Localized fibrous plates or, rarely, diffuse pleural fibrosis
epanchements pleural
Parenchymale interstitial fibrosis (asbestosis)
Bronchial carcinoma
Mesotheliomes
Larynx and perhaps other extrapulmonary neoplasms, including carcinoma of the colon.
An increased incidence of cancer of asbestosis-related family members of asbestos workers alerted the public to the potential dangers of asbestos in the environment. The good public health policy toward low level of exposure that may be encountered in old buildings or schools is controversial, with some experts questioning the wisdom of costly plans for the disposal of asbestos airborne with fiber heads environments that are up 100 times lower than allowed by the Standards.
Pathogenesis. Concentration, the size, shape and the solubility of the different forms of asbestos dictate, whether diseases cocurs. There are two geometrical forms of asbestos: sepentine (looped and flexible fibers) and amphiboles (stright, rigid, brittle and fiber) The chemical form of serpentine chrysotile, mostly accounts of the asbestos used in the industry. The amphibole include crocidolite, amosite, tremolite, anthophyllite and actinolyte. This confusion of terms table is important because amphiboles, although they are less common, are more pathogenic than chrysotiles, particularly with regard to the induction of malignant pleural tumers (mesotheliomas). Some studies have shown the connection of mesothelioma is almost always the amphibole exposure. The relatively few cases of mesothelioma occurring in the chrysotile workers are, in all probability, because of the contamination of chrysotile with amphiboles tremolite.
Most pathogenicity right and steep amphiboles is apparently related to their solubility and aerodynamic properties. Chrysotiles, with their more flexible, curled structure, are likely to become an impact in the upper respiratory tract and removed by the mucociliary elevator. Moreover, once trapped in the lungs, crysotiles are gradually leached of tissues because they are more soluble than amphiboles. On the other hand, the right, stiff amphiboles May align themselves with airsteam and thus be delivered more deeply into the lungs, where they can penetrate the epithelial cells and reach the interstices. The length of amphibole fibers also plays a role in the pathogenicity, those over 8 mm and a thickness of less than 0.5 mm is more harmful than the shorter, thicker. Nevertheless, the two amphiboles, and winds are fiber, and increasing doses are associated with a higher incidence of all diseases linked to asbestos, except that only amphibold exposure is correlated with mesothelioma. Unlike other inorganic dust, asbestos can also act as both a tumor initiator and promoter of a tumor. Potentially toxic chemicals absorbed asbestos fibers on however undoubtedly contribute to the oncogenicity fiber. For example, the adsorption of carcinogens in tobacco smoke on the asbestos fibers can be significant in the remarkable synergy between smoking and the development of a bronchogenic carcinomas to asbestos workers. A study of asbestos workers have found a 5-fold increase in lung carcinoma exposure to asbestos alone, while exposure to asbestos and smoking and led to a 55 times greater cancer risk lung.
Asbestosis, similar to the other pnumoconioses depends on the interaction of inhaled fibers with lung macrophages and other parenchymal cells. The initial injury occurs at bifurcations of the small airways and ducts, where land and stiff fibers penetrate. Macrophages both interstitial and alveolar attempt to ingest and clear fibers and are activated to release chemotactic factors and fiber mediators that amplify the response. Deposits fiber chronic and persistent mediators release ultimately led to widespread inflammation and interstitial pulmonary interstitial fibrosis. It is not fully understood why silicosis is a nodular fibrosing disease and asbestosis a difuse interstitial process. The more diffuse distribution can be linked to the ability of asbestos to reach the alveoli more coherent or its ability to penetrate the epithelial cells, or both.
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