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Great Smog of 1952

The Great Smog 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 60s

The following articles relate:

British MetOffice Report
Historic smog death toll rises
The Killer Fog of '52
See also

British MetOffice Report

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.

Hazardous driving condition during the London smog of 1952Fig 1: Hazardous driving conditions due to smog

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.

Graph show death rates and pollution levels during the 1952 London smogFig 2: The London smog disaster of 1952.

Death rate with concentrations of smoke

 The fog of December 1952 was by no means the first to bring death and inconvenience to the capital.

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 dismall 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.

As if it were not enough that they brought on agues, 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.

Meterological chart during the London smog of 1952Fig 3
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 katabatically 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.

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-soupers 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 than 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, benzines and aldehydes. 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 for hundreds of years.


Historic smog death toll rises
aken from the BBC: Thursday, 5 December, 2002

The Great London Smog of 1952The smog caused death and disruption

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 who 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.

Death toll
"The interesting thing is that no one realised at the time that the no of deaths were increasing," he told the BBC.  "There weren't bodies lying around in the street and no one really noticed that more people were dying."

"One of the first indications was that undertakers were running out of coffins and florists were running out of flowers.  The number of deaths per day during and just after that smog were three to four times the normal."

The smog, which lasted for five days, was so bad that it infiltrated hospital wards.

Maureen Scholes, a nurse at the Royal London Hospital at the time, recalls being unable to see from one end of the ward to the other because of the pollution.

"You couldn't see along the corridor that you walked in when you came on duty.  You couldn't see actually from one end of the ward to the other and it's not that enormous a length."

Hospitals filled up quickly as many struggled to cope with the pollution.

Dr Waller adds: "In the wards, where there were many patients, you couldn't see clearly to the end of the ward. There were many patients admitted but there were too many affected and they apparently couldn't get into hospital and perished outside,"

The smog prompted the government to introduce legislation to cut smoke emissions.  While the threat of smog has been tackled, other pollutants continue to pose a risk to people living in Britain's major cities.

Dr Tony Fletcher, of the London School of Hygiene and Tropical Medicine, says pollution is still responsible for causing respiratory problems in many people.

"We still have part pollution in the cities. The much finer particles are able to get deep into the lungs.  There is a new problem of ozone which is more a problem in the summer than the winter but is also a cause of respiratory disease now."

Still a problem
Richard Mills, secretary general of the National Society for Clean Air, warns that there is still more to do to protect people from pollution.

"We are better off but not as much better off as we might have thought. Fifty years on the great smogs are gone but invisible pollutants are still taking a major toll on health. "Some 20,000 in England alone suffer shortened lives each year."  He says vehicle emissions are the main culprits and believes the government should be doing more to tackle the problem.

He adds that the great London smog should act as a lesson to politicians now.  "All of us can learn from the aftermath of the great smog that you cannot just assume that because you cannot see the pollution that it is not there," he warns.


The Killer Fog of '52

Thousands Died as Poisonous Air Smothered London

London's death rate shot up during the week of Dec. 5, 1952, with the smog killing thousands already weakened by respiratory illnesses.

December 12, 2002 · Fifty years ago, a toxic mix of dense fog and sooty black coal smoke killed thousands of Londoners in four days. It remains the deadliest environmental episode in recorded history.

The so-called killer fog is not an especially well-remembered event, even though it changed the way the world looks at pollution. Before the incident, people in cities tended to accept pollution as a part of life. Afterward, more and more, they fought to limit the poisonous side effects of the industrial age.

NPR's John Nielsen went to London to prepare two reports on the killer fog of 1952.
Funeral director Stan Cribb of T. Cribb and Sons has led thousands of funeral trains through the smoggy streets of London. But he says the 1952 event dwarfs all others he has seen. He remembers the moment he saw the first gray wisps:

"You had this swirling," Cribb recalls, "like somebody had set a load of car tires on fire."
Cribb was then a mortician’s assistant, working for Tom Cribb, his elderly uncle. On Friday Dec. 5, they were driving to a wake, with a line of cars full of mourners close behind. Neither man knew a catastrophe was brewing. They didn't know that a mass of stagnant air had just clamped a lid over London, trapping the smoke from millions of residential coal fires at ground level.

Cribb remembers being stunned by the blackness of the gathering fog. After a few minutes he couldn't see the curb from his spot behind the wheel. After a few more minutes, Tom Cribb got out and started walking in front of the hearse, to keep his nephew on the road. He carried a powerful hurricane lantern in one hand, but it was useless.

"It's like you were blind," says Cribb.

Everyone in London walked blind for the next four days. By the time the smog blew off on Tuesday Dec. 9, thousands of Londoners were dead, and thousands more were about to die. Those who had survived no longer spoke of London's romantic pea-soup fog.

As the smoke coming out of London's chimneys mixed with natural fog, the air turned colder. Londoners heaped more coal on their fires, making more smoke. Soon it was so dark some said they couldn't see their feet.

By Sunday, Dec. 7, visibility fell to one foot.

Roads were littered with abandoned cars. Midday concerts were cancelled due to total darkness. Archivists at the British Museum found smog lurking in the book stacks. Cattle in the city's Smithfield market were killed and thrown away before they could be slaughtered and sold -- their lungs were black.

On the second day of the smog, Saturday, Dec. 6, 500 people died in London. When the ambulances stopped running, thousands of gasping Londoners walked through the smog to the city's hospitals.

The lips of the dying were blue. Heavy smoking and chronic exposure to pollution had already weakened the lungs of those who fell ill during the smog. Particulates and acids in the killer brew finished the job by triggering massive inflammations. In essence, the dead had suffocated.
Some 900 more people died on Tuesday, Dec. 9, 1952. Then the wind swept in unexpectedly. The killer fog vanished as quickly as it had arrived.

In his 60 years as a mortician, Stan Cribb has only stopped two funeral trains. Once in the fog of '52, and once when Nazi warplanes bombed the road around him. In the blitz, 30,000 Londoners died. According a recent study in the journal Environmental Health Perspectives, 12,000 may have been killed by the great smog.
John Nielsen

See also

The Great stink
Britain’s Domestic Waste
Radioactive waste
Nuclear waste’s final resting place