The companies that produced Asbestos knew it was a Carcinogen back in the 1930's... And they pushed it for a whole bunch of reasons, anyway.
Asbestos Inc. : The New Yorker
In the nineteen-twenties, doctors first documented deaths from asbestosis—a scarring of the lungs caused by the inhalation of asbestos fibres—and it later became clear that asbestos was also to blame for a deadly cancer called mesothelioma. Asbestos manufacturers knew at least some of these risks before the Second World War, but hid them. This prevarication led to the deaths of tens of thousands of workers. It also laid the groundwork for one of the costliest legal battles in U.S. history.
Read more: Asbestos Inc. : The New Yorker
Well, I think when My dad (who died at 56 from lung cancer) was told the Asbestos he was working with was perfectly safe, and he'd better just climb in ther and work with it, that was kind of forcing him.