December 5th 1952: Great Smog of London begins
On this day in 1952, the Great Smog descended on London, beginning a national crisis which lasted for four days. Following the Industrial Revolution, which began in the late eighteenth century, London saw a sharp rise in polluted, smoky fog (known as smog) due to toxic coal fumes emitted by factories. Smog, unlike fog, is often thick, discoloured, and foul-smelling, and several smogs affected London throughout the nineteenth century. December 1952 was bitterly cold, and as Londoners burned large amounts of coal to keep warm, the smoke joined with toxic fumes from factories. The smoke was trapped by an anticyclone in the region, and, unable to disperse, combined with fog to create a smog. The thick smog caused chaos in London, with traffic halted by poor visibility of a few metres, opportunists committing crime, and the poisonous air filling hospitals with people suffering from breathing problems. Around 4,000 people, plus numerous animals and livestock, are known to have died as a result of the fog, though recent estimates taking into account long-term damage are much higher at 12,000. The smog was London’s worst civilian disaster, producing more casualties than any single incident during the Second World War and the Blitz. To prevent future disasters, Parliament passed the Clean Air Act of 1956 which tried to limit smoke emissions. Innovations in technology and environmental legislation ensured that no such smog has ever occurred again, but invisible pollution remains a grave concern for modern cities.
(see: metoffice.gov.uk, historytoday.com)