneth F. Cherry, Asbestos, 2020
Asbestos, tremolite, anthophyllite, and actinolite can cause disabling respiratory disease and various types of cancers if the fibers are inhaled. Inhaling or ingesting fibers from contaminated clothing or skin can also result in these diseases. The symptoms of these diseases generally do not appear for 20 or more years after initial exposure.
Analytical transmission electron microscopy of amosite asbestos from South Africa
Published in Archives of Environmental & Occupational Health, 2020
Amosite is a mineral name for grunerite asbestos derived from South African mines and is based on the acronym “Amosa” for the mining company “Asbestos Mines of South Africa.” The name “amosite” specifically refers to the South African grunerite asbestos, which is the only known commercial-grade grunerite asbestos in the world. Amosite is one of the five amphibole asbestos minerals regulated under occupational laws. The other four regulated amphibole minerals are tremolite, actinolite, crocidolite, and anthophyllite.1 The extreme hazard of exposure to amosite fibers has been established. A landmark study2 involved 230 men exposed to amosite dust during and prior to 1954, when the production was moved to Texas,3 in a group of former employees followed between 1960 and 1971.2 During this time, there were 105 deaths, while 46.4 were expected. Twenty-five lung cancers were diagnosed, while 2–3 were expected. Five deaths were from mesothelioma occurred during the period of observation, while virtually none would be expected; 14 deaths occurred due to asbestosis. There were no other known exposures to asbestos.2
Characterization of pulmonary responses in mice to asbestos/asbestiform fibers using gene expression profiles
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Naveena Yanamala, Elena R. Kisin, Dmitriy W. Gutkin, Michael R. Shurin, Martin Harper, Anna A. Shvedova
Asbestos is a term for a set of commercially important naturally occurring fibrous silicate minerals. Crocidolite (asbestiform riebeckite), amosite (asbestiform cummingtonite-grunerite), actinolite-tremolite asbestos, and anthophyllite asbestos belong to the amphibole minerals, while chrysotile is a serpentine mineral (Wylie and Candela 2015). The term “asbestiform” corresponds to a mineralogical habit or form of a mineral in which single fibers (fibrils) occur in bundles that can be detached into finer fibers and display curvature (Lowers and Meeker 2002). Similar to main asbestos types described above, there are “other regulated asbestiform minerals” fibers such as durable asbestiform zeolite minerals (e.g., erionite). The term asbestos has been used in commerce and regulations, but is not recognized in geology as referring to species separate from non-asbestos analogs of these minerals (Lowers and Meeker 2002). These materials were widely used for textiles and in construction, as well as in industrial application, until the 1970’s in the USA (Williams, Phelka, and Paustenbach 2007). Although the use has declined, asbestos continues to be utilized for certain applications in the USA and elsewhere (Dodson 2016; LaDou et al. 2010). Known human diseases associated with exposure to asbestos/asbestiform fibers include asbestosis, bronchial adenocarcinoma, squamous cell carcinoma of the respiratory epithelium and large/small cell lung carcinoma and diffuse malignant mesothelioma (Andujar et al. 2016; Lemen 2016; Ndlovu et al. 2017).
Anthophyllite asbestos from Staten Island, New York: Longitudinal fiber splitting
Published in Archives of Environmental & Occupational Health, 2022
We conclude that elongate mineral particles do not have to be asbestiform to be toxic. The anthophyllite asbestos ore from Staten Island closely resembles the anthophyllite asbestos ore from the North Savo anthophyllite mine, Finland that was associated with excess lung cancer and mesothelioma2–4,6 and should be assumed to be equally dangerous. Although the crushed anthophyllite particles described here include thin respirable fibers with parallel sides and aspect ratios > 20:1 our evidence indicates that in general the Staten Island anthophyllite fibers fail to meet criteria necessary to qualify as asbestiform.7,21 They commonly display step-like profiles or ledges caused by removal of longitudinally split segments some of which are still partially attached but more importantly they do not form by separation along grain boundaries from polyfilamentous bundles of fibrils about 0.03 µm in diameter13 as in the case of chrysotile asbestiform fibers. Instead our evidence indicates that they split longitudionally along plains of weakness caused by CMFs. Split fibers in a regulatory setting are technically "cleavage fragments" and not asbestos (OSHA).21 HRTEM assisted observation of Staten Island anthophyllite fibers do not reveal bundels of fibrils but instead reveal nothing more than double chains spaced less than 1 nm apart and CMFs parallel to (010) that are randomly spaced about 3 to 30 nm apart. Therefore, anthophyllite and amosite fibers are not asbestiform in the same way as chrysotile fibers but are nevertheless potentially dangerous.