London’s Great Smog – 1952

Throughout the 19th and early 20th centuries London was notorious for the thick fogs which often descended on the city in the late autumn. These ‘London particulars’ were not so much an atmospheric effect as the consequent pollution from a vast and dense urban population. Unchecked factory emissions mingled in the city air with smoke from half a million domestic coal fires to produce a phenomenon for which a new term was coined: smog. The image of the murky, mist-shrouded streets of Victorian London has been immortalized in the novels of Charles Dickens and the adventures of Sherlock Holmes; indeed, fog has been dubbed ‘the greatest character in 19th-century fiction’.

These ‘pea-soupers’ (a reference to the yellowish hue the fogs often had) may have been a part of London’s unique appeal, but they also caused serious disruption and disease. Things came to a head in 1952.

A new monarch was on the throne, giving promise of better times ahead, but the close of the year brought a stark reminder of bad old days. In early December a period of high humidity, freezing temperatures and an anticyclone causing very still air produced a heavy accumulation of domestic coal smoke. With smoke and sulphur dioxide levels in the foul-smelling air ten times higher than normal, the dense fog hung over London for four long days, bringing the city to a standstill. Cars were abandoned, conductors walked in front of their buses with flares, washing turned black on the line, theatres closed because no one could see the stage.

The smog exposed the failure of existing pollution controls and led directly to the Clean Air Act of 1956, which permitted local authorities to designate smoke control areas and to regulate what fuels could be burned in people’s homes.

When: December 5-9 1952

Where: London, UK

Death toll: During the winter of 1952 there were reckoned to have been at least 4,000 more deaths in London than normal for the time of year, mostly caused by respiratory conditions in infants and the elderly, such as bronchial asthma and pneumonia.

You should know: The Act took several years to come into full effect, during which time London continued to suffer periodic dense smogs; as late as December 1962,750 people died as a direct result of one. This type of air pollution finally disappeared as urban overcrowding was tackled and people gradually switched to gas and electricity.