Industrial air pollution including fluoride produced thick unhealthy smog. This Canadian TV production shows how Canada had no air pollution regulations at that time, while the United States had started implementing these regulations. After pollution controls were put in place and heavy industry declined in the United States we have much cleaner air today. The film also shows fluoride pollution from a phosphate fertilizer plant damaging crops, livestock, and a farmer's health. That phosphate plant installed polution scrubbers and provided scrubber liquor which due to it's high fluoride content was added to drinking water for fluoridation in Canadian cities.
Scary old video. His forecast was not right fortunately Although I remember being covered from the fall out from the old QE liner's funnels in Southampton couldn't happen now.