Occasionally, at this time of the year, I remember 1952 and the Great smog that settled over London that December. The centre of a large anticyclone settled above the town trapping a layer of colder air close to the ground, held in position by an inverse temperature gradient
keeping a warmer layer above. A fog developed, as one might expect under those conditions, but it was particularly dense. People in something approaching a million homes tried to keep warm by lighting their coal fires but, because of the atmospheric conditions, the smoke from their chimneys only reached little height before turning over and
sinking down to add to the fog, much of the industry was also powered by coal fired steam boilers, town gas was produced from coal, and in the middle of it all was the coal fired Battersea Power Station. The smoke from this coal burning contained a high proportion of particulates of soot and minute droplets of tar that added to the fog and increased its
density (Battersea did have filters to reduce their emissions of particulates). Road traffic also produced particulates including lead, (although the lead tended to fall to the ground relatively quickly) along with more pollutants. Apart from the particles the exhausts from
all this combustion of coal and other fuels contained a number of noxious gases, in particular the highly toxic and corrosive sulphur dioxide as well as some oxides of nitrogen and small amounts of carbon monoxide, together with a whole lot of carbon dioxide. The net result was a ghastly yellowish unhealthy smog that tended to thicken over the
next few days.
It seems almost beyond belief that visibility could be reduced to no more than one metre in some places, but it was so. This meant that an adult would not be able to see their feet. You had to walk with very small steps for fear of bumping into people or things, or tripping over unseen kerbs. Walking along a suburban street you stuck close to the garden walls or fences because once you ventured away from the edge it was very easy to lose your bearings. Driving was impossible in these very dense areas and elsewhere it was almost as bad.
On the first day I struggled to get home as the smog thickened, it was dark and I had my rather feeble headlamps on. All I could see was the fog illuminated by the headlamps so I crawled along struggling to see anything that might appear in the lights. One thing that did appear was one of the roadside bins used for holding grit for icy roads, this meant
that I had somehow got on to the pavement. Buses crawled along as their conductors walked alongside the nearside front wheel carrying a flaming torch, the heat from the torch actually thinned the fog in its immediate vicinity but, of course, the smoke went on to add to the smog. I was lucky to have one such bus go past me, I tagged on behind, driving very
close to the back of the bus. Train drivers could not see signals, trains moved slowly, small charges were placed on the rail that exploded when the train wheels ran on to it to warn the driver of a signal.
Many people wore smog masks, either bought or homemade versions, examination of the mask after just half an hour outside revealed the dirt that had been prevented from entering one’s lungs. If you had a window open just an inch the evidence would be there on the curtains, especially if they were lace curtains. The smog penetrated buildings, this was very noticeable in large buildings, so much so that some cinemas were forced to close because it was difficult to see the screen.
Not surprisingly many of the sick, especially those with respiratory problems, and elderly suffered health consequences. At the time it was thought that 4000 people died prematurely as a result. I understand that later research put the number at nearer 12000 and that is roughly half of the number killed in the blitz.
The government were stirred into action; they soon introduced the clean air act banning the burning of coal on open fires in towns, although cleaner burning fuels such as coke were permitted. That was the start of efforts to improve the quality of the air we breathe in towns, that are continuing today with increasing concern over the particulates
produced by the large number of diesel engines. Lead in petrol was prohibited some years ago and limits imposed on carbon monoxide, nitrogen oxides and hydrocarbons from vehicle exhausts. Petrol engines fitted with catalytic converters are remarkably clean these days.
That great smog lasted several days, but it wasn’t the last smog.
Fortunately those that followed were never quite so bad and, more importantly, never lasted so long. My wife and I worked together in the fifties and travelled together, we developed a technique for driving in very dense fog/smog. I would control the accelerator, brake etc, she would watch the edge of the road from the front passenger seat and steer. This way we would progress slowly whilst I stared into the fog looking for anything that might be in our path. We were very often dismayed to see the speed with which some drivers attempted to drive when their forward vision was so limited, and not surprised at the number of minor accidents as a result.
Since those days we have had fogs, often quite dense, but nothing to compare with those London smogs of the fifties and before, nevertheless, because of motorways and other roads that permit high speeds under normal conditions, fogs these days can be equally deadly for some.
Do take care this winter.