Asbestos is a fine example to support my point, thank you. It was first recognised by the US government that asbestos posed a risk to health in 1918, and asbestosis was discovered in 1930. Asbestos wasn't banned in the UK until 1999, some 70 odd years later. But few doctors would lose their funding for discovery of a harmful substance in construction. A discovery in the field of medicine that holds the field of medicine in disrepute though, is a different story. People don't shit on their own doorstep.