Great Smog of London

Nelson's Column during the Great Smog of 1952

The Great Smog or Big Smoke was a severe air pollution event that affected London in December 1952. A period of cold weather combined with an anticyclone and windless conditions, collected airborne pollutants mostly from the use of coal to form a thick layer of smog over the city. It lasted from Friday 5th to Tuesday 9 December 1952, then quickly dispersed after a change in the weather.

Although it caused major disruption due to the effect on visibility, and even penetrated indoor areas, it was not thought to be a significant event at the time, with London having experienced many smog events in the past, so called "pea soupers". In the following weeks however, medical reports estimated that 4,000 had died prematurely and 100,000 more were made ill due to the smog's effects on the human respiratory tract. More recent research suggests that the number of fatalities was considerably higher at around 12,000.

It is considered the worst air pollution event in the history of the United Kingdom, and the most significant in terms of its impact on environmental research, government regulation, and public awareness of the relationship between air quality and health. It led to several changes in practices and regulations, including the Clean Air Act 1956.

Events

Sources of Pollution

The weather preceding and during the smog meant that Londoners had to burn more coal than usual to keep warm. Post-war domestic coal tended to be of a relatively low-grade, sulphurous variety, which increased the amount of sulphur dioxide in the smoke (economic necessity meant that higher quality 'hard' coals tended to be exported). There were also numerous coal fired power stations within the Greater London area including Battersea, Bankside, and Kingston upon Thames, all of which added to the pollution levels. (Research suggests that additional pollution prevention systems fitted at Battersea may actually have worsened the air quality, reducing the output of soot at the cost of increased sulphur dioxide, though this is not clear). In addition there was pollution and smoke from vehicle exhausts – particularly from diesel-fuelled buses which had replaced the recently scrapped electric tram system – and from other industrial and commercial sources. Prevailing winds had also blown heavily-polluted air across the English Channel from industrial areas of Europe.

Weather

On Thursday 4 December 1952, an anticyclone settled over a windless London, causing a temperature inversion with very cold, stagnant air trapped under a layer (or "lid") of warm air. The resultant fog, mixed with chimney smoke, particulates (e.g. from vehicle exhausts) and other pollutants (particularly sulphur dioxide) resulted to form a persistent smog, which blanketed the capital (the presence of tarry particles of soot gave the smog its yellow-black colour – hence the nickname "peasouper"). The absence of si m, nmnjmgnificant wind prevented its dispersal and allowed an unprecedented build up of pollutants.

Impact on London

Although London was accustomed to thick fogs, this one was denser and longer lasting than any previously seen. Visibility was reduced to a few yards ("It's like you were blind", commented one observer), making driving difficult or impossible. Public transport ground to a halt – apart from the London Underground – and the ambulance service stopped running, forcing the sick to make their own way to hospital. The smog even seeped indoors, resulting in the cancellation or abandonment of concerts and film screenings (as visibility fell in large enclosed spaces, and stage and screens became harder to see from the seats). Outdoor sports events were also affected.its worst

Health Impact

Initially, there was no great panic, as London was renowned for its fog. In the weeks that followed, however, statistics compiled by medical services found that the fog had killed 4,000 people. Most of the victims were very young, elderly, or had pre-existing respiratory problems. Deaths in most cases were due to respiratory tract infections from hypoxia, and due to mechanical obstruction of the air passages by pus arising from lung infections caused by the smog.

The lung infections were mainly bronchopneumonia or acute purulent bronchitis superimposed upon chronic bronchitis.

A total of 12,000 people are believed to have died in the weeks and months that followed.

Environmental Impact

The death toll formed an important impetus to the modern environmental movement, and led to a rethinking of air pollution, as the smog had demonstrated its lethal potential. New regulations were put in place restricting the use of dirty fuels in industry and banning black smoke. In the years that followed, various legislation such as the Clean Air Acts of 1956 and 1968, and the City of London (Various Powers) Act 1954, greatly restricted air pollution.y its so HOPELESS ....the hell is just not getting

See also

• St. Louis smog episode (1939)
• Donora Smog of 1948

Further reading

• Bell, Michelle L. and Davis, Devra Lee. Reassessment of the Lethal London Fog of 1952: Novel Indicators of Acute and Chronic Consequences of Acute Exposure to Air Pollution ("Environmental Health Perspectives", June 2001).
• Berridge, Virginia (Ed.). The Big Smoke: Fifty Years After the 1952 London Smog (University of London, Institute of Historical Research, 2005)
• Brimblecombe, Peter. The Big Smoke: A History of Air Pollution in London Since Medieval Times (Routledge Kegan & Paul, 1987).
• Greater London Authority. 50 Years On: The struggle for air quality in London since the great smog of December 1952 (Dec 2002).

External links

• A proper pea-souper. Photos of the 1952 London smog (nickelinthemachine.com).
• The London Smog Disaster of 1952 (Edinburgh University).
• 1952: London fog clears after days of chaos BBC News, 1952-12-09.
• London Fog ("Best London Scenes)
• Days of toxic darkness (BBC News).