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London Smog of 1952. A Environmental disaster


The London Smog of 1952 -The Great Smog of London as it is called befell London starting on December 4, 1952, and lasted until March of 1953. It was a great disaster that killed thousands and formed an important impetus to the modern environmental movement.

In early December of 1952, a cold fog descended upon London. Because of the cold, Londoners began to burn more coal than usual. At the same time, the final conversion of London's electric trams to diesel buses was completed. The resulting air pollution was trapped by the heavy layer of cold air, and the concentration of pollutants built up dramatically. The smog was so thick that it would sometimes make driving impossible. It entered indoors easily, and concerts and screenings of films were cancelled as the audience could not see the stage or screen.

Since London was known for its fog, there was no great panic at the time. In the weeks that followed, the medical services compiled statistics and found that the fog had killed 4,000 people-most of whom were very young or elderly, or had pre-existing respiratory problems. Another 8,000 died in the weeks and months that followed.

These shocking revelations led to a rethinking of air pollution. The disaster demonstrated to people around the world that it was a real and deadly problem. New regulations were put in place restricting the use of dirty fuels in industry and banning black smoke. These included the Clean Air Acts of 1956 and of 1968, and the City of London (Various Powers) Act of 1954.

Despite clean air laws, smog persisted into the 1960’s...

Since Roman times, if not before, Britain has been known to people abroad as a land of mists and fogs. Until recently, indeed, visitors to the capital could take home with them tins of 'London fog'!

For hundreds of years, the mists and fogs of Britain's major cities were all too often polluted and noxious, with London especially badly affected. The fogs endangered health and also posed a threat to travellers who lost their way and thus became an easy prey to robbers. Around 1807, the smoke-laden fog of the capital came to be known as a 'London particular', i.e. a London characteristic. Charles Dickens used the term in Bleak House (published in 1853) and provided graphic descriptions of London's fogs in this and other novels.

The smoke-laden fog that shrouded the capital from Friday 5 December to Tuesday 9 December 1952 brought premature death to thousands and inconvenience to millions.

An estimated 4,000 people died because of it, and cattle at Smithfield, were, the press reported, asphyxiated.

Road, rail and air transport were almost brought to a standstill and a performance at the Sadler's Wells Theatre had to be suspended when fog in the auditorium made conditions intolerable for the audience and performers.

The death toll of about 4,000 was not disputed by the medical and other authorities, but exactly how many people perished as a direct result of the fog will never be known. Many who died already suffered from chronic respiratory or cardiovascular complaints. Without the fog, they might not have died when they did. The total number of deaths in Greater London in the week ending 6 December 1952 was 2,062, which was close to normal for the time of year. The following week, the number was 4,703. The death rate peaked at 900 per day on the 8th and 9th and remained above average until just before Christmas. Mortality from bronchitis and pneumonia increased more than sevenfold as a result of the fog.

On 27 December 1813 fog was so dense that the Prince Regent, having set out for Hatfield House, was forced to turn back at Kentish Town. The fog persisted for almost a week and on one day was so thick that the mail coach from London to Birmingham took seven hours to reach Uxbridge. Contemporary accounts tell of the fog being so thick that the other side of the street could not be seen. They also tell of the fog bearing a distinct smell of coal tar. After a similar fog during the week of 7-13 December 1873, the death rate in the Administrative County of London increased to 40 per cent above normal.

Marked increases in death rate occurred, too, after the notable fogs of January 1880, February 1882, December 1891, December 1892 and November 1948. The worst affected area of London was usually the East End, where the density of factories and domestic dwellings was greater than almost anywhere else in the capital. The area was also low-lying, which inhibited fog dispersal.


At the beginning of January 1900, when he reported for duty as the newly appointed Director of The Meteorological Office, Dr (later Sir) Napier Shaw received from the Bishop of London a 'letter of condolence', expressing sorrow that he (Shaw) should have to work in 'this place of darkness' - a reference to the smoke-laden fogs of London and the fogginess of that winter in particular. One of the projects initiated by Shaw soon after he became Director was an inquiry into the occurrence and distribution of fog in the capital. The investigation confirmed that smoke from the chimneys of London served to aggravate fog problems.

