When a killer smog hit London

It began late on December 4th, 1952, and lasted about a week. It was London’s Great Smog, a name that derived from the combination of smoke and fog. Unusually cold weather coupled with an anticyclone and windless conditions created a pall of airborne pollutants that gripped the UK’s capital city for days.

Virtually all of London’s several million homes were heated by coal fires, and the coal used was a low-grade, high sulphur variety, since the higher grade ‘hard’ coals such as anthracite were mostly exported. To the smoke from domestic fires was added that of coal-fired power stations, such as those in Battersea, Bankside, Fulham, Greenwich and Kingston upon Thames.

The UK’s meteorological office estimated that there were emitted each day of the Great Smog some 1,000 tonnes of smoke particles, 140 tonnes of hydrochloric acid, 14 tonnes of fluorine compounds, and 370 tonnes of sulphur dioxide which may have been converted to 800 tonnes of sulphuric acid. In other words, it was a very sooty and acidic cloud that enveloped London for several days. It was also the worst air pollution event in UK history.

It reduced visibility, in some cases to a few feet. People groped their way along hedges to find their homes. The combination of sulphurous chemicals and tarry soot particles gave the smog its yellow-black colour, like pea soup. Londoners called it a ‘pea-souper.’ Vehicular traffic virtually stopped, except for the London Underground. Ambulances could not run. Theatres and cinemas closed because audiences could not see the stage or the screen. Sports events, indoors and outdoors, were cancelled. It saw the appearance of the new white ‘smog masks’ on people’s faces.

There were deaths resulting from various lung diseases, including several forms of bronchitis and other respiratory tract infections. Estimates at the time suggested 6,000 deaths, but research afterwards, including those who died in the weeks and months following as a result, put the figure at 12,000 dead and over 100,000 suffering related illnesses.

The Great Smog raised public awareness of the poor quality of London’s air and that of other cities, and led to the passing of the 1956 Clean Air Act which restricted emissions, and ultimately banned coal burning in cities. From the late 1970s a clean-up took place across a London whose buildings, including Parliament and Westminster Abbey, were jet-black from centuries of soot-laden smoke. London’s blackened buildings were systematically spray cleaned to reveal the red brick and honey-coloured stone that characterize them today.

A problem was identified, and measures were taken to redress it. Similar action was taken with the River Thames, then biologically dead but now, after regulations were put into effect, teeming with life again. The same is being done with the UK’s emissions. Coal is rapidly being phased out, with oil to follow. Much cleaner gas is being used as a stop-gap until wind, solar and other renewables can supply our power, and electricity can drive our vehicles. Despite somewhat hysterical talk of the coming extinction of humankind, the problem is being addressed and solved, just as the problem of the London smog was solved.