Amosite asbestos
描述
Amosite is one of the six naturally occuring minerals that may compose asbestos. Asbestos minerals consist of thin, separable fibers that have a parallel arrangement. Amosite belongs to the amphibole family of minerals and has needlelike fibres. The most common use for amosite asbestos is as a fire retardant in thermal insulation products and ceiling tiles. Abestos is toxic and inhalation of asbestos fibers can cause serious illnesses, including malignant mesothelioma, lung cancer, and asbestosis. While all forms of asbestos are hazardous and can cause cancer, amphibole forms of asbestos are considered to be somewhat more hazardous than their serpentine counterpart (chrysotile). (L221, L222)
类别
"Industrial/Workplace Toxin", "Pollutant", "Airborne Pollutant", "Natural Toxin"
同义词
"Amosite", "Brown asbestos", "Cis-dihydronarciclasine", "Trans-dihydronarciclasine"
化学式
(Na, K)0-1(Fe2+, Mg)2(Fe2+, Mg)5Si8O22(OH)2, approx. Fe2+5Mg2
简化分子线性输入规范
OC1CC2C(NC(=O)C3=C(O)C4=C(OCO4)C=C23)C(O)C1O
InChI 标识符
InChI=1S/C14H15NO7/c16-6-1-5-4-2-7-13(22-3-21-7)11(18)8(4)14(20)15-9(5)12(19)10(6)17/h2,5-6,9-10,12,16-19H,1,3H2,(H,15,20)
键
InChIKey=SBTGHBALOCEVOR-UHFFFAOYSA-N
地位
Detected and Not Quantified
蜂窝位置
"Cytoplasm", "Extracellular"
外貌
Grey to green fibrous crystals.
暴露途径
Inhalation (L222) ; injection (L222)
毒性机制
When asbestos fibers are inhaled, many are deposited on the epithelial surface of the respiratory tree. Fibers that are retained in the lung or mesothelium for long periods of time are capable of producing chronic inflammation and fibrotic and tumorigenic effects. These effects may be mediated by direct interactions between the fiber and key cellular macromolecules, or they may be mediated by the production of reactive oxygen species and other cellular factors originating from alveolar macrophages. In addition, the physical-chemical nature of the fiber appears to be an important determinant of toxicity. It is generally agreed that exposure to amphibole fibers can produce mesothelioma, and that the potency of amphibole fibers to produce mesothelioma is greater than that of chrysotile. Asbestos fibers can adsorb to a variety of cellular macromolecules (e.g., proteins,membrane lipids, RNA, DNA). The coulombic forces between the asbestos fiber and some of these macromolecules may induce conformational changes, and these changes could affect protein function and chromosomal fidelity. Fibers found to be translocated near the nucleus can interact with the cytoskeleton and interfere with chromosome segregation. (L222)
代谢
Asbestos fibers are not metabolized in the normal sense of the word, and amphibole fibers that are retained in the lung do not appear to undergo any major changes. Some of the fibers will be deposited in the air passages and on the cells that make up your lungs. Most fibers are removed from the lungs by being carried away or coughed up in a layer of mucus to the throat, where they are swallowed into the stomach. Fibers that are deposited in the deepest parts of the lung are removed more slowly. In fact, some fibers may move through the lungs and can remain in place for many years and may never be removed from the body. Longer fibers that are retained in the lung may undergo a number of processes including translocation, dissolution, fragmentation, splitting, or protein encapsulation. Long fibers that reside in the lung can become encapsulated in protein, forming what is often referred to as an "asbestos body". In response to asbestos fibers, alveolar macrophages produce reactive oxygen species in an attempt to digest the fiber. The reactive oxygen species include hydrogen peroxide and superoxide radical anion (O2-). Fibers that have been swallowed (those present in water, or those moved to the throat from the lungs) almost all pass along the intestines within a few days and are excreted in the feces. (L222)
致癌性
1, carcinogenic to humans. (L224)
用途/来源
Asbestos are used in building materials (roofing shingles, ceiling and floor tiles, paper products, and asbestos cement products), friction products (automobile clutch, brake, and transmission parts), heat-resistant fabrics, packaging, gaskets, and coatings. Some vermiculite or talc products may contain asbestos. Exposure most likely by breathing air containing asbestos fibers or by drinking asbestos fibers that are present in water. (L222)
健康影响
Infected people develop a slow buildup of scar-like tissue in the lungs and in the membrane that surrounds the lungs, so breathing becomes difficult. Blood flow to the lung may also be decreased, and this causes the heart to enlarge. This disease is called asbestosis. Infected people have increased chances of getting two principal types of cancer: cancer of the lung tissue itself and mesothelioma, a cancer of the thin membrane that surrounds the lung and other internal organs. The cellular immune system of the patient can be depressed. Also, deletions of chromosome segments have been noted in human mesothelioma cells or cell lines. (L222)
症状
Symptoms of asbestos exposure include shortness of breath, often accompanied by a cough. (L222)
治疗
In vitro studies have shown that the effects of asbestos can be diminished by compounds that reduce the levels of reactive oxygen species, such as free radical scavengers (ascorbic acid, bemitil, mannitol, salicylate, 5,5'-dimetyl-l-proline N-oxide, rutin, vitamin E, vitamin A) and enzymes that catalyze the decomposition of reactive oxygen species (catalase, superoxide dismutase). Patients should quit smoking, perform bronchial drainage and can use chest physical therapy techniques to further aid in removing secretions. Shortness of breath is treated with bronchodilators, inhaled or oral medications that open up the bronchial tubes and allow the passage of air. In more severe asbestosis cases, supplemental oxygen may be required. Productive cough is treated with humidifiers and chest percussion. Asbestosis can be treated, but not cured. (L222, L227)
创建于
2009-03-06 18:58:08 UTC
更新于
2014-12-24 20:21:10 UTC