Smog Is A Mixture of Different Air Pollutants

Smog is a low-level atmospheric mixture of several different kinds of air pollution. In some areas, such as those near coal-fired power plants, the main constituents of smog are the byproducts of fossil-fuel burning such as sulfur dioxide, ground level ozone and carbon monoxide. Massive smog events can also be caused by residential coal burning, as in the case of the “Great London Smog of 1952” that killed thousands in a few weeks.

Officials believe that as many as 12,000 people may have died in the great London smog of 1952. A cold fog descended upon London early in that December. The Londoners began to burn more coal than usual, resulting in the air pollution being trapped by the dense blanket of cold air. Concentrations of the pollutants began to build, especially the coal smoke. The coal was also high in sulphur.

Authorities didn’t realize the severity of the problem because people were not dying in the streets. It wasn’t until florists were running out of flowers and the undertakers were running out of coffins.

Hospitals could not handle the patient admissions and were turning people away. The hospitals were also full of smog.

Different Cities and Different Types of Smog

Cities that are near active volcanoes (such as Mt. Etna in Sicily and many others) are especially likely to suffer from infrequent but very traumatic smog events. In this case, though entirely natural, many of the chemical components of this “vog” are the same as what might be seen with petrochemical smog. Sulfur dioxide and very harmful, tiny, caustic particles are also a concern.