The mesothelium is a membrane that covers and protects most of the internal organs of living. It consists of two layers of cells: One layer immediately surrounds the organ, the other bag around it. The mesothelium produces a lubricating fluid released from these layers, so that moving parts (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures.
Mesothelium has different names depending on its location in the body. Peritoneum is the mesothelial tissue that covers most organs in the abdominal cavity. Pleura is the membrane that surrounds the lungs and lines the wall of the thoracic cavity, while the pericardium covers and protects the heart. mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis and the tunica serosa uteri covers the internal reproductive organs in women.
Working with asbestos is the major risk factor for mesothelioma. A history of asbestos at work is reported in about 70 to 80 percent of cases. However, mesothelioma has been reported in some individuals without known exposure to asbestos.
There is some evidence that family members and others living in asbestos workers have an increased risk of developing mesothelioma, asbestos and possibly other related diseases. This risk can be caused by exposure to asbestos dust brought home the clothes and hair of asbestos workers. In order not to expose family members to asbestos fibers, asbestos workers are usually required to shower and change clothes before leaving the workplace.
Smoking does not appear to increase the risk of mesothelioma. But the combination of smoking and asbestos exposure increases a person's risk of developing lung cancer