Who Gets Mesothelioma

Mesothelioma is relatively rare. In the United States about 2,500 men and women are diagnosed with the disease each year. The average age at diagnosis is 50 to 70 years old and it affects more men than women. Most people who are diagnosed with mesothelioma have breathed asbestos fibers and dust at their jobs. Family members can also be exposed to asbestos at home from fibers that cling to workers’ clothes and hair. Approximately 50%-70% of cases are associated with asbestos exposure.

From the 1940s to the 1970s, many workers were exposed to asbestos. Those most at risk include asbestos miners, factory workers, insulation manufacturers, railroad workers, ship builders, automotive workers, and workers in the heating and construction industries. Before its use was banned in 1986, asbestos was also used in homes, schools, and commercial buildings.

Mesothelioma can take a long time to develop. The time between exposure to asbestos and development of mesothelioma is usually between 20 and 40 years.

Today, limits for acceptable levels of asbestos exposure have been set by the U.S. Occupational Safety and Health Administration (OSHA). People who work with asbestos now wear protective equipment to reduce their risk of exposure.

The process of developing mesothelioma from asbestos exposure is a long one. Furthermore, while the development of mesothelioma correlates with asbestos exposure, such exposure isn’t an absolute indicator of who will get the tumor and who won’t. Since there is no national or international mesothelioma registry, statistics for the disease vary widely, depending upon the source. Nevertheless, there is a valid statistical relationship between the amount of exposure to asbestos and the incidence of mesothelioma.

If we contain this discussion to the subject of pleural mesothelioma, we will find that well over fifty years of published studies have established three primary groups of individuals by virtue of their exposure. These are: -1- individuals with high levels of exposure of a short duration, -2- individuals with high levels of exposure of long duration and -3- individuals with low levels of exposure of long duration.

The majority of studies showed that group -1- exposure sometimes led to gradual impairment of lung function but it didn’t always rise to the level of asbestosis, i.e. there was little evidence of plaque or nodules in the pleural space. Group -1- also had a relatively high incidence of cancer, most of which was later to be called mesothelioma.

The second case, -2-, led to very high levels of impairment with asbestosis and early death from from the effects of the impairment. secondary illnesses with some cases of mesothelioma.

The third case -3- led to gradual impairment with asbestosis and death caused by a broad spectrum of secondary conditions such as pneumonia, emphysema, tuberculosis etc. Asbestosis appeared to greatly reduce the patient’s ability to resist secondary diseases, raising some of these to the level of fatal illnesses.

Mesothelioma was not seen as often in groups two and three. Medical researchers felt that this was because patients either didn't live long enough to develop cancer or weren't genetically at risk. Ironically, only after dust abatement practices were mandated into the workplace did the incidence of mesothelioma become a significant health issue in the literature and in the vernacular of the medical community, lending credence to the theory about group two.

Studies also revealed a clear relationship between the amount of dust inhaled over a lifetime and the development of asbestosis. Trades with a history of working with asbestos tend to dominate the population of mesothelioma patients. The greater the former, the more likely it would be that signs of asbestosis would be observed. Conversely, it was discovered that there was no safe level of asbestos exposure with respect to mesothelioma, since even short exposures could create the cancer, with or without asbestosis symptoms.