The widespread use of asbestos exposed millions of American workers and their families to a toxin that can both scar the lungs and cause a variety of cancers. The United States Occupational Safety and Health Administration (OSHA) has stated that it is aware of no instance in which exposure to a toxic substance has more clearly demonstrated deleterious health effects on humans than has asbestos exposure.

Between 1940 and 1979, approximately 27.5 million people were exposed to asbestos at work. Almost 19 million of these workers are believed to have had heavy exposure to the toxic mineral. Workers were exposed to asbestos in a variety of industrial and construction environments. It has been estimated that approximately 900,000 workers have been exposed to asbestos from automobile brake and clutch work alone. And the asbestos problem is far from behind us: by one estimate, 1.2 billion square feet of asbestos-containing insulation is housed in 190,000 buildings in the United States.

Workers may be exposed to asbestos in a wide range of job sites and trades, ranging from milling and mining to manufacturing and construction industries. According to one estimate from the Asbestos Information Association, there are over 3,000 discrete uses of asbestos. These uses have resulted in exposures through the mining and milling process, in primary and secondary manufacturing of asbestos-containing products, in shipbuilding and repair, and in construction.

Hazardous exposures to asbestos have also occurred as a result of off-site releases from the mining, milling and manufacture of asbestos products. Residents in nearby communities may have been exposed as a result. It has been estimated that the off-site release from construction sites has resulted in environmental asbestos levels a hundred times over natural environmental levels.