Also sometimes called The Big Smoke, was a severe air-pollution event that affected London in December of 1952. A period of cold weather, combined with an anticyclone and windless conditions to collect airborne pollutants. Coal use was the main culprit, and it all came together to form a thick layer of smog over the city. It lasted from Friday, 5 December to Tuesday, 9 December 1952 and then dispersed quickly once the weather changed.
It caused major disruption by reducing visibility and even penetrating indoor areas. It was far more severe than previous smog events experienced in the past called “pea-soupers”. However, the effects were more long lasting than the smog itself. Government medical reports in the following weeks estimated that up until 8 December, 4,000 people had died as a direct result of the smog. To compound that 100,000 more were made ill by the smog’s effects on their respiratory systems. More recent research suggests that the total number of fatalities was considerably greater, about 12,000.
The Great Smog was the worst air-pollution event in the history of the United Kingdom. It led to several changes in practices and regulations, including the Clean Air Act 1956.