Mesothelioma: True Causes

The relationship between mesotheliomas and asbrstos was first reported in by Wagner and colleagues in 1960. After that time, this relationship has been confirmed by other reliable reports.

Asbestos touches on six naturally occurring minerals with prospicient fibers, including chrysotile, ammonite, crocidolite, anthophyllite, tremolite, and actinolite. There is a long reaction time period between the exposure and the development of mesothelioma, which is generally between 30 – 40 years.

Industrial exposure to asbestos increased significantly during the world war II when there was a dramatic need for manufacturing requiring asbestos-related products. Asbestos is widely used for industrial purposes in more than 3,500 diverse products because of its tensile strength, thermal resistance, and chemical stability.

Its primary uses are in cement pipes and construction products such as flooring, roofing, insulation, tiles, packing and gaskets, electrical products, friction products, and coatings.

In the United States, occupational exposure is limited to not more than two fibers (0.5um in length) in 0.5 Cm3 of air in an eight-hour period. It is expected that this regulation will significantly decrease the future incidence of mesothelioma.

Roughly 70% of patients have had exposure. In addition Para-occupational exposure by household members and persons living downwind of factories or mines may account for 8% to 20% of cases. The risk of mesothelioma is increased 40-fold for insulation workers and threefold to tenfold for construction and shipyard workers. Cigarette smoking does not increase the risk of mesothelioma, but the combination of cigarette smoking and asbestos exposure markedly increase the risk of lung cancer.

Pleural mesotheliomas are much more common in men, whereas peritoneal mesotheliomas are about equal in frequency between the sexes. Asbestos fibers are thought to reach the peritoneum via the pleural lymphatics.