The exact method by which asbestos causes mesothelioma isn’t known with certainty. Animal models have provided some understanding of the type of damage that asbestos fibers can do, but the exact mechanism hasn’t been found yet. After asbestos became a commercially successful product, it was soon apparent that asbestos workers were an at-risk population.
Starting at the turn of the century, British investigators discovered a relationship between exposure to high levels of asbestos and respiratory disease. These early studies were often suppressed by government at the request of the asbestos industry. By the mid 50’s American medical researchers had joined the chorus of concerned professionals identifying asbestos as hazardous. Much of their work was never published or was suppressed and/or disputed by scientists in the pay of the asbestos lobby.
Figure 3: Amphiboles Protruding, Brook T. Mossman, UVM College of Medicine.
Asbestos fibers have been detected in many resected surgical specimens from mesothelioma patients. In pleural mesothelioma, asbestos fibers are found trapped in the tissues from the lower parts of the lung and they are sometimes concentrated into nodules or spots on the parietal pleura, the primary location for mesothelioma in the thoracic cavity. These fibers are found using electron beam microscopy. They are invisible to the naked eye and are not routinely commented upon in a typical pathology report. Although smoking while exposed to asbestos is known to significantly increase lung cancer risks, smoking is not a risk factor in the formation of mesothelioma. It is not uncommon to find pleural plaques in the lungs of patients with primary peritoneal mesothelioma which is indicative of heavy asbestos exposure.
Genetic susceptibility may also contribute to the cause of malignant mesothelioma. Populations of three small villages located in Turkey has been environmentally exposed to a rare asbestos-like fiber called erionite for generations.
50% of all deaths in these villages was attributable to malignant mesothelioma. All villagers lived in homes built with this mineral and research by Dr. Michele Carbone discovered that those who developed mesothelioma had a genetic predisposition to the disease . Predisposed individuals who lived in villages without erinote were not found to develop mesothelioma. Further research into the residents of these communities has confirmed an autosomal dominant pattern of susceptibility to malignant mesothelioma and disease develops in the presence of asbestos-like fibers.
from : www.curemeso.org
from : www.curemeso.org
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