Epidemiologic Features of Mesothelioma

The rising worldwide incidence of malignant mesothelioma is not expected to peak for another 10
to 20 years. It is possible that the disease has already reached its peak incidence in the United States,
whereas the anticipated peaks in Europe and Australia are not predicted to occur for another 10
to 15 years. Furthermore, in Japan and other non- Western countries, in which heavy use of asbestos
occurred later than in the Western world, there is a corresponding delay in the anticipated peak incidence
of mesothelioma (Table 1).
There is substantial concern that the increased use of asbestos in developing countries may result in an increase in the number of cases of malignant mesothelioma for many decades to come unless strong occupational health controls are put in place.Malignant mesothelioma has occurred in three principal cohorts of asbestos-exposed persons.
The initial cases occurred in people who were directly exposed to asbestos in their work, especially
those exposed to blue asbestos during its mining or milling. The clearest and best-studied example of
such exposure occurred at the blue-asbestos mine in Wittenoom, Australia, the site of one the worst
industrial disasters in history. Not only were the miners heavily exposed to asbestos, but the soft asbestos
tailings were used instead of grass to cover the schoolyards and playgrounds of the town, resulting
in a huge outbreak of mesotheliomas, many in young adults who had played in the asbestos dust
as children.Subsequently, asbestos-related diseases were noted in other workers who were exposed
later in the chain of manufacture and use of asbestos products, such as plumbers, carpenters,
defense personnel, and installers of asbestos insulation.A third group of affected people, accounting

for 20 to 30 percent of current cases of malignant mesothelioma, consists of those who were exposed to asbestos unknowingly and incidentally in the myriad situations in which asbestos fibers are released
into the atmosphere in industrialized countries. There have been several reports of familial clustering of malignant mesothelioma, including one cluster showing a possible autosomal dominant pattern in subjects studied in Cappadocia, Turkey

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