In When Rivers Burned: The Earth Day Story, I talk about the 1948 smog in Donora, PA, which killed twenty people there.
But the United States wasn’t the only country with smog problems. The deadliest smog in recorded history was a “killer fog” that struck London in December 1952.
It was so thick that people couldn’t see their feet. Thousands of people were hospitalized, lips blue, struggling for breath. At least 4,000 people died. The death toll could actually be many times higher.
This incident led to Britain’s Clean Air Act.
Find out more at the History Channel website:http://www.history.com/news/the-killer-fog-that-blanketed-london-60-years-ago