Dec. 4th: On this day in 1952, a heavy blanked of smog settled over London. Before it cleared, about four days later, it caused respiratory illness so severe that up to 12,000 people died, according to estimates. The weather had been cold, so home furnaces burning coal added a lot of extra smoke and soot to factories’ and vehicles’ output. When cold air moving in from the west collided with a high-pressure air mass arriving from the east, the pollution was temporarily trapped over the city.
If you were walking down the street on Dec. 7 that year, you could see as little as 15 feet in any direction, thanks to the heavy haze. Unfortunately, you can still have that experience today, in places like Beijing. The Great Smog of ’52, aka the Big Smoke, contributed to the creation and passage of the UK’s Clean Air Act of 1956 and other measures that reduced coal burning. Nevertheless, another series of really bad air days followed, exactly 10 years later, in Dec. 1962, killing about 750 Londoners.
Great Smog — Wikipedia
The Great Smog of 1952 — Met Office Education
11 Incredible Pictures From the Great Smog of 1952 — The Huffington Post
Air Pollution ‘Kills 7 Million People a Year‘ – The Guardian