As long ago as the 13th century, air pollution was recognised as a public-health problem in the cities and large towns of the British Isles, and the burning of coal was identified as the principal source. Four centuries later, in his Fumifugium, published in 1661, John Evelyn wrote of the 'Hellish and dismal cloud of sea-coale' that lay over London and recommended that all noisome trades be banished from the city. The authorities did not, however, take his advice. The burning of coal continued and the pall of soot over London grew worse.

The industrial revolution brought factory chimneys that belched gases and huge numbers of particles into the atmosphere. Some of these particles caused lung and eye irritations. Others were poisonous. All were potentially condensation nuclei, the tiny hygroscopic particles on which condensation forms. From the gases, corrosive acids were formed, notably sulphuric acid, which is produced when sulphur dioxide combines with oxygen and water.

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As if it were not enough that they brought on rheumatism and fevers and carried particles of soot from coal fires. The fogs of the British Isles now became even more unpleasant, for the noxious emissions from factory chimneys gave them an acrid taste, an unpleasant odour and a dirty yellow or brown colour. These fogs, so different from the clean white fogs of country areas, came to be known as 'pea soupers', not only in London but also in other industrial areas of the British Isles. The particles in the atmosphere made buildings dirty and the acids attacked ironwork, stonework and fabrics.

In early December 1952, the weather was cold, as it had been for some weeks. The weather of November 1952 had been considerably colder than average, with heavy falls of snow in southern England towards the end of the month. To keep warm, the people of London were burning large quantities of coal in their grates. Smoke was pouring from the chimneys of their houses and becoming trapped beneath the inversion of an anticyclone that had developed over southern parts of the British Isles during the first week of December. Trapped, too, beneath this inversion were particles and gases emitted from factory chimneys in the London area, along with pollution which the winds from the east had brought from industrial areas on the continent.

Early on 5 December in the London area, the sky was clear, winds were light and the air near the ground was moist.

Accordingly, conditions were ideal for the formation of radiation fog.

The sky was clear, so a net loss of long-wave radiation occurred and the ground cooled. The moist air in contact with the ground cooled to its dew-point temperature and condensation occurred.

Cool air drained katabolically into the Thames Valley. Beneath the inversion of the anticyclone, the very light wind stirred the saturated air upwards to form a layer of fog 100-200 metres deep. Along with the water droplets of the fog, the atmosphere beneath the inversion contained the smoke from innumerable chimneys in the London area and farther afield. Elevated spots such as Hampstead Heath were above the fog and grime. From there, the hills of Surrey and Kent could be seen.

During the day on 5 December, the fog was not especially dense and generally possessed a dry, smoky character. When nightfall came, however, the fog thickened. Visibility dropped to a few metres. The following day, the sun was too low in the sky to make much of an impression on the fog. That night and on the Sunday and Monday nights, the fog again thickened. In many parts of London, it was impossible at night for pedestrians to find their way, even in familiar districts. In the Isle of Dogs, the visibility was at times nil. The fog there was so thick that people could not see their own feet! Even in the drier thoroughfares of central London, the fog was exceptionally thick. Not until 9 December did it clear. In central London, the visibility remained below 500 metres continuously for 114 hours and below 50 metres continuously for 48 hours. At Heathrow Airport, visibility remained below ten metres for almost 48 hours from the morning of 6 December.

Huge quantities of impurities were released into the atmosphere during the period in question. On each day during the foggy period, the following amounts of pollutants were emitted: 1,000 tonnes of smoke particles, 2,000 tonnes of carbon dioxide, 140 tonnes of hydrochloric acid and 14 tonnes of fluorine compounds. In addition, and perhaps most dangerously, 370 tonnes of sulphur dioxide were converted into 800 tonnes of sulphuric acid. At London's County Hall, the concentration of smoke in the air increased from 0.49 milligrams per cubic metre on 4 December to 4.46 on the 7th and 8th.

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The infamous fog of December 1952 has come to be known as 'The Great Smog'; the term 'smog' being a portmanteau word meaning 'fog intensified by smoke'. The term was coined almost half a century earlier, by HA Des Voeux, who first used it in 1905 to describe the conditions of fuliginous (sooty) fog that occurred all too often over British urban areas. It was popularised in 1911 when Des Voeux presented to the Manchester Conference of the Smoke Abatement League of Great Britain a report on the deaths that occurred in Glasgow and Edinburgh in the autumn of 1909 as a consequence of smoke-laden fogs.

Legislation followed the Great Smog of 1952 in the form of the City of London (Various Powers) Act of 1954 and the Clean Air Acts of 1956 and 1968. These Acts banned emissions of black smoke and decreed that residents of urban areas and operators of factories must convert to smokeless fuels. As these residents and operators were necessarily given time to convert, however, fogs continued to be smoky for some time after the Act of 1956 was passed. In 1962, for example, 750 Londoners died as a result of a fog, but nothing on the scale of the 1952 Great Smog has ever occurred again.

Pea-souper's have become a thing of the past, thanks partly to pollution legislation but also to slum clearance, urban renewal and the widespread use of central heating in the houses and offices of British towns and cities. As recently as the early 1960s, winter sunshine totals were thirty per cent lower in the smokier districts of London as in the rural areas around the capital. Today, there is little difference.


We should not, however, be complacent. The air now contains other types of pollutants, many of them from vehicle exhausts. Among these pollutants are carbon monoxide, nitrogen dioxide, ozone, benzene’s and aldehyde's. They are less visible than the pollutants of yesteryear, but are equally toxic, causing eye irritation, asthma and bronchial complaints. To some extent, we have simply replaced one form of air pollution with another. We may question whether or not the major cities of the British Isles are any less polluted now than they have been

Officials believe that as many as 12,000 people may have died in the great London smog of 1952. Many of those killed were elderly people or those who were already weak or ill. According to medical staff that treated patients at the time, few people realised the extent of the impact.

Dr Robert Waller was working at St Bartholomew's Hospital in the capital in the early 1950s. He says a shortage of coffins and high sales of flowers were the first indications that many people were being killed.


Pauline R on May 17, 2012:

As a child in the fifties I was taken on a weeks visit from Norfolk to London...I was deeply disappointed. All of the buildings were black and ugly; everywhere was gloomy blackness.

The much talked about capital held an aura of despair, even the hotel we stayed in seemed to be penetrated by the blackness with dark and dirtied decor;I couldn't wait to get home!

The difference now is astonishing, the once black buildings are a creamy colour with beautiful shapes and carvings once hidden by that awful blackness.

This didn't happen overnight took many years to clean up those beautiful old buildings you now see.

jax on March 06, 2012:


jasmine on March 06, 2012:

this is so amazing and interesting

ROBIN on March 06, 2012:


shelia on March 06, 2012:

i think this is a great website people who ever u are

N.D Rumaya wickremasinghe on January 28, 2012:

wow i just got to know today that this big capital city is a disaster to many lovable families but nowadays it is one of the most exciting places to everyone in the world,including me ........... luckily i'm wasn't there in 1952,don't u think....................Ausome article

anamika sharma on November 17, 2011:

this is really a great disaster.

kajol on November 05, 2011:

its very interesting................and very shocking too.

Loveofnight Anderson from Baltimore, Maryland on April 23, 2010:

cracking write-up.......interesting topic as well.

Beth on April 13, 2010:

This website has given me a lot of information for my one page report. It is about the Deathly Smog, London. So thank you for this website. I really like the website it was very cool to read. So thank you agian.

Camlo De Ville from Cologne, Germany on November 08, 2009:

This is really interesting. I grew up in London and heard about the fogs -- especially that they had been particularly bad in the fifties. But nobody seems to mention just how bad, or this particular one of 1952.

Reading this was fascinating.

Thank you for this very informative article!

serina on January 16, 2009:

'iM camE frOm lonDon..... wOw sincE i was $ yr. old.. ha!

Tony Sky from London UK on July 26, 2008:

Hi Barry,

I was Born n bred In London, and had have obviously heard about this, but not the true extent of how bad it actually was!, \

As desert blondie was saying, we have a much cleaner air quality!

Thanks for a late and needed History lesson!

Joanna McKenna from Central Oklahoma on July 21, 2008:

I had no idea the famous "London fog" was really killer smog. Or that the deadliest event happened so recently (as opposed to the late 19th century). The upside to eliminating the pollution, aside from the health benefits, is the facades of many of London's oldest and therefore dirtiest buildings have been cleaned and restored to their original glory.

desert blondie from Palm trees, swimming pools, lots of sand, lots of sunscreen on July 21, 2008:

Wonderfully, London is now one of the cleanest air cities in Europe! They really, understandably, are proud of this accomplishment. Interesting hub!

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