How many times have you heard someone say, ‘I think I’ll go out for a breathe of fresh air’? Have you ever stopped to think what this means in our industrialized world? Of course, if you happen to be living high up among the mountains where there is little or no industry and few people, your chances of finding fresh air are quite good. But what of the build up areas of Britain and Europe or America?
Even if you have not experienced it yourself, we expect you have heard of smog. This word is mixture of the words ‘smoke’ and ‘fog’, which is very apt because smog really is smoky fog. London was once famed for its ‘pea-soupers’, that is, fog containing so much sulfurous waste that it resembled the yellowish green color of pea soup and was almost as difficult to breathe and see through. These smogs usually occured during the early months of winter when the fogs that would normally be present at that time of year became contaminated with all the smoke from cars and factory chimneys. It is interesting to note how much influence pollution of the air, at first by smells of household waste and later by pollution, has influenced the distribution of people in cities like London.
As you probably know, London has an ‘East end’ and a ‘West end’. Until quite recently the East end has been by far the poorer half of the city. This is because winds usually blow from west to east carrying the dirty air with them. People who could afford to choose where they wanted to live went to the western side leaving the smelly east for those with smaller incomes. In Los Angeles, in America, which is also famed for its smogs, the prevailing winds are from east to west so that the London situation is reversed.
Today, many industrial countries have introduce ‘Clean Air Acts’ preventing the burning of ordinary coal in homes in certain areas and controlling the amount of smoke that factories can release. This means that some areas, such as London, certainly, have air containing much less dust and dirt, and smogs are almost a thing of the past. In general, however, the air in our countries is far from fresh. The millions of cars on the road pour vast quantities of poisonous carbon monoxide gas into the atmosphere. It has even been suggested that if supersonic flight became popular, with the planes flying at such high altitudes, the upper atmosphere could bee affected in such a way as to permit deadly cosmic rays to reach the Earth.
The next time that you see some plants or trees next to a busy road, take a closer look at the leaves. You will probably find that they are covered with a film of black, oily dust. Remember that this is the same air that we are all breathing.