How the Great Smog of London killed thousands in 1952
In 1952, a dense smog settled over London, killing at least 4,000 and sending many more to the hospital. Its causes? A deadly mixture of weather and coal.
Image: Heritage Image Partnership Ltd / Alamy Stock Photo
The city of London has experienced many crises and tragedies in its nearly 2,000 years of history. From the Great Fires of London in 1212 and 1666 to the Great Stink of 1858, London’s emergencies have ranged from merely unpleasant to deadly.
But one of its most lethal disasters is less often discussed today. In December of 1952, a thick smog descended over the city for four days, sickening many and killing at least 4,000 people.
What caused the smog?
Smog is a combination of smoke and fog – and London had both in abundance.
The smoke was air pollution, the product of factories, power stations and hearths in private houses. It was largely caused by the burning of coal, a common fuel at the time.
London had suffered from coal-related air pollution for centuries. But, of course, as the city and industry grew, so did the problem – although migration out of the city in the 20th century helped a little. New diesel-powered busses, however, did not help.
An additional contributing factor to London’s smoke problem was the type of coal it burned. Anthracite is a harder coal that burns more cleanly, but it was more expensive. Much of the coal used in London was softer and therefore smokier.
Into this picture came a patch of cold weather at the end of 1952. Households without central heating stoked their fires high to keep warm, producing yet more smoke.
The other condition that created the Great Smog was a particular kind of weather system that resulted in fog. It was an anticyclone, a high-pressure system in which a blanket of warm air higher in the atmosphere traps cold air lower down.
Held under the anticyclone, the smoke produced by the coal could not escape. Meanwhile, the cold air created fog when it met the damp ground. When this fog and smoke mixed in the still air, they produced an incredibly dense and polluted smog that hung over the city for four days – from 5th to 9th December 1952.
What was the Great Smog like?
It is difficult to overstate the impact that the dark smog had on the city. Londoners simply could not see what was around them. In some areas, they could not even see their own feet.
Most transportation was impossible in such poor visibility. Sometimes, lacking any other option, drivers abandoned their cars on the road. The London Underground, however, was still able to operate.
It was also said that cattle in the famous Smithfield meat market died of smoke inhalation.
How many died?
The Great Smog was not just inconvenient. It was toxic, containing minute particles of smoke that affected breathing. Moreover, the sulphur dioxide created by the combustion of soft coal became sulphuric acid in the smog.
Therefore, breathing problems were rife among Londoners – some who had previously suffered respiratory issues and some who had not. The smoke particles prevented them from taking in enough oxygen, and the toxic pollutants damaged their respiratory systems.
Official sources estimated at the time that 4,000 excess deaths occurred because of the smog. More recently, researchers have posited that the phenomenon caused up to 12,000 fatalities. Among the dead was Charles Herbert Lightoller, a man who survived both the sinking of the Titanic and the waters off Dunkirk.
What happened after the Great Smog?
This shocking and lethal event could not fail to make an impact on the public consciousness. The government knew it had to act to prevent such a smog from occurring again.
So, legislation was introduced to prohibit much of the coal combustion that had fed the smog with smoke. In 1956, Parliament passed the Clean Air Act, which endeavoured to reduce the city’s reliance on coal. The Clean Air Act of 1968 imposed more rules to this end.
The problem was not resolved immediately or even within a decade after the Great Smog. But slowly, London’s skies began to clear.
The Great Smog was significant for a broader reason, too. With deadly clarity, it illustrated the connection between environmental pollution and harm – the problem could no longer be ignored. That is why the Great Smog is known as one of the factors that produced environmentalism today.
Could it happen again?
In the 21st century, some of London’s energy still comes from coal – but not much. Most of the city’s air pollution now comes from road traffic.
Where sulphur dioxide was a harmful pollutant that came from coal combustion, today’s greater concern is nitrogen dioxide from car engines. This pollutant and other pollutants in traffic fumes have caused some smaller smogs, such as one in December 1991 that is thought to have led to over 100 excess deaths.
Other deadly air pollution incidents have occurred around the globe for different reasons. In 1984, a tragic industrial disaster in Bhopal, India created a poisonous gas cloud that killed over 4,000 people – but this was caused by lax safety practices in a factory that created pesticides. Wildfires are also major producers of heavy smoke that can cause breathing problems.
Will London see another Great Smog like the one in 1952? Perhaps not – London no longer suffers the heavy 'pea-souper' fogs it was once known for. But air pollution still presents a risk to public health worldwide, and the Great Smog of 1952 teaches us that the cleanliness of our air is not a factor that can be overlooked
