Unluckily, the incidence of malignant mesothelioma has not shown any omen of vanishing anywhere in the globe. While the exposure to asbestos in the workplaces has widely been eliminated in the United States and Europe, environmental exposure which results from outdoor air pollution has not and may even be increasing as natural piles of asbestos and erionite are disturbed by various human activities which includes land development. Asbestos is widely spread in the area due to former industrial activities, because asbestos is so hard to remove, and since houses are constructed near natural geological deposits of asbestos orerionite. In addition, as time flies, asbestos containing products degrade and more fibers of asbestos are dispersed in the environment, for instance, from the asbestos roofs still widely used in various United States homes. In other words, in the Europe and US, exposure to high levels of asbestos in the workplaces has widely been eliminated. But, the number of people that are exposed to “low” but “above background” levels of asbestos has risen. How these changes can impact th future incidence of malignant mesothelioma is not yet known.
Data available in the literature have yet to allow an estimation of the risk of malignant mesothelioma following low environmental exposure to asbestos, for instance, in an urban city. When environmental asbestos exposures are high, such as among the residents of the city of Wittenoom, which is an Australian town close to crocidolite mine, or in the city of CasaleMonferrato, which is an Italian city close to asbestos cement factory, or among individuals that live near geological asbestos deposits in New Caledonie, then the risk of developing malignant mesothelioma is several folds even higher. A significant increase in Malignant mesothelioma incidence in the third world, typically in India, where the use of the very substances has been increasing exponentially and few precautions, if any, are taken so as to prevent the exposure. The impact of erionite in the incidence of malignant mesothelioma in the United States cannot be projected yet since the extent of exposure to asbestos has remained to be fathomed.
Mesothelioma in women
Among women, malignant mesothelioma develops in the absence of evidence for asbestos exposure. But, some researches have suggested that a lot of female malignant mesothelioma patients, like their spouse, have known history of asbestos exposure. In his research, Dawson at al(1993) has found that 80% female mesothelioma patients had a long history of exposure to asbestos in UK. Nevertheless, as noted by most scientists, these cases were from referrals to the Environmental Lung Disease Research Group Department of Histopathology. Therefore consideration of this notion has to be taken seriously when interpreting the results. By basing the concept on the date from medical-legal documents, Roggliet al (1997) reported a history of the exposure to asbestos in 76 % female malignant mesothelioma cases. However as the date were obtained from the collections of legal cases, there is inherent bias in favour of exposure. A note of caution has to be introduced about the reliability of this history of exposure. The histories are generally reliable when examining the cohort, yet reliability falls down at the individual level.
