Asbestos is a group of naturally occurring minerals which are hydrous magnesium silicates, and which separate into long, thin fibers. An extraordinarily fire-resistant, strong and durable substance, it was used for many years to insulate and fireproof buildings.
In the 1970s, a medical study at Mt. Sinai Medical School suggested that the concentration inhalation of asbestos fibers can cause serious illnesses, including cancer. This unleashed decades of litigation by trial attorneys to sue on behalf of nearly anyone who had been exposed to asbestos, which were millions. Many billions of dollars have been collected in these lawsuits, and companies have been bankrupted. The banning of asbestos from buildings by the EPA has led to the use of less-effective substitutes[Citation Needed] and even prison terms for workers who removed or allowed asbestos contrary to the federal regulations.
The original study has been criticized for failing to separate the effects of cigarette smoking from the effects of asbestos.