Historical Importance: When a thick fog engulfed London from December 5 to December 9, 1952, it mixed with black smoke emitted from homes and factories to create a deadly smog. This smog killed approximately 12,000 people and shocked the world into starting the environmental movement.
Dates: December 5-9, 1952
Also Known As: The Big Smoke
Overview of the Great Smog of 1952:
When a severe cold spell hit London in early December 1952, Londoners did what they usually did in such a situation; they burned more coal to heat up their homes. Then on December 5, 1952, a layer of dense fog engulfed the city and stayed for five days.
Since the smoke from the coal burning in homes, plus all of London's usual factory emissions, had been prevented from escaping into the atmosphere by an inversion, the fog and smoke combined into a rolling, thick layer of smog.
Londoners, used to living in a city known for its pea-soup fogs, were not shocked to find themselves surrounded by such thick smog. Yet, although the dense smog did not instill panic, it nearly shut down the city from December 5 to December 9, 1952.
Visibility across London became extremely poor. In some places, visibility had literally gone down to one foot, meaning that you couldn't see your own feet when looking down nor your own hands if held out in front of you. Transportation across the city came to a standstill and many people didn't venture outside for fear of getting lost in their own neighborhoods. At least one theater was closed down because the smog had seeped inside and the audience could no longer see the stage.
It wasn't until after the fog lifted on December 9 that the deadliness of the smog was discovered. In the five days the smog had covered London, over 4,000 more people had died than usual for that time of year. In the following weeks, approximately 8,000 more died from exposure to what has become known as the Great Smog of 1952. Most of those killed by the Great Smog were people who had pre-existing respiratory problems and the elderly.
The death toll of the Great Smog of 1952 was shocking. Pollution, which many had thought was just a part of city life, had killed 12,000 people. It was time for change.
It was the black smoke that had caused the most damage. Thus, in 1956 and 1968, Parliament passed two Clean Air Acts, which began the process of eliminating the burning of coal in both people's homes and in factories.