The Great Smog of '52 or Big Smoke was a severe air pollution
event that affected London during December 1952. A period of
cold weather, combined with an anticyclone and windless
conditions, collected airborne pollutants mostly from the use of
coal to form a thick layer of smog over the city. It lasted from
Friday 5 to Tuesday 9 December 1952, and then dispersed quickly
after a change of weather. Although it caused major disruption
due to the effect on visibility, and even penetrated indoor
areas, it was not thought to be a significant event at the time,
with London having experienced many smog events in the past, so
called "pea soupers". However, government medical reports in the
following weeks estimated that up until 8th December 4,000
people had died prematurely and 100,000 more were made ill
because of the smog's effects on the human respiratory tract.
More recent research suggests that the total number of
fatalities was considerably greater at about 12,000. It is known
to be the worst air pollution even