People were dying from asbestos exposure, in large numbers. There is a long time lag between being exposed to asbestos and symptoms presenting themselves – and we mean a long time lag (known as the latency period). It can be anything between 10 and 60 years from exposure to symptoms appearing. Most cases of asbestos disease do not appear until at least 20 years from exposure.
Deaths from asbestosis started to peak in the 1980s, from mesothelioma, during the 1990s onwards. The dangers of asbestos were known about much earlier than that though. There was undoubtedly a will among business owners for asbestos to be used as long as possible. It was a cheap, flexible material as is evidenced from the wide range of industries in which it was used.
On the other hand, come the early 1980s, not only were the dangers of asbestos known, but asbestos disease was also killing  a lot of people. As a result of these competing interests – business vs workers health - getting asbestos banned, was not an overnight occurrence.