Mesothelioma- the silent killer

Asbestos has been mined and used commercially since the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not known.

However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other trades people.

Working with asbestos is the major risk factor for mesothelioma. A history of asbestos exposure exists in almost all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with :

• irradiation,
• intrapleural thorium dioxide (Thorotrast),
  
• and inhalation of other fibrous silicates, such as erionite

Exposure to asbestos fibres has been recognised as an occupational health hazard since the early 1900s. The risk of asbestos-related disease increases with heavier exposure to asbestos and longer exposure time. However, some individuals with only brief exposures have developed mesothelioma. On the other hand, not all workers who are heavily exposed develop asbestos-related diseases.

There is some evidence that family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos-related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibers, asbestos workers are usually required to shower and change their clothing before leaving the workplace.

Many building materials used in both public and domestic premises prior to the banning of asbestos may contain asbestos. This greatly increases the incidence of mesothelioma occurrence. However, Incidence of mesothelioma also had been found to be higher in populations living near naturally occuring asbestos. This shows the influence of environmental exposures to occurrence of this fatal disease.