Mesothelioma

Mesothelioma in the United States

During the industrialization associated with the early 20th century in the United States, asbestos was viewed as a "wonder" product, having the capability to save lives due to its fire retardant and durability characteristics. Between 1940 and 1979 an estimated 27 million workers in the United States were exposed to asbestos fibers. Since the early 1900s industrialization of the United States brought about the mining, processing and use of more than 30 million tons of asbestos. The most prevalent use of asbestos has been in the construction industry. In 1988, 6,300,000 workers in the United States were employed in the construction trades. Two-thirds of asbestos produced in the United States is used in this construction. Carpenters, utility workers, electricians, pipe fitters, steel mill workers, sheet metal workers, boiler makers, and laborers are at risk for exposure of asbestos through construction materials; insulation coverings of pipes, boilers, industrial furnaces, and other sources. Automobile mechanics working with brake and transmission products also are exposed to asbestos. Add to this the exposure from renovating and demolition and the risk to these workers from exposure to asbestos becomes considerable. Additionally, the families of these workers were also affected through secondary exposure.

Secondary exposure occurs when asbestos fibers are released into the air and are inhaled by persons not directly working with asbestos. This secondary exposure can be as extensive and as harmful as direct exposure to asbestos workers themselves. An asbestosis prevalence of 11% in wives, 8% in sons, and 2% in daughters was reported in families of asbestos-exposed shipyard workers. Mesothelioma and other asbestos-related diseases have developed in members of workers' families whose only contact with asbestos was dust from an exposed worker's clothing. Mesothelioma and other asbestos related diseases also have developed in persons who as children lived within one-half mile of an asbestos factory. In the workplace persons not directly working with asbestos or asbestos products also have had secondary exposure to asbestos. An example is the four to 5 million shipyard workers who were exposed when insulation workers applied asbestos to ships' pipes and hulls. People in contact with work clothes of asbestos workers or with asbestos containing household products have developed pleural abnormalities. Low exposures from work-related, household, and natural sources can induce pleural plaques. For diffuse, pleural thickening, higher exposure levels might be required.