Fifty Years Later: Clearing the Air over the London Smog. (NIEHS News)

Article excerpt

Between 5 December and 9 December 1952, one of the deadliest recorded episodes of urban smog occurred in London, England. New research indicates that as many as 12,000 people may have died as a result of the smog, and morality from respiratory illnesses such as bronchitis and pneumonia increased more than seven-fold during the smog. Overall death rates during the first half of that month were three times higher than normal, and morbidity and mortality rates in greater London remained elevated well into March of 1953.

The severity of the 1952 London Smog, along with the publicity surrounding it and other smog episodes in the early twentieth century, had two effects. First, they sparked an increased public health effort to understand the effects of air pollution on human health. Second, they prompted the formulation of governmental regulations on air pollution in many countries. This milestone event in the history of environmental health will be commemorated at the conference "The Big Smoke: Fifty Years after the 1952 London Smog," cosponsored by the NIEHS along with the Health Effects Institute, the Wellcome Trust, the Greater London Authority, the London borough of Camden, Sypol (a British environmental health and safety consulting group), the Shell Foundation, and the International Society for Environmental Epidemiology. Organized by Tony Fletcher and Virginia Berridge, professors of environmental epidemiology and history, respectively, at the London School of Hygiene and Tropical Medicine, the conference will be held 9-10 December 2002 at the University of London.

Programs will include historical perspectives of the 1952 London Smog and of air pollution in London in general. London had experienced smog events since the twelfth century, when coal was discovered along England's northeast coast and became the fuel of choice. But such events increased during and after the Industrial Revolution as both manufacturing and the population--both then dependent on burning large amounts of coal--expanded dramatically in the city.

For much of November 1952, temperatures in southern England were unusually low, causing people to heavily stoke their coal-burning home furnaces to keep warm. In the first days of December, high atmospheric pressure over the area caused an inversion that trapped soot and other air pollutants near ground level. Because of the smog, visibility in some areas of central London was reduced to nearly zero for 48 hours. Measurements taken at the time revealed that during that first week of December 370 metric tons of sulfur dioxide were released into the air, where it was converted into sulfuric acid. Large amounts of particulate matter also were released.

One seminar at the conference will bring together physicians, researchers, and others who remember the 1952 smog to present their eyewitness accounts of the event. These accounts will eventually be compiled into a book by historians at the London School of Hygiene and Tropical Medicine.

Other presentations will discuss the health impacts of the 1952 smog and the public health response. …