Exposure to asbestos
Asbestos-related pleuropulmonary pathology
Asbestos are silicate minerals that can break into fiber. The use of asbestos have developed several diseases, mainly pleuropulmonary diseases, all of them characterized by a long latency period. Asbestos have been classified as Group 1ª by WHO from 1987. The use of asbestos is forbiden in Spain from 2002.
The pulmonary disease developed after asbestos exposition depends on the intensity of the exposure and the size and aerodynamic characteristics of the fibers. When the fibers are in the alveoli, they interact with the cells of the immune system modifying their function, increasing the risk of fibrosis and tumours appearance.
Asbestos related pathology
Focal pleural fibrosis or pleural plaques: these are circumscribed damages, sometimes with calcifications, localized in the parietal pleura or above the tendionus portion of the diaphragma, and usually in both sides. It is usually diagnosed using thorax X-ray.
Difuse pleural fibrosis: it is a difuse fibrosis of the visceral pleura. It is usually related to fibrous band and parenchyma. It could be associated with pleural plaques.
Pleural spilling by asbestos: it is an exudate, just in one side, of a small volumen. Most of the middle of these are serous or serohematics, and one third has eosinophilia. It is a dianosis of exclusión and it is recomended to monitorig for at least three years in order to dismiss malignant characteristics.
Round atelactasis: it is a peripheral pulmonary collapse with similar radiographic appearance to neoplastic. It is produced as a consecuence of an incomplete expansión of pulmonary tissue. The most frecuent origin is asbestos exposure, but it is not the only reason. HRCT is used to diagnose it and an oval opacity with pleural thikening is observed, with a curve of the blood vessels and bronchios, called comet-tail. It is common to find it just in one side and in the lower lobes.
Asbestosis: this is a diffuse interstitial lung disease, with fibrosis, caused by asbestos fibers inhalation. It is related with long exposure periods, frequently between 10 and 20 years. Asbestosis is more frequent and complicated in tobacco consumers.
Bronchogenic carcinoma: the main risk factor for lung cancer is asbestos exposure, mainly when people are tobacco consumers. Lung cancer in asbestos exposure patients is not distinguished from lung cancer in people not exposed to the agent, taking into account histological lining and location.
Malignant Pleural Mesothelioma: this is a malignant tumour produced from the mesotelial cells which cover serous cavities. Depending on the situation, this tumour could be pleural (the most common), pericardial, peritoneal or tunica vaginalis. In all of them, the main etiological factor is asbestos exposure. Pleural Mesothelioma affects the pleural lining, encapsulating the lung.
Other neoplasias: The International Agency for Reasearch of Cancer considers that there is an etiological link betwen exposure and larynge and ovary tumors, and a link between the exposire and digestives tumors development (pharynx, oesophagus, stomach, colon and rectum